Patent Application
20230354961
The invention relates to manufacturing of breathable and waterproof footwear. The invention also relates to a method for manufacturing a footwear.
It is known in the art that shoe comfort is not only linked to the anatomic configuration of the fit but also to optimal vapor permeability from the inside of the shoe to the outside. Vapor permeable materials are usually naturally materials such leather or equivalent products, which however in the presence of rain or humid weather do not ensure good waterproofing and may indeed absorb rather easily water which can also penetrate through the stitched seams used for assembly.
One solution to this problem is to provide a layered construction of a footwear upper where one or more layers may be vapor permeable while another layer may be a liquid impermeable, while still being vapor permeable. This type of layer may be called a functional layer, which is e.g. provided by a manufacturer like WL Gore, in the form of a Gore-Tex material, which is a layered material, having pores so that liquid molecules cannot penetrate, and thus are vapor permeable and water impermeable layers.
A challenge in relation to such layered construction of a footwear is that attaching the layers involves stitching that provide passages for water and reduce the flexibility.
Thus, there is a need for footwear comprising stitches highly efficiently connecting a breathable membrane to an insole having the flexibility required for a footwear insole.
The invention relates to a footwear comprising an upper (U) and a sole (S),
wherein the upper comprising a membrane (MEM) and at least one outer layer (OL),
wherein the membrane (MEM) is attached to the outer layer (OL) and the membrane (MEM) is attached to an insole (IS),
wherein the membrane (MEM) is attached to the insole (IS) by stitching (STI) a lower end of the membrane (LMEM) to the circumference of the insole (IS),
wherein the minimum length (L) of stitches of the stitching (STI) is at least 1.0 mm,
wherein the membrane (MEM) is a waterproof breathable membrane,
wherein the insole (IS) is attached to the sole (S).
The inventive footwear upper has several advantages over prior art footwear involving the stitches length of the stitches attaching the footwear upper, comprising a breathable and waterproof membrane and an outer layer, to an insole.
The present invention makes it possible to obtain stitches highly efficiently connecting a breathable membrane to an insole having the flexibility required for a footwear insole and also e.g. allowing a sufficient penetration of e.g. PU for attaching the footwear upper to a footwear sole.
Moreover, it is noted that the applied stitch length with respect to the insole stitching makes it both possible to stitch without folding of the membrane during stitching and thus avoiding folding of the membrane onto the insole during stitching. This is possible with a relatively small stitch length as the person stitching the membrane may utilize the flexibility of the membrane and also ensure that no large folds will occur. Large folds may compromise the final and desired sealing between the membrane and the sole.
In the present context an insole should be referred to as a part of the sole, which is applied to form a kind of sock for accommodating the foot of a user when the insole is stitched to the upper. This sole may be some be referred to as a strobel sole, but in the present context the insole is functionally understood as a part of the sole which is forming an anchoring interface to the sole. It is in particular noted that the stitching of the insole in practice is performed prior to either cementing or direct injection of a sole to the upper. The stitching is not a part of these two types of processes in the present context. Thus, further sole(s) may be inserted into the footwear as basically a loose and exchangeable part of the footwear within the scope of the invention without compromising the above understanding of what an insole is.
The sole as such may comprise a combination of the insole, an outer sole and further optional sole layers or members. In this particular present context an insole may be regarded as a part of the sole due to its durable attachment to the sole. It is noted that the definitions applied elsewhere in this application may also, for logical reason, regard the insole as a part of the upper or as a part of both the sole and the upper.
An advantage of an embodiment of the invention may be that the lower end of the membrane may be sealed to the sole by means of the adhesive cementing the upper to the sole or by means of sole material injected by a DIP process to the upper.
This sealing may according to a preferred embodiment of the invention by obtained without the use of further sealings members, such as gaskets etc.
Thus, in an embodiment of the invention, the footwear is gasket free.
Stitches
In an embodiment of the invention, the length (L) of stitches of the stitching (STI) is 1.5 mm, such as at least 3 mm, such as at least 5 mm, such as between 1.0 mm to 12 mm, such as 1 mm to 10 mm, such as 1.5 mm to 9 mm, such as 1.5 mm to 8 mm, such as 4 mm to 7 mm, such as between 5 mm to 7 mm, such as 2 mm to 4 mm, such as between 6 mm to 7 mm.
In an embodiment of the invention, the length (L) of stitches of the stitching (STI) is 2 to 6 mm.
In an embodiment of the invention, the length (L) of stitches of the stitching (STI) is less than 15 mm, such as less than 12 mm, such as less than 10 mm.
In an embodiment of the invention, the length (L) of stitches of the stitching (STI) is less than 10 mm, such as less than 8 mm, such as less than 7 mm.
In an embodiment of the invention, the length (L) of stitches of the stitching (STI) is between 1-5 stitch/cm, such as between 2-4 stitch/cm, such as 3 stitch/cm.
In an embodiment of the invention, the stitch width (W) of the stitching (STI) is at least 2 mm, such as at least 4 mm, such as between 2 mm to 10 mm, such 3 mm to 10 mm, such as 3 mm to 9 mm, such as 3 mm to 8 mm, such as between 5 mm to 7 mm.
In a very advantageously embodiment of the invention, the use of an insole extending wider according to embodiments of the invention, facilitates longer stitch length. Longer stitch lengths facilitate a higher flexibility of the upper, less folding and less use of thread.
If any damage is done to the membrane during stitching to the strobel sole it may be made waterproof by the PU or glue during when the outer sole is attached.
According to embodiments of the invention, stitch length should be understood as the length from one stitch top to the next stitch top in the stitching direction.
The stitch length may also be measured as stitches pr. cm.
According to embodiments of the invention, stitch width should be understood as the total width from top to top in the transverse direction of the stitching. For further explanation of stitch length (L) and stitch width (W) please refer to the description the associated figures.
According to an embodiment of the invention, the length (L) of the stitches of the stitching (STI) may be determined for an outer part stitch length (LOUT) and/or an inner part stitch length (LINP), when the membrane (MEM) is attached to the insole (IS) by a non-linearly progressing stitching.
Hereby, it may be achieved that an effective stitch length may be established with greater accuracy, e.g. in order to assure that the effective stitch length will be larger than a minimum value and/or that the effective stitch length will be smaller than a predefined maximum value, e.g. as it has been specified above in regard to stitch lengths. Such a value or values may have been determined in view of characteristics of the membrane material and/or the insole material, e.g. in order to avoid any damage or detrimental effect on a material due to stitch holes being too close or e.g. in order to avoid an unsatisfying gathering of the membrane and the insole due to the stitches being too widely spaced at certain parts of the stitching, e.g. at heel and/or toe parts, where the stitching is progressing in a relatively largely curved manner. Furthermore, folding of the membrane material or the insole material, which may be detrimental to e.g. waterproofness, may in this manner be avoided.
It is noted that in some applications it will suffice to rely on only one of the two stitch lengths, i.e. the outer part stitch length (LOUT) and the inner part stitch length (LINP), for example depending on the type of shoe being manufactured. Also, it is noted that with knowledge of the outer part stitch length (LOUT) and/or the inner part stitch length (LINP) relating to a particular footwear, the limits may be fulfilled in a practical manner by adjusting e.g. a strobel sewing apparatus to sew with a certain stitch length, e.g. 2 mm, whereby it will be known that the outer part stitch length (LOUT) and/or the inner part stitch length (LINP) relating to the particular footwear will fulfill the requirements, e.g. that the outer part stitch length (LOUT) will be at least 1.0 mm.
Also, it is noted that instead of applying the parameter stitch length L being x mm, the parameter number of stitches per cm may be used as it will be clear to a skilled person. However, the latter may be less suitable when determining stitch length for an outer part stitch length LOUT and/or an inner part stitch length LINP.
In an embodiment of the invention, the membrane (MEM) is attached to the outer layer (OL) by an anchoring adhesive (AA).
If any damage is done to the membrane during stitching to the insole, such damage may be compensated/made waterproof by the adhesive applied during the process of attaching a sole to the upper.
Stitching Techniques
In an embodiment of the invention, the stitches of the stitching are made as two thread stitches.
In an embodiment of the invention, the stitches of the stitching are made as single thread stitches.
In an embodiment of the invention, stitching only uses one thread.
According to embodiments of the invention, the strobel sewing technique may only use an upper thread.
Upper thread and top thread may be used interchangeable according to embodiments of the invention. Lower thread and bottom thread may be used interchangeable according to embodiments of the invention.
According to embodiments of the invention, the stitches of the stitching may also be made as sewing techniques such as e.g. zig-zag, tacking, topstitching, edgestitching, stay stitching and/or understitching.
In an embodiment of the invention, the stitches of the stitching are made on a strobel sewing machine.
In an embodiment of the invention, the strobel sewing machine is an overlocking or overseaming strobel stitcher.
Needle/Thread
In embodiments of the invention, the needle size may be in a size between 90 to 120.
For stitching the membrane to the insole, it may be preferred to use a needle in a smaller size, such as e.g. 90.
The function of the needle is to produce holes in the material and to carry the needle thread through the material and there form a loop and then pass the needle thread through the loop.
Needles for sewing machines typical comprises and upper part, a butt and shank and a lower part comprising the shaft, front groove, eye and point. The point penetrates the material and may have a variety of forms depending on the application or material types to be sewn in. The point may have a set/spear point, a ball point or a wedge point.
According to embodiments of the invention, the thread (TH) for stitching may comprise cotton and/or polyester and the size of the thread may e.g. be a thread size between 10/3 wt to 120/3 wt, wherein a 60/3 wt thread may be preferred.
The needle and the thread should optimally fit each other by size. If the needle is too small for the thread, the thread will not pass freely through the eye and can lead to costly thread breakages in the production. Further, a too thick needle may block the penetration of PU during DIP or adhesive during cementing.
If the needle is too large for the thread there will be poor control of the loop formation which may cause slip stitches, create holes in the fabric which are too big for the stitches and may damage the fabric along the stitch line.
According to embodiments of the invention, the holes of the sewing also provide holes for the PU to penetrate during DIP or adhesive during cementing.
According to embodiments of the invention, the thread may be thinner than the threads used for other types of stitches of footwear uppers.
In an embodiment of the invention, the anchoring adhesive (AA) has a melting point of at least 50 degrees Celsius, such as at least 60 degrees Celsius, such as at least 70 degrees Celsius, such as at least 80 degrees Celsius, such as at least 90 degrees Celsius, such as at least 100 degrees Celsius, such as at least 110 degrees Celsius, such as at least 120 degrees Celsius, such as at least 130 degrees Celsius, such as at least 140 degrees Celsius.
In an embodiment of the invention the anchoring adhesive (AA) has a melting point between 30-200 degrees Celsius, such as between 50-180 degrees Celsius, such as between 70-160 degrees Celsius, such as between 90-140 degrees Celsius, such as between 100-120 degrees Celsius.
In an embodiment of the invention, the drying time of the anchoring adhesive (AA) is maximum 5 hours, such as 4 hours, such as 3 hours, such as 2 hours, such as 1 hour, such as 45 min, such as 30 min.
In an embodiment of the invention, the bonding time of the anchoring adhesive (AA) is less than 5 hours, such as 4 hours, such as 3 hours, such as 2 hours, such as 1 hour, such as 45 min, such as 30 min.
In an embodiment of the invention, the anchoring adhesive (AA) is a non-water-based adhesive.
In an embodiment of the invention, the anchoring adhesive (AA) is a water-based adhesive.
In an embodiment of the invention, the anchoring adhesive (AA) is heat-activated.
In an embodiment of the invention, the anchoring adhesive (AA) is a liquid.
In an embodiment of the invention, the anchoring adhesive (AA) is a film.
In an embodiment of the invention, the anchoring adhesive (AA) is a tape.
In an embodiment of the invention, the anchoring adhesive (AA) is a two-component adhesive.
In an embodiment of the invention, the anchoring adhesive (AA) is a cold glue.
In an embodiment of the invention, the anchoring adhesive (AA) is at least one of following adhesives:
According to embodiments of the invention, the anchoring adhesive may be present in a continuous layer or be present as a “perforated” or non-continues adhesive layer facilitating both sufficient bonding but also breathing or some kind of moisture transport through the layers.
The application of anchoring adhesive to the leather parts may be in the form of a prelamination.
According to embodiments of the invention, the adhesive may depend on the type of material.
Adherence Process
In an embodiment of the invention, the membrane (MEM) is attached to the outer layer (OL) by an anchoring adhesive (AA) process.
In an embodiment of the invention, the anchoring adherence (AA) process comprises application of heat.
In an embodiment of the invention, the anchoring adhesive (AA) process comprises a period of application of heat and wherein the period of application of heat is at least 5 sec, such as at least 7 sec, such as at least 9 sec., such as at least 13 sec.
In an embodiment of the invention, the anchoring adhesive (AA) process comprises a period of application of heat and wherein the period of application of heat is between sec-15 sec, such as between 7 sec-13 sec, such as between 7 sec-10 sec.
In an embodiment of the invention, the anchoring adherence (AA) process comprises application of heat and wherein the application of heat is between 90-160 degrees Celsius, such as between 100-140 degrees Celsius.
In an embodiment of the invention, the anchoring adherence (AA) process comprises application of heat and wherein the application of heat is at least 90 degrees Celsius, such as at least 110 degrees Celsius, such as at least 130 degrees Celsius.
In an embodiment of the invention, the anchoring adherence (AA) process comprises application of pressure.
In an embodiment of the invention, the anchoring adherence (AA) process includes application of pressure at least during or subsequent to reactivation of the anchoring adhesive and pressing the outer layer together with the membrane, and wherein the pressure is at least 2 bar, such as at least 3 bar, such as at least 4 bar.
In an embodiment of the invention, the anchoring adherence (AA) process comprises application of pressure and wherein the pressure is between 2 bar-7 bar, such as between 3 bar-5 bar.
In an embodiment of the invention, the anchoring adherence process comprises application of heat and pressure.
In an embodiment of the invention, the anchoring adherence process comprises application of heat and pressure, wherein the application of heat is between 90-160 degrees Celsius and application of pressure is between 2 bar-7 bar.
Anchoring Pattern
In an embodiment of the invention, the membrane (MEM) is further attached to the lower end of the outer layer (LOL) along at least a part of the circumference of the lower end of the outer layer by means of an anchoring adhesive (AA).
In an embodiment of the invention, the membrane (MEM) is further attached to the lower end of the outer layer (LOL) along the complete part of the circumference of the lower end of the outer layer (LOL) by means of a continues an anchoring adhesive (AA).
Outer Layer
In an embodiment of the invention, the outer layer (OL) is formed by a leather.
In an embodiment of the invention, the outer layer (OL) is formed by a woven or non-woven textile.
In one or more embodiments, the outer layer may be an outermost layer of the upper.
The outer layer is the material facing the outer environment and may be an aesthetic pleasing material such as e.g. leather material, knitted, polymer, canvas or other types of material applied in footwear manufacturing. The outer material gives the footwear a specific look or have a specific function such as e.g. color, elasticity, stiffness, weight, or other characteristics. These materials are often liquid permeable materials.
The outer layer may be a textile layer, a leather layer, a nubuck layer, a knitted layer, a polymer and/or canvas or any type of layer that may be used as the outermost layer of a footwear upper, where the other layer may provide the outer appearance of the footwear. The outer layer may be outermost layer of the outer layer, however, the outer layer may also comprise other layers or treatments covering the other layer as an extra outer layer for e.g. strengthening, protection or aesthetical appearance.
The outer layer is generally designating a layer separated from a foot of a wearer by the breathable waterproof membrane the foot of a wearer of the footwear. The outer layer is thus designated relative to the waterproof breathable membrane whereas and further layers or structures may thus be added onto the outside of the outer layer of the footwear without compromising the understanding of what an outer layer is defined as.
The outer layer may this e.g. further comprise embossing, attachments and or logos on the side of the outer layer pointing away from the waterproof breathable membrane.
Likewise, the outer layer may further comprise a coating, impregnation or even further layers on top to the outer layer facing away from the waterproof breathable membrane.
DIP
In an embodiment of the invention, the sole is injection molded to the upper.
For a direct injection production (DIP) process, a shoe upper including an attached insole is placed on a last, wherein the last with the shoe upper is placed into a mold and wherein subsequently a liquid sole material such as for example liquid polyurethane (PU) is injected into the mold to effect a strong attachment of the upper to the sole.
Furthermore, a durable and reliable anchoring makes it attractive to manufacture a footwear by a direct injection process as the foaming of the material used for molding of the outsole will not expand into the space between the membrane and the outer layer at the lower end of the upper.
According to embodiments of the invention, the sole may be a multi component sole and may have polymeric materials that may have different density, elasticity, stiffness, wear resistance, or other properties, in order to provide the desired type of footwear.
In an embodiment of the invention, the material of the sole is a polymer material.
In an embodiment of the invention, the material of the sole is a polymer material, optionally a polyurethane (PU), optionally a thermoplastic polyurethane (TPU), or a multi component sole comprising different parts of polymeric materials having different properties.
Cemented
In an embodiment of the invention, the upper (U) is cemented to the sole (S).
In an embodiment of the invention, the upper (U) is cemented to the sole (S) by at least an adhesive.
According to embodiments of the invention, the sole may be attached to the upper by use of adhesives, wherein the adhesives may be a hot melt adhesive, a two-component adhesive, or similar.
Footwear Upper
According to embodiments of the invention, the footwear upper may be an upper suitable for any footwear types and may be for example a shoe, a boot, a golf shoe, an athletic shoe.
According to embodiments of the invention, the footwear upper may comprise at least two footwear parts and may be for example
Insole
In an embodiment of the invention, the stitching (STI) attaches the lower end of the membrane (LMEM) to the insole (IS) by stitches without perforating the lower end of the outer layer (LOL).
In an embodiment of the invention, the stitching (STI) is sealed by a waterproof sealing forming at least a part of a waterproof bottom sealing the insole (IS) of the footwear.
In an embodiment of the invention, the attachment of the insole to the lower end of the membrane is waterproof and forming at least a part of a waterproof bottom sealing (WBS) sealing at least the insole (IS) and the lower part of the upper (U) of the footwear.
In an embodiment of the invention, the attachment of the insole to the lower end of the membrane is performed by means of stitching (STI).
In an embodiment of the invention, the stitching (STI) is sealed by a waterproof sealing forming at least a part of a waterproof bottom sealing (WBS) sealing at least the insole (IS) and the lower part of the upper (U) of the footwear.
It is noted in connection with the waterproof bottom sealing that such sealing is reliable over the prior art as the waterproof sealing is applied directly onto the lower end of the membrane rather than e.g. applying it onto the membrane via e.g. a net/mesh. Such application of an adhesive through other mechanical structures to make the desired sealing may be difficult to perform as it is difficult to predict or check whether the adhesive in fact has passed the mesh and forms a uniform sealing at the other side of the mesh. In other words, the process of applying the adhesive to the membrane through a mesh is not very suitable for state of the art sealing processes.
In an embodiment of the invention, the thickness of the insole is at least 0.1 mm, such as at least 0.5 mm, such as at least 1 mm, such as between 0.1 mm to 10 mm, such as between 0.5 mm to 9 mm, such as between 1 mm to 8 mm, such as between 2 mm to 7 mm, such as between 3 mm to 6 mm.
In an embodiment of the invention, the insole is a strobel sole.
In an embodiment of the invention, the insole comprises a non-woven material.
In an embodiment of the invention the insole comprises a woven material.
In an embodiment of the invention the insole material comprises foam.
Membrane
In one or more embodiments, the membrane may be a waterproof and vapor permeable functional layer. A waterproof and vapor permeable functional layer is well known within the art, such as commercially available GORE-TEX® laminate from W.L. Gore & Associates, Sympatex, Cosmo, Outdry, Covestro, Respilon, Schoeller or Wilhelm.
In an embodiment of the invention, the thickness of the membrane (MEM) is at least 0.01 mm, such as at least 0.1 mm, such as between 0.3 mm to 5 mm, such as between 0.5 mm to 4 mm, and such as between 1 mm to 3 mm.
In an embodiment of the invention, the thickness of the membrane (MEM) is between 0.01 and 5 mm and the thickness of the insole (IS) is between 0.1 mm to 10 mm.
In an embodiment of the invention, the membrane (MEM) and the insole (IS) are dissimilar as regards the thickness.
In an embodiment of the invention, the thickness of the membrane (MEM) and the thickness of the insole (IS) differ by at least 0.01 mm, such as at least 0.1 mm, such as at least 0.3 mm, such as at least 0.5 mm, such as at least 1 mm, such as least 2 mm, such as at least 4 mm, such as at least 6 mm, such as at least 8 mm and such as at least 10 mm.
According to embodiments of the invention, the membrane may comprise several layers.
Other layers to be included or attached to the membrane includes fabric on one or both sides of the membrane layer. Such layers may e.g. be included for strength purposes, layers or treatment on the membrane for reducing the surface tensions, layers for providing color and/or e.g. a lining. In the latter case a footwear lining may thus form a part of what is referred to in the description as membrane.
Other
In an embodiment of the invention, the lower part of the waterproof membrane has a lower circumference area than the area of the outer material in the horizontal plane.
In an embodiment of the invention, the lower end of the outer layer (LOL) is adhered only partly around the circumference to the lower end of the membrane (LMEM).
In an embodiment of the invention, the lower end of the outer layer (LOL) is adhered around substantially the total circumference to the lower end of the membrane (LMEM).
In an embodiment of the invention, the footwear upper comprises a lining.
The footwear upper may besides the waterproof membrane comprise a inner lining the comes in contact with the entire foot. The advantage of the lining is to cover the inside seams of the shoe, strengthen the footwear and lengthen the shoe's lifespan. The lining may be of different materials such as e.g. leather, fabric or a synthetic lining.
Stitch-Free Distance (STFD)
In an embodiment of the invention, the stitches of the stitching (STI) perforating and engaging with the lower end of the membrane (MEM) are made with a distance to the lower end of the outer layer (LOL) which is greater than a stitch-free distance (STFD) which is at least 1 mm, such as at least 2 mm.
In the present context a stitch-free-distance, when applied in connection with the lower end of the membrane and the lower end of the outer layer, refers to the distance from where the outer layer does not overlap the membrane layer. In other words, this distance will be found in the final product as the distance from the stitching between the insole and the membrane to where the outer layer further comprises the outer layer. It should be noted that this membrane part will be somewhat hidden at the lower end of the upper as this part of the membrane needs to be reinforced in terms of strength as the outer layer in this part of the footwear construction is not protecting or reinforcing the membrane directly. In practice the membrane will be covered by the sole by extending the membrane below the part of the upper of the final footwear to contain a user's foot and anchoring it to the sole below. Alternatively, or in combination therewith, the membrane may be protected from the side of the sole to which the upper is anchored. In both instances, the membrane will be hidden and protected by the sole below the lower part of the upper and/or by parts of the sole extending from below and partially covering the lowest part of the upper from the side.
The stitch-free-distance in the present context is given as a maximum, meaning that the distance at no given place should be shorter unless specific supplementing provisions are applied so as to sealing the potentially compromised outer layer.
In an embodiment of the invention, the stitch-free distance (STFD is between 1 mm and 20 mm, such as 1 mm and 10 mm, such as between 1 mm and 6 mm.
Stitch-Free Distance (STFD and Mark-Free Distance
In an embodiment of the invention the stitches of the stitching (STI) perforating and engaging with the lower end of the membrane (MEM) are made with a stitch-free-distance to the lower end of the outer layer (LOL) being at least 1 mm, such as at least 2 mm and wherein marks provided by a feeding mechanism of a sewing machine during stitching to the insole (IS) has a lateral distance (MFD) which is less than 10 mm, such as less than 6 mm, such as less than 3 mm.
In the present context a feeding mechanism may also be referred to as feed dogs or functionally equivalent parts of a sewing machine, which is providing a feeding movement of the membrane and insole material during the stitching of the insole to the membrane. Depending on the applied membrane, such feeding may leave marks or even damage the membranes ability to be waterproof, and such damage must be kept in check with the applied waterproof sealing thereby extending the sealing area to not only the stitching area but also to the part of membrane which is affected by the feeding mechanism of the sewing machine during stitching of the membrane to the insole.
It should be noted that the so-called lateral distance from the feed marks in principle may be negative as it is noted that such marks, when made from the side of the membrane facing outwardly towards in outer layer will be made in the outer layer, if the feeding mechanism is accidently or on purpose engaging the outer layer. The lateral distance mentioned in this context may also be referred to in the description as a mark-free-distance.
This feature of allowing a setting of marks relatively close to where the outer layer starts (as seen from the lower end of the upper), makes it possible to provide a safe, durable and very cost-effective waterproof and breathable footwear.
In an embodiment of the invention the stitches of the stitching (STI) perforating and engaging with the lower end of the membrane (MEM) are made with a stitch-free-distance to the lower end of the outer layer (LOL) being at least 1 mm, such as at least 2 mm and wherein marks provided by a feeding mechanism of a sewing machine during stitching to the insole (IS) has a lateral distance (MFD) which is less than 10 mm, such as less than 6 mm, such as less than 3 mm and wherein the marks MA are provided on the side of the upper to which a sole has been attached or is to be attached.
Cementing/Adhering the Outer Layer LOL
In an embodiment of the invention at least 3 mm of the lower end of the outer layer is cemented or adhered to the sole (S).
In an embodiment of the invention 4 to 15 mm of the lower end of the outer layer is cemented or adhered to the sole (S), such as 5 to 12 mm of the lower end of the outer layer is cemented or adhered to the sole (S).
In an embodiment of the invention at least 4 mm of the lower end of the outer layer is roughed prior to cementing to the sole (S) and wherein the outer layer is formed by leather.
In an embodiment of the invention at least 4 mm of the lower end of the outer layer is pre-adhered with the first adhesive (FAD) prior to cementing the upper (U) to the sole (S).
In an embodiment of the invention the breathable membrane (MEM) is attached to the outer layer (OL) at least at the upper or lower end (LEND) of the footwear.
In an advantageous embodiment to the top end of the membrane is attached in a durable way, e.g. by stitching or adhesion to the outer layer while at the same being attached at the lower end of the upper to the outer layer around discreet points of the lower circumference of the membrane, discrete areas or continuously around the whole circumference. The attachment at the lower end of the membrane to the outer layer should be stitch-free so as to avoid penetration of the membrane which is difficult to seal.
In an embodiment of the invention the breathable membrane (MEM) is attached to the outer layer (OL) at the lower end of the upper (U).
In an embodiment of the invention the breathable membrane (MEM) is attached to the outer layer (OL) at the lower end of the upper (U) by an anchoring adhesive (AA).
In an embodiment of the invention the breathable membrane (MEM) is also attached to the outer layer (OL) at the lower end of the upper (U) by an adhesive (LAD) adhesion around the circumference of the lower end of the outer layer (OL).
Reinforcing Member
In an embodiment of the invention the lower end of the membrane is at least partly provided with a reinforcing member (RM) and wherein the stitching (STI) attaching the insole (IS) to the membrane (MEM) is at least partly encapsulating the reinforcing member (RM).
According to an advantageous embodiment of the invention a reinforcing member is attached at the lower end of the membrane, partly or around the complete circumference of the lower end of the membrane. This reinforcing band may e.g. be stitched or adhered to the membrane, It should be noted that the member may e.g. be a band or a string as long as it can serve as a support to the stiches of the stitching in the membrane when the upper is mounted on a last. By “encapsulating” the reinforcement member by the stitching, the reinforcement band will ensure that the perforations related to the stitches in the membrane are not breaking or elongated to a degree is unacceptable.
The reinforcement member, e.g. a band, may be provided at both the inside and/or the outside of the membrane, i.e. on the side facing towards the inside of the footwear and to the outside of the membrane facing away from inside of the footwear.
In an embodiment of the invention, the membrane (MEM) is attached to the outer layer (OL) by means of said anchoring adhesive (AA) at an attachment surface area, wherein the attachment surface is less than 20% of the inner area of the outer layer, such as less than 10% of the outer layer.
In an embodiment of the invention, the upper (U) comprises an upper top end (UTEND), an upper intermediate area (UINA) and an upper lower end (ULEND), wherein the upper (U) is at least partly provided by a membrane (MEM) and an outer layer (OL) and wherein the membrane (MEM) is attached to the upper top end (UTEND) and the upper lower end (ULEND).
In an embodiment of the invention, the upper (U) is at least partly provided by a membrane (MEM) and an outer layer (OL), wherein the outer layer comprises an outer layer top end (TOL), an outer layer intermediate layer end (OIL) and an outer layer lower end (LOL) and wherein the membrane (MEM) is attached to the outer layer lower end (LOL) and the outer layer top end (TOL).
In an embodiment of the invention, the attachment of the membrane (MEM) to the outer layer lower end (LOL) and the outer layer top end (TOL) constitute less than 50% of the total upper area.
Attachment of the membrane to no more than 50%, such as less than 40%, such as less than 30% of the total outer layer area should be understood as the membrane is attached to the top end of the outer layer and the lower end of the outer layer and there is no attachment of the membrane in the intermediate area between the top end of the upper and the lower end of the upper.
In an embodiment of the invention, there is no attachment means in the upper intermediate area (UINA).
In an embodiment of the invention, the upper intermediate area (UINA) is a non-attachment area.
In an embodiment of the invention, the upper intermediate area (UINA) is a non-attachment area and wherein the non-attachment area is contiguous.
An advantage of having no attachment in the intermediate area of the outer layer may be a higher breathability of the upper compared to e.g. a laminate where the upper and membrane is fully attached by e.g. glue, film or similar.
A further advantage of having no attachment means in the upper intermediate area is that the adhesive areas are subsequently covered by e.g. the sole and therefore does not need to provide breathability of the upper. This means, highly advantageously, that any adhesive may be used e.g. more robust adhesives can be used during manufacturing of the footwear without compromising breathability of the upper.
In an embodiment of the invention, the membrane (MEM) is attached to the upper outer layer lower end (LOL) by means of an anchoring adhesive (AA).
In an embodiment of the invention, the membrane (MEM) is attached to the upper outer layer lower end (LOL) by means of an anchoring adhesive (AA) and the membrane (MEM) is attached to the upper top end (TOL) by means of an attachment arrangement (ATTA).
In an embodiment of the invention, the membrane (MEM) is attached to the upper outer layer lower end (LOL) by means of an anchoring adhesive (AA) and the membrane (MEM) is attached to the upper top end (TOL) by means of adhesive and/or stitching.
In an embodiment of the invention, the membrane (MEM) is attached to the upper outer layer lower end (LOL) by means of an anchoring adhesive (AA) and the membrane (MEM) is attached to the upper top end (TOL) by means of stitching.
In an embodiment of the invention, the attached outer layer (OL) and membrane (MEM) is a non-laminate.
In an embodiment of the invention, the membrane (MEM) is including at least one functional layer facilitating both water proof-ness and breathability and wherein the membrane has a protective layer facing towards the outer layer and a lining facing towards the interior of the footwear.
In an embodiment of the invention, the membrane (MEM) is including at least one functional layer facilitating both water proof-ness and breathability and wherein the membrane has a protective layer facing towards the outer layer and a lining facing towards the interior of the footwear and wherein the sealing of the membrane between the sole (S) and the lower end of the membrane (LMEM) is made between the protective layer of the membrane and the sole.
Sealing in the present context may also be referred to as suppressing water bridges as understood within the art of footwear.
The invention moreover relates to a method for making a footwear comprising an upper (U) and a sole (S), wherein the upper comprising a membrane (MEM) and at least one outer layer (OL), wherein the membrane (MEM) is attached to the outer layer (OL) and the membrane (MEM) is attached to an insole (IS), wherein the membrane (MEM) is attached to the insole (IS) by stitching (STI) a lower end of the membrane (LMEM) to the circumference of the insole (IS), wherein the minimum length of stitches of the stitching (STI) is 1.0 mm, wherein the membrane (MEM) is a waterproof breathable membrane, wherein the insole (IS) is attached to the sole (S).
Moreover, the invention relates to a method according to claim 91 and wherein the membrane (MEM) is attached to the outer layer (OL) by an anchoring adhesive (AA) according to any of the claims 1-90.
Sole and outsole may be used interchangeably.
The invention will now be described with reference to the drawing where
The outer layer OL comprises two surfaces; a surface OSF that faces the foot insertion volume FIV of the upper U, and a surface OSO that is facing outwards and in the opposite direction of a surface BSF that faces the foot insertion volume FIV.
The membrane MEM comprises two surfaces; a surface BSF that faces the foot insertion volume FIV of the upper U, and a surface BSO that is facing the outer layer surface OSF.
The upper U may comprise more than two layers, where a third, fourth or subsequent layers may be provided. The membrane MEM however should be positioned between the foot insertion volume FIV and the outermost layer of the upper, in order to prevent liquids to enter the foot insertion volume. Further layers and/or attachments may of course be applied within the scope of the invention.
The upper U has an upper part UP and a lower part LP, where the lower part LP abuts the upper facing surface UFS of the sole S. The sole S has a sole upper edge SUE. The sole may comprise several parts and layers (not shown).
The sole S further has a ground contacting surface GCS, which is intended to come into contact with the ground when the article of footwear FW is worn by a user. In accordance with one or more embodiments the sole S may comprise a midsole, where the ground contacting surface GCS may be an outsole facing surface, in case there is an outsole applied between the midsole and the ground, or any other form for a sole part located between the ground and the midsole. Thus, the term ground contacting surface may be replaced by the term ground facing surface.
The outer layer OL has a lower end LOL that extends past the sole upper edge SUE of the upper surface and extends in a, preferably, downward direction towards the bottom BUA of the upper and both the lower end of the membrane LMEM and the lower end of the outer layer LOL forms a part of an area where the upper U and the sole S are joined. The lower end of the membrane is furthermore connected to an insole IS around the circumference of the insole IS. The insole may optionally be connected by means of stitching and thus forming part of the upper. This may also be referred to as a strobel stitching. It should be noted, unless otherwise specified, that the stitching is optional and other means of connecting the insole to the upper may be applied within the scope of the invention, e.g. by means of adhesion.
As may be seen in
The illustrated footwear may in principle be manufactured as both a cemented footwear, i.e. where the sole S is cemented to a pre-manufactured upper U and a footwear manufactured by direct-injection, i.e. where the sole is molded onto the upper by a direction injection process. These two processes are known in relation to conventional footwear, but is should be noted that the method needs specific and unique modifications to be applied in the context of the present invention.
Other methods which may be applied within the scope of embodiments of the invention may include vulcanization of rubber onto the upper, casted sole or e.g. 3D printing directly onto the lower end of the upper.
In connection with the gathering of the upper with a sole, the above manufacturing methods may preferably include a roughing step if the outer layer is a top grain leather layer. At least a part of the lower end of the outer layer LOL should thus be roughed in order to e.g. attach to the cement or the DIP material to be used.
In an area where the outer layer OL and the membrane MEM overlap, they may be attached by an anchoring adhesive AA. The anchoring adhesive AA is applied for the purpose of securing the membrane to the outer layer OL around the lower end of the membrane thereby ensuring that the membrane do not fold inside the shoe. The adhesive also serves as a means for ensuring that adhesive, when sole S is attached by cementing does not progress to much between the membrane MEM and the outer layer OL. If the shoe is made by means of direct injection, the sole S would be attached to the upper by means of a direct-injection-process. In such a case, the anchoring adhesive should furthermore serve, preferably as a continuous or as a part of a continuous anchoring around the complete circumference of the lower end of the upper, thereby ensuring that the material applied for direct injection is not progressing or foaming in between the membrane and the outer layer in a undesired and unpredictable way.
The above illustrated embodiment of the invention may serve as a reference for different aspects of the present invention below. It should nevertheless be noted that the aim would overall to achieve a footwear which is waterproof above the lower end of the upper, i.e. the lower end of the membrane LMEM and the lower end of the outer layer LOL. How high such waterproofness is required may depend on the footwear design as long as it goes above the lower end of the outer layer. The outer layer OL and the membrane should also be breathable.
The waterproofness is fully required from above the lower end of the membrane and included the lower part of the upper, including the sole S. It should be noted that the waterproofness at the lower end of the footwear FW is primarily designed to keep the inside of the footwear waterproof. In other words. The combination of the outer layer and the membrane must ensure waterproofness with respect to water passing from there into the foot insertion volume FIV. It may be a little different with respect to the lower part LP of the upper in combination with the sole S, as the breathability through the sole is not and absolute requirement, but it is necessary that the water does not pass into the foot insertion volume FIV. This means that there is degree of freedom in terms of design when establishing the sole structure. A part of the sole, e.g. the lower part may thus be non-waterproof as long as the a part of the sole S or the insole IS comprise a waterproof barrier which may prevent water from passing from the outside of the footwear FW into the foot insertion volume FIV through the sole S of through the critical transition between the lower end of the membrane LMEM and the insole IS and/or the sole S.
A part of such waterproof barrier may thus in another embodiment by implemented by the application of a waterproof sole which is connected in a waterproof way the membrane of the upper.
It should thus be noted that, according to an embodiment of the invention, that both the upper U and the S/insole IS are applied as breathable and waterproof, whereas another attractive embodiment of the invention is waterproof and breathable with respect to the upper (at least the lower part of the upper) and only waterproof with respect to the sole and/or the insole.
Outer Layer
The outer layer may be a fabric/textile layer, a leather layer, a nubuck layer, a knitted layer, polymer, canvas, or any type of layer that may be used as the outermost layer of a footwear upper, where the other layer may provide the outer appearance of the footwear.
The outer layer may be outermost layer of the outer layer, however, the outer layer may also comprise other layers or treatments covering the other layer as an extra outer layer for e.g. strengthening, color, elasticity, stiffness, weight, protection or aesthetical appearance.
Examples Leather
Examples of leather types that may be used within the scope of invention may be types such as full grain or top grain leather, embossed grain leather, suede and nubuck.
In principle, the leather can derive from any source, including cow hide, horse hide, goat skin, sheep skin, kangaroo hide, reptiles, fish and the like. Even so, preferably the leather is a mammal or marsupial leather (i.e. derives from a hide from a mammal such as a cow or horse, or a marsupial such as a kangaroo). Mammal leathers are most often used.
In terms of terminology, top grain surface is the upper portion or outer covering of the animal whereas split is the under layer which is removed by splitting operation in the leather making/tanning process.
Full grain refers to top grain leather where no sanding of the surface takes place. Nubuck leathers have the surface layer removed or modified typically by a buffing process. Although the leather still has the pronounced network of natural fibers and corium structure giving the leather strength, the very top grain surface is effectively removed. The buffing process used to form nubuck leathers leaves protein fibers that produce a velvet-like feel. Artificially embossing nubuck leather can create a surface texture, but often the embossing step damages the protein fibers and undermines the velvet-like feel. Split leather is created from the fibrous part of the hide left once the top-grain has been separated from the hide, e.g. to be used as full grain or top grain leather. Split grain leather may have reduced strength as compared to comparable thicknesses of top grain leather, as the fibers tend to be more aligned.
Membrane
The outer layer may be provided as a layer that may be liquid and/or vapor permeable, as any liquids that can pass the first layer, are prevented from entering the foot insertion volume by the breathable waterproof membrane.
In one or more embodiments the membrane may be a waterproof and vapor permeable functional layer. A waterproof and vapor permeable functional layer is well known within the art, such as commercially available GORE-TEX® laminate from W.L. Gore & Associates, Sympatex, Cosmo, Outdry, Covestro, Respilon, Schoeller or Wilhelm.
The membrane may comprise a single layer of material or may comprise two or more layers of materials that are provided in a laminate, creating a functional layer assembly. The membrane may be in the form of any layer, or a laminate of layers that create a waterproof and vapor permeable layer for the upper. The vapor permeability of the layer may be adjusted in accordance with the specific use of the footwear, so that for some uses the vapor permeability may be greater than other uses, such as a hiking boot versus a casual shoe.
Other layers to be included or attached to the membrane includes fabric on one or both sides of the membrane layer. Such layers may e.g. be included for strength purposes, layers or treatment on the membrane for reducing the surface tensions, layers for providing color and/or e.g. a lining. In the latter case a footwear lining may thus form a part of what is referred to in the description as membrane.
In one or more embodiments of the invention, the membrane may be a kind of textile fabric compounded with polymer waterproof breathable materials (PTFE) membrane) plus fabric. The membrane. The membrane may also be characterized as microporous membrane expanded Teflon (polytetrafluoroethylene) more formally known as ePTFE. that is e.g. provided in a thickness of about a 0.01 mm when not including the thickness of further laminated fabrics etc.
The waterproof membrane may comprise other layers and the thickness may depend on the applied layers. In some or more embodiments of the invention, the membrane may be e.g. 0.3 mm or 0.6 mm and in other applications such as e.g. a shoe suitable for cold weather, the membrane may e.g. be 2.5 mm or thicker.
The materials of the membrane layers may vary according to the application and relevance for use, wherein a thin and flexible membrane may be relevant for e.g. athletic shoes and membranes comprising e.g. wool or similar layers may be suitable for e.g. winter boots.
Breathable membrane, waterproof membrane, breathable waterproof membrane and membrane may be used interchangeably according to the invention.
Insole
The insole is the sole that binds the footwear upper to the rest of the footwear and the material of the insole depends on the type of footwear construction and materials may be woven, non-woven, fabric, textile, canvas, leather, membrane, PU and/or foam material and may comprise additional materials for comfort or functionality.
According to embodiments of the invention, the footwear manufacturing may also be made without an insole. In this case only edging and a cord “criss-cross” the sole and the method may also be termed as “string lasting”.
Insole and strobel sole may be used interchangeably according to the invention.
The insole may be stitched to the lower end of the membrane by a strobel stitching technique that may are made by a strobel stitching machine.
An example of a strobel stitching machine may e.g. be a Strobel 141-23 EV single thread overseaming machine. A needle type may e.g. be a needle type 134.
Adhesive
In embodiments of the invention, anchoring adhesive may be attached to a surface area of the membrane, and does not penetrate the membrane, either partly or fully. Thus, the water and vapor impermeability of the membrane is not affected by the adhesive. Thus, it may be important to ensure that the adhesive does not increase the water or vapor permeability of the membrane. The adhesive may provide a waterproof seal between the outer layer and the membrane of the upper.
In one or more embodiments the anchoring adhesive may extend from the lower end of the outer layer and extending along the outer layer of the total circumference of the lower end direction.
The anchoring adhesive may be an adhesive layer but may also be a weld joint, a melted joint, or any suitable adhesives that is capable of attaching and/or fixing the outer layer to the membrane.
The anchoring adhesive may be part of the outer and/or the membrane, e.g. where the outer layer may be melted to the membrane, or vice versa, or the layers may be melted to each other. Alternatively, the anchoring adhesive may be a separate member, that is positioned between the two layers, e.g. an adhesive layer.
In one or more embodiment the anchoring adhesive may extend continuously along the entire lower end of the membrane. The anchoring adhesive may be a waterproof sealing/adhesive that means that the adhesion is capable of preventing water to penetrate the foot insertion volume of the footwear.
The anchoring adhesive AA used for adhering the outer layer and membrane at the lower end as described according to the invention, may be any suitable adhesives.
Examples of anchoring adhesives may e.g. be, non-water-based adhesives, water-based adhesives, heat-activated adhesives, two-component adhesives, cold glue.
Examples of anchoring adhesives may e.g. be epoxies, methyl methacrylates, silicone adhesives, urethanes.
Examples of adhesives used according to the invention may be Locite Aquace W-01, Helmitin 11019 Helmitin GPV and/or Helmitin 49631.
The anchoring adhesive AA used according to the invention may be in various forms such as e.g. liquid, film, tape that may adhere on one or both sides.
According to embodiments of the invention, the adhesive may be present in a continuous layer or be present as a “perforated” or non-continues adhesive layer facilitating both sufficient bonding but also breathing or some kind of moisture transport through the layers.
The application of adhesive to the leather parts may be in the form of a prelamination.
According to embodiments of the invention, hot melt adhesive or hot melt glue is used to attach the sole to the upper.
Assembly
After the strobel stitching, the upper is drawn over a last LA that may be specially designed for the footwear. To make the upper flexible prior to lasting, the upper may be treated first with e.g. steaming. The treatment makes the upper easier to last and prevents the upper material from tearing.
To ensure that the sole material binds efficiently to the upper, the upper may first be roughed or scratched at the lower end of the outer layer.
The illustrated upper U is shown as mounted on a last LA. The last LA has thus been introduced into the foot insertion volume FIV. The lower end of the outer layer LOL has prior to lasting been adhered to the lower end of the membrane LMEM with an anchoring adhesive AA.
The lower end LMEM of the membrane MEM is attached to an insole IS, and the insole IS is attached to the lower end LMEM of the membrane MEM along the entire periphery of the membrane MEM, in order to provide an anchor for the membrane MEM to the sole S which is attached to the upper U subsequently and while the upper is still lasted.
The anchoring adhesive AA ensures that the lower end LMEM does not move when the last LA were introduced into the foot insertion volume FIV, and it maintains the position of the membrane partly during use but primarily during attachment to the sole S.
The attachment between the insole IS and the membrane MEM may e.g. be made via an insole stitch STI, e.g. a strobel stitch. The adhesive AA ensures that the position of the lower end LOL of the outer layer OL is maintained in its position, when the last LA is introduced into the foot insertion volume FIV so that the lower end LOL does not move significantly (upwards, sidewards or downwards) when the last LA stretches out the outer layer OL, the membrane MEM and the insole IS.
Prior to an injection molding of the sole S to the upper U the positioning of the lower end of the outer layer LOL ensures that at least part of the lower end of the membrane LMEM facing away from the last is exposed to its surroundings, as well as the lower surface LS of the insole IS and at least part of the surface of the outer layer OL. This means that when the upper U is positioned inside a mold (not shown), and the mold is closed towards the surface of the lower end of the outer layer LOL, the molded material can come into direct contact with the surface of the lower end of the outer layer LOL, the lower end of the membrane EMEM, as well as the lower surface of the insole IS.
If the upper U is to be cemented to a sole S, the same principles applies principally as mentioned above. In that case, the cement to be applied between the sole S and the upper U would be applied to the outer area of the lower end of the outer layer LOL, the exposed and lower end of the membrane LMEM and the insole IS.
It should be noted that the stitching STI will be stretched when the upper us mounted on the last LA and the perforations associated with the stitches of the stitching STI in the lower end of the membrane will be stretched to a degree that it is almost certain that the desired waterproofness in the transition between the lower end of the membrane and the insole IS is lost, even if the insole is waterproof when the upper is initially mounted on the last. This lack of waterproofness will be compensated during the subsequent attachment to the sole.
If applying a DIP process, the result of the application of the sole S to the upper U is shown in
Also, here a sealing between the lower end of the membrane LMEM and the sole S may be obtained insofar an adhesive cement AC is applied properly to the lower end of the outer layer LOL, the lower end of the membrane LMEM and the sole S.
In the present context it is important that the cement is waterproof.
The last has now been removed, and the sole S has been bonded to the upper U by a layer of adhesive cement AC, to create a seal between the surface of the lower end of the membrane LMEM and a waterproof material forming the sole S. This seal prevents that liquids can pass and ensures that the foot insertion volume FIV may be maintained dry, even if water may pass below the edge of the sole e.g. via the lower end of the outer layer LOL, as the water cannot pass the seal formed by the combined transition of the lower end of the membrane LMEM and the sole S. The seal should preferably extend along the entire circumference of the lower end of the membrane LMEM, ensuring that liquids cannot pass into the foot insertion volume FIV.
An anchoring adhesive (not shown) has been applied at the lower end of the outer layer LOL around the complete circumference of the lower end if the outer layer LOL to adhere the outer layer to the membrane MEM.
The illustrates merely serves to illustrates the embodiment of e.g.
An anchoring adhesive (not shown) has been applied at the lower end of the outer layer LOL around a part of the circumference or around the complete circumference of the lower end of the outer layer to adhere the outer layer to the membrane MEM. The illustrates merely serves to illustrates the embodiment of e.g.
Due to the continuous implementation of the anchoring adhesive, this embodiment in suitable for both cemented footwear and DIP'ed footwear as described in relation to earlier DIP embodiments of the invention. The continuous adhesive anchoring thus ensures that foam will not progress up between the outer layer OL and the membrane MEM during DIP of a sole to the upper.
Due to the continuous implementation of the anchoring adhesive, this embodiment in suitable for both cemented footwear and DIP'ed footwear as described in relation to earlier DIP embodiments of the invention. The continuous adhesive anchoring thus ensures that foam will not progress up between the outer layer OL and the membrane MEM during DIP of a sole to the upper.
A heel cap HC and a toe cap TC have been adhered between the outer layer OL and the membrane MEM in the toe end of the footwear and a heel cap HC has been adhered between the outer layer OL and the membrane MEM in the heel end of the footwear. Dashed lines are illustrating two continuous anchoring adhesive AA lines at the medial and the lateral side of the footwear between the lower end of the outer layer LOL and the membrane MEM. Together the heel cap HC, the toe cap TC and the anchoring adhesive AA lines provides a continuous adhesive anchoring of the membrane around the periphery of the lower end of the outer layer LOL.
The toe cap TC and heel cap HC serves two purposes, namely providing a 3D shape in the toe end and the heel end of the footwear while at the same time functioning as an adhesive anchoring of the lower end of the membrane around the toe end and the heel end part of the circumferential adhesive anchoring AA.
The toe cap and heel cap as applied above are in particular attractive in terms of manufacture as attachment in the toe and heel section for the establishment of a stable shape are well known in the art and already implemented as such in the manufacturing line at many footwear producers. A modified attachment and mounting of the toe and heel cap with the footwear as a part of the adhesive anchoring of the lower end of the membrane may relatively easy be implemented in the manufacturing line and it is also noted that such process is relatively attractive when compared to a manual circumferential adding of an anchoring adhesive AA line in the toe end and the heel end of a footwear may be somewhat complex and difficult compared to the application of a toe cap and a heel cap with double sided adhesive.
The toe cap TC, the heel cap HC the adhesive anchoring AA lines should thus first be applied to the layers and, in terms of the anchoring lines, then be activated prior to the total adhering of the lower end of the membrane LMEM to the lower end of the outer layer LOL.
The details of the lower end of the footwear, in particular the sole S and the interfacing with the lower end of the upper is not described in this illustration, but reference is made to
Both embodiments are seen from the side of the upper which is eventually to be the inside of the upper U. In the illustrated embodiment the membrane has been partly attached at a part of the lower end of the membrane LMEN and a part has bee folded back towards the reader to illustrate the lines of anchoring the membrane to the upper.
After this step, the upper is going to the attached, preferably by stitching to an insole (not shown) to provide a sock of the upper
Subsequently, the upper is to be mounted on a last (not shown) for the further processing, including attachment of a sole to the insole of the upper sock by a DIP process or by cementing.
The illustrated upper has been attached to an insole IS be means of stitching STI to a lower end of a membrane MEM. Two sections, SEC1 and SEC2 have been shown to illustrate that a stitching in the present context is understood as having a direction D following the circumference of the insole IS. It may easily be understood from the figure that the direction will vary around the circumference of the insole as illustrated by the arrows. The direction of the stitching will thus be given by the arrows D and the direction of the stitching should at any point of the stitching be determined as the direction of the gradient of the progressing stitching pattern. In other word, a stitch length of the stitching is to be determined as the stitch length in the direction D of the stitching. The stitch length may, depending on the applied stitch pattern vary somewhat depending e.g. whether the stitch length is determined at a part of the stitching where the direction is relatively progressing as a straight line or whether the progression of the stitching is bowed. The stitch length should be determined at a part of the stitching, which is progressing in a relatively straight line, i.e. e.g. in the illustrated section SEC1.
As mentioned above, the stitch length may, depending on the applied stitch pattern vary somewhat depending on e.g. whether the stitch length is determined at a part of the stitching where the direction D is relatively progressing as a straight line or whether the progression of the stitching is bowed or curved. As it also has been mentioned above, the stitch length should normally be determined at a part of the stitching, which is progressing in a relatively straight line.
It is further noted as mentioned above that stitch length may be given in e.g. mm and designate the length in the longitudinal direction between two stitch-tops.
As shown in
As shown for the cut-out CO1 in the enlarged view, the stitching length will differ for the curved part, depending on whether the stitch length is determined between two stitch-tops at the insole IS, where the stich length in this context will be designated the inner part stitch length LINP, or at the membrane MEM, where the stich length between two stitch-tops in this context will be designated the outer part stitch length LOUT and where the outer part stitch length LOUT tends to be larger. The difference will, as it appears from the schematic illustration of
Correspondingly, as shown for the cut-out CO2 in the enlarged view, the stitching length will differ for this concavely curved part, depending on whether the stitch length is determined between two stitch-tops at the insole IS, where the stich length in this context will be designated the inner part stitch length LINP, or at the membrane MEM, where the stich length between two stitch-tops in this context will be designated the outer part stitch length LOUT and where the inner part stitch length LINP tends to be larger. The difference will, as it appears from the schematic illustration of
Thus, in an embodiment of the invention, the length L of the stitches of the stitching STI is determined to be fulfilled for one or both of the outer part stitch length LOUT and the inner part stitch length LINP, e.g. where the minimum length of the outer part stitch length LOUT and/or the inner part stitch length LINP of stitches of the stitching STI is at least 1.0 mm, where the outer part stitch length LOUT and/or the inner part stitch length LINP is for example between 1.0 mm to 12 mm, such as 1 mm to 10 mm, such as 1.5 mm to 9 mm, such as 1.5 mm to 8 mm, such as 4 mm to 7 mm, such as between 5 mm to 7 mm, such as 2 mm to 4 mm, etc. as further specified in the appended claims.
Hereby, it is made possible to obtain stitches highly efficiently connecting the breathable membrane to the insole having the flexibility required for a footwear insole while avoiding any damage to the membrane and/or the insole by the stitching. Furthermore, folding of the membrane material or the insole material, which may be detrimental to e.g. waterproofness, may in this manner be avoided.
Besides all the features of
The marks are typically made by a sewing machine during manufacture of the upper during the process step where the upper is stitched to the insole IS. These marks MA are primarily made because the membranes applied for the purpose of obtaining the waterproofness while still being breathable are typically very thin. This thinness combined with the relative weakness of the membrane (even if further layers of fabric are laminated to the membrane) results in that a sewing machine when attaching the membrane to the insole are deformed or potentially damaged during the process. It should be noted that there may often be a significant difference in the thickness of the insole when compared to the membrane. It is however noted that according to an advantageous embodiment of the invention, this distance may be kept extremely short insofar the stitching made into the membrane are made from the illustrated side of the combined upper and insole. It is noted that the stitching and the resulting marks, when made from the illustrated side (i.e. the outside of the upper and insole, then the outer layer will protect the membrane during stitching as the feeder will set marks in the lower end of the outer layer rather than make marks in the membrane. This is attractive as the marks set “below” the lower end of the outer layer OL, e.g. in the area defined by the stitch-free-distance STFD may be sealed during the attachment of the sole to the upper of which the illustrated section is a part of (not shown).
The stitches of the stitching STI perforating and engaging with the lower end of the membrane MEM may advantageously be made with a stitch-free-distance to the lower end of the outer layer LOL being at least 1 mm, such as at least 2 mm and wherein marks provided by a feeding mechanism of a sewing machine during stitching to the insole IS has a lateral distance MFD which is less than 10 mm, such as less than 6 mm, such as less than 3 mm and wherein the marks MA are provided on the side of the upper to which a sole has been attached or is to be attached.
In
Furthermore, a sole S, e.g. an outsole, is provided with a pre-adhered second adhesive SAD.
In
It is noted that the perforations in the membrane provided in relation to the stitches of the stitching STI in the final product are sealed in a reliable way due to the application of the first adhesive previous to the gathering of the insole and the outsole. It is furthermore noted that the stitches of the stitching are mechanically supported by the adhesive to the outsole, thereby reducing the risk of unnecessary stretching of the lower end of the membrane during use of the use. Also, if the above process, typically performed on a last, has resulted in a stretching of the perforations related to the stitching, such expanded perforations may be sealed effectively during the final cementing of the sole S to the insole IS, thereby resulting in a completely waterproof sealing WS extending from the insole to where the membrane is perforated or ending at the attached upper. The water proof sealing is thus in the present context at least constituted by the lower end of the membrane LMEM, the first adhesive FAD sealing the stitches and optional damage done to the lower end of the membrane during stitching, the second adhesive SAD, the outsole if waterproof and preferably also the third adhesive TAD.
Different attractive embodiments within the scope of the invention may be applied when cementing a footwear within the scope of the invention. Thus, in the above embodiment of a manufacturing procedure, stitching STI is applied subsequent to pre-adhering of the first adhesive FAD to the lower end of the membrane LMEM and the lower end of the outer layer LOL and pre-adhering of the third adhesive TAD to the insole IS.
In an alternative embodiment of the process within the scope of the invention, the first adhesive and optionally also the third adhesive TAD is applied after the stitching. In practice such application of adhesive may advantageously be applied when the upper has been positioned on a last (not shown).
After re-activation of the pre-adhered first adhesive FAD, third adhesive TAD and the second adhesive SAD the sole S the upper U and the sole S may be gathered under pressure and harden subsequently or typically during application of pressure. In this way, adhesive may be applied directly to the stitches after the upper has been positioned at a last and the stitches penetrating the lower end of the membrane has been expanded.
Also, in this case, the lower end of the membrane with stitching, although stressed and very likely weakened during positioning on a last, may be directly and reliable supported and secured despite such weakening
Other sequences may be applied within the scope of the invention as long as a first adhesive is pre-adhered directly on the lower end of the membrane preferably including on the stitching thereby obtaining both strength and sealing when re-activated and attached to a sole S.
It should be noted that different configurations of a waterproof bottom sealing WBS may also be applied within the scope of the invention. It is thus noted that membrane LMEM, the first adhesive FAD, second adhesive SAD by themselves may form a waterproof bottom sealing WBS.
In the present above configuration it is more or less implied that the sole S may be made of a waterproof material which is not necessarily breathable.
Such configuration may e.g. be obtained by the use of breathable materials in the sole D, the adhesives and or the insole IS.
It should also be noted that the footwear illustrated in the above embodiment should include, as explained in the description a waterproof a breathable membrane of which the lower end LMEM is shown. The rest of the upper may of course also be waterproof.
Other components of the footwear is not shown, although such components may of course be applied according to the provisions of the invention. Such further components may include lining, further sole components, further sole inlay etc. (not shown).
In the illustrated embodiment the insole IS may generally be exchanged with a string lasting as long as it is possible to connect the lower end of the membrane LMEM to the waterproof sole or waterproof sole part in a reliable and sealable way and thereby still obtain a desired waterproof bottom sealing WBS. The application of insole is however preferred.
The reinforcing member RM is applied for the purpose of serving a support of the stitching connecting the insole IS and the membrane MEM. The stitching STI must encapsulate the reinforcing member RM so as to ensure that stretching on the lower end of the membrane MEM especially during positioning of the upper on a last (not shown) is counteracted by the reinforcing member RM
The attachment of the membrane MEM to the outer layer OL of the upper top end UTEND may be mediated by an attachment arrangement ATTA, such as adhesive and/or stitching. The attachment of the membrane MEM to the outer layer OL of the upper lower end ULEND may be mediated by an adhesive, such as an anchoring adhesive.
It should further be understood that there is not attachment arrangement, anchoring adhesive or any attachment of the membrane MEM to the outer layer OL of the upper in the upper intermediate area UINA. The size of the upper intermediate area UINA may vary according to the design of the footwear, the size of the footwear etc.
Also illustrated in
The lining material may be a material with strong moisture absorption capacity maximizing the comfort dry inner environment of the footwear.
The backing fabric may be constructed of a material knitted from synthetic fibers such as polyamide fibers.
The important part of the overall membrane is that part of the membrane facing towards the sole, here the backing fabric, is sealable with sole material, adhesive or other appropriate sealant applied onto the surface.
The membrane is attached to an insole IS by stitching STI and the inner sock-like membrane stitched to the insole is then cemented or DIP'ed to the sole of the footwear.
Further and as illustrated in
The height of the anchoring adhesive should in a preferred embodiment of the invention be at least 4 mm and/or between 4-20 mm, such as between 5-15 mm. The lower anchoring adhesive should preferably have the aforementioned height and be unbroken along the complete anchoring adhesive circumference, including the anchoring formed by means of adhesive onto the toe cap and/or the heel cap.
| Number | Date | Country | Kind |
|---|---|---|---|
| PA202070098 | Feb 2020 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DK2021/050045 | 2/19/2021 | WO |
