Patent Application
20230189928
The present invention relates to a high-heeled shoe comprising an insert (E) and a base body (G), wherein the base body (G) is produced as a single part via a 3D printing process. The insert (E) comprises a surface (EF) that has an upper side (EO) and a lower side (EU), wherein a heel (A) is formed on the lower side (EU). The base body (G) comprises a base surface (F) and an inner flap (I), wherein the base surface (F) has an upper side (FO), a lower side (FU) and a first cavity (H1), and the inner flap (I) has an upper side (IO) and a lower side (IU), wherein the lower side (IU) of the inner flap (I) is joined with the upper side (FO) of the base surface (F) of the base body (G) such that, between the lower side (IU), the upper side (FO) and the first cavity (H1), a second cavity (H2) is formed which forms an overall cavity (HG) with the first cavity (H1), wherein the overall cavity (HG) essentially corresponds to the shape of the insert (E). The insert (E) is positioned in the overall cavity (HG) such that the lower side (EU) of the surface (EF) of the insert (E) is completely contacted with the upper side (FO) of the base surface (F) of the base body (G), and the lower side (IU) of the inner flap (I) completely covers the upper side (EO) of the surface (EF) of the insert (E). The present invention furthermore relates to a process for producing the high-heeled shoe and to the use of an inner flap (I) for completely covering the upper side (EO) of the surface (EF) of an insert (E) in a high-heeled shoe.
The production of shoes, which is also referred to as “shoemaking” by those skilled in the art, involves a multiplicity of work steps and in principle proceeds identically for all forms of shoes, for example low shoes and ankle boots. A shoe normally comprises an upper part, the upper, and a lower part, the bottom or sole, with the upper and the sole being bonded to one another. In bespoke shoes, the upper and the sole are adapted to the individual shape of the foot by the shoemaker. Shoes produced in industrial mass production are based on set sizes, i.e. averages, used for the last construction of the shoe.
The lasts, which model the foot, form the basis for each pair of shoes. They account for size and shoe model and are also responsible for wear comfort. Standardized lasts for “average feet” are used for industrially manufactured shoes. Lasts are traditionally made from solid wood, such as for example beech. Plastic lasts or aluminum lasts are also especially used in the shoe industry. In general, a right last and a left last (crooked lasts) are produced.
Depending on the model of shoe, the bottom consists of one or more soles. A characteristic example of a shoe having only one sole is a moccasin. Otherwise, shoes generally have two or more soles: the inner sole (insole) and the outsole. In addition, some shoes are equipped between the inner sole and the outsole with further cushioning midsoles or additional insert soles. For the production of the upper, the shoemaker or upper maker draws up a cutting pattern for the upper parts on the basis of a last copy. This cutting pattern is used as a basis for cutting or stamping the individual upper parts and stitching or adhesively bonding them. Good uppers consist of an inner upper (lining), an intermediate upper (interlining) and an outer upper (upper material).
The actual shoemaking is effected by stretching the upper over the last using upper pincers, shaping it and bonding (pinching) it to the inner sole. Depending on the style, this bond is flexibly stitched, topstitched or welt-stitched. In mass production, the upper and the inner sole are often adhesively bonded.
At the end of shoe production, the shaping last is removed from the finished shoe. This laborious work is performed either by hand or by machine.
The individual parts of the upper and of the sole(s) generally comprise a very wide variety of materials and are typically produced separately by a variety of processes. By way of example, the materials for the sole(s) and the upper are selected from real leather, artificial leather, various further polymers and paperboard. It the upper and the sole(s) comprise a polymer, they are generally produced by injection molding in a mold.
A high-heeled shoe generally comprises many individual materials: It may for example comprise, among other things, an outsole made from a thermoplastic rubber, a heel made from an acrylonitrile-butadiene-styrene copolymer with metal insert, an inner sole made from an ethylene-vinyl acetate copolymer foam and an upper made from a polyvinyl chloride layer (artificial leather) and a polyester layer, with the individual components preferably being produced individually via an injection molding process and then being bonded to one another.
A disadvantage with this is that many different individual parts have to be bonded to one another, which involves a great many work steps and is therefore highly time-consuming and expensive. In addition, the resulting high-heeled shoe is difficult to recycle on account of the many different materials.
Further costs are incurred as a result of the fact that in general a last is required for the production of each high-heeled shoe. Furthermore, in the case where the sole(s) and the upper are produced via an injection molding process, a mold is required for each sole and for each upper. Post-processing steps are frequently needed after the injection molding as well, such as for example cutting off undesired parts.
EP 3 381 314 and US 201 8/0271 21 1 disclose a midsole for footwear comprising a three-dimensional mesh. The entire midsole or the three-dimensional mesh can be produced via an additive manufacturing process.
US 2014/0109441 describes a shoe construction comprising a sole made from sintered material. The shoe construction is drainable and can be used as a shower shoe.
WO 2019/160632 discloses a process for processing a sinter powder that can be used to produce a sole structure for footwear.
It is an object of the present invention to provide a novel process for producing a high-heeled shoe and a novel high-heeled shoe as such.
This object is achieved by a high-heeled shoe comprising the following components
The use of the 3D printing process in the process of the invention for producing high-heeled shoes enables the production of the base body (G) without using molds. Instead, the base body (G) is produced layer by layer. The saving on, or rather the dispensing with, molds results in considerably lower costs for the manufacturer for small series runs of the high-heeled shoe according to the invention, and therefore for the customer too.
In addition, the base body (G) is produced as a single part from a single material via a single process, whereas the base bodies (G) of the prior art each comprise a plurality of different elements made from different materials which are possibly produced by different processes and additionally need to be assembled. The use of a 3D printing process in the production of the high-heeled shoe according to the invention therefore means that work steps, such as for example the adhesive bonding of individual elements, such as the base surface and the inner flap, are dispensed with and the resulting high-heeled shoe according to the invention is easier to recycle compared to high-heeled shoes from the prior art.
Furthermore, the use of a 3D printing process in the production of high-heeled shoes makes it more readily possible to adapt the high-heeled shoe in a customer-specific manner, since the fabrication of a multiplicity of molds is dispensed with. Thus, for example, the base body (G), in particular the base surface (G) thereof, the inner flap (I) thereof and possible the upper (S) thereof, and/or the insert (E) can for example be adapted individually to the length and width of the foot of a high-heeled shoe wearer, and also to the weight and gait of said wearer.
A further advantage of the process according to the invention for producing a high-heeled shoe is that no post-treatment steps, such as for example cutting off undesired parts, are necessary after the production of the base body (G). The consistency and reproducibility in the production of the high-heeled shoe are therefore also improved.
In cases where the high-heeled shoe according to the invention comprises a thermoplastic polymer such as for example thermoplastic polyurethane (TPU), polyethylene (PE), polystyrene (PS) or polypropylene (PP), this can be a renewable thermoplastic polymer that has for example been obtained from maritime waste.
Furthermore, it is advantageously possible, in the case where the lower side (IU) of the inner flap (I) is not irreversibly bonded to the upper side (EO) of the surface (EF) of the insert (E), to lift the inner flap (I) and exchange the insert (E).
The high-heeled shoe according to the invention additionally has a high stability, even when running. Even after a multiplicity of loads, no external damage, for example to the heel (A), is visible.
The high-heeled shoe according to the invention and the process for producing same according to the invention are elucidated in more detail below.
The term “high-heeled shoe” is known to a person skilled in the art. A high-heeled shoe generally comprises a heel (A) that preferably has a height of at least 3 cm, more preferably of at least 4 cm and most preferably of at least 5 cm. The heel (A) can have any desired three-dimensional geometric shape, for example it can be in the shape of a cube or a cylinder. Depending on the shape of the heel (A), the heel (A) can for example be referred to as a stiletto, block or tapered heel.
The high-heeled shoe according to the invention comprises an insert (E) and a base body (G). Furthermore, the high-heeled shoe can also comprise further components, for example at least one further component selected from the group consisting of a heel cap, a metal insert, an outer sole and an inner sole.
It is also possible that the high-heeled shoe according to the invention comprises an upper (S1) in addition to the insert (E) and the base body (G), wherein the upper (S1) comprises at least one third thermoplastic polymer (TP3) that preferably differs from the at least one second thermoplastic polymer (TP2) described below, and wherein the base body (G) and the upper (S1) are each produced via a 3D printing process.
The at least one third thermoplastic polymer (TP3) is preferably a polyamide.
The present invention therefore also further provides an upper (S1) comprising at least one third thermoplastic polymer (TP3), preferably a polyamide, for use in a high-heeled shoe, wherein the upper (S1) is produced via a 3D printing process.
Two uppers (S1) produced via a selective laser sintering process are illustrated in
The insert (E) comprises a surface (EF) that has an upper side (EO) and a lower side (EU), wherein a heel (A) is formed on the lower side (EU).
In the context of the present invention, the term “heel (A)” is understood to mean a raised part on the lower side (EU) of the surface (EF) of the insert (E). This raised part can have any desired three-dimensional geometric shape, and preferably is in the shape of a cube, a cuboid or a cylinder.
If the heel (A) is in the shape of a cube, the edge length of the cube is preferably at least 3 cm, more preferably at least 4 cm and most preferably at least 5 cm.
If the heel (A) is in the shape of a cuboid, preferably at least one edge length of the cuboid is preferably at least 3 cm, more preferably at least 4 cm and most preferably at least 5 cm.
If the heel (A) is in the shape of a cylinder, the height of the cylinder is preferably at least 3 cm, more preferably at least 4 cm and most preferably at least 5 cm.
It is clear to those skilled in the art that the abovementioned edges mean the edges that extend from the lower side (EU) of the surface (EF) of the insert (E) down to a lower end of the heel (A). In the context of the present invention, the “lower end of the heel (A)” is understood to mean the end of the heel (A) in proximity to the ground. The edge lengths mentioned above thus correspond to the height of the heel (A). It is further clear to those skilled in the art that the abovementioned height of the cylinder means the height that extends from the lower side (EU) of the surface (EF) of the insert (E) down to a lower end of the heel (A). It therefore corresponds to the height of the heel (A).
The surface (EF) is preferably curved. It preferably has a heel end and a toe end. The heel (A) is preferably formed on the lower side (EU) of the heel end. If the surface (EF) is curved, the upper end of the heel (A), which starts at the lower side (EU) of the surface (EF) of the insert (E), is likewise preferably curved. In this case, the height of the heel (A) corresponds to the length of the edge having the maximum length or the maximum height of the cylinder.
The insert (E) can be produced by all methods known to those skilled in the art. The insert (E) is preferably produced via a 3D printing process or via an injection molding process, more preferably via an injection molding process.
The insert (E) can for example be produced from polyamide, polypropylene, polyester, polyurethanes or a thermoset.
In the context of the present invention, the insert (E) preferably comprises at least one first thermoplastic polymer (TP1), preferably a polyamide.
A particularly suitable polyamide (PA) is for example polyamide 11 (PA 11).
Furthermore, the insert (E) can comprise at least one further component selected from the group consisting of reinforcers and additives.
In the context of the present invention, a reinforcer is understood to mean a material that improves the mechanical properties of shaped bodies (here, of the insert (E)) compared to shaped bodies (inserts (E)) that do not comprise the reinforcer.
Reinforcers as such are known to those skilled in the art. The reinforcer may, for example, be in spherical form, in platelet form or in fibrous form.
Preferably, the reinforcer is in platelet form or in fibrous form.
A “fibrous reinforcer” is understood to mean a reinforcer in which the ratio of length of the fibrous reinforcer to the diameter of the fibrous reinforcer is in the range from 2:1 to 40:1, preferably in the range from 3:1 to 30:1 and especially preferably in the range from 5:1 to 20:1, where the length of the fibrous reinforcer and the diameter of the fibrous reinforcer are determined by microscopy by means of image evaluation on samples after ashing, with evaluation of at least 70 000 parts of the fibrous reinforcer after ashing.
The length of the fibrous reinforcer in that case is typically in the range from 5 to 1000 μm, preferably in the range from 10 to 600 μm and especially preferably in the range from 20 to 500 μm, determined by means of microscopy with image evaluation after ashing.
The diameter in that case is, for example, in the range from 1 to 30 μm, preferably in the range from 2 to 20 μm and especially preferably in the range from 5 to 15 μm, determined by means of microscopy with image evaluation after ashing.
In a further preferred embodiment, the reinforcer is in platelet form. In the context of the present invention, “in platelet form” is understood to mean that the particles of the at least one reinforcer have a ratio of diameter to thickness in the range from 4:1 to 10:1, determined by means of microscopy with image evaluation after ashing.
Suitable reinforcers are known to those skilled in the art and are selected, for example, from the group consisting of carbon nanotubes, carbon fibers, boron fibers, glass fibers, glass beads, silica fibers, ceramic fibers, basalt fibers, aluminosilicates, aramid fibers and polyester fibers.
Additives as such are likewise known to those skilled in the art. For example, the additive is selected from the group consisting of antinucleating agents, stabilizers, conductive additives, end group functionalizers, dyes, antioxidants (preferably sterically hindered phenols) and color pigments.
An example of a suitable antinucleating agent is lithium chloride. Suitable stabilizers are, for example, phenols, phosphites and copper stabilizers. Suitable conductive additives are carbon fibers, metals, stainless steel fibers, carbon nanotubes and carbon black. Suitable end group functionalizers are, for example, terephthalic acid, adipic acid and propionic acid. Suitable dyes and color pigments are, for example, carbon black and iron chromium oxides.
An example of a suitable antioxidant is Irganox® 245 from BASF SE.
The base body (G) comprises a base surface (F) and an inner flap (I). The base body (G) may optionally also comprise an upper (S) in addition to the base surface (F) and the inner flap (I).
The base surface (F) has an upper side (FO), a lower side (FU) and a first cavity (H1).
The base surface (F), like the insert (E), preferably has a heel end and a toe end. The first cavity (H1) is preferably positioned at the heel end of the base surface (F).
The inner flap (I) has an upper side (IO) and a lower side (IU), wherein the lower side (IU) of the inner flap (I) is joined with the upper side (FO) of the base surface (F) of the base body (G) such that, between the lower side (IU) of the inner flap (I), the upper side (FO) of the base surface (F) and the first cavity (H1), a second cavity (H2) is formed which forms an overall cavity (HG) with the first cavity (H1), wherein the overall cavity (HG) essentially corresponds to the shape of the insert (E).
In the context of the present invention, the expression “essentially correspond to the shape of the insert (E)” is understood to mean that the insert (E) has a shape which corresponds to the shape of the overall cavity (HG) to an extent of preferably at least 90%, more preferably at least 95%, particularly preferably at least 98% and especially 100%, and has a size that corresponds to the size of the overall cavity (HG) to an extent of preferably at least 90%, more preferably at least 95%, particularly preferably at least 98% and especially 100%.
The base body (G) preferably comprises at least one second thermoplastic polymer (TP2). In a preferred embodiment, the at least one second thermoplastic polymer (TP2) differs from the at least one first thermoplastic polymer (TP1).
Preferably, the at least one second thermoplastic polymer (TP2) is selected from the group consisting of impact-modified vinylaromatic copolymers, thermoplastic styrene-based elastomers (S-TPEs), polyolefins (POs), aliphatic-aromatic copolyesters, polycarbonates, thermoplastic polyurethanes (TPUs), polyamides (PAs), polyphenylene sulfides (PPSs), polyaryletherketones (PAEKs), polysulfones and polyimides (PIs), more preferably from thermoplastic styrene-based elastomers (S-TPEs), thermoplastic polyurethanes (TPUs) and polyamides, and particularly preferably from thermoplastic polyurethanes (TPUs).
The thermoplastic polyurethane (TPU) may be prepared by all methods known to those skilled in the art.
In a preferred embodiment, the thermoplastic polyurethane (TPU) is prepared by reacting the following components:
In the context of the present invention, number-average molecular weight MN is determined by means of gel permeation chromatography.
The thermoplastic polyurethane (TPU) preferably has a weight-average molecular weight MW of at least 100 000 g/mol, more preferably of at least 400 000 g/mol and especially preferably of at least 600 000 g/mol. The thermoplastic polyurethane (TPU) also preferably has a weight-average molecular weight MW of at most 800 000 g/mol.
In the context of the present invention, weight-average molecular weight MW is determined by means of gel permeation chromatography.
Furthermore, the base body (G) can additionally also comprise at least one further component selected from the group consisting of reinforcers and additives.
The examples and preferences with respect to the insert (E) are correspondingly applicable here.
In the context of the present invention, the insert (E) is positioned in the overall cavity (HG) such that the lower side (EU) of the surface (EF) of the insert (E) is completely contacted with the upper side (FO) of the base surface (F) of the base body (G).
In the context of the present invention, the term “completely contacted” is understood to mean that the lower side (EU) of the surface (EF) of the insert (E) is contacted with the upper side (FO) of the base surface (F) of the base body (G) preferably to an extent of at least 90%, more preferably to an extent of at least 95%, particularly preferably to an extent of at least 98% and especially to an extent of 100%.
Furthermore, in the context of the present invention, the term “contacts” is understood to mean that the lower side (EU) of the surface (EF) of the insert (E) touches the upper side (FO) of the base surface (F) of the base body (G). However, the lower side (EU) of the surface (EF) of the insert (E) is preferably not irreversibly bonded to the upper side (FO) of the base surface (F). It is, however, also possible for the lower side (EU) of the surface (EF) of the insert (E) to additionally be irreversibly bonded to the upper side (FO) of the base surface (F), for example by adhesive bonding or by thermal welding.
The insert (E) is also positioned in the overall cavity (HG) such that the lower side (IU) of the inner flap (I) completely covers the upper side (EO) of the surface (EF) of the insert (E).
In the context of the present invention, the term “completely covers” is understood to mean that the upper side (EO) of the surface (EF) of the insert (E) is covered by the lower side (IU) of the inner flap (I) preferably to an extent of at least 90%, more preferably to an extent of at least 95%, particularly preferably to an extent of at least 98% and especially to an extent of 100%.
In the context of the present invention, the term “cover” is understood to mean that the upper side (EO) of the surface (EF) of the insert (E) is hidden beneath the lower side (IU) of the inner flap (I). However, the term “cover” is not understood to mean that the upper side (EO) of the surface (EF) of the insert (E) and the lower side (IU) of the inner flap (I) are irreversibly bonded to one another.
It is, however, also possible that the lower side (IU) of the inner flap (I) is additionally irreversibly bonded to the upper side (EO) of the surface (EF) of the insert (E), for example by adhesive bonding or by thermal welding. In a preferred embodiment, however, the lower side (IU) of the inner flap (I) reversibly covers the upper side (EO) of the surface (EF) of the insert (E).
The base body (G) is produced as a single part via a 3D printing process.
In the context of the present invention, the expression “as a single part” is understood to mean that the base body (G) is produced as a single element, comprising a base surface (F) and an inner flap (I), in a single 3D printing process and not by the bonding of individual single elements, i.e. the base surface (F) and the inner flap (I).
If the base body (G) comprises an upper (S) in addition to the base surface (F) and the inner flap (I), in the context of the present invention the expression “as a single part” is understood to mean that the base body (G) is produced as a single element, comprising a base surface (F), an inner flap (I) and an upper (S), in a single 3D printing process and not by the bonding of individual single elements, i.e. the base surface (F), the inner flap (I) and the upper (S).
However, it is also possible that, as described above (upper (S1)), the upper is produced separately, for example via a separate 3D printing process, and for example is stitched to the base body (G) after the latter has been produced. In this case, the upper is understood not to be part of the base body (G).
3D (three-dimensional) printing processes as such are known to those skilled in the art. According to the invention, in principle, all known different 3D printing techniques, such as for example selective laser melting, electron beam melting, selective laser sintering (SLS), the multijet fusion (MJF) process, stereolithography or the fused deposition modeling (FDM) process, can be used. The same also applies analogously to the corresponding starting materials such as powder or filaments, which are applied layer by layer in the respective 3D printing process in order to produce the desired three-dimensional (3D) object.
In the context of the present invention, the 3D printing process is preferably a sintering process, more preferably a selective laser sintering (SLS) process or a multijet fusion (MJF) process.
The provision of the base body (G) via a sintering process preferably comprises the following steps b-1) and b-2):
After step b-2), the layer of the sinter powder (SP) is typically lowered by the layer thickness of the layer of the sinter powder (SP) provided in step b-1) and a further layer of the sinter powder (SP) is applied. This is subsequently sintered again in step b-2).
This firstly bonds the upper layer of the sinter powder (SP) to the lower layer of the sinter powder (SP); in addition, the particles of the sinter powder (SP) within the upper layer are bonded to one another by fusion.
In the process according to the invention, steps b-1) and b-2) can thus be repeated.
By repeating the lowering of the powder bed, the applying of the sinter powder (SP) and the sintering and hence the melting of the sinter powder (SP), the base body (G) is produced. No additional support material is necessary since the unmolten sinter powder (SP) itself acts as a support material.
The particularly preferred 3D printing processes—the selective laser sintering (SLS) process or the multijet fusion (MJF) process—are known to those skilled in the art and are described in detail, for example, in U.S. Pat. No. 4,863,538 (SLS), U.S. Pat. No. 5,658,412 (SLS), U.S. Pat. No. 5,647,931 (SLS) and WO 2015/108543 (MJF).
The sinter powder (SP) typically comprises particles. These particles have, for example, a size (D50) in the range from 10 to 190 μm, preferably in the range from 15 to 150 μm, more preferably in the range from 20 to 110 μm and especially preferably in the range from 40 to 100 μm.
In the context of the present invention, the “D50” is to be understood to mean the particle size at which 50% by volume of the particles based on the total volume of the particles are smaller than or equal to the D50 and 50% by volume of the particles based on the total volume of the particles are larger than the D50.
The sinter powder (SP) typically has a melting temperature (TM(SP)) in the range from 80 to 220° C. Preferably, the melting temperature (TM(SP)) of the sinter powder (SP) is in the range from 100 to 190° C. and especially preferably in the range from 120 to 170° C.
The melting temperature (TM(SP)) is determined in the context of the present invention by means of differential scanning calorimetry (DSC). Typically, a heating run (H) and a cooling run (C) are measured, each at a heating rate/cooling rate of 20 K/min. This gives a DSC diagram. The melting temperature (TM(SP)) is then understood to mean the temperature at which the melting peak of the heating run (H) of the DSC diagram has a maximum.
The present invention also provides a process for producing a high-heeled shoe, comprising the following steps a) to c):
The present invention further provides for the use of an inner flap (I) for completely covering the upper side (EO) of a surface (EF) of an insert (E) in a high-heeled shoe, comprising
The present invention is further illustrated by the following examples without being restricted thereto.
A high-heeled shoe was produced by positioning an insert (E) in the overall cavity (HG) of a base body (G) which comprises a base surface (F) and an inner flap (I), wherein the base surface (F) has an upper side (FO), a lower side (FU) and a first cavity (H1), and the inner flap (I) has an upper side (IO) and a lower side (IU), wherein the lower side (IU) of the inner flap (I) is joined with the upper side (FO) of the base surface (F) of the base body such that, between the lower side (IU) of the inner flap (I), the upper side (FO) of the base surface (F) and the first cavity (H1), a second cavity (H2) is formed which forms an overall cavity (HG) with the first cavity (H1), wherein the overall cavity (HG) essentially corresponds to the shape of the insert (E). The insert comprises a surface (EF) that has an upper side (EO) and a lower side (EU), wherein a heel is formed on the lower side (EU). The insert was produced from polyamide 11 (PA 11) in a selective laser sintering process. The base body (G) was produced from thermoplastic polyurethane in a multijet fusion (MJF) process.
The insert (E) was positioned in the overall cavity (HG) such that the lower side (EU) of the surface (EF) of the insert (E) is completely contacted with the upper side (FO) of the base surface (F) of the base body (G), and the lower side (IU) of the inner flap (I) completely covers the upper side (EO) of the surface (EF) of the insert (E).
The high-heeled shoe was additionally reinforced with a metal insert and a heel cap. An outer sole was also applied by bonding.
A test in accordance with PFI 00/1002 was performed with the high-heeled shoe produced. Even after 100 000 loads with a force of ±120 N, no damage to the high-heeled shoe produced, especially to the heel (A), was detectable visually. This demonstrates the high mechanical stability of the high-heeled shoe according to the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20174967.8 | May 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/062863 | 5/14/2021 | WO |
