Patent Application
20250012016
The present invention relates to a receptacle mould and a method of manufacturing a receptacle mould. The receptacle mould is useable to mould a receptacle from a fibre suspension, such as a fibre suspension comprising paper pulp. The receptacles may form consumer packaging, such as bottles, useful for holding liquids, powders, other flowable materials or solid objects.
Bottles made from a fibre suspension are known and may be used in place of plastic bottles. These “pulp-moulded” bottles can therefore reduce the amount of plastic used in disposable consumer goods.
Published patent document WO2018/020219A1 describes forming a bottle from paper pulp in a mould. A fibre suspension is introduced into a mould and a layer is deposited on the inside of the mould. From here, a deflated “bladder” is introduced into the mould and is inflated. The expansion of the bladder presses the fibre suspension against the mould to force at least some water out of the fibre suspension, resulting in a bottle being formed. This process of removing water is commonly known as “dewatering”.
As mentioned, the use of an inflatable bladder (referred to herein as an expandable member) in forming pulp-moulded receptacles is known. However, a problem with using these expandable members is that they can sometimes contact and damage the delicate layer of the fibre suspension spread across the inside of the mould as the expandable member is first introduced into a cavity of the mould. For example, when the expandable member is passed through an opening of the mould, the expandable member (which is currently not expanded/inflated) can contact the mould, causing the expandable member to fold and/or rebound as it passes into the cavity and then contact the layer of fibre suspension. This contact can then rupture the receptacle and/or cause the receptacle to have an uneven wall thickness, which compromises the structural integrity of the receptacle.
To mitigate this problem, the inventors have designed a receptacle mould having a “guide channel” that precisely guides an expandable member, such as such an inflatable member, into the cavity of the mould to reduce or avoid contact with the fibre suspension layer that coats a surface of the cavity. The guide channel has a specific form that guides the expandable member from outside the mould into the cavity of the mould. The guide channel therefore extends from an outer surface of the mould into the cavity. A first end, or first portion, of the guide channel therefore exists at the outer surface of the mould, and a second end of the guide channel exists where the guide channel opens into the cavity. In other examples, there is an additional portion of the guide channel between the first portion and the outer surface of the mould. In some examples, the additional portion of the guide channel has a width that is less than, equal to, or greater than the width of the first portion. In a first aspect, a first opening (at the first end) of the guide channel is wider than a second opening (at the second end) of the guide channel. This means that the guide channel narrows along its length. In an example, the guide channel tapers along its length. By having a receptacle mould with a guide channel that is wider at one end (such as the outer face/surface of the receptacle mould) and narrower at the other end (opening into the cavity), the expandable member can be guided into the cavity of the mould and may be kept away from an inner surface of the cavity. When the fibre suspension (from which the receptacle is to be moulded) is located on the inner surface of the cavity, this can reduce the likelihood of the expandable member from damaging or disturbing the material during insertion of the expandable member.
As such, according to a first aspect of the present invention, there is provided a receptacle mould defining a cavity in which a receptacle is mouldable, wherein the receptacle mould comprises a guide channel for guiding, into the cavity, an expandable member that is usable to help mould the receptacle in the cavity. The guide channel has: (i) a first end and a second end, the second end opening into the cavity, wherein the expandable member is guidable through the guide channel from the first end to the second end and into the cavity, (ii) a first cross-sectional width at the first end, and (iii) a second cross-sectional width at the second end, the second cross-sectional width being less than the first cross-sectional width.
In some examples, the cross-sectional widths are cross-sectional diameters.
The cross-sections may be taken in a plane parallel to a longitudinal axis of the receptacle mould.
In some examples, the guide channel has a cross-sectional width that smoothly varies. A smoothly varying cross-sectional width does not have any discontinuities. A guide channel that has a stepped profile, for example, would have discontinuities.
In some examples, the expandable member is supported by a support that moves the expandable member towards the mould and introduces the expandable member into the cavity. The support may be a “bung” for example, that abuts the mould while the expandable member is expanded. Thus, the relative movement between the mould and the expandable member (and/or support) causes the expandable member to be guided into the cavity via the guide channel.
In certain examples, the receptacle may be known as a moulded receptacle, an article, a bottle, a container, a receptacle for containing fluid (such as a liquid) or solids (such as pharmaceutical or other tablets/capsules), an article for containing fluid, a bottle for containing fluid, a container for containing fluid, etc. The receptacle may be moulded from a fibre suspension, including constituents such as paper pulp. A fibre suspension may contain, amongst other things, cellulose fibres and a liquid, such as water. Additives may be present in the fibre suspension.
The receptacle may have a longitudinal axis along its length. The length/height of the receptacle may be greater than a width and/or depth of the receptacle. In some examples, the receptacle may have a generally circular footprint owing to a generally cylindrical form of the receptacle (at least along a portion of its length). In some examples, the receptacle may have a footprint that is square or squircular.
The receptacle mould (also referred to as a mould) defines a cavity (also known as a “mould cavity”) therein, and a layer or coating of the fibre suspension can be applied to the inner wall of the cavity (the “mould cavity wall”). This initial layer/coating may have a first thickness, and after the expandable member has been expanded, the layer/coating may have a second thickness that is less than the first thickness, owing to the compaction of the fibres and removal of some of the liquid.
In certain examples, a fibre suspension used to form the receptacle is introduced into the cavity via the guide channel.
In some examples, instead of a fibre suspension, a partially formed receptacle is introduced into the cavity. The partially formed receptacle may be “unfinished” and have been formed in another mould. The expandable member is used to urge the partially formed receptacle against the inner wall of the cavity as part of a drying (such as thermoforming) step. The mould may be heated, in some examples.
In some examples, the cavity has a main body portion (also known as a first portion) and a neck portion (also known as a second portion). Both portions of the cavity together form the cavity. The neck portion may be used to form a neck of the receptacle. A lid/cap may be applied to an end of the neck of the receptacle, for example, later in the process of manufacturing the receptacle. In some examples, the main body portion has a cross-sectional width that is larger than the cross-sectional width of the neck portion (the cross-section being taken in a plane parallel to a longitudinal axis of the receptacle mould).
The cavity or mould cavity is the part of the mould which contains the whole partially formed receptacle, the whole receptacle, or the whole of the fibre suspension that is introduced into the cavity. The mould cavity therefore fully contains a component therein, the component being a fibre suspension or a partially formed receptacle. As such, any part of a mould which contacts the component is part of the cavity/cavity wall, rather than part of the guide channel. In some examples, parts of the mould cavity wall may not contact the component, but may still be part of the cavity. That is, the mould cavity may be larger than the component contained within it. For example, there may be a part of the cavity between the second end of the guide channel and the component referred to as a spacing portion of the cavity. The spacing portion does not contact the component but is not part of the guide channel. As such, when the second end of the cavity opens into the cavity, it may open into the spacing portion of the cavity.
In some examples, the mould is part of a split-mould, the split-mould being made of two or more moulds or “splits”. For example, the mould may form half (or a third, or a quarter, etc.) of a split-mould and be brought together with at least one other mould before receiving the fibre suspension therein. The cavity of the mould may therefore only form a portion of the overall cavity of the split-mould and the cavity may therefore be used to form only part of an outer surface of the moulded receptacle. In some examples, the moulds forming the split-mould may be identical, but in other examples they may differ.
In some examples, the cavity has apertures formed on/through the mould cavity wall. This allows liquid to pass from within the cavity to the outside of the mould. The apertures may therefore extend from the cavity to an outer surface of the mould.
In an example, the mould is formed via a 3D printing or other additive manufacturing technique.
In a particular example, the receptacle has a width (such as a diameter) of between about 65 mm and 70 mm, a height of between about 190 mm and about 200 mm, and a volume of between about 500 ml and 600 ml. In a further example, the receptacle has a diameter of about 68 mm, a height of about 196 mm and a volume of about 550 ml. The cavity may therefore be dimensioned accordingly.
In certain arrangements, a midpoint of the guide channel at the second end is coaxial with an axis (such as a longitudinal axis) of the cavity. This ensures that the expandable member is directed into the middle of the cavity as it is introduced into the cavity, thereby further reducing the likelihood of damaging the receptacle being formed in the cavity.
In some examples, the cavity has a third cross-sectional width where the second end of the guide channel opens into the cavity, and the third cross-sectional width is greater than the second cross-sectional width by at least about 4 mm. In one example, the third cross-sectional width is greater than the second cross-sectional width by between about 4 mm and about 22 mm, such as between about 11 mm and 15 mm, such as about 13 mm. By having the cavity wider than the second end of the guide channel by at least 4 mm, there is a reduced chance of the expandable member contacting the fibre suspension or receptacle as the expandable member enters or is removed from the cavity. In an example, the fibre suspension (or a partially formed receptacle) within the cavity has a particular wall thickness and the third cross-sectional width is greater than the second cross-sectional width by at least four times the wall thickness. In a particular example, the third cross-sectional width is greater than the second cross-sectional width by least 2 mm greater than the average wall thickness of the fibre deposition. In some examples, the expandable member has a cross-sectional width narrower than the cross-sectional width of the guide channel at the second end. Thus, this ensures that the distance between the expandable member and the fibre suspension (or partially formed receptacle) is equal to or greater than at least twice the wall thickness. In some examples, the expandable member has a cross-sectional width that is equal to or greater than the cross-sectional width of the guide channel at the second end.
In an example, the guide channel defines an overhang at the second end. The overhang reduces the chance of the expandable member contacting the fibre suspension or receptacle in the cavity as the expandable member enters or is removed from the cavity.
In some examples, the guide channel has an axis that is coaxial with an axis of the cavity. The axes may be longitudinal axes, for example. This means that the guide channel is centrally located relative to the cavity and ensures that the expandable member is centrally located in the cavity when it is inserted into the mould.
In some arrangements, the guide channel has a first cross-sectional shape at the first end and a second cross-sectional shape at the second end, where the first cross-sectional shape and the second cross-sectional shape are the same. Having the first and second ends the same shape ensures that the expandable member is not twisted or unevenly deformed/compressed as it passes through the guide channel.
In a particular arrangement, the first and second cross-sectional shapes are the same shape as a cross-sectional shape of the expandable member, thereby allowing the expandable member to pass through the guide channel more easily.
In one example, the first and second cross-sectional shapes are circular. This means that there are no sharp edges that may damage the expandable member. The expandable member may also have a generally circular cross-sectional shape when not expanded (i.e., deflated).
In some examples, the cavity has a third cross-sectional shape where the second end of the guide channel opens into the cavity, and the first cross-sectional shape, the second cross-sectional shape and the third cross-sectional shape are the same. This ensures that the expandable member can more easily pass into the cavity without being subjected to non-uniform forces, because the guide channel and the cavity have the same shape.
In certain examples, the second end of the guide channel comprises a fillet edge or a chamfered edge where the second end opens into the cavity. The second end therefore has a “smooth” edge that reduces the likelihood of damaging the expandable member when it is inserted into or removed from the cavity.
In some arrangements, the surface gradient along the guide channel gradient changes along its length. Having different gradients along the length of the guide channel allows the position of the expandable member to be controlled as it passes through the guide channel. Accordingly, in an example, the guide channel has a first surface gradient, relative to an axis that is perpendicular to an axis of the receptacle mould, at a first point, and a second surface gradient, relative to the axis that is perpendicular to the axis of the receptacle mould, at a second point, where the first and second surface gradients are different, and the first point is closer to the first end than the second point. The axis of the receptacle mould may be a longitudinal axis, in some examples.
The second point may be at, or close to (such as less than 10 mm or less than 5 mm) the second end. The first point may be at, or close to (such as less than 10 mm or less than 5 mm) the first end. In an example, the first point is at a midpoint along the length of the guide channel.
In a particular example, the second surface gradient is greater than the first surface gradient. The shallower (first) surface gradient cases the transition of the expandable member into the guide channel, and the steeper (second) surface gradient controls placement and the trajectory of the expandable member into the cavity, reducing the likelihood that the expandable member contacts material in the cavity from which the receptacle is to be formed.
In some examples, the surface gradient along the guide channel smoothly varies. A smoothly varying surface gradient does not have any discontinuities. The gradient variation may be constant or non-constant. In a particular example, the surface gradient along the guide channel is non-constant and smoothly varies.
According to a second aspect of the present invention, there is provided a method of manufacturing a receptacle mould, the method comprising: (i) forming a cavity of the receptacle mould, the cavity being configured to mould a receptacle, and (ii) forming a guide channel in the receptacle mould. The guide channel has: (a) a first end and a second end, the second end opening into the cavity, wherein an expandable member is guidable through the guide channel from the first end to the second end and into the cavity, (b) a first cross-sectional width at the first end, and (c) a second cross-sectional width at the second end, the second cross-sectional width being less than the first cross-sectional width.
The mould may comprise any or all of the features discussed above and/or below.
In some examples, forming the cavity comprises providing the cavity with a third cross-sectional width where the second end of the guide channel opens into the cavity, and wherein the third cross-sectional width is greater than the second cross-sectional width by at least 4 mm.
In some examples, forming the guide channel comprises providing the guide channel with a first cross-sectional shape at the first end and a second cross-sectional shape at the second end, wherein the first cross-sectional shape and the second cross-sectional shape are the same.
In a particular example, forming the cavity comprises providing the cavity with a third cross-sectional shape where the second end of the guide channel opens into the cavity, and wherein the first cross-sectional shape, the second cross-sectional shape and the third cross-sectional shape are the same.
In some examples, forming the guide channel comprises providing the second end of the guide channel with a fillet edge or a chamfered edge where the second end opens into the cavity.
In some examples, forming the guide channel comprises providing the guide channel with: (i) a first surface gradient, relative to an axis that is perpendicular to an axis of the receptacle mould, at a first point, and (ii) a second surface gradient, relative to the axis that is perpendicular to the axis of the receptacle mould, at a second point, the first and second surface gradients being different and the first point being closer to the first end than the second point.
In the above aspects, the receptacle mould has a guide channel that is wider at one end than the other. In another aspect, the guide channel may not have one end wider than the other. For example, the two ends may have the same cross-sectional width or the second end may be wider than the first end. In this aspect, the guide channel and cavity may be sized relative to each other such that as the expandable member passes into the cavity, there is a distance of at least twice the wall thickness of the fibre suspension (or a partially formed receptacle) between the surface of the cavity and the expandable member at the second end of the guide channel. Maintaining the distance of at least twice the wall thickness reduces a likelihood of the expandable member contacting a component in the cavity, which could otherwise disturb or damage the component (the component being the fibre suspension or a partially formed receptacle, for example).
As such, according to a third aspect of the present invention there is provided a method of moulding a receptacle, the method comprising: (i) providing a receptacle mould, the receptacle mould having a cavity in which a receptacle is mouldable and a guide channel, wherein the guide channel has a first end and a second end, the second end opening into the cavity, (ii) passing an expandable member into the cavity via the guide channel, the cavity housing a component on a surface thereof, the component being a fibre suspension or a partially formed receptacle, wherein the component has a wall thickness, (iii) as the expandable member passes into the cavity, maintaining a distance, of at least twice the wall thickness, between the surface of the cavity and the expandable member at the second end of the guide channel, and (iv) expanding the expandable member to compress the component against the surface. In one example, the expandable member is an inflatable member and the expanding the expandable member comprises inflating the inflatable member.
The mould may comprise any or all of the features discussed above and/or below.
In some examples, the method further comprises introducing the component into the cavity of the receptacle mould. Introducing a component into the cavity of the receptacle mould may comprise spraying/inserting/drawing the fibre suspension into the first mould. In some instances, the fibre suspension may be introduced under vacuum (i.e., a vacuum is applied to the mould or first cavity). Introducing a component into the first cavity of the receptacle mould may comprise inserting or placing a partially formed receptacle into the first mould.
The surface of the cavity may be known as a cavity wall or a mould cavity wall in some examples. The wall thickness may be the initial wall thickness, before the expandable member is expanded. In examples where the expandable member has a varying cross-sectional width along its length, the distance may be measured at the widest point of the expandable member (so that the distance is the smallest distance between the expandable member and the surface of the cavity).
Preferably, the distance is at least 2.5 times the wall thickness. Still more preferably, the distance is at least 3 times the wall thickness.
In one particular example, the guide channel has a first cross-sectional width at the first end and a second cross-sectional width at the second end, the second cross-sectional width being less than the first cross-sectional width. Thus, in certain examples, the guide channel also has the tapered configuration, in addition to maintaining the correct distance between the cavity wall and the expandable member.
The mould of the third aspect may have any or all of the features described above in relation to the first and second aspects.
In a fourth aspect, there is provided a method of moulding a receptacle, the method comprising: (i) providing a receptacle mould, the receptacle mould having a cavity in which a receptacle is mouldable and a guide channel, wherein the guide channel has: (a) a first end and a second end, the second end opening into the cavity, and (b) a first cross-sectional width at the first end and a second cross-sectional width at the second end, the second cross-sectional width being less than the first cross-sectional width, (ii) passing an expandable member into the cavity via the guide channel, the cavity housing a component on a surface thereof, the component being a fibre suspension or a partially formed receptacle, and (iii) expanding the expandable member to compress the component against the surface.
The mould may comprise any or all of the features discussed above and/or below.
In a fifth aspect, there is provided a kit comprising a plurality of receptacle moulds according to the first aspect, wherein the plurality of receptacle moulds are co-operable to mould the receptacle. Thus, as mentioned, the moulds may be part of a split-mould and may be brought together to form a larger mould.
Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
The following description presents exemplary embodiments and, together with the drawings, serves to explain principles of the invention.
In this example, providing the fibre suspension comprises preparing the fibre suspension from ingredients thereof. More specifically, the preparing comprises providing pulp fibres, such as paper pulp fibres, and mixing the pulp fibres with a liquid to provide hydrated pulp fibres. In this example, the pulp fibres are provided in sheet form from a supplier and the liquid comprises water and one or more additives. In this example, the liquid is mixed with the pulp fibres to provide hydrated pulp fibres having a solid fibres content of 1 wt % to 5 wt % (by dry mass of fibres). In examples, the one or more additives includes a shorting agent, such as alkylketene dimer (AKD). The hydrated pulp fibres typically comprise AKD in an amount of 0.4 wt % with respect to the total dry mass of the solid fibres in the hydrated pulp fibres. In some examples, one or more additives are present in the liquid at the point of mixing the pulp fibres with the liquid In some examples, one or more additives are included in the hydrated pulp fibres after mixing the pulp fibres with the liquid (e.g. the pulp fibres are hydrated for a period of time, such as from 2 to 16 hours, and then one or more additives are supplied to the hydrated pulp fibres). The hydrated pulp fibres are passed between plates of a valley beater 11 or refiner that are in motion relative to each other. This fibrillates some or all of the fibres, meaning that cell walls of those fibres are caused to become partially delaminated so that wetted surfaces of those fibres comprise protruding hairs or fibrillations. These fibrillations will help to increase a strength of bonds between the fibres in the dried end product. In other examples, the valley beater 11 or refiner may be omitted.
The resultant processed pulp is stored in a vat 12 in a relatively concentrated form (e.g. a solid fibres content of 1 wt % to 5 wt %) to reduce a required storage space. At an appropriate time, the processed pulp is transferred to a mixing station 13 at which the processed pulp is diluted in further water and, optionally, mixed with one or more additives (as well as, or in place of, the one or more additives provided with the hydrated pulp fibres) to provide the fibre suspension ready for moulding. In this example, the solid fibres account for 0.7% wt of the resultant fibre suspension by dry weight of fibres), but in other examples the proportion of solid fibres in the fibre suspension may be different, such as another value in the range of 0.5 wt % to 5% wt, or 0.1 wt % to 1 wt %, of the fibre suspension (by dry weight of fibres). In some examples, the one or more additives mixed with the processed pulp and water includes a dewatering agent. In some examples, the one or more additives are mixed with the water, and the water and one or more additives subsequently mixed with the processed pulp; in other examples, the processed pulp and water are mixed, and the one or more additives subsequently mixed with the processed pulp and water. The fibre suspension typically comprises dewatering agent in an amount of 0.3 wt % with respect to the total dry mass of the solid fibres Mixing of the fibre suspension at the mixing station 13 helps to homogenise the fibre suspension. In other examples, the processed pulp or the fibre suspension may be provided in other ways, such as being supplied ready-made.
In this example, the porous first mould 15 comprises two half-moulds that are movable towards and away from each other, in this case using a hydraulic ram. In this example, each of the half-moulds is a monolithic or unitary tool formed by additive manufacturing (e.g. 3D-printing) that defines a mould profile, and when the half-moulds are brought into contact with each other their respective mould profiles cooperate to define the mould cavity in which the wet precursor or moulded receptacle is to be formed. Each half-mould may itself define a smaller moulding cavity and when brought into cooperation with a second half-mould, the smaller moulding cavities may combine to provide the overall mould cavity. The two half-moulds may themselves be considered “splits” or “moulds” and the overall porous first mould 15 may be considered a “split-mould” or, again, a “mould”. In other examples, the porous first mould 15 may comprise more than two splits, such as three, four or six splits, that cooperate to define the moulding cavity.
In
In one form, in order to remove further suspending liquid (e.g. water) from the embryo, and form or consolidate the three-dimensional shape of the receptacle, an impermeable inflation element 19, e.g., a collapsible bladder (also known as an expandable member), is inserted into the porous mould 15 and expanded to act as an internal high-pressure core structure for the porous mould 15. This process strengthens the wet embryo so that it can be handled, and displaces water from in between the fibres, thereby increasing the efficiency of a subsequent drying process. The inflation element 19 is actuated and regulated using a hydraulic pump 20. The pump 20 has a cylinder that displaces a fluid in a line 21 into the inflation element 19, to expand the inflation element 19 radially and into conformity with the mould cavity. Fluid within the line 21 is preferably non-compressible, such as water. Water also has the advantage over other non-compressible liquids that any leaking or bursting of the bladder 19 will not introduce a new substance to the system (since the suspending liquid is already water, or predominantly water).
Demoulding occurs when the porous mould 15 opens for removal of the self-supporting moulded receptacle 22. Mould cleaning 23 is preferably performed subsequently, to remove small fibres and maintain a porosity of the porous mould 15. In this example, a radially firing high-pressure jet is inserted into the mould cavity while the mould 15 is open. This dislodges fibres from the wall of the mould cavity. Alternatively, or in addition, water from the tank 17 is pressurised through the back of the porous mould 15 to dislodge entrapped fibres. Water is drained for recycling back to an upstream part of the system. It is noteworthy that cleaning is important for conditioning the porous mould 15 for re-use. The porous mould 15 may appear visibly clean after removal of the receptacle, but its performance could be compromised without cleaning.
According to
A drying stage 29 (e.g. a microwave drying process or other drying process) is performed downstream of the thermoforming, as shown. In one example, the drying stage 29 is performed before thermoforming. However, moulding in the mould 25 requires some water content to assist with bonding during the compression process.
The moulded receptacle 22 is then subjected to a coating stage during which, in this example, a spray lance 31 is inserted into the moulded receptacle 22 and applies one or more surface coatings to internal walls of the moulded receptacle 22. In another example, the moulded receptacle 22 is instead filled with a liquid that coats the internal walls of the moulded receptacle 22. In practice, such coatings provide a protective layer to prevent egress of contents into the bottle wall, which may permeate and/or weaken it. Coatings will be selected dependent on the intended contents of receptacle 22, e.g., a beverage, detergent, pharmaceutical product, etc. In some examples, the further drying stage 30 is performed after the coating stage (or both before and after the coating stage). In this example, the moulded receptacle 22 is then subjected to a curing process 34, which can be configured or optimised dependent on the coating, e.g., drying for twenty-four hours at ambient conditions or by a flash drying method. In some examples, e.g. where the further drying stage 30 occurs after the coating stage, the curing process 34 may be omitted.
At an appropriate stage of production (e.g., during thermoforming, or before or after coating) a closure or mouth forming process may be performed on the moulded receptacle 22. For example, as shown in
In more detail,
The cavity 36 of the mould 15 comprises a mould cavity wall 40 (i.e., the cavity 36 has an inner wall). The cavity 36 comprises apertures (not shown) that allow liquid to pass therethrough, and thus the mould 15 is porous. The apertures extend from the mould cavity wall 40 and through the mould 15 to an outer surface of the mould. In other examples the cavity 36 is non-porous. In
In the example of
The mould 15 also has a guide channel 38. An expandable member 56 (shown in
As shown, the guide channel 38 has a first (outer) end 38a and a second (inner) end 38b. The first end 38a opens to an outer surface 15a (or top surface) of the mould 15 and the second end 38b opens into the cavity 36. The first end 38 is therefore formed at the outer surface 15a of the mould 15. The guide channel 38 extends between the outer surface 15a and the cavity 36, or more particularly, between the outer surface 15a and the neck portion 36b of the cavity 36. When an expandable member 56 is introduced into the cavity 36, it therefore passes from the first end 38a to the second end 38b and into the cavity 36. In other words, it passes from the first end 38a to the cavity 36 via the second end 38b.
In this example, the guide channel 38 has a first cross-sectional width 42 at the first end 38a and a second cross-sectional width 44 at the second end 38b, and the first cross-sectional width 42 is greater than the second cross-sectional width 44. As mentioned earlier, the guide channel 38 of this example has a tapered/funnelled shape to guide the expandable member 56 into the cavity 36, thereby reducing the chance that the expandable member 56 contacts the fibre suspension layer (or receptacle) that is contained inside the cavity 36.
In examples, the first cross-sectional width 42 is between about 38 mm and about 47 mm and the second cross-sectional width 44 is between about 25 mm and about 34 mm. In this example, the first cross-sectional width 42 is 38 mm, and the second cross-sectional width 44 is 25 mm.
In the example of
In the example of
In this particular example, an axis 48 (such as a longitudinal axis) of the guide channel 38 is coaxial with an axis 50 (such as a longitudinal axis) of the cavity 36. The first 38a and second 38b ends of the guide channel 38 are therefore centred above the cavity 36 so that the expandable member 56 is inserted into the midpoint/centre of the cavity 36 (i.e., the expandable member 56 is equidistant from the cavity walls 40) as it passes through the opening into the cavity 36.
As shown most clearly in
In the example of
In certain examples, the guide channel 38 has a non-constant surface gradient along its length. As shown in
After the fibre suspension has been applied to the mould cavity wall 40, an expandable member 56 is introduced into the cavity 36 and is expanded, which presses/compacts the fibre suspension layer 58 and helps to drive out liquid. This liquid may then pass through the apertures (if present), in some cases under vacuum.
As shown most clearly in
Accordingly, as the expandable member 56 is introduced into the cavity, there is a distance 64 of at least twice the wall thickness 60 between the cavity wall 40 and the expandable member 56 at the second end 38b of the guide channel 38.
By reference to both
In examples, the expandable member 56 has a cross-sectional width of between about 25 mm and about 100 mm at its widest point (in the non-expanded state). In this particular example, the expandable member 56 has a cross-sectional width of about 70 mm at its widest point. Although the expandable member 56 may have a cross-sectional width that is greater than the width of the second end in a resting/deflated state, during insertion the narrowing of the guide channel is such that the expandable member 56 is compressed in the width-wise direction and avoids contacting the fibre suspension.
In the examples of
The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2204817.7 | Apr 2022 | GB | national |
This application is a continuation under 35 U.S.C. § 120 of International Application No. PCT/GB2023/050833, filed Mar. 30, 2023, which claims priority to United Kingdom Application No. GB 2204817.7, filed Apr. 1, 2022 under 35 U.S.C. § 119 (a). Each of the above-referenced patent applications is incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/GB2023/050833 | Mar 2023 | WO |
| Child | 18887940 | US |
