A CLOSURE SYSTEM COMPRISING A PULP MOLDED CAP AND A PULP MOLDED CONTAINER, A PULP MOLDED CONTAINER, A PULP MOLDED CAP, A METHOD AND A TOOL FOR PRODUCING A CAP OR CAP PART FROM A PULP SLURRY

Abstract

The present disclosure relates to a closure system (100), comprising: a pulp molded container (200) comprising a wall portion (201) which surrounds a product space (2000) presenting a cross-sectional area, wherein said wall portion extends along an axial direction perpendicular to the cross-sectional area, between a first open end (203) and a second end (204) being axially opposite said first open end, wherein a first end wall portion (205) extending from said first open end has a first substantially conical sealing surface (206) presenting a first angle relative to the axial direction; and a pulp molded cap (300) having a second substantially conical scaling surface (306) presenting a second angle relative to the axial direction; wherein the first and second angles substantially match, and wherein one of said first and second substantially conical sealing surfaces (206, 306) presents at least one male partial thread (210) and the other one of said first and second substantially conical sealing surfaces (206, 306) presents at least one corresponding female partial thread (310). The disclosure further relates to a method for producing a cap or cap part from a pulp slurry, and a tool for producing a cap or cap part from a pulp slurry.

Description

TECHNICAL FIELD

The disclosure relates to a closure system comprising a pulp molded cap and a pulp molded container. The disclosure also relates to a pulp molded container and a pulp molded cap. The disclosure further relates to a method for producing a cap or cap part from a pulp slurry. The disclosure further relates to a tool for producing a cap or cap part from a pulp slurry.

BACKGROUND

There is a general desire to use biodegradable packages in the distribution of various products, such as food products, beverages, and other household products. Many of these packages require a cap sealing, such as beverages and other liquids. These cap sealings have mostly been provided as plastic articles, but as the packaging business have become more sustainable, there is a need for a fully disposable and biodegradable sealings in forms of biodegradable screw caps as well.

It is known to produce screw caps from a paper blank material. For example, GB607700 A discloses a method of producing a threaded paper cap from a paper blank material. WO2012046215 A also discloses a screwable closing cap formed from a paper sheet material, but which is adapted to be internally fitted into a container instead of engaging with threads on an outer surface of the container neck. In similar, GB428909 A and GB468161 A also disclose threaded closing caps which are adapted to be internally fitted into a container.

Further, it is known to mold a screw cap from a pulp material. For example, EP3081691 A1 discloses a method for producing a screw cap of cellulose fiber material, wherein the fiber material is placed into a heated female die and an elongated structure with external threads is then screwed into the molded product.

However, a challenge lies in producing recyclable, biodegradable and/or compostable screw caps that have threads with sufficient quality and strength for providing a reliable screw cap sealing.

A further challenge lies in providing an efficient process for producing pulp screw caps.

Thus, it is desirable to provide an improved process for producing a cap of a pulp material with high quality and strength, and wherein the manufacturing cost is low. It is also desirable that the produced cap is easy to use, has high quality in regard to moisture-resistance and provides for an efficient and leakage proof sealing for liquid containers.

SUMMARY

It is therefore an object of the present disclosure to provide an improved closure system for pulp molded packaging products which eliminates at least some of the drawbacks as stated above. It is also an object to provide an improved pulp molded cap which has high quality, high strength, is easy to use, is childproof, and/or has a low manufacturing cost. It is also an object to provide an improved process for producing a cap or cap part from a pulp slurry, said cap or cap part having a low manufacturing cost and high quality and strength. It is further an object to provide an improved tool for use in producing a cap or cap part from a pulp slurry.

The invention is defined by the appended independent claims. Embodiments are set forth in the appended dependent claims and in the following description and drawings.

According to a first aspect, there is provided a closure system, comprising: a pulp molded container comprising a wall portion which surrounds a product space presenting a cross-sectional area, wherein said wall portion extends along an axial direction perpendicular to the cross-sectional area, between a first open end and a second end being axially opposite said first open end, wherein a first end wall portion extending from said first open end has a first substantially conical sealing surface presenting a first angle relative to the axial direction; and a pulp molded cap having a second substantially conical sealing surface presenting a second angle relative to the axial direction; wherein the first and second angles substantially match, and wherein one of said first and second substantially conical sealing surfaces presents at least one male partial thread and the other one of said first and second substantially conical sealing surfaces presents at least one corresponding female partial thread.

Said container may for example be a pulp molded bottle or a pulp molded cup. Thus, an open end portion of the container can be seen to form a neck portion of said container.

A “pulp molded” device is a device which is dry or wet molded from pulp.

“Substantially conical” encompasses forms with diminishing cross sections. Such cross sections may diminish linearly or along a curved path.

The first and second sealing surfaces can be seen to present matching substantially conical surfaces. When in use, the first and second sealing surfaces are adapted to interact such as to seal said container.

By substantially matching first and second angles is meant that the first and second angles may correspond such that the angles match by +/−0-2 degrees, preferably by +/−0-1 degrees, more preferably by +/−0-0.5 degrees. By “a partial thread” is meant a thread segment extending over a distance corresponding to less than one turn.

The male partial thread can be formed as a ridge shaped thread segment.

The female partial thread can be formed as groove shaped thread segment.

The pulp molded cap may comprise at least one male partial thread and the container opening may comprise at least one matching female partial thread. Alternatively, the pulp molded cap may comprise at least one female partial thread and the container opening may comprise at least one matching male partial thread.

Thus, the pulp molded cap comprises at least one partial thread and the container opening comprises at least one matching partial thread.

When in use, the at least one male partial thread and the at least one female partial thread are adapted to interact such as to seal said container. The male and female partial threads may be seen to interact in a bayonet-like manner.

The interacting substantially conical sealing surfaces of the cap and container, in combination with the interacting at least one male partial thread and at least one corresponding female partial thread allows for an improved seal while also being easy to use, allowing for a quick sealing of the container.

Consequently, according to the above, an improved closure system for pulp molded packaging products can be provided, which has high quality and strength, has low manufacturing cost, is easy to use, and which provides for a tight, reliable leakage proof seal.

The first substantially conical sealing surface may be a first inwardly substantially conical sealing surface, and the second substantially conical sealing surface may be a second outwardly substantially conical sealing surface.

Hence, the pulp molded cap may be adapted to be internally fitted into the pulp molded container for sealing of the container.

A cross section of the first substantially conical sealing surface may diminish inwardly from the open end.

The first end wall portion may form an inner wall portion that extends from the open end and which has said first substantially conical sealing surface. The wall portion, i.e. said wall portion surrounding the product space, may form an outer wall portion, formed radially outwardly of the inner wall portion and extending from the open end towards the second end of the container. An axial extent of the outer wall portion may be greater than an axial extent of the inner wall portion. The inner and outer wall portions may be formed in one piece of material.

Thus, the inner wall portion can be seen to extend in a downward direction from the open end, i.e. in a direction towards the second end of the container.

A transition portion between the inner and outer wall portion can be seen to form a lip portion of the container opening.

Hence, a container that is easy to manufacture can be provided.

Furthermore, a container according to the above provides a spill protection or splash protection.

As one alternative, the first substantially conical sealing surface May be a first outwardly substantially conical sealing surface, and the second substantially conical sealing surface may be a second inwardly substantially conical sealing surface.

Hence, the pulp molded cap may be adapted to be externally fitted to a container opening of the pulp molded container for sealing of the container.

A cross section of the first substantially conical sealing surface may increase outwardly along the axial direction from the open end. Alternatively, a cross section of the first substantially conical sealing surface may increase outwardly along the axial direction towards the open end.

A container wall portion at the second end of the container may be inwardly conical with a cross section diminishing inwardly along the axial direction from the second end.

The at least one partial thread may be spaced from at least one, preferably both, axially extreme portions of at least one of the first and second substantially conical sealing surfaces.

Thus, the at least one partial thread of the pulp molded container may be spaced from at least one, preferably both, axially extreme portions of the first substantially conical sealing surface.

The at least one partial thread of the pulp molded cap may be spaced from at least one, preferably both, axially extreme portions of the second substantially conical sealing surface.

The at least one partial thread may be spaced from the at least one axially extreme portion at least by a distance corresponding to 1-50%, preferably 1-40%, 1-35%, 1-30%, 2-25%, 3-20%, 4-15% or 5-10%, of an axial extent of said at least one of the first and second substantially conical sealing surfaces.

Thus, the at least one partial thread of the pulp molded container may be spaced from the least one axially extreme portion of the first substantially conical sealing surface, at least by a distance corresponding to 1-50%, preferably 1-40%, 1-35%, 1-30%, 2-25%, 3-20%, 4-15% or 5-10% of an axial extent of the first substantially conical sealing surface.

The at least one partial thread of the pulp molded cap may be spaced from the least one axially extreme portion of the second substantially conical sealing surface, at least by a distance corresponding to 1-50%, preferably 1-40%, 1-35%, 1-30%, 2-25%, 3-20%, 4-15% or 5-10% of an axial extent of the second substantially conical sealing surface.

Alternatively, the at least one partial thread may extend between a first and a second axially extreme portion of at least one of the first and second substantially conical sealing surfaces.

Thus, the at least one partial thread of the pulp molded container may extend between a first and a second axially extreme portion of the first substantially conical sealing surface.

The at least one partial thread of the pulp molded cap may extend between a first and a second axially extreme portion of the second substantially conical sealing surface.

Further, the at least one partial thread may have a thread rising angle being larger than 0° and less than 90°, preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

Thus, the at least one partial thread of the pulp molded container may have a thread rising angle being larger than 0° and less than 90°, preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

The at least one partial thread of the pulp molded cap may have a thread rising angle being larger than 0° and less than 90°, preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

By thread rising angle is meant an angle as measured between the tangent of the partial thread and a plane perpendicular to an axial direction of the container and cap respectively.

A length of the at least one partial thread may correspond to about 1/32 to ⅓ of a turn, preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn. A turn corresponds to 360 degrees.

Thus, the at least one partial thread of the pulp molded container may have a length corresponding to about 1/32 to ⅓ of a turn, preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn. The at least one partial thread of the pulp molded cap may have a length corresponding to about 1/32 to ⅓ of a turn, preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn.

Further, the at least one partial thread may have a tapering end portion.

Thus, the at least one partial thread of the pulp molded container may have a tapering end portion.

The at least one partial thread of the pulp molded cap may have a tapering end portion.

The tapering end portion enables manufacturing of said pulp molded container and/or said pulp molded cap.

The at least one male partial thread may comprise portions of varying height.

The at least one female partial thread may comprise portions of varying depth.

The at least one partial thread may be straight or curved. Further, said first and/or second angles may be 2-15° relative to the axial direction, preferably 2.5-12°, 3-10° or 4-6°.

Further, the pulp molded cap may comprise: a first part formed of a pulp material, wherein the first part comprises said second substantially conical sealing surface, and a second part formed of a pulp material, wherein the second part is adapted to at least partly enclose said first part.

Hence, the pulp molded cap may be seen to form a two-part pulp molded cap. The first part of the pulp molded cap can be seen to form an at least partially threaded part of pulp material. The second part of the cap can be seen to form a cover part.

The first part may comprise an open end and an opposite closed end. The second part may be adapted to cover the open end of the first part, as seen when the first and second parts are mounted together to form said pulp molded cap.

The first and second parts may be permanently attached to one another.

By “permanently attaching” is meant that the established attachment between the two parts is permanent, i.e. the two parts cannot be separated unless the cap is broken.

The first and second parts may be pulp molded together. Hence the first and second parts may be attached by means of fiber bonding. Alternatively, or additionally, the first and second parts may be attached to one another by means of any suitable adhesive and/or adhesive film. For example, the first and second parts may be laminated together.

Alternatively, or additionally, the first and second parts may be attached by an interference fit, also known as a press fit or friction fit. For example, the first and second parts may be provided with mating interlocking portions, such as a groove and a corresponding protrusion for joining the first and second parts.

The first and second parts may be movably attached to one another. When in use, a radial pressure and/or axial pressure may be applied to the second part in order to be able to also rotate the first part, hence unscrewing the cap from the container. Such cap can form a type of safety cap, such as a child proof cap.

According to a second aspect of the invention, there is provided a pulp molded container, wherein the container comprises: a wall portion which surrounds a product space presenting a cross-sectional area, wherein said wall portion extends along an axial direction perpendicular to the cross-sectional area, between a first open end and a second end being axially opposite said first open end, wherein a first end wall portion extending from said first open end has a substantially conical sealing surface, and wherein the substantially conical sealing surface presents at least one partial thread.

Said container may for example be a pulp molded bottle or a pulp molded cup. The container may form part of a closure system as described above.

The substantially conical sealing surface may be seen to form an inwardly substantially conical sealing surface. Alternatively, the substantially conical sealing surface may be seen to form an outwardly substantially conical sealing surface. The substantially conical sealing surface may be formed according to what has been described above in relation to the closure system.

The at least one partial thread may be a male partial thread. Alternatively, the at least one partial thread may be a female partial thread. The at least one partial thread may be formed according to what has been described above in relation to the closure system.

A container wall portion at the second end may be inwardly conical with a cross section diminishing inwardly from the second end.

According to a third aspect, there is provided a pulp molded cap comprising: a substantially conical sealing surface, wherein the substantially conical sealing surface presents at least one partial thread.

Said pulp molded cap may for example be a pulp molded screw cap. The pulp molded cap may form part of a closure system as described above.

The substantially conical sealing surface may be seen to form an outwardly substantially conical sealing surface. Alternatively, the substantially conical sealing surface may be seen to form an inwardly substantially conical sealing surface. The substantially conical sealing surface may be formed according to what has been described above in relation to the closure system.

The at least one partial thread may be a male partial thread. Alternatively, the at least one partial thread may be a female partial thread. The at least one partial thread may be formed according to what has been described above in relation to the closure system.

The pulp molded cap may comprise: a first part formed of a pulp material, wherein the first part comprises said substantially conical sealing surface, and a second part formed of a pulp material, wherein the second part is adapted to at least partly enclose the first part.

Hence, the pulp molded cap may be seen to form a two-part pulp molded cap. Such two-part pulp molded cap may be formed according to what has been described above in relation to the closure system.

The second part may be fixedly attached to the first part.

Alternatively, the second part may be rotatably connected to the first part.

The first and second parts may present selective engagement means configured such that at least one of the first and second parts is deformable between a first state, wherein the first and second parts are rotatable relative to each other and a second state, wherein a torque, is transferrable from the second part to the first part, said torque being sufficient to connect or disconnect the first part to or from a container by means of the partial thread. Hence, a pulp molded cap requiring application of a radial pressure and/or an axial pressure to the second part in order to engage the first part may be provided. Thereby, making it possible to unscrew the cap from the container. Thus, a childproof pulp molded cap may be provided.

The first part may comprise at least one first indentation and the second part may comprise at least one second indentation, the first and second intendations being seperated by a gap.

Hence, a childproof pulp molded cap may be provided. When in use, a pressure may be applied downwardly, such as to close said gap. Thereby making it possible to unscrew the pulp molded cap from the container opening.

Further, the first part may comprise a first central substantially conical portion provided with a recess. The second part may comprise a corresponding second central substantially conical portion provided with a protrusion adapted to interact with said recess such as the second part is rotatable relative the first part.

The first and second central substantially conical portions may present substantially matching angled surfaces.

Thus, the first and second part of the pulp molded cap can be seen to comprise two draft-matched substantially conical surfaces at a central portion of the cap. The recess can be seen to form a notch of the first central substantially conical portion. The recess and protrusion can be seen to form a turnable connection between the first and second parts of the pulp molded cap.

The second part may comprise a at least partly reversed rim portion. Thus, a rim portion of the second part may present one or several portions extending radially inwardly.

A rim portion of the second part may comprises a plurality of dents.

The dents can be seen to extend radially inwardly. The pulp material forming said dents may be molded as protrusions extending outwardly from said rim portion, and subsequently pushed inwardly in a reverse direction in order to form said dents.

Further, the first part may presents a substantially circular cross-sectional area.

The second part may present a substantially circular cross-sectional area.

Alternatively, the second part may present a substantially oval cross-sectional area.

Said engagement means may be positioned at a portion of the second part where a radial distance to the first part is near a maximum.

The second part may present a substantatially circular cross-sectional area further comprising a first protruding portion and an opposite second protruding portion.

A childproof pulp molded cap according to the above may form part of the closure system as described in relation to the first aspect of the invention.

According to a fourth aspect, there is provided a method for producing a cap or cap part from a pulp slurry, comprising: applying a pulp slurry layer to a porous product face of a male tool, wherein said porous product face of the male tool comprises an at least partially threaded portion, and in a first dewatering step, dewatering the pulp slurry layer through said porous product face of the male tool.

The term “pulp” should be constructed as to include materials comprising fibers such as cellulose, minerals and starch, or combination of these materials. The pulp preferably contains a liquid carrier, which may contain water.

The pulp slurry layer may have a water content of 95-99.9% by weight, preferably 99-99.9% by weight.

By “product face” is meant a surface of a tool of a mold that is adapted to be in contact with a pulp slurry layer or pulp product during forming of such a pulp slurry layer or pulp product.

For the purpose of the present disclosure, the term “porous tool” is referring to a tool having a tool wall portion comprising a product face, for contacting the product, and a rear face on the other side of the wall relative to the product face, wherein the tool wall portion presents pores. The pores may be provided by a plurality of channels extending through the tool wall portion, from the product face to the rear face (pore channels).

Thus, the term “porous product face” is referring to a plurality of pore openings at the product face of a tool.

For the purpose of the present disclosure, the term “porosity” is referring to the ratio of pore opening area to total product face area (including the pore openings) of a predetermined product face portion.

The at least partially threaded portion may present a nonhomogeneous porosity.

The at least partially threaded portion may present a higher porosity at a thread crest adapted to form a thread root of said pulp slurry layer, than at a thread root adapted to form a thread crest of said pulp slurry layer.

By “a male tool” is meant a “positive tool”. The male tool is configured to receive a forming material, such as pulp slurry, over a surface of the tool.

In contrast, “a female tool”, being a “negative tool”, is configured to receive a forming material, such as pulp slurry, inside the tool rather than over it. Hence, a “female tool” can be seen to have a geneally concave shape.

By “a at least partially threaded portion”, is meant that the porous product face of the male tool may present a portion comprising at least one continuous thread, at least one non-continuous thread, at least one interrupted thread or at least one partial thread.

By continuous thread is meant a thread extending continuously over a distance corresponding to one turn or more. The continuous thread may extend without any interruption. By non-continuous thread is meant a thread extending non-continuously over a distance corresponding to one turn or more. As one example, the non-continuous thread may extend with one or several interruptions, for example one or several gaps, thereby forming an interrupted thread. Thus, as one example, a non-continuous thread may be provided in form an interrupted thread.

A thread of the at least partially threaded portion may be formed as a helical ridge.

The at least partially threaded portion of the porous product face of the male tool may comprise at least one external thread.

The at least partially threaded portion of the porous product face of the male tool may comprise at least one recessed groove.

The at least partially threaded portion may present a plurality of thread crests and a plurality of thread roots.

Consequently, it is understood that the at least partially threaded portion of the porous product face of the male tool may be formed such that a continuous thread cap, a lug or twist cap, triple thread cap or other forms of screw caps can be produced.

The at least partially threaded portion of the porous product face of the male tool may be formed such that a closure with at least one partial thread can be produced.

Hence, the method can be used to produce a screw cap of pulp material. The method can be used to produce an internally threaded screw cap adapted to engage with an externally threaded container neck or opening. Alternatively, the method can be used to produce an externally threaded screw cap adapted to engage with an internally threaded container neck or opening.

The method can be used to produce a screw cap part, meaning a at least partially threaded pulp part adapted to form part of a two-part pulp cap. Such a two-part pulp cap may comprise of said at least partially threaded pulp part forming an inner part of said two-part cap, and a pulp cover part forming an outer part of said two-part cap. Such two-part pulp cap may be adapted to be internally fitted into a container neck or opening.

The method as described above eliminates the need for initially forming a preform cap before forming the thread(s) or the at least one partial thread. Thereby, the method as described above allows for a more efficient pulp molding process for producing caps, such as screw caps, and an increased throughput of such a process.

The male tool may substantially have a shape of a conical cylinder, wherein the first end has a first diameter, and a second end, opposite to the first end, has a second diameter. The second diameter may be smaller than the first diameter.

By the second end of the male tool having a smaller diameter than the first end, a draft angle α can be seen to be provided between the first end and the second end. The draft angle can enable the release of a at least partly molded pulp cap or cap part from the male tool.

A wall of the cylinder may taper from the first end to the second end, with an angle α of 2-15° relative to the axial direction, preferably 2.5-12°, 3-10° or 4-6°.

The male tool may be formed as a hollow conical cylinder comprising external threads. Thus, the male tool may have a hollow core.

The at least partially threaded portion of the male tool may comprise at least one partial thread.

The at least one partial thread may have a thread rising angle, as measured relative to a plane perpendicular to a central axis of the male tool, said angle being larger than 0° and less than 90°, preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

A length of the at least one partial thread may correspond to about 1/32 to ⅓ of a turn, preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn.

The at least one partial thread may have a tapering end portion.

The at least partially threaded portion of the male tool may comprise at least two partial threads separated by a gap.

The partial threads may be seen to form thread segments.

The at least partially threaded portion may be seen to comprise at least one interrupted thread.

As one alternative, the at least partially threaded portion of the male tool may comprise at least one continuous thread. Said continuous thread extending over a distance corresponding to one turn or more.

The step of applying the pulp slurry layer to the porous product face of the male tool may comprise applying a dose of pulp slurry from a dosing system holding at least one pulp slurry dose above said male tool.

By pulp slurry dose is meant a dose of pulp slurry sufficient to form a pulp slurry layer of the pulp product to be produced.

Alternatively, the step of applying a pulp slurry layer to a porous product face of a male tool may comprise immersing the porous product face into a bath containing a pulp slurry, while drawing a vacuum through the porous product face.

Alternatively, the pulp slurry layer may be applied by spraying or pouring a pulp slurry onto the porous product face, while drawing a vacuum through the porous product face.

The first dewatering step may comprise evacuating water from the pulp slurry layer through the porous male tool by means of gravity and/or drawing a vacuum through the porous product face of the male tool.

The first dewatering step may comprise pressing the pulp slurry layer between the porous product face of the male tool and a second product face of the first press tool.

The first press tool may be a female tool. The second product face may be porous, non-porous or partly porous. Preferably, the second product face of the first press tool is heated during said pressing. During said pressing, water and/or steam may be evacuated through the porous male tool by means of gravity and/or drawing a vacuum through the porous product face.

Alternatively, or additionally, a vacuum may be drawn through the second product face of the first press tool.

The first press tool may be rotated onto the male tool holding the pulp slurry layer.

The method may further comprise a step of releasing said pulp slurry layer from said male tool, wherein during said step of releasing, a pressure is supplied through the porous product face of the male tool in a direction easing the release of the pulp slurry layer from the male tool.

The release may be performed while rotating the male tool, rotating a first press tool and/or rotating a transfer tool.

The step of releasing may comprise blowing air through the porous product face of the male tool. For example, a pressure greater than ambient air pressure may be supplied through the porous product face of the male tool. A vacuum may be drawn through the first press tool or the transfer tool.

By suppling a pressure in a releasing direction, the release of the pulp slurry layer, i.e. the at least partly molded cap or cap part, from the male tool will be enabled.

The pulp slurry layer may be released from the male tool by initially rotating a first press tool or a transfer tool approximately 10-180°, preferably 10-20°, 20-30°, 30-40°, 40-50°, 50-60°, 70-80°, 80-90°, 90-100°, 100-110°, 110°-120°, 120-130°, 140°-150°, 150-160°, 160-170° or 170-180°, before lifting the pulp slurry layer off the male tool.

Thus, a releasing of the pulp slurry layer may be achieved through a twist-and-lift operation. As one example, the pulp slurry layer may be released from the male tool by a quarter of a turn and lift-off operation.

The pulp slurry layer may be released from the male tool when a water content of the pulp slurry layer is about 40-75% by weight, preferably about 40-50% by weight.

The method may further comprise applying the pulp slurry layer onto a second male tool and pressing the pulp slurry layer in a second pressing step. The second male tool may comprise a third product face. The third product face of the second male tool may be porous, partly porous, or non-porous.

The transfer to the second male tool may be performed by the first press tool or by a separate transfer tool.

Thus, the method as described above, may be performed in several subsequent pressing steps.

The method may comprise pressing the pulp slurry layer in a second pressing step, using a second mold, while heating the pulp slurry layer and/or drawing a vacuum through at least one porous product face of the second mold.

The second mold may comprise the first press tool and a second male tool. Alternatively, the second mold may comprise a second press tool and a second male tool.

The method may further comprise pressing the pulp slurry layer in a third pressing step, using a third mold, while heating the pulp slurry layer and/or drawing a vacuum through at least one porous product face of the third mold.

The third mold may comprise the first press tool and a third male tool. Alternatively, the third mold may comprise the second press tool and a third male tool. Alternatively, the third mold may comprise a third press tool and a third male tool.

The method may further comprise: providing a second part formed of a pulp material, and joining the produced cap part and the second part such as the second part at least partly encloses said cap part.

The produced cap part may be formed with an open end and an opposite closed end. Hence, the method may comprise: providing a second part formed of a pulp material, and joining said cap part and the second part such that the second part at least covers the open end of said cap part.

Further, the method may comprise: fixedly attaching the second part to the first part.

Alternatively, the method may comprise: rotatably connecting the second part to the first part.

The two parts may be pulp molded together. Hence, a two-part cap, such as a two-part screw cap, may be formed without use of any adhesive such as glue.

Alternatively, or additionally, the cap part and the second part may be joined by any suitable adhesive, such as glue, and/or an adhesive film.

Alternatively, or additionally, the cap part and the second part may be attached by an interference fit, also known as a press fit or friction fit. For example, the parts may be provided with mating interlocking portions, such as a groove and a corresponding protrusion for joining the cap part and the second part.

According to a fifth aspect of the invention, there is provided a tool for producing a cap or cap part from a pulp slurry, wherein said tool is a male tool comprising a self-supporting tool wall portion having a product face, adapted for contacting a pulp slurry layer, and a rear face on the other side of the wall portion relative to the product face, wherein the tool wall portion presents pores, which are provided by a plurality of channels extending through the tool wall portion, from the product face to the rear face, wherein each channel presents a channel opening at the product face, wherein the porous product face comprises an at least partially threaded portion. At least some of the channel openings at the at least partly threaded portion presents a channel flow direction, wherein an angle between said channel flow direction and a component substantially parallel with a screwing direction of the tool is non-perpendicular, preferably less than 80°, less than 70° or less than 60°, more preferably less than 50°, less than 40°, less than 30° or less than 20°.

The term “self-supporting” means that the tool wall portion is sufficiently rigid and has a melting point that is sufficiently high for the tool wall portion not to require any support structure for maintaining its shape during operation.

By “channel flow direction” is meant the flow direction of any fluid or medium adapted to flow through said channel when in use. The channel flow direction may be seen to coincide with an axis substantially parallel with at least one channel wall of said channel. Thus, the channel flow direction may be seen to be substantially parallel with at least one channel wall of said channel.

By “screwing direction” is meant the direction of movement of the pulp slurry layer formed on the male tool when the pulp slurry layer is unscrewed of the tool, i.e. when the pulp slurry layer is released from the male tool.

A male tool according to the above makes it possible to direct a pressure provided through the channels during said release of the pulp slurry layer in a direction which will enable said release.

The channel openings of the at least partly threaded portion may be directed such that air can be supplied underneath the pulp slurry layer, enabling release of the pulp slurry layer from the tool. Hence, when in use, air may be blown along the product face, in the screwing direction, thereby enabling release of said pulp slurry layer.

Thus, the male tool allows for an improved quality control when forming a pulp cap or pulp cap part comprising an at least partly threaded portion. Hence, a cap or cap part with stronger thread(s) or partial thread(s) can be provided. Thereby deformation of the cap or cap part can be prevented, allowing the thread(s) or partial thread(s) to keep their intended shape. Thus, by means of a tool according to the above, pulp caps or pulp cap parts with increased strength and quality can be produced.

A tool according to the above may be used to produce a pulp molded cap of a closure system as described in relation to the first aspect of the invention. A tool according to the above may be used to produce a pulp molded cap as described in relation to the third aspect of the invention. A tool according to the above may be used in a method as described in relation to the fourth aspect of the invention.

At least some of the channel openings on the product face at the at least partly threaded portion may comprise a downstream part and an upstream part, as seen relative to a screwing direction of the tool.

An axis coinciding with said channel flow direction may be provided within said upstream part.

The at least partially threaded portion of the male tool may comprise at least one partial thread.

The at least partially threaded portion of the male tool may comprise at least two partial threads separated by a gap.

The partial threads can be seen to form thread segments.

The at least partially threaded portion may be seen to comprise at least one interrupted thread.

Further, the at least one partial thread may have a length corresponding to about 1/32 to ⅓ of a turn, preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn.

The at least one partial thread may have a thread rising angle, as measured relative to a plane perpendicular to a central axis of the male tool, said angle being larger than 0° and less than 90°, preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

The at least one partial thread may have a tapering end portion.

As one alternative, the at least partially threaded portion of the male tool may comprise at least one continuous thread. The continuous thread extending over a distance corresponding to one turn or more.

Further, the male tool may substantially have a shape of a conical cylinder, wherein the first end has a first diameter, and a second end, opposite to the first end, has a second diameter. The second diameter may be smaller than the first diameter.

The male tool may be formed as a hollow conical cylinder comprising external threads. Thus, the male tool may have a hollow core.

The second end of the male tool having a smaller diameter than the first end can be seen to create a draft angle α between the first end and the second end. The draft angle can enable the release of a at least partly molded pulp cap or cap part from the male tool.

A wall of the conical cylinder may taper from the first end to the second end, with an angle of 2-15° relative to an axial direction, preferably 2.5-12°, 3-10° or 4-6°.

The at least partially threaded portion may present a nonhomogeneous porosity.

Hence, the at least partially threaded portion may present a varying porosity. The porosity may vary depending on surface profile of the product face of the male tool.

The at least partially threaded portion may present a higher porosity at a thread crest than at a thread root.

Consequently, a male tool which allows for an improved quality control when applying the pulp slurry layer onto the male tool and/or when forming the pulp slurry layer into a pulp molded cap, such as a pulp molded screw cap, can be provided.

Further, the tool may be rotatable. By the tool being rotatable is meant that the tool can be turned or rotated around a central axis of the tool. As one example, the tool may be mounted to a tool holder, wherein said tool holder is turnable.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present solution will now be described, by way of example, with reference to the accompanying schematic drawings in which:

FIGS. 1a-1f schematically illustrate one embodiment of a closure system comprising a pulp molded container and a pulp molded cap.

FIGS. 2-4 illustrate various alternative embodiments of a partial thread of the closure system as illustrated in FIGS. 1a-1f.

FIGS. 5a-5b schematically illustrate a container wall portion at a second end of the container.

FIGS. 6a-6c schematically illustrate one embodiment of a closure system comprising a pulp molded container and a pulp molded cap.

FIGS. 7a-7b schematically illustrate another embodiment of a closure system comprising a pulp molded container and a pulp molded cap. FIGS. 8a-8b schematically illustrate yet another embodiment of a closure system comprising a pulp molded container and a pulp molded cap. FIGS. 9a-9b schematically illustrate yet another embodiment of a closure system comprising a pulp molded container and a pulp molded cap. FIGS. 10a-10b schematically illustrate one embodiment of a childproof pulp molded cap.

FIGS. 11a-11b schematically illustrate another embodiment of a childproof pulp molded cap.

FIGS. 12a-12b schematically illustrate yet another embodiment of a childproof pulp molded cap.

FIGS. 13a-13b schematically illustrate yet another embodiment of a childproof pulp molded cap.

FIGS. 14a-4e schematically illustrate various designs of a closure system.

FIGS. 15a-15e schematically illustrate one embodiment of a method for producing a cap or cap part from a pulp slurry.

FIGS. 16a-16l schematically illustrate another embodiment of a method for producing a cap or cap part from a pulp slurry.

FIGS. 17a and 17b schematically illustrate a section view of a male tool.

FIGS. 17c-17d schematically illustrate a pore channel opening of a male tool.

FIGS. 18a-18e schematically illustrate different embodiments of a male tool for use in producing a cap or cap part from a pulp slurry.

FIG. 18f schematically illustrates a body of a male tool having a tapering tool wall portion.

DETAILED DESCRIPTION

In relation to FIGS. 1-14, a closure system for pulp molded packaging products will now be described.

FIGS. 1-4 illustrates a closure system 100 that comprises a pulp molded container 200 and a pulp molded cap 300. FIGS. 1-4 illustrates a container 200 in form of a pulp molded bottle. However, it is understood that other types of containers are possible, such as for example a pulp molded cup, jar etc.

Although FIGS. 1-4 only illustrate a top portion of the container 200 it is understood that the closure system described below can comprise any type of pulp molded container comprising at least one open end. Different sizes and shapes of the container is possible.

As illustrated in FIGS. 1-4, the pulp molded container 200 comprises a wall portion 201 which surrounds a product space 2000 presenting a cross-sectional area. Said wall portion 201 extends along an axial direction perpendicular to the cross-sectional area, between a first open end 203 and a second end 204 (not illustrated in FIGS. 1-4) being axially opposite said first open end. The second end 204 can be seen to form a bottom end of the container 200. FIG. 5a-5b illustrates two different examples of a bottom portion of the container 200 of the closure system 100 as described in relation to FIGS. 1-4.

Various shapes and sizes of the product space may be provided. For example, the cross-sectional area of the product space 2000 may be at least partly constant along the axial direction from the first end 203 to the second end 204. As another example, the cross-sectional area of the product space 2000 may be seen to increase, as seen in the axial direction from the first end 203 to the second end 204.

As illustrated in FIGS. 1b, 1d, 1f, 2b-2c, 3b-3c and 4b-4c, a first end wall portion 205 can be seen to extend from said first open end 203. The first end wall portion 205 comprises a first substantially conical sealing surface 206. The sealing surface 206 can be seen to present a first angle as seen relative to the axial direction.

The first substantially conical sealing surface 206 presents at least one partial thread 210. As illustrated in FIGS. 1-4, the at least one partial thread 210 may be provided in form of male thread. However, as an alternative, the at least one partial thread 210 may be a female thread.

As illustrated in FIGS. 1b, 1d, 1f, 2b-2c, 3b-3c and 4b-4c, a cross section of the first substantially conical sealing surface 206 may diminish inwardly from the open end 203.

Further, a container wall portion 207 at the second end 204 may be inwardly conical with a cross section diminishing inwardly from the second end 204, see FIGS. 5a-5b. Thus, the container 200 may present conical surfaces at both the first and second ends 203, 204 of the container 200.

As illustrated in FIGS. 1b, 1d, 1f, 2b-2c, 3b-3c and 4b-4c, the first end wall portion 205 can be seen to form an inner wall portion. Thus, the inner wall portion can be seen to extend from the open end 203 and comprise said first substantially conical sealing surface 206. The inner wall portion can be seen to extend in a downward direction from the open end 203, i.e. in a direction towards the second end 204 of the container.

Further, the wall portion 201 can be seen to form an outer wall portion. The outer wall portion can be seen to be formed radially outwardly of the inner wall portion. The outer wall portion can be seen to extend from the open end 203 towards the second end 204 of the container.

As illustrated in FIGS. 1b, 1d, 1f, 2b-2c, 3b-3c and 4b-4c, an axial extent of the outer wall portion can be greater than an axial extent of the inner wall portion. The inner and outer wall portions can be formed in one piece of material. A transition portion between the inner and outer wall portion can be seen to form a lip portion 209 of the container.

Further, as illustrated in FIGS. 1-4, the pulp molded cap 300 compries a second substantially conical sealing surface 306. The second substantially conical sealing surface 306 can be seen to present a second angle as seen relative to the axial direction.

The second substantially conical sealing surface 306 presents at least one partial thread 310. As illustrated in FIGS. 1-4, the at least one partial thread 310 may be provided in form of female thread. However, as an alternative, the at least one partial thread 310 may be a male thread.

As illustrated in FIGS. 1-4, the first substantially conical sealing surface 206 may be seen as a first inwardly substantially conical sealing surface. The second substantially conical sealing surface 306 may be seen as a second outwardly substantially conical sealing surface. When in use, the first and second sealing surfaces are adapted to interact such as to seal said container.

As illustrated in FIGS. 1b, 1d, 1f, 2b-2c, 3b-3c and 4b-4c, said first and second angles substantially match. The first and second angles may correspond such that the angles match by +/−0-2 degrees, preferably by +/−0-1 degrees, more preferably by +/−0-0.5 degrees. Said first and/or second angles may be 2-15° relative to the axial direction, preferably 2.5-12°, 3-10° or 4-6°.

As illustrated in FIGS. 1-4, the second substantially conical sealing surface 306 of the pulp molded cap 300 can present at least one female partial thread. Further, as illustrated in FIGS. 1-4 the first substantially conical sealing surface 206 of the pulp molded container 200 can present at least one corresponding male partial thread.

Although, FIGS. 1-4 illustrate a pulp molded cap comprising at least one female partial thread and a container comprising at least one corresponding male partial thread, it is understood that the pulp molded cap can comprise at least one male partial thread, and the container can comprise at least one corresponding female partial thread. See for example FIGS. 6a and 6c.

Hence, the pulp molded cap 300 may comprise at least one female partial thread 310 and the container opening may comprise at least one matching male partial thread 210, see FIGS. 1-4. Alternatively, the pulp molded cap 300a may comprise at least one male partial thread 310a and the container opening may comprise at least one matching female partial thread 210a, see FIG. 6c. Thus, the pulp molded cap 300, 300a can be seen to comprise at least one partial thread 310, 310a and the container 200, 200a can be seen to comprise at least one matching partial thread 210, 210a. When in use, the at least one male partial thread and the at least one female partial thread are adapted to interact such as to seal said container. The male and female partial threads may be seen to interact in a bayonet-like manner. The male partial thread may be seen to be formed as a ridge shaped thread segment. The female partial thread may be seen to be formed as a groove shaped thread segment.

Further, as illustrated in FIGS. 1a-1f and FIGS. 2a-2c, the at least one partial thread 210 of the pulp molded container 200 may be spaced from both a first and a second axially extreme portion 207, 208 of the first substantially conical sealing surface 206. The at least one partial thread 310 of the pulp molded cap 300 may be spaced from both a first and a second axially extreme portion 307, 308 of the second substantially conical sealing surface 306.

Alternatively, as illustrated in FIGS. 3a-3c, the at least one partial thread 210 of the pulp molded container 200 may be spaced only from the second axially extreme portion 208 of the first substantially conical sealing surface 206. The at least one partial thread 310 of the pulp molded cap 300 may be spaced only from the second axially extreme portion 308 of the second substantially conical sealing surface 306.

Alternatively, the at least one partial thread 210 of the pulp molded container 200 may be spaced only from the first axially extreme portion 207 of the first substantially conical sealing surface 206 (not illustrated). The at least one partial thread 310 of the pulp molded cap 300 may be spaced only from the first axially extreme portion 307 of the second substantially conical sealing surface 306 (not illustrated).

As yet another alternative, as illustrated in FIGS. 4a-4c, the at least one partial thread 210 of the pulp molded container 200 may extend between the first and second axially extreme portions 207, 208 of the first substantially conical sealing surface 206. The at least one partial thread 310 of the pulp molded cap 300 may extend between the first and second axially extreme portions 307, 308 of the second substantially conical sealing surface 306.

The at least one partial thread 210 of the pulp molded container 200 may be spaced from the least one axially extreme portion 207, 208 of the first substantially conical sealing surface 206, at least by a distance corresponding to 1-50%, preferably 1-40%, 1-35%, 1-30%, 2-25%, 3-20%, 4-15% or 5-10% of an axial extent of the first substantially conical sealing surface 206. The at least one partial thread 310 of the pulp molded cap 300 may be spaced from the least one axially extreme portion 307, 308 of the second substantially conical sealing surface 306, at least by a distance corresponding to 1-50%, preferably 1-40%, 1-35%, 1-30%, 2-25%, 3-20%, 4-15% or 5-10% of an axial extent of the second substantially conical sealing surface 306.

Further, as illustrated in for example FIG. 1b and FIG. 2b, the at least one partial thread 210 of the pulp molded container 200 may have a thread rising angle θ₂ being larger than 0° and less than 90°. The thread rising angle θ₂ is preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

The at least one partial thread 310 of the pulp molded cap 300 may have a thread rising angle θ₁ being larger than 0° and less than 90°. The thread rising angle θ₁ is preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

Further, the at least one partial thread 210 of the pulp molded container 200 may have a length corresponding to about 1/32 to ⅓ of a turn. Preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn. The at least one partial thread 310 of the pulp molded cap 300 may have a length corresponding to about 1/32 to ⅓ of a turn. Preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn.

Further, as illustrated in for example FIG. 1d and FIG. 2b, the at least one partial thread 210 of the pulp molded container 200 may have a tapering end portion 211. The at least one partial thread 310 of the pulp molded cap 300 may have a tapering end portion 311.

Although not illustrated in FIGS. 1-4, the at least one male partial thread may comprise portions of varying height. Further, although not illustrated in FIGS. 1-4, the at least one female partial thread may comprise portions of varying depth.

Further, the at least one partial thread 210, 310 may be straight. Alternatively, the at least one partial thread 210, 310 may be curved.

FIGS. 6a-6c illustrates one embodiment of a closure system 100a comprising a pulp molded container 200a and a pulp molded cap 300a. The pulp molded container 200a and the pulp molded cap 300a may be formed essentially the same as described above in relation to FIGS. 1-4. However, as illustrated in FIG. 6a-6c, the pulp molded cap 300a comprises at least one male partial thread 310a, and the container 200a comprises at least one corresponding female partial thread 210a.

The at least one partial thread 210a, 310a may be formed according to what has been described above in relation to FIGS. 1-4.

For example, as illustrated in FIG. 6a, the at least one partial thread 310a of the pulp molded cap 300a may have a tapering end portion 311a.

As another example, as illustrated in FIG. 6a, the at least one partial thread 310a may comprise portions of varying height.

FIG. 6a illustrates two male partial threads 310a. However, it is understood that the number of partial threads may vary.

Hence, a pulp molded cap 300, 300a according to the closure system 100, 100a as described above in relation to FIGS. 1-6 may present one or several partial threads. The pulp molded container 200, 200a according to the closure system 100, 100a as described above in relation to FIGS. 1-6 may present one or several partial threads. Preferably 1-20 partial threads are provided, more preferably 1-15, 1-10 partial threads, or even more preferably 1-5, 1-4, 1-3 or 1-2 partial threads.

Further, the pulp molded cap 300, 300a may be sized and shaped to form a space 340 between the pulp molded cap and the lip portion 209, as seen when the pulp molded cap is mounted to seal the pulp molded container 200, see for example FIG. 1f, 2c, 3c, 4c. See also FIG. 7b.

FIGS. 7a-7b illustrate a closure system 100b comprising a pulp molded container 200 as described above in relation to FIGS. 1-6, and a pulp molded cap 300b. The pulp molded cap 300b may be formed essentially the same as described above with regard to FIGS. 1-4. The pulp molded cap 300b may be shaped and sized to form a space 340b between the pulp molded cap 300b and the lip portion 209, as seen when the pulp molded cap 300b is mounted to seal the pulp molded container 200, see FIG. 7b.

Hence, the pulp molded cap 300, 300a, 300b may be sized and shaped to not abut the lip portion 209 of the container, as seen when mounted to seal the pulp molded container 200.

Although not illustrated in FIGS. 1-4 or FIGS. 7a-7b, as an alternative, the pulp molded cap may be sized and shaped to abut the lip portion 209 of the container, as seen when mounted to the seal the pulp molded container 200.

Further, the pulp molded cap 300, 300a may be sized and shaped such that a wall portion 333, 333a of the pulp molded cap 300, 300a substantially matches an end portion 202 of the outer wall portion of the container 200, see for example FIGS. 1f, 2c, 3c and 4c. Said end portion 202 being located closer the first open end 203 of the container than the second end 204. The wall portion 333, 333a of the pulp molded cap may extend substantially parallel with said end portion 202 of the outer wall portion. An inner surface of the wall portion 333, 333a of the pulp molded cap 300, 300a can substantially match an outer surface of the end portion 202 of the outer wall portion. The inner surface of the wall portion 333, 333a may abut the outer surface of the end portion 202 of the outer wall portion, as seen when the pulp molded cap 300, 300a is mounted to seal the pulp molded container 200, 200a.

As an alternative, the pulp molded cap may be shaped and sized to form a space 341 between the pulp molded cap and the end portion of the outer wall portion of the container 200, as seen when the pulp molded cap is mounted to seal the pulp molded container 200. See for example FIG. 7b which illustrates that the pulp molded cap 300b may be shaped and sized such that a space 341 is formed between the wall portion 333b of the pulp molded cap 300b and the end portion 202 of the outer wall portion of the container 200, as seen when the pulp molded cap 300b is mounted to seal the pulp molded container 200.

Further, although FIGS. 1-7 illustrate one embodiment of a pulp molded container 200, it is understood that other embodiments of a container comprising a substantially conical sealing surface having at least one partial thread, may be provided. For example, FIGS. 8a-8b illustrate a closure system 100c comprising a pulp molded container 200c and a pulp molded cap 300c.

In similar with what has been described in relation to FIGS. 1-7, the pulp molded container 200c comprises a wall portion 201c which surrounds a product space 2000c presenting a cross-sectional area, wherein said wall portion 201c extends along an axial direction perpendicular to the cross-sectional area, between a first open end 203c and a second end (not illustrated) being axially opposite said first open end of the container 200c. The second end of the container 200c may be formed in similar to what has been described above, for example as illustrated in FIG. 5a or 5b.

Further, as illustrated in FIG. 8b, a first end wall portion 205c extending from the first open end 203c of the container 200c has a first substantially conical sealing surface 206c presenting a first angle as seen relative to the axial direction. The first substantially conical sealing surface 206c may be seen as a first inwardly substantially conical sealing surface. The first substantially conical sealing surface 206c may be formed essentially the same as described above in relation to FIGS. 1-7. The first substantially conical sealing surface 206c comprises at least one partial thread 210c. The at least one partial thread 210c may be formed essentially the same as described above in relation to FIGS. 1-7.

As illustrated in FIG. 8b, the first end wall portion 205c can be seen to form part of said wall portion 201c.

Hence, the wall portion 201c, extending between the first open end 203c and the second opposite end (not illustrated) of the container 200c, can be seen to comprise, as seen from the first open end 203c: the first end wall portion 205c comprising the first substantially conical sealing surface 206c, an outwardly extending shoulder wall portion 2011c, and a body wall portion 2012c.

As illustrated in FIG. 8b, a cross section of the first substantially conical sealing surface 206c can diminish inwardly from the open end 203c.

A cross-sectional area of the product space 2000c can be seen to increase, as seen from a cross section taken at a transition point between the first end wall portion 205c and the shoulder wall portion 2011c, to a cross section taken at a transition point between the shoulder wall portion 2011cand the body wall portion 2012c.

Further, a cross-sectional area of the product space 2000c may be seen to increase from a cross section taken at a transition point between the shoulder wall portion 2011c and the body wall portion 2012c, to the second end (not illustrated) of the container 200c. Alternatively, the cross-sectional area of the product space 2000c may be constant from a cross section taken at a transition point between the shoulder wall portion 2011c and the body wall portion 2012c, to the second end (not illustrated) of the container 200c. Further, the pulp molded cap 300c can be formed essentially the same or similar as described with regards to FIGS. 1-7.

As illustrated in FIG. 8b, the pulp molded cap 300c comprises a second substantially conical sealing surface 306c presenting a second angle as seen relative to the axial direction. The second substantially conical sealing surface 306c may be formed essentially the same as described above in relation to FIGS. 1-7. The second substantially conical sealing surface 306c comprises at least one partial thread 310c. The at least one partial thread 310c may be formed essentially the same as described above in relation to FIGS. 1-7.

Further, as illustrated in FIG. 8b, the pulp molded cap 300c may be sized and shaped to abut a lip portion 209c of the container, as seen when the pulp molded cap 300c is mounted to seal said container 200c.

The pulp molded cap 300c may comprise a wall portion 333c. The pulp molded cap 300c may be sized and shaped such as to form a space 341c between the first end wall portion 205c of the container 200c and the wall portion 333c of the pulp molded cap 300c, as seen when the pulp molded cap 300c is mounted to seal the container 200c, see FIG. 8b.

As illustrated in FIG. 8b the first and second angles of the first and second substantially conical sealing surfaces 206c, 306c substantially matches. Further, as illustrated in FIG. 8b one of said first and second substantially conical sealing surfaces 206c, 306c presents at least one male partial thread 210c and the other one of said first and second substantially conical sealing surfaces presents at least one corresponding female partial thread 310c.

FIGS. 9a-9b illustrate another example of a closure system 100d comprising a pulp molded container 200d and a pulp molded cap 300d.

In similar with what has been described above with regard to FIGS. 1-8, the pulp molded container 200d comprises a wall portion 201d which surrounds a product space 2000d presenting a cross-sectional area, wherein said wall portion 201d extends along an axial direction perpendicular to the cross-sectional area, between a first open end 203d and a second end (not illustrated) being axially opposite said first open end 203d.

The second end of the container 200d may be formed in similar to what has been described above, for example as illustrated in FIG. 5a or 5b.

Further, as illustrated in FIG. 9b, a first end wall portion 205d extending from the first open end 203d of the container 200d has a first substantially conical sealing surface 206d presenting a first angle as seen relative to the axial direction. The first substantially conical sealing surface 206d may be seen as a first outwardly substantially conical sealing surface. A cross section of the first substantially conical sealing surface 206d may increase outwardly along the axial direction from the open end 203d.

The first substantially conical sealing surface 206d comprises at least one partial thread 210d. As illustrated in FIG. 8b, the at least one partial thread 210d may be a female partial thread. Alternatively, the at least one partial thread may be a male thread. The at least one partial thread 210d may be formed essentially the same as described above in relation to FIGS. 1-7.

As illustrated in FIG. 9b, the first end wall portion 205d can be seen to form part of said wall portion 201d.

Hence, the wall portion 201d, extending between the first open end 203d and the second opposite end (not illustrated) of the container 200d, can be seen to comprise, as seen from the first open end 203d: the first end wall portion 205d comprising the first substantially conical sealing surface 206d, an outwardly extending shoulder wall portion 2011d, and a body wall portion 2012d.

Further, as illustrated in FIG. 9b, the pulp molded cap 300d comprises a second substantially conical sealing surface 306d presenting a second angle as seen relative to the axial direction. The second substantially conical sealing surface 306d may be seen as a second inwardly substantially conical sealing surface. The second substantially conical sealing surface 306d comprises at least one partial thread 310d. As illustrated in FIG. 8b, the at least one partial thread 310d may be a male partial thread. Alternatively, the at least one partial thread may be a female thread. The at least one partial thread 310d may be formed essentially the same as described above in relation to FIGS. 1-7.

As illustrated in FIG. 9b the first and second angles of the first and second substantially conical sealing surfaces 206c, 306c can substantially match. Further, as illustrated in FIG. 9b one of said first and second substantially conical sealing surfaces 206d, 306d presents at least one male partial thread 310d and the other one of said first and second substantially conical sealing surfaces presents at least one corresponding female partial thread 210d.

Consequently, as illustrated in FIGS. 1-4 and FIG. 6-8 the pulp molded cap 300, 300a, 300b, 300c, may be adapted to at least partly be internally fitted into the pulp molded container 200, 200c for sealing of the container.

Alternatively, as illustrated in FIGS. 9a-9b, the pulp molded cap 300d may be adapted to be at least partly externally fitted to a container opening of the pulp molded container 200d for sealing of the container.

Further, as illustrated in FIGS. 1-4 and FIGS. 6-9, the pulp molded cap 300, 300a, 300b, 300c, 300d can comprise a first part 320, 320a, 320b, 320c, 320d formed of a pulp material. The first part 320, 320a, 320b, 320c, 320d can comprise said second substantially conical sealing surface 306, 306a, 306b, 306c, 306d.

The first part 320, 320a, 320b, 320c, 320d can comprise an open end 321, 321a, 321b, 321c, 321d and an opposite closed end 322, 322a, 322b, 322c, 322d, see for example FIGS. 1a-1b, FIG. 6a, FIG. 7b, FIG. 8b and FIG. 9b.

A wall portion presenting said second substantially conical sealing surface 306, 306a, 306b, 306c can be seen to extend between the open end 321, 321a, 321b, 321c and the closed end 322, 322a, 322b, 322c, see FIGS. 1a-1b, FIG. 6a, FIG. 7b, and FIG. 8b.

As illustrated in FIG. 9b, a wall portion presenting said second substantially conical sealing surface 306d may be seen to extend outwardly from the open end 321d.

Further, the open end 321, 321a, 321b, 321c, 321d can comprise a rim portion 324, 324a, 324b, 324c, 324d, see for example FIGS. 1a-1b, FIG. 6a, FIG. 7b, FIG. 8b and FIG. 9b.

The rim portion can be seen to comprise a first surface portion 325, 325a, 325b, 325c, 325d see for example FIG. 1b, FIGS. 6a and 6c, FIG. 7b, FIG. 8b and FIG. 9b. Further, the rim portion can be seen to comprise a second opposite surface portion 326, 326a, 326b, 326c, 326d.

A space 340, 304b may be seen to be formed between said first surface portion 325, 325a, 325b, and the lip portion 209, as seen when the pulp molded cap 300, 300a, 300b is mounted to seal said container 200, see for example FIG. 1f, FIG. 2c, FIG. 3c, FIG. 4c and FIG. 7b.

Alternatively, the first surface portion 325c may be adapted to abut on and/or engage the lip portion 209c of the container 200c, see for example FIG. 8b.

The pulp molded cap 300, 300a can further comprise a second part 330, 330a, 330b, 330c, 330d formed of a pulp material. The second part may be seen to comprise a wall portion 333, 333a, 333b, 333c, 333d. The wall portion may be seen to extend between an open end 331, 331a and an opposite, axially spaced apart closed end 332, 332a of the second part, see for example FIGS. 1a-1b and FIG. 6b.

As illustrated in FIGS. 1-4, FIG. 6c, FIG. 7b, FIG. 8b and FIG. 9b, the second part 330, 330a, 330b, 330c, 330d, may be adapted to at least partly enclose the first part 320, 320a, 320b, 320c, 320d.

Further, the second part 330, 330a, 330b, 330c, 330d may be adapted to at least cover the open end 321, 321a, 321b, 321c, 321d of the first part 320, 320a, 320b, 320c, 320d, as seen when the first and second parts are mounted together to form said pulp molded cap 300, 300a, 300b, 300c, 300d.

Thus, the first part 320, 320a, 320b, 320c, 320d of the pulp molded cap 300, 300a, 300b, 300c, 300d can be seen to form an at least partially threaded part of pulp material. The second part 330, 330a, 330b, 330c, 330d of the pulp molded cap 300, 300a, 300b, 300c, 300d can be seen to form a cover part. Together, the first and second parts can be seen to form a two-part pulp molded cap, such as a two-part screw cap.

The second part 330, 330a, 330b, 330c, 330d may be fixedly attached to the first part 320, 320a, 320b, 320c, 320d. Alternatively, the second part 330, 330a, 330b, 330c, 330d may be rotatably connected to the first part 320, 320a, 320b, 320c, 320d.

As one example, the first and second parts may be attached to one another by means of any suitable adhesive and/or adhesive film. For example, an adhesive may be applied to the second surface portion 326, 326a, 326b, 326c, 326d. Alternatively, or additionally, an adhesive may be applied to an inner surface portion of the second part 330, 330a, 330b, 330c, 330d.

Alternatively, or additionally, the first and second parts 320, 330, 320a, 330a, may be pulp molded together. Hence the first and second parts 320, 330, 320a, 330a may be attached by means of fiber bonding.

Alternatively, or additionally, the first and second parts may be attached by an interference fit, also known as a press fit or friction fit. For example, the first and second parts may be provided with mating interlocking portions, such as a groove and a corresponding protrusion for joining the first and second parts.

Consequently, as described above, the pulp molded cap 300, 300a, 300b, 300c, 300d of the closure system 100, 100a, 100b, 100c, 100d may be provided in form of a two-part pulp molded cap. Although FIGS. 1-4 and FIGS. 6-9 illustrates a two-part pulp molded cap, it is understood that as an alternative, a pulp molded cap formed in one piece may be provided. FIGS. 10-13 illustrate various embodiments of a closure system 100e, 100f, 100g, 100h comprising a pulp molded container 200 and a childproof pulp molded cap 300e, 300f, 300g 300h. The container may be designed essentially the same or similar to what has been described above in relation to FIGS. 1-9. Although FIGS. 10-13 illustrate one embodiment of a container, it is understood that other embodiments are possible.

A childproof pulp molded cap will now be described in relation to FIGS. 10-13. Such a childproof pulp molded cap may form part of any of the closure systems as described above in relation to FIGS. 1-9.

When in use, a radial pressure and/or an axial pressure may be applied to the cap in order to be able to turn the cap. For example, an axial pressure may be required in order to be able to turn the cap, see for example FIGS. 10-11. As another example, a radial pressure may be required in order to be able to turn the cap, see for example FIGS. 12-13. The cap 300h as illustrated in FIGS. 13a-13b may require a greater radial pressure as compared with the cap 300g as illustrated in FIGS. 12a-12b.

As illustrated in FIGS. 10-13, the childproof pulp molded cap may be provided in form of a two-part pulp molded cap, in similar to what has been described above in relation to FIGS. 1-9.

The pulp molded cap 300e, 300f, 300g 300h may comprise a first part 320e, 320f, 320g, 320h formed of a pulp material, in similar to what has been described above in relation to FIGS. 1-9. The first part may comprise a substantially conical sealing surface 306e, 306f, see for example FIG. 10b and FIG. 11b. The substantially conical sealing surface may be formed essentially the same as described above in relation to FIGS. 1-7. The substantially conical sealing surface 306e, 306f may comprise at least one partial thread 310e, 310f, see for example FIG. 10b and FIG. 11b. The at least one partial thread 310e, 310f may be formed essentially the same as described above in relation to FIGS. 1-7.

Further, the pulp molded cap 300e, 300f, 300g, 300h may comprise a second part 330e, 330f, 330g, 330h formed of a pulp material, in similar to what has been described above in relation to FIGS. 1-9. The second part 330e, 330f, 330g, 330h is adapted to at least partly enclose said first part 320e, 320f, 320g, 320h.

Further, the first and second parts 320e, 320f, 320g, 320h, 330e, 330f, 330g, 330h may present selective engagement means. The selective engagement means may be configured such that at least one of the first and second parts is deformable between a first state, wherein the first and second parts are rotatable relative to each other and a second state, wherein a torque, is transferrable from the second part to the first part. Said torque being sufficient to connect or disconnect the first part 320e, 320f, 320g, 320h to or from a container 200 by means of a partial thread.

Said selective engagement means may for example be provided in form of corresponding indentations 327e, 337e, 327f, 337f and/or at least one pair of a corresponding groove and protrusion 329g, 339g, 329h, 339h.

As one example, the first part 320e, 320f may comprises at least one first indentation 327e, 327f, see FIG. 10b and FIG. 11b. Further, the second part 330e, 330f may comprises at least one second indentation 337e, 337f. The first and second intendations 327e, 337e, 327f, 337f, can be seen to be seperated by a gap 345e, 345f.

When in use of such a pulp molded cap 300e, 300f, a pressure may be applied downwardly, such as to close said gap 345e, 345f. Thereby making it possible to unscrew the pulp molded cap from the container opening. Further, as illustrated in FIGS. 10a-10b, the first part 320e may comprise a first central substantially conical portion 328e. The first central substantially conical portion 328e may be provided with a recess 3281. Further, the second part 330e may comprise a corresponding second central substantially conical portion 338e. The second central substantially conical portion 338e may be provided with a protrusion 3381. The protrusion 3381 may be adapted to interact with said recess 3281 such as the second part 330e is rotatable relative the first part 320e. The first and second central substantially conical portions 328e, 338e may present substantially matching angled surfaces.

Thus, the first and second part 320e, 330e of the pulp molded cap 300e can be seen to comprise two draft-matched substantially conical surfaces at a central portion of the cap. The recess 3281 can be seen to form a notch of the first central substantially conical portion 328e. The recess and protrusion 3281, 3381 can be seen to form a turnable connection between the first and second parts 320e, 330e of the pulp molded cap 300e.

Further, as illustrated in FIGS. 11a-11b, the second part 330f may comprise an at least partly reversed rim portion 335. For example, as illustrated in FIGS. 11a-11b, a rim portion of the second part 330f may be provided with a plurality of dents 3351. The dents can be seen to extend radially inwardly. The pulp material forming said dents 3351 may be molded as protrusions extending outwardly from said rim portion, and subsequently pushed inwardly in a reverse direction in order to form said dents. Further, the first part 320e, 320f, 320g, 320h may present a substantially circular cross-sectional area.

Further, the second part 330e, 330f may presents a substantially circular cross-sectional area. Alternatively, the second part 330g may present a substantially oval cross-sectional area, see for example FIGS. 12a-12b.

As yet another alternative, the second part 330h may present a substantatially circular cross-sectional area further comprising a first protruding portion 336a and an opposite second protruding portion 336b, see for example FIGS. 13a-13b.

As illustrated in for example FIG. 12b and FIG. 13b, said engagement means 329g, 339g, 329h, 339h may be positioned at a portion of the second part 330g, 330h where a radial distance to the first part 320g, 320h is near a maximum.

Further, it is understood that other sizes and shapes of the container and/or the pulp molded cap than the ones illustrated in FIGS. 1-13 may be provided. For example, FIGS. 14a-14e illustrates various designs of a closure system 100i, 100j, 100k, 100l, 100m comprising a pulp molded container 200i, 200j, 200k, 200l, 200m and a pulp molded cap 300i, 300j, 300k, 300l, 300m. The pulp molded container 200i, 200j, 200k, 200l, 200m may be formed essentially the same as described in relation to any one of FIGS. 1-13. The pulp molded cap 300i, 300j, 300k, 300l, 300m may be formed essentially the same as described in relation to any one of FIGS. 1-13.

The closure system as described above may be produced by using at least one porous tool formed by additive manufacturing. Such tools are known, see for example WO2016101976 A1.

A pulp molding system comprising at least one of the following may be used: a pick-up press tool, a porous tool, a press tool and a transfer tool. Such pulp molding systems are known, see for example WO2016101976 A1 and WO2020141209 A1.

Furthermore, the closure system may be produced by a pulp molding process comprising two or more subsequent pressing steps. Pressing in several subsequent pressing steps is known, see for example WO2016101976 A1, WO2020016416 A2 and WO2020141209 A1.

In relation to FIGS. 15a-5e, a method of producing a cap, such as a screw cap, from a pulp slurry will now be described.

FIG. 15a schematically illustrates a male tool 50a, having a porous product face 51a, wherein a pulp slurry layer 3 has been applied to the porous product face 51a.

As illustrated in FIG. 15a-15e, the porous product face 51a of the male tool 50a comprises a at least partially threaded portion 57a. FIG. 15a-15e illustrates a male tool with a continuous thread. As illustrated in FIG. 15a-15e, the continuous thread extends over a distance corresponding to more than one turn. However, it is understood that other embodiments of a male tool comprising an at least partly threaded portion may be provided. For example, a tool with at least one partial thread may be provided. FIGS. 17-18 illustrates various examples of a male tool that may be used in the method.

Hence, the method as will be described in relation to FIGS. 15a-15e may be used for producing various types of caps from a pulp material. For example, the method may be used to produce a continuous thread cap, a lug or twist cap, a triple thread cap, a cap with one partial thread, a cap with a plurality of partial threads or other forms of screw caps. As an alternative, the method may be used to form an at least partially threaded part, forming part of a pulp molded cap. The method may be used to form an at least partially threaded part of a two-part pulp molded cap. For example, the method may be used to form the first part 320, 320a, 320b, 320c, 320d, 320e, 320f, 320g, 320h of the two-part pulp molded cap as described above in relation to FIGS. 1-14.

The method comprises applying a pulp slurry layer 3 to the porous product face 51a of the male tool 50a.

The step of applying the pulp slurry layer 3 to the porous product face 51a of the male tool 50a may comprise applying a dose of pulp slurry from a dosing system (not illustrated) holding at least one pulp slurry dose above said male tool. During said application by means of a dosing system, the pulp slurry layer formed on the porous product face of the male tool may simultaneously be dewatered through the porous product face of the male tool. The dewatering may be achieved by gravity and/or by drawing a vacuum through the porous product face of the male tool.

Alternatively, the step of applying the pulp slurry layer 3 to the porous product face 51a of a male tool 50a may comprise immersing the porous product face into a bath (not illustrated) containing a pulp slurry, while drawing a vacuum through the porous product face.

As yet another alternative, the pulp slurry layer may be applied by spraying or pouring a pulp slurry onto the porous product face, while drawing a vacuum through the porous product face.

The pulp slurry layer may have a water content of 95-99.9% by weight, preferably 99-99.9% by weight.

When applying the pulp slurry layer 3 to the porous product face 51a of the male tool 50a, a vacuum may be drawn through the porous product face 51a of the male tool 50a.

The method further comprises, in a first dewatering step, dewatering the pulp slurry layer 3 through said porous product face 51a of the male tool 50a.

In the first dewatering step, an initial water content of the pulp slurry layer may be about 70-90%, 95-99.9% or 99-99.9% by weight. A final water content of the first dewatering step may be about 40-75% by weight, preferably 40-50% by weight.

The first dewatering step may comprise evacuating water from the pulp slurry layer 3 through the porous male tool 50a by means of gravity. Alternatively, or additionally, the pulp slurry layer may be dewatered by drawing a vacuum through the porous product face 51a of the male tool 50a. The pulp slurry layer 3 may initially be dewatered by means of gravity and subsequently by drawing a vacuum through the male tool 50a.

Hence, as illustrated in FIG. 15a, the pulp slurry layer 3 applied to the porous product face 51a of the male tool 50a may be dewatered by means of gravity and/or use of vacuum.

The evacuated water may be evacuated at a first end 56a of the male tool 50a.

The method may further comprise transferring the pulp slurry layer 3 to a first pressing arrangement. The transfer may be performed by the male tool 50a.

The first dewatering step may comprise pressing the pulp slurry layer 3 between the porous product face of the male tool 50a and a second product face 70a of a first press tool 71a, see FIG. 15b.

Thus, after the pulp slurry layer 3 is applied, the first male tool 50a and the first press tool 71a, may be brought into engagement to press the pulp slurry such as to at least partly form the cap, as illustrated in FIG. 15b. Hence, the first dewatering step may be seen to comprise a first pressing step.

The first press tool 71a may be a female tool. The second product face 70a may be porous, non-porous or partly porous. The first press tool 71a may be rotated onto the male tool 50a holding the pulp slurry layer 3. Thus, the first press tool 71a may be turnable.

The second product face 70a of the first press tool 71a may be heated during said pressing. During said pressing, water and/or steam may be evacuated through the porous male tool 50a by means of gravity and/or drawing a vacuum through the porous product face 51a. Alternatively, or additionally, a vacuum may be drawn through the second product face 70a of the first press tool 71a.

The method may further comprise a step of releasing the pulp slurry layer 3 from the male tool 50a, see FIG. 15c. The releasing may be performed by turning or rotating the first press tool 71a. For example, the first press tool 71a may be mounted to a tool holder 72a, wherein said tool holder is turnable, as illustrated in FIG. 15c. The turning function of said tool holder 72a enables a release of the pulp slurry layer from the male tool by a turning movement.

The step of releasing may comprise blowing air through the porous product face 51a of the male tool 50a. The air may be blowed in a direction from the rear of the male tool, to the product face side of the male tool. For example, a pressure greater than ambient air pressure may be supplied through the porous product face 51a of the male tool 50a. A vacuum may be drawn through the first press tool 71a.

During the step of releasing, see FIG. 15c, a pressure may be supplied through the porous product face of the male tool 50a in a direction easing the release of the pulp slurry layer from the male tool. By suppling a pressure in a releasing direction, the release of the pulp slurry layer, i.e. the at least partly molded cap, from the male tool will be enabled.

The pulp slurry layer 3 may be released from the male tool 50a by initially rotating the first press tool 71a 10-180°, preferably 10-20°, 20-30°, 30-40°, 40-50°, 50-60°, 70-80°, 80-90°, 90-100°, 100-110°, 110°-120°, 120-130°, 140°-150°, 150-160°, 160-170° or 170-180°, before lifting the pulp slurry layer 3 off the male tool 50a.

Thus, a releasing of the pulp slurry layer may be achieved through a twist-and-lift operation. For example, the pulp slurry layer may be released from the male tool 50a by a quarter of a turn and lift-off operation.

When initiating the releasing step, a water content of the pulp slurry layer 3 may be about 40-75% by weight, preferably about 40-50% by weight.

FIG. 15d illustrates a transfer step of transferring the pulp slurry layer 3, being a at least partly formed pulp product, to a second pressing arrangement for subsequent forming. The transfer may be performed by means of the first press tool 71a, as illustrated in FIG. 15d. As an alternative, a separate transfer tool may be used for transferring the pulp slurry layer to a subsequent pressing arrangement.

As illustrated in FIG. 15e, the first press tool 71a and a second male tool 80a may form a second pressing arrangement. Hence, the method may further comprise applying the pulp slurry layer 3 onto a second male tool 80a, see FIG. 15e. The first press tool 71a holding the pulp slurry layer 3, may be rotated onto the second male tool 80a.

The second male tool 80a may comprise a third product face 81a. The third product face 81a of the second male tool 80a may be porous, partly porous or non-porous.

Hence, the method may comprise pressing the pulp slurry layer 3 in a second pressing step. The pulp slurry layer 3 may be pressed between the third product face 81a of the second male tool 80a and the second product face 70a of the first press tool 71a.

In the second pressing step, the pulp slurry layer 3 may be heated. One or both of the tools of the second pressing arrangement may be heated. Thus, one or both of the first press tool 71a and the second male tool 80a may be heated in the second pressing step. Thus, the second product face 70a of the first press tool 71a may be heated during said pressing.

Alternatively, or additionally, the third product face 81a of the second male tool 80a may be heated.

During said second pressing step, water and/or steam may be evacuated through a porous product face of the second male tool 80a by means of gravity and/or by drawing a vacuum through the porous product face of the second male tool 80a. Alternatively, or additionally, a vacuum may be drawn through the second product face 70a of the first press tool 71a.

Thus, the method as described above, may be performed in several subsequent pressing steps.

After the second pressing step, the pulp slurry layer 3, now with most of its solvent removed, may be released. The release may be performed by rotating at least one of the tools 71a, 80a. The pulp slurry layer 3, being a at least partly formed pulp product in form of a cap or cap part, may then be transferred out of the pressing arrangement.

Although FIGS. 15a-15e illustrates a method comprising two subsequent pressing steps, it is understood that several subsequent pressing steps may be used. For example, the method may further comprise pressing the pulp slurry layer in a third pressing step.

FIGS. 16a-16l, illustrate another embodiment of a method of producing a cap, such as a screw cap, from a pulp slurry.

FIG. 16a schematically illustrates a male tool 50d, having a porous product face 51d, wherein a pulp slurry layer 3 has been applied to the porous product face 51d.

As illustrated in FIG. 16a-16l, the porous product face 51d of the male tool 50d comprises an at least partially threaded portion 57d. FIGS. 16a-16l illustrate a male tool with two partial threads 571d₁, 571d₂. However, it is understood that other embodiments of a male tool comprising an at least partly threaded portion may be provided. For example, a male tool with one partial thread may be provided or a male tool with more than two partial threads. Alternatively, a male tool with a continuous thread, such as the one illustrated in FIGS. 15a-15e may be provided. FIGS. 17-18 illustrates various examples of a male tool that may be used in the method.

Hence, the method as will be described in relation to FIGS. 16a-16l may be used for producing various types of caps from a pulp material. For example, the method may be used to produce a continuous thread cap, a lug or twist cap, a triple thread cap, a cap with one partial thread, a cap with a plurality of partial threads or other forms of screw caps. As an alternative, the method may be used to form an at least partially threaded part, forming part of a pulp molded cap. The method may be used to form an at least partially threaded part of a two-part pulp molded cap. For example, the method may be used to form the first part 320, 320a, 320b, 320c, 320d, 320e, 320f, 320g, 320h of the two-part pulp molded cap as described above in relation to FIGS.

1-14.

The method comprises applying a pulp slurry layer 3 to the porous product face 51d of the male tool 50d. The pulp slurry layer 3 may be applied in similar what has been described above in relation to FIGS. 15a-15e.

The method further comprises, in a first dewatering step, dewatering the pulp slurry layer 3 through said porous product face 51d of the male tool 50d. The dewatering may be achieved in similar to what has been described above in relation to FIGS. 15a-15e.

The first dewatering step may comprise pressing the pulp slurry layer 3 between the porous product face of the male tool 50d and a second product face 70d of a first press tool 71d, see FIG. 16b-16d.

Thus, after the pulp slurry layer 3 is applied, the first male tool 50d and the first press tool 71d, may be brought into engagement to press the pulp slurry such as to at least partly form the cap or cap part.

Hence, the first dewatering step may be seen to comprise a first pressing step. The first pressing step may be performed in similar to what has been described above in relation to FIGS. 15a-15e. The first press tool 71d may be designed essentially the same as the first press tool 71a. Alternatively, the first press tool 71d may be designed differently than the first press tool 71a.

The first press tool 71d may be a female tool. The second product face 70d may be porous, non-porous or partly porous. The first press tool 71d may be rotated onto the male tool 50d holding the pulp slurry layer 3, see FIG. 16b-16c. Thus, the first press tool 71d may be turnable.

FIG. 16e illustrates removing the first press tool 71d from the first male tool 50d. The first press tool 71d may be rotated of the male tool 50d. The first press tool 71d may initially be rotated 10-180°, preferably 10-20°, 20-30°, 30-40°, 40-50°, 50-60°, 70-80°, 80-90°, 90-100°, 100-110°, 110°-120°, 120-130°, 140°-150°, 150-160°, 160-170° or 170-180°, and then lifted upwardly.

Thus, the removal of the first press tool 71d from the first male tool 50d after the first pressing step may be achieved by a twist-and-lift operation. For example, the removal may be performed by a quarter of a turn and lift-off operation.

FIG. 16f illustrates the first male tool 50d holding the pulp slurry layer 3, being in form of a at least partly formed pulp cap or cap part.

FIGS. 16g-6k illustrate a transfer step of transferring the pulp slurry layer 3 to a second pressing arrangement for subsequent pressing. FIG. 16g illustrates a transfer tool 60d rotated onto the first male tool 50d holding the pulp slurry layer 3. The transfer tool 60d may present a porous product face 61d. While rotating the transfer tool 60d onto the first male tool 50d, a pressure greater than ambient air pressure may be supplied through the porous product face of the transfer tool 60d. Additionally, or alternatively, air may be blown through the porous product face 51d of the male tool 50d. The air may be blown in a direction from the rear of the male tool, to the product face side of the male tool. Hence, a reverse blow may be achieved.

When the transfer tool 60d has been rotated onto the male tool 50d, see FIG. 16h, a vacuum may be drawn through the porous product face of the transfer tool 60d. Additionally, or alternatively, air may be blown through the porous product face 51d of the male tool 50d. The air may be blown in a direction from the rear of the male tool, to the product face side of the male tool.

FIG. 16i illustrate the transfer tool 60d, holding the pulp slurry layer 3, being rotated off the male tool 50d. A vacuum may be drawn through a porous product face of the transfer tool 60d. Additionally, or alternatively, air may be blown through the porous product face 51d of the male tool 50d.

Preferably, a pressure may be supplied through the porous product face of the male tool 50d in a direction easing the release of the pulp slurry layer 3 from the male tool 50d.

Hence, FIG. 16h-16i can be seen to illustrate a step of releasing the pulp slurry layer 3 from the first male tool 50d by means of a transfer tool 60d.

As illustrated in FIGS. 16j-16l, the method may further comprise transferring the pulp slurry layer 3 to a second pressing arrangement for subsequent pressing.

FIG. 16j-16l illustrate the transfer being performed by means of the transfer tool 60d. The transfer tool 60d may transfer the pulp slurry layer 3, being in form of a at least partly formed pulp cap or cap part, to a second male tool 80d. The second male tool 80d may be designed essentially the same as the second male tool 80a described in relation to FIGS. 15a-15e. Alternatively, the second male tool 80d may be designed differently than the first male tool 80a. The second male tool 80d may comprise a third product face 81d. The third product face 81d of the second male tool 80d may be porous, partly porous or non-porous.

The method may further comprise pressing the pulp slurry layer in a second pressing step. The second pressing may be performed in similar to what has been described above in relation to FIGS. 15a-15e.

The pulp slurry layer 3 may be pressed between the product face 61d of the transfer tool 60d and the product face 81d of the second male tool 80d, see FIG. 16l. Hence, the transfer tool 60d may be seen to form a combined transfer-and-press-tool. Consequently, the transfer tool 60d and the second male tool 80d may be seen to form the second pressing arrangement.

Alternatively, the transfer tool 60d may be rotated off the second male tool 80d, the second male tool holding the pulp slurry layer 3. A second cooperating press tool (not illustrated) may then be rotated onto the second male tool 80d for pressing the pulp slurry layer 3.

During the second pressing step, at least one of the tools of the second pressing arrangement may be heated. For example, in the step as illustrated in FIG. 16l, the product face 81d of the second male tool 80d may be heated. During said second pressing step, water and/or steam may be evacuated through a porous product face of the second male tool 80d by means of gravity and/or by drawing a vacuum through the porous product face of the second male tool 80d. Alternatively, or additionally, a vacuum may be drawn through the porous product face 61d of the transfer tool 60d. Alternatively, or additionally, when in use of said second press tool (not illustrated), a vacuum may be drawn through a porous product face of said second press tool (not illustrated).

After the second pressing step, the pulp slurry layer 3, now with most of its solvent removed, may be released and transferred out of the second pressing arrangement.

Although FIGS. 16a-16l illustrates a method comprising two subsequent pressing steps, it is understood that several subsequent pressing steps may be used. For example, the method may further comprise pressing the pulp slurry layer in a third pressing step.

The method as described above in relation to FIGS. 15a-15e and FIGS. 16a-16l may be used to form an at least partly threaded cap part, such as the first part 320, 320a, 320b, 320c, 320d, 320e, 320f, 320g, 320h of the two-part pulp molded cap as described above in relation to FIGS. 1-14. Thus, the method may comprise forming the cap part with an open end and an opposite closed end.

The method may further comprise providing a second part formed of pulp material. For example, the method may comprise providing a cover part formed of pulp material.

The method may further comprise joining said cap part and said second part such that the second part at least partly encloses said cap part.

The method may further comprise joining said cap part and said second part such that the second part at least covers the open end of said cap part.

The two parts may be pulp molded together. Hence, a two-part cap, such as a two-part screw cap, may be formed without use of any adhesive such as glue.

Alternatively, or additionally, the cap part and the second part may be joined by any suitable adhesive, such as glue, and/or an adhesive film.

Thus, the two parts may be permanently attached to one another.

Alternatively, or additionally, the cap part and the cover part may be attached by an interference fit, also known as a press fit or friction fit. For example, the parts may be provided with mating interlocking portions, such as a groove and a corresponding protrusion for joining the cap part and the cover part.

According to one embodiment, the joining may comprise moveably attaching the cap part and second part to one another, such that at least one of the parts of the final two-part pulp molded cap is at least partly moveable relative the other part.

In relation to FIGS. 17-18, a tool for use in producing a cap or cap part from a pulp slurry will now be described. For example, the tool may be used for producing a closure system as described in relation to FIGS. 1-14. The tool may be used in a method as described in relation to FIGS. 15-16.

FIGS. 17-18 illustrates various embodiments of a tool comprising an at least partly threaded portion. FIGS. 17-18 illustrates a tool in form of a male tool 50, 50a, 50b, 50c, 50d, 50e, 50f comprising a self-supporting tool wall portion 510 having a product face 51, 51a, 50b, 51c, 51d, 51e, 51f adapted for contacting a pulp slurry layer 3. The tool further comprises a rear face 505 on the other side of the wall portion 510 relative to the product face. The tool wall portion 510 presents pores, which are provided by a plurality of channels 501 extending through the tool wall portion 510, from the product face to the rear face 505. Each channel 501 presents a channel opening 503 at the product face.

FIG. 17a schematically illustrates one example of a plurality of channels 501 extending through a tool wall portion of a male tool. However, although not illustrated, other embodiments are also possible.

Further, as illustrated in FIG. 17b and FIGS. 18a-18e, the porous product face 51, 51a, 50b, 51c, 51d, 51e, 51f comprises an at least partially threaded portion 57, 57a, 57b, 57c, 57d, 57e, 57f.

As illustrated in FIG. 17d, at least some of the channel openings 503 at the at least partly threaded portion 57, 57a, 57b, 57c, 57d, 57e, 57f, may present a channel flow direction W_a. An angle β between said channel flow direction W_a and a component z substantially parallel with a screwing direction of the tool may be non-perpendicular. Preferably said angle β may be less than 80°, less than 70° or less than 60°. More preferably said angle β may be less than 50°, less than 40°, less than 30° or less than 20°.

The channel flow direction W_a may be seen to be substantially parallel with at least one channel wall 5011a, 5011b of said channel 501.

At least some of the channel openings 503 on the product face at the at least partly threaded portion 57, 57a, 57b, 57c, 57d, 57e, 57f may be seen to comprise a downstream part 503a and an upstream part 503b, as seen relative to a screwing direction of the tool, see FIG. 17c.

The male tool 50, 50a, 50b, 50c, 50d, 50e, 50f may have a body formed substantially as a cylinder, preferably a conical cylinder, see FIG. 18f.

Said cylinder or conical hollow cylinder can be seen to comprise at least one external thread, thread portion and/or partial thread.

A first end 56, 56a, 56b, 56c, 56d, 56e of the tool may present a first diameter d₁. A second end 58, 58a, 58c, 58d, 58e opposite to the first end may present a second diameter d₂. The second diameter d₂ may be smaller than the first diameter d₁, see for example FIGS. 18c, 18d and 18f.

Thus, a wall of the conical cylinder 59 may be seen to taper from the first end 56 to the second end 58, with an angle α of 2-15° relative to an axial direction, preferably 2.5-12°, 3-10° or 4-6°, see FIG. 18f.

The tapering form of the male tool provides a draft angle, which can enable the release of the at least partly molded pulp product from the male tool.

Alternatively, the diameters d₁ and d₂ may be equal or substantially the same.

Further, the male tool may be substantially formed as a hollow cylinder, preferably a hollow conical cylinder 59. Said hollow cylinder or conical hollow cylinder can be seen to comprise at least one external thread, thread portion and/or partial thread. Consequently, the male tool may have a hollow core 500, see FIGS. 17a-17b. The hollow core 500 may act as a canal, allowing waste, air streams, steam and liquids such as evacuated water, to pass through said tool. The hollow core 500 also allows for application of a vacuum over the product face when in use.

The at least partly threaded portion 57a, 57b, 57c of the male tool 50a, 50b, 50c, may comprise at least one continuous thread, see for example FIGS.

18 a-18c. The continuous thread may be provided in form of a helical ridge. As illustrated in FIGS. 18a-18c, the continuous thread may extend over a distance corresponding to more than one turn.

As illustrated in FIGS. 18a-18c, the at least partially threaded portion of the porous product face of the male tool 51a, 51b, 51c may comprise at least one external thread. Further, as illustrated in FIGS. 18b, the at least partially threaded portion of the porous product face of the male tool may comprise at least one recessed groove. Further, as illustrated in FIGS. 18a-18c, the at least partially threaded portion may present a plurality of thread crests 53a, 53b, 53c. Further, as illustrated in FIGS. 18a-18c, the at least partially threaded portion may present a plurality of thread roots 54a, 54b, 54c. As illustrated in FIG. 18a, the thread root 54a may be proportionally wider than the thread crests 53a. Alternatively, as illustrated in FIG. 18b, the thread crest 53b may be proportionally wider than the thread root 54b.

Alternatively, or additionally, the porous product face of the male tool may present an at least partially threaded portion comprising at least one non-continuous thread (not illustrated).

Alternatively, or additionally, the at least partially threaded portion 57d, 57e, 57f of the male tool 50d, 50e, 50f may comprise at least one partial thread 571d₁, 571d₂, 571e₁, 571f₁, 571f₂, 571f₃, 571f₄.

As illustrated in for example FIG. 18e, the at least partially threaded portion of the male tool may comprise a plurality of partial threads 571f₁, 571f₂, 571f₃, 571f₄ each separated by a gap 572f₁, 572f₂, 572f₃, 572f₄. Hence, the at least partially threaded portion of the male tool may comprise at least two partial threads separated by a gap.

The at least one partial thread 571d₁, 571d₂, 571e₁, 571f₁, 571f₂, 571f₃, 571f₄ may have a length t corresponding to about 1/32 to ⅓ of a turn. Preferably 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn. See for example FIG. 18e.

Further, the at least one partial thread 571d₁, 571d₂, 571e₁, 571f₁, 571f₂, 571f₃, 571f₄ may have a thread rising angle θ, as measured relative to a plane perpendicular to a central axis C of the male tool, see FIG. 8d. The angle θ may be larger than 0° and less than 90°, preferably 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° or 80-85°, most preferably 50-80°.

At least one partial thread 571d₁, 571d₂, 571e₁, 571f₁, 571f₂, 571f₃, 571f₄ of the tool may present a tapering end portion 575, see FIG. 8d.

The at least one partial thread 571d₁, 571d₂, 571e₁, 571f₁, 571f₂, 571f₃, 571f₄ of the tool may be provided in form of a ridge shaped thread segment.

Alternatively, the at least one partial thread 571d₁, 571d₂, 571e₁, 571f₁, 571f₂, 571f₃, 571f₄ of the tool may be provided in form of a groove shaped thread segment.

Further, the at least partially threaded portion 57, 57a, 57b, 57c, 57d, 57e, 57f may present varying porosity.

For example, a thread crest 53, 53a, 53b, 53c of the at least partially threaded portion 57, 57a, 57b, 57c may present a higher porosity than a thread root 54, 54a, 54b, 54c of the at least partially threaded portion 57, 57a, 57b, 57c.

When in use of the male tool, a thread crest 53, 53a, 53b, 53c can be seen to form a thread root 93a of the pulp slurry layer 3 being formed on the tool, see FIG. 15d.

When in use of the male tool, a thread root 54, 54a, 54b, 54c can be seen to form a thread crest 94a of the pulp slurry layer 3 being formed on the tool, see FIG. 15d.

The at least one thread crest 53, 53a, 53b, 53c of the at least partially threaded portion 57, 57a, 57b, 57c may present a first porosity. The at least one thread root 54, 54a, 54b, 54c of the at least partially threaded portion 57a, 57b, 57c may present a second porosity. At least one thread flank 55, 55a, 55b, 55c of the at least partially threaded portion 57, 57a, 57b, 57c may present a third porosity. The first, second and/or third porosity may differ as compared to one another.

Further, the male tool may be mounted to a tool holder 550a, 550b, 550c, 550d, 550e.

The male tool 50, 50a, 50b, 50c, 50d, 50e, 50f may be rotatable. Hence, the tool can be turned or rotated around a central axis of the tool. As one example, the tool may be mounted to a tool holder, wherein said tool holder is turnable.

Further, the male tool 50, 50a, 50b, 50c, 50d, 50e, 50f may be adapted to be connected to a vacuum source (not illustrated) when in use. A vacuum chamber may be provided at a rear side of the tool wall portion. For example, the hollow core 500 as illustrated in FIG. 17b can be seen to form a vacuum chamber. The vacuum chamber may be adapted to be connected to a pressure regulator (not illustrated) when in use. The pressure regulator may be adapted for providing an air pressure other than ambient pressure when in use. The rear face 505, opposite to the porous product face, of the male tool may be at least 50%, preferably at least 70%, or at least 90%, exposed to a vacuum chamber.

Further, the male tool 50, 50a, 50b, 50c, 50d, 50e, 50f may comprise at least one heating element adapted to supply heat to a product face of the male tool 51, 51a, 50b, 51c, 51d, 51e, 51f when in use.

Claims

1. A closure system comprising: a pulp molded container comprising a wall portion which surrounds a product space presenting a cross-sectional area, wherein said wall portion extends along an axial direction perpendicular to the cross-sectional area, between a first open end and a second end being axially opposite said first open end, wherein a first end wall portion extending from said first open end has a first substantially conical sealing surface presenting a first angle relative to the axial direction; anda pulp molded cap having a second substantially conical sealing surface (306) presenting a second angle relative to the axial direction;wherein the first and second angles substantially match, andwherein one of said first and second substantially conical sealing surfaces (206, 306) presents at least one male partial thread and the other one of said first and second substantially conical sealing surfaces presents at least one corresponding female partial thread.

2. The closure system according to claim 1, wherein the first substantially conical sealing surface is a first inwardly substantially conical sealing surface, and the second substantially conical sealing surface is a second outwardly substantially conical sealing surface.

3. The closure system according to claim 1, wherein a cross section of the first substantially conical sealing surface diminishes inwardly from the open end.

4. The closure system according to claim 1, wherein the first end wall portion forms an inner wall portion that extends from the open end and which has said first substantially conical sealing surface; andthe wall portion (201) forms an outer wall portion, formed radially outwardly of the inner wall portion and extending from the open end (203) towards the second end (204) of the container,wherein an axial extent of the outer wall portion is greater than an axial extent of the inner wall portion, andwherein the inner and outer wall portions are formed in one piece of material.

5. The closure system according to claim 1, wherein the first substantially conical sealing surface is a first outwardly substantially conical sealing surface, and the second substantially conical sealing surface is a second inwardly substantially conical sealing surface.

6. The closure system according to claim 1, wherein a cross section of the first substantially conical sealing surface increases outwardly along the axial direction from the open end.

7. The closure system according to claim 1, wherein a container wall portion at the second end is inwardly conical with a cross section diminishing inwardly along the axial direction from the second end.

8. The closure system according to claim 1, wherein the at least one partial thread is spaced from at least one, or both, axially extreme portions of at least one of the first and second substantially conical sealing surfaces.

9. The closure system according to claim 8, wherein the at least one partial thread is spaced from the at least one axially extreme portion at least by a distance corresponding to 1-50%, 1-40%, 1-35%, 1-30%, 2-25%, 3-20%, 4-15% or 5-10%, of an axial extent of said at least one of the first and second substantially conical sealing surfaces.

10. The closure system according to claim 1, wherein the at least one partial thread extend between a first and a second axially extreme portion of at least one of the first and second substantially conical sealing surfaces.

11. The closure system according to claim 1, wherein the at least one partial has a thread rising angle being larger than 0° and less than 90°, or 1-5°, 5-10°, 10-15°, 15-20°, 20-25°, 25-30°, 30-35°, 35-40°, 45-50°, 50-55°, 55-60°, 60-65°, 65-70°, 70-75°, 75-80° er 80-85°, or 50-80°.

12. The closure system according to claim 1, wherein a length of the at least one partial thread corresponds to about 1/32 to ⅓ of a turn, 1/32 to ¼ of a turn, 1/24 to ⅕ of a turn, 1/16 to ⅙ of a turn, or 1/12 to ⅛ of a turn.

13. The closure system according to claim 1, wherein the at least one partial thread has a tapering end portion.

14. The closure system according to claim 1, wherein the at least one male partial thread comprises portions of varying height.

15. The closure system according to claim 1, wherein the at least one female partial thread comprises portions of varying depth.

16. The closure system according to claim 1, wherein the at least one partial thread is straight or curved.

17. The closure system according to claim 1, wherein said first and/or second angles are 2-15° 2.5-12°, 3-10° or 4-6° relative to the axial direction.

18-21. (canceled)

22. A pulp molded container, wherein the container comprises: a wall portion which surrounds a product space presenting a cross-sectional area, wherein said wall portion extends along an axial direction perpendicular to the cross-sectional area, between a first open end and a second end being axially opposite said first open end,wherein a first end wall portion extending from said first open end has a substantially conical sealing surface, andwherein the substantially conical sealing surface presents at least one partial thread.

23. A pulp molded cap comprising: a substantially conical sealing surface,wherein the substantially conical sealing surface presents at least one partial thread.

24. The pulp molded cap according to claim 23, comprising: a first part (320) formed of a pulp material, wherein the first part comprises said substantially conical sealing surface, anda second part (330) formed of a pulp material, wherein the second part is adapted to at least partly enclose the first part (320).

25-64. (canceled)