A method of forming an upper for a shoe

Abstract

A method of forming a shoe upper comprising providing a shoe last with a lower portion 104 in the shape of a shoe and an upper portion 102 extending from the lower portion, forming a material layer 11

Description

FIELD OF THE INVENTION The present invention relates to a method of forming a shoe. In particular, the present invention relates to a method of forming an upper for a shoe. BACKGROUND Traditional methods for creating shoe uppers often involve processes, including cutting, stitching, and moulding various materials to achieve the desired shape and structure. More recently, additive manufacturing techniques such as 3D printing have been explored as alternatives for shoe upper production. However, these methods come with their own set of challenges and limitations, including cost, complexity, and material constraints. The traditional method of cutting, sewing, and lasting (where a sewn upper is pulled over a last to mould it into shape) offers versatility. However, this technique is labour-intensive and requires a high level of technical expertise. Consequently, it often results in prolonged production lead times and is predominantly confined to specialized shoemaking regions. The substantial labour costs associated with this process have led to numerous reports of labour exploitation as manufacturers attempt to mitigate expenses. Additionally, cutting upper patterns from flat materials generates significant waste due to the material leftover in-between spaces. One of the primary challenges in 3D printing shoes lies in achieving the desired balance between print speed, material quality, and cost. 3D printing shoes can be time-consuming on expensive machinery, especially for large batches. Improving print speed and cost efficiency while achieving a textual quality of a generally acceptable level for consumers is a constant challenge in 3D printing. Moreover, developing scalable production processes that can accommodate both individual customization and large-scale manufacturing is complex. Injection moulding is another technique used to create uppers or entire shoes. This process involves injecting molten polymer into an aluminium mold, which is then split apart to remove the formed product. While this method is cost-effective for large-scale production, the complex aluminium moulds are prohibitively expensive for smaller quantities. Additionally, the products manufactured through injection moulding are typically favoured by consumers for situations where exposure to water is likely, such as jelly shoes or pool slides, or for protective footwear like Wellington boots used in wet and muddy conditions. 3D knitting is another technique for creating shoe uppers, utilizing yarn or thread knitted into the desired shape. This method can be cost-effective due to the large amount of automation and rapid production speed. The distinctive knit is particularly desirable for athletic footwear, as it is lightweight and offers improved breathability, allowing air to circulate with relative ease. However, this same quality may be less desirable for everyday footwear, where greater protection from the external elements is often required. It is an object of the present invention to provide an alternative technique for forming an upper for a shoe. SUMMARY OF INVENTION According to first aspect of the invention, there is provided a method of forming an upper for a shoe. The method comprising providing a shoe last having a lower portion generally in the shape of a shoe and an upper portion, wherein the upper portion extends from the lower portion. The method further includes forming a material layer on the upper and lower portions of the shoe last; and folding down the material layer formed on the upper portion of the shoe last so that it overlaps the material layer formed on the lower portion of the shoe last in order to form the upper. In some arrangements the upper portion of the shoe last may also be generally in the shape of a shoe, and the upper portion of the shoe last may be arranged upside down relative to the lower portion. In this way, a method of creating an upper is achieved which allows the creation of an upper in an efficient and swift manner without requiring time consuming, inefficient, and expensive conventional manufacturing techniques. The overlapping of one layer over another enables the easy formation of multiple layers while also allowing for the desired characteristics such as texture for an upper’s air-facing side to be achieved in a straightforward and rapid manner. In some arrangements, if the upper still needs further shaping to conform to the final desired shape the upper should represent, then the formed upper is transferred from the shoe last to another last that forms the shape of the final design. Preferably, forming the material layer comprises dipping the shoe last in a bath of material to form the material layer and drying the material layer. By dipping the shoe last in the bath and then drying the material layer, different layers of an upper can be formed quickly, eliminating the need for time consuming and inefficient conventional manufacturing methods. The dipping of the shoe last enables the control of densities of different layers along the cross section of the upper. By folding down the layers formed by the dipping bath it is possible to achieve faster construction of the upper with significantly reduced wastage of raw material when compared to conventional manufacturing methods. Preferably, the material formed on the lower portion of the shoe last is different to the material formed on the upper portion of the shoe last. The different material of the material layers can provide different properties throughout a cross section of the upper being formed. In this way, layers of an upper with desired functionalities can be easily formed. For instance, the material layer on the upper portion of the shoe last can be made of waterproof or water-repellent material to create an air-facing side that prevents water from seeping into the shoe. Additionally, using a different material layer on the lower portion of the shoe last can result in a soft inner layer that provides comfort to the wearer. Consequently, shoes suitable for wet weather conditions can be manufactured efficiently without compromising the wearer's comfort. Preferably, one or more external components are sandwiched between the material layer on the lower portion and the folded down material layer formed on the upper portion. In this way, components, such as paddings and / or reinforcements can be sandwiched between the formed layers, which facilitates the creation of an upper with desired functionalities. The incorporation of additional components in this manner allows for customized upper formation to meet various shoe specifications without necessitating significant alterations to the manufacturing process. Preferably, the method further comprising attaching the material layer formed on the lower portion and the folded down material layer formed on the upper portion. Preferably, a portion of the material layer is formed on a top surface of the upper portion of the shoe last in order to form a latching feature that can latch onto a bottom surface of the lower portion of the last when the material is folded down. The step of covering at least a portion of a top surface of the upper portion of the shoe last is performed before the step of forming the material layer such that the covered portion of the top surface is not provided with a material layer, thereby to form the latching feature. The latching feature facilitates the clipping of the material layer at the top surface onto the bottom surface of the lower portion of the shoe last when the material layer of the upper portion is folded down, thereby aiding in the adhesion of the material layer on the lower portion and the folded down material layer of the upper portion. For instance, the folded down material layer of the upper portion and the material layer on the lower portion can be attached together using any suitable adhesive, heat welding, or crosslinking mechanism, which is further reinforced through the latching feature, thereby enhancing a bond between the folded down material layer and the material layer on the lower portion. Preferably, the upper portion comprises a textured outer surface and the layer of material formed on the upper portion forms an inverse of the textured outer surface. Thus, a desired texture of an air-side surface of an upper is achieved in an easy and efficient manner which may include embossed features. According to second aspect of the invention, a shoe last is provided. The shoe last comprises a lower portion and an upper portion, wherein the lower portion and the upper portion are in the shape of a shoe or having a shape that corresponds to an upper that would form a shoe. The upper portion extends from the lower portion and is arranged upside down relative to the lower portion. Preferably, the upper portion comprising a textured outer surface. According to a third aspect of the invention, a shoe is provided. The shoe comprising a sole attached to an upper, wherein the upper is formed by the method as disclosed above in the first aspect of the invention. BRIEF DESCRIPTION OF DRAWINGS Embodiments of the invention are now described, by way of example, with reference to the drawings, in which: Figure 1A is a schematic cross-sectional side view of a shoe last, in an embodiment of the present invention; Figure 1B is another schematic cross-sectional side view of the shoe last of Figure 1A having a material layer; Figures 1C is another schematic cross-sectional side view of the shoe last of Figure 1A having a raised middle portion on a top surface; Figures 1D is another schematic cross-sectional side view of the shoe last of Figure 1A during a process in which the material layer is folded; Figure 1E is another schematic cross-sectional side view of the shoe last of Figure 1A showing a further step in the process in which the material layer from the upper portion is folded and attached to the lower portion; Figure 1F is another schematic cross-sectional side view of the shoe last of Figure 1A showing a further step in the process in which external components are sandwiched between the material layer folded from the upper and a material layer formed on the lower portion; and Figure 1G is another schematic cross-sectional side view of the shoe last of Figure 1A illustrating different properties of material layers formed on the shoe last. DETAILED DESCRIPTION Typically, a shoe last (also known as a last) is a mold that can be either solid or hollow, designed with a three-dimensional, 3D, shape which is used to shape an upper of a shoe to be created. In the present invention, a shoe last 100 comprises an upper portion 102 in the shape of a shoe and a lower portion 104 also in the shape of a shoe, as shown in figure 1 A. Although the upper portion 102 and the lower portion 104 have been shown in the shape of a shoe, they may also have a shape that differs from that of a shoe. The upper portion 102 extends from the lower portion 104 and is arranged upside down relative to the lower portion 104. As shown in figure 1A, a neck portion 108 of the lower portion 104 is attached to a neck portion 106 of the upper portion 102 when the upper portion 102 is arranged upside down relative to the lower portion 104 so that the upper portion 102 extends from the lower portion 104. The shoe last 100 comprises a top surface 112 opposite to the neck portion 106 of the upper portion 102 and a bottom surface 110 opposite to the neck portion 108 of the lower portion 104. A material layer 114 is formed on both the upper portion 102 and the lower portion 104, as illustrated in Figure 1B. Specifically, the material layer 114 is formed on the upper portion 102 and the lower portion 104, as well as the bottom surface 110 of the shoe last 100. However, only a portion of the material layer 114 is formed on the top surface 112 to form a latching feature (described in detail below with respect to figure 1D). The material layer 114 may be any one or combination of a variety of dippable materials or materials able to be applied to a three-dimensional, 3D, surface, such as non-woven textiles, fibres, engineered foams, polymers, synthetic leathers, and the like. In one example, forming the material layer 114 involves dipping the shoe last 100 into a bath of the desired material and then drying it. The shoe last 100 is first submerged into the material bath to ensure a uniform coating on outer surfaces of the upper portion 102 and the lower portion 104, along with the bottom surface 110 and a portion of the top surface 112. Upon withdrawal, the coated shoe last 100 undergoes a drying process to solidify the material layer 114. The drying process may involve air drying or heat drying the material layer 114. By dipping the shoe last 100 in the bath and then drying the material layers formed on the shoe last 100, multiple layers of an upper can be formed quickly, eliminating the need for complex conventional upper manufacturing techniques. Dipping the shoe last ensures a uniform application of the material leading to consistent thickness and coverage, which enhances the structural integrity and aesthetic of the shoe. In one example, a portion 120 of the top surface 112 is covered before forming the material layer 114 on the upper portion 102, thereby resulting in formation of the material layer 114 only on a front edge 118a and a rear edge 118b at the top surface 112. Alternatively, once the material layer 114 is formed on whole of the top surface 112, the material layer corresponding to the portion 120 is cut-out to reveal the material-free portion 120 of the top surface 112. In another embodiment, the top surface 112 of the upper portion 102 is provided with a raised middle portion 122. In this arrangement, during the dipping process the top surface 112 is only partially submerged. As illustrated in figure 1C, the upper portion 102 is dipped into the bath in such a way that the material is deposited only on the front edge 118a and the rear edge 118b, without any material being deposited on the raised middle portion 122. This process results in the creation of the material-free portion 120 of the top surface 112. In figure 1B, it appears that the portion of the material layer 114 covers only the front edge 118a and the rear edge 118b of the top surface 112 of the shoe last 100. However, figure 1B is a cross-sectional view and the portion of the material layer 114 is in fact provided on edges around the full perimeter of the top surface 112 of the shoe last 100. The portion of the material layer 114 formed on the top surface 112 is not limited only to the edges 118a and 118b, and in fact any area of the top surface 112 can be covered by the material layer 114. Folding down the layers formed by the dipping bath facilitates faster construction of the upper with significantly reduced wastage of raw material as compared to the conventional upper manufacturing methods. Dipping the shoe last 100 results in less material waste since excess material can drip off and be reused or collected. In one example, the same material layer 114 is formed on both the upper portion 102 and the lower portion 104, as illustrated in figure 1B. For explanatory purposes, the material layer formed on the upper portion 102 is referred to as 114a and the material layer 114 formed on the lower portion 104 is referred to as 114b, as also illustrated in figure 1D. Once the material layers 114a and 114b are dried following the dipping of the shoe last 100 in a bath, the solidified material layer 114a on the upper portion 102 is pulled off (illustrated in figure 1D) from the upper portion 102 and is folded down (illustrated in figure 1E) to overlap the material layer 114b of the lower portion 104 of the shoe last 100 in order to form an upper of a shoe. When the material layer 114a is to be folded down, the material layer 114a is hinged at a point 116 where the neck portions 106 and 108 of the upper portion 102 and the lower portion 104, respectively, are attached to each other. The hinge point 116 is selected to ensure that the entire material layer 114a of the upper portion 102 overlaps the entire material layer 114b of the lower portion 104. The dipping of the shoe last 100 in a bath to create material layers 114a and 114b, and subsequently overlapping the material layer 114a over the material layer 114b facilitates easy formation of multiple layers while affording enhanced control over the thickness of the upper. In one example, a greater number of layers could be formed towards the top portion 112 and the bottom portion 110 of the last as compared to the neck portions 106 and 108. For instance, once the upper portion is dipped in a bath, the layer 114a is formed as discussed above. However, the upper portion 102 can be dipped again but in a controlled manner such that only a portion around the top surface 112 is dipped into the bath, resulting in more than one material layer 114a being formed only around the top surface 112. Similarly, more than one layer 114b can be formed on the portion around the bottom surface 110. This would result in an upper having a thickness increasing towards the bottom portion as compared to the neck portion, thereby leading to the upper having an enhanced structural integrity at the foot section and an improved breathability at the ankle section. In another example, different material layers may be formed on the upper portion 102 and the lower portion 104, respectively. The upper portion 102 may be dipped in a bath of the desired material without dipping the lower portion 104 to form the material layer 114a. For instance, the material layer 114a on the upper portion of the shoe last can be made of waterproof or water-repellent material to create an air-facing side that prevents water from seeping into the shoe. In figure 1G, a zoom-in on a cross section of the formed material layers on the upper portion 102 shows that the formed material layers on the upper portion 102 have different properties across a cross section of the upper created by dipping of the shoe last 100 several times into baths of different materials. As illustrated in figure 1G, the formed layer 130 represents a water repellent clear coating, the formed layer 132 represents an aesthetic or coloured visible layer, and the formed layer 132 represents a non-visible fibrous layer offering a tear resistance to the upper. In the arrangement of figure 1G, it will be appreciated that the upper portion of the shoe last 102 has a different shape to the lower portion 104 in order to create desirable features in the upper. The skilled person will appreciate that various shapes may be provided for the upper and lower shoe last portions in order to provide different shapes and different aesthetic designs. Once the material layer 114a is dried, the lower portion 104 may be dipped in a bath of a material different than the material used for the material layer 114a, without dipping the upper portion 102 having the formed layer 114a. For instance, the second material layer 114b can be of a soft non-woven material to form a softer inner layer that provides comfort to the wearer. Subsequently, the formed layer 114a on the upper portion 102 is folded down on the softer inner layer 114b formed on the lower portion 104 in order to form an upper which is having the water-proof material at the air-facing side and a softer inner layer at a skin-facing side. Consequently, shoes suitable for wet weather conditions can be manufactured efficiently without compromising the wearer's comfort. In this way, layers of an upper with desired functionalities can be easily formed leading to an improved manufacturing of a shoe. As illustrated in figure 1E, when the material layer 114a formed on the upper surface 102 is folded down, the portion of the material layer formed on the top surface 112 overlaps a portion of the bottom surface 110 of the shoe last 100. Since the material layer 114a is formed only on a portion of the top surface, i.e., only at the edges 118a and 118b (as shown in figure 1B) at the top surface 112, the folded down material layer 114a overlaps the material layer 114b up to edges 118c and 118d at the bottom surface, thereby allowing the material layer 114a to latch onto the edges 118c and 118d at the bottom surface 110. Therefore, the portion of the material layer 114a formed on the top surface 112 provides the latching feature which allows the material layer 114a overlapping the material layer 114b to latch onto the bottom surface 110 of the shoe last. The latching feature aids in the adhesion of the material layer 114b on the lower portion and the folded down material layer 114a of the upper portion. For instance, the folded down material layer 114a of the upper portion 102 and the material layer 114b of the lower portion can be attached together using any suitable adhesive, heat welding, or cross-linking mechanism, which is further reinforced through the latching feature, thereby enhancing a bond between the folded down material layer 114a and the material layer 114b. Therefore, in this way, a method of creating an upper is achieved which allows to create an upper in an efficient and swift manner, providing a desirable alternative to conventional manufacturing techniques. In one example, external components such as padding or reinforcements are sandwiched between the material layer 114b and the folded down material layer 114a. The incorporation of such components facilitates the creation of an upper with desired functionalities effortlessly and allows for customized upper formation to meet various shoe specifications without necessitating significant alterations to the manufacturing process. As illustrated in figure 1F, a foam 128 and stiffeners 124 have been sandwiched between the material layer 114b and the folded down material layer 114a. To accommodate the foam 128, the upper portion 102 is designed to have a notch 126 such that when the material layer 114a is formed and subsequently folded down over the material layer 114b, the material layer 114a would be having a recess to accommodate the foam 128 therein. In one example, the material layer 114b can be attached to the folded down material layer 114a using any suitable adhesives, heat welding, or cross-linking mechanism. Once, the folded down material layer 114a is attached to the material layer 114b, the bottom surface 110 could be attached to a sole through stitching and / or gluing. In one example, the outer surface of the upper portion 102 of the shoe last 100 is textured or embossed or includes other design features. When the material layer 114a is folded down, an inverse of the first material layer 114a becomes an air-facing side of the upper. Due to the textured outer surface of the upper portion 102, the final airfacing side of the upper is also formed being textured. Therefore, the formation of the upper's air-facing side with desired characteristics is facilitated in a straightforward and rapid manner.

Claims

1. A method of forming an upper for a shoe, the method comprising:providing a shoe last having a lower portion that is generally in the shape of a shoe and an upper portion, wherein the upper portion extends from the lower 5 portion;forming a material layer on the upper portion and the lower portion of the shoe last; andfolding down the material layer formed on the upper portion of the shoe last so that it overlaps the material layer formed on the lower portion of the shoe last in 10 order to form the upper.

2. The method of claim 1, wherein forming the material layer comprises: dipping the shoe last in a bath of material to form the material layer; and drying the material layer.

153. The method of any one of the preceding claims, wherein the material formed on the lower portion of the shoe last is different to the material formed on the upper portion of the shoe last.20 4. The method of claim 3, wherein the different material of the material layersprovides different properties throughout a cross section of the upper being formed.

5. The method of any one of the preceding claims further comprising sandwiching one or more external components between the material layer on the 25 upper portion and the material layer on the lower portion.

6. The method of any one of the preceding claims further comprising attaching the material layer formed on the lower portion and the folded down material layer formed on the upper portion.

307. The method of any one of the preceding claims, wherein a portion of the material layer is formed on a top surface of the upper portion of the shoe last in orderto form a latching feature that can latch onto a bottom surface of the lower portion of the last when the material is folded down.

8. The method of claim 7 further comprising the step of covering at least a 5 portion of a top surface of the upper portion of the shoe last before the step of forming the material layer such that the covered portion of the top surface is not provided with a material layer, thereby to form the latching feature.

9. The method of any one of the preceding claims, wherein the upper portion 10 comprising a textured or embossed outer surface and the layer of material formed on the upper portion forms an inverse of the textured outer surface.15

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