WO2003051614A2

WO2003051614A2 - A mould

Info

Publication number: WO2003051614A2
Application number: PCT/GB2002/005777
Authority: WO
Inventors: Chris Towns
Original assignee: C & J Clark International Limited
Priority date: 2001-12-19
Filing date: 2002-12-19
Publication date: 2003-06-26
Also published as: AU2002352450A1; GB0130297D0; WO2003051614A3

Abstract

A mould having an inner chamber of a predetermined shape and size, and an outer chamber of predetermined shape and size, the inner and outer chambers being in fluid communication with one another.

Description

A MOULD

This invention relates to a mould for forming an item of footwear or a component thereof, to a footwear or footwear component formed from such a mould, and to a method of forming a composite structure using the mould.

The term "footwear" is used herein to refer to any type of footwear, for example to include shoes, sandals and boots.

It is well known that a shoe is formed from an upper portion, and a lower portion known as a sole having an external surface and an internal surface.

It is known to cover the internal surface of the sole with an insole, and in turn to cover the insole of the shoe with an under-foot layer. Optionally a mid sole may be positioned beneath the insole.

The insole is positioned above the sole, and the uppers forming the shoe are attached to the insole.

In other embodiments of known shoes, no insole is present, and the uppers and any under-foot layers are attached directly to the sole.

The unαer-ioot layer may be fixed in a way which does not allow easy removal from the insole. Alternatively it may be positionable on the insole in such a way that it is readily removable by a wearer. This may be advantageous since it allows the under-foot layer to be washed periodically and then returned to the shoe. Alternatively it allows a wearer to replace the under-foot layer with a more comfortable or better fitting under-foot layer.

The under-foot layer thus provides an interface between a wearer's foot and the insole. As such the under-foot layer should be soft but also mouldable to a shape which supports the foot of a wearer. At the same time it should have sufficient strength to withstand forces applied to it by a wearer during use of the shoe.

It is known to make an under-foot layer entirely from a polymer, typically from polyurethane (PU), or ethyl vinyl acetate (EN A). These materials are relatively cheap, soft and flexible. As they are moulded, they also offer a designer freedom to style the under-foot layer or to add functional features such as air channels or supportive pads. Such materials however result in under-foot layers which are relatively impermeable to sweat. They can therefore cause problems due to the fact that sweat may be held in contact with the skin of a wearer's foot.

It is therefore also known to form a under-foot layer from two pieces of material, the first piece of material defining the overall shape of the under-foot layer, and a second piece of material which maybe inserted into the first piece of material which is known as an insertion. Typically, the first piece of material is made from a plastics material such as polyurethane, and the insertion is formed from a material such as felt which has been cut out to have a shape appropriate to fit into the particular under-foot layer. In particular, the insertion material is a non-woven felt or similar permeable material. Felts used to form an insertion may be made from fibres of polyester, nylon, viscose, wool and similar materials. Most typically these felts are made from polyester which has a relatively low cost and high durability. In addition, more expensive materials such as a mixture of 70% wool and 30% viscose may also be used. This particular mix of material is typically used by podiatrists in medical applications.

Alternatively, the insertion maybe made from a highly porous (open celled) foam.

Whilst the felt provides comfort to the wearer, it is not sufficiently rigid to maintain a particular shape or to be moulded into a shape which will support the foot of a user. It is therefore known to reinforce the felt insertion with a polymer such as polyurethane which adds rigidity to the under-foot layer. The combination of the felt and the polymer provides strength and comfort to the under-foot layer.

The presence of the felt results in a under-foot layer which is permeable to sweat thus overcoming, or at least reducing problems associated with sweat.

The polymer provides areas of extra shock absorption, as felt does not absorb much energy on impact. In addition, the polymer provides areas of extra and durable support, as felt will collapse over time. Further, the presence of the polymer provides dimensional stability, as the fibre of felt can migrate, causing deformation.

Finally, the presence of the polymer allows the addition of air channels to be included in the under-foot layer, along with other aesthetic or functional design features which majj e moulded into the ^ polymer.

It is known to form a under-foot layer having a felt insertion by using an adhesive which is painted or rolled onto the felt in the areas where it is required to bond the felt to the remainder of the under-foot layer.

Once the adhesive has been painted or rolled onto the felt it must be allowed to sink in. This process is imprecise and time consuming.

In addition, many adhesives are environmentally unfriendly and have a tendency to migrate through the product in wear. This results in areas of highly polished thin polymer on the surface of ajoining components of a shoe.

In other words, the known method of forming a under-foot layer having a felt insertion requires the insertion and the polymer portion to be moulded in separate moulding processes, and to then bind the felt insertion to the polymer portion.

According to a first aspect of the present invention there is provided a mould for forming an item of footwear, or a component thereof formed from a composite material comprising a porous material and a pourable material, the mould having a first chamber of a predetermined shape and size and adapted to receive the non- woven material, and a second chamber of predetermined shape and size, the first and second chambers being in fluid communication with one another, the second chamber comprising an inlet through which the pourable material may be injected or poured into the second chamber, the mould being shaped such that on passing from the second chamber to the first chamber the flow of the pourable material is reduced before entry into the first chamber.

The invention may be used to form any one of a number of components forming an item of footwear, or may even be used to form a completed item of footwear. The invention is particularly useful for forming an under-foot layer which may comprise a footbed, an insole, a mid sole or an out sole.

It has previously been thought impossible to form a under-foot layer of this type using only a moulding process. This is because existing moulds and mould techniques are not suitable for forming such a product. Using known techniques, the mould is shaped to define a cavity having substantially the same size and shape as the under-foot layer. The mould is usually formed in two parts, a bottom mould part and a top mould part each shaped to define a recess. When the two parts of the mould are combined the mould is completed and the two recesses together define the cavity.

A felt insertion is placed in the recess formed by one of the mould portions, and then the mould is closed by placing the second portion over the first portion. A polymer such as polyurethane (PU) is then poured or injected into the mould to completely fill the parts of the cavity not already occupied by the felt insert. The polyurethane would thus flood the entire cavity and would come into contact with the felt.

As a result, the polyurethane impregnates the felt, reducing the flexible properties of the felt. This in turn creates a hard plastic edge to the felt which would cause discomfort to the user when wearing the shoe. In the areas where the polyurethane mix contacted the felt, a composite material would be formed, with the fibres of the felt becoming locked in the polyurethane foam matrix. These areas would then become hard and uncomfortable. They also exhibit low breathability and form barriers to moisture dispersal within the final under-foot layer.

A mould according to the first aspect of the present invention is particularly suitable for forming a under-foot layer. A piece of porous material suitably shaped to form part of a under-foot layer can be placed in the first chamber of the mould, such a piece of material is known as an insertion.

The insertion is preferably formed from a non-woven material and typically is formed from felt. The insertion is separated from the second chamber except where the first and second chambers are in fluid communication with one another. It is thus possible to pour or inject a pourable material such as a polymer, for example polyurethane (PU) initially into the second chamber. The polyurethane will then flow from the second chamber into the first chamber. By the time the polymer enters the first chamber, its flow has slowed, and it is less likely to cause damage to the insertion. The second chamber thus effectively separates the pourable material emerging from, for example, an injector, from the first chamber where the porous material is receivable. This feature is very different to features found in known moulds and known moulding techniques where any attempt to moderate the flow of for example a polymer is carried out in order to ensure that the temperature and/or pressure of the polymer is as high as possible when reaching the chamber defining the shape of the finished product formed from the polymer. In known moulds, by ensuring that the polymer remains at a lower viscosity, disadvantageous features such as "cold weld" lines and air trapping can be avoided.

Preferably, the first chamber comprises an inner chamber, and the second chamber comprises an outer chamber, although in certain embodiments the first chamber could be the outer chamber and the second chamber could be the inner chamber.

Preferably the pourable material comprises a polymer such as polyurethane.

Preferably, the porous material comprises a non- woven material such as felt.

The porous material may also comprise woven or knitted materials.

For example the porous material may comprise Poliyou (registered trademark of Jones and Nining) a porous foam or spacer knit fabrics (produced by Heathcoats of Tiverton, UK), which are highly porous knitted fabrics. Another suitable material is synthetic weave article A904, containing antibacterial treatment 'Amicor' (woven by Lenzi Egisto of Naiano, Italy) which is a woven textile with beneficial properties.

In other known moulds it is known to have an inner chamber and an outer chamber. However in the outer chamber in such known moulds comprises the injection piston and typically holds uncured polymer or rubber which is to be injected under pressure from the injection piston into an inner chamber defining the shape of a finished product.

Thus, by means of the present invention, an additional chamber (the second chamber) exists within a mould which effectively represents an intermediate area between an injection piston or other receptacle for holding a pourable material before introducing the pourable material into the mould, and the first chamber.

Many different moulding techniques maybe used in conjunction with a mould according to the first aspect of the present invention. The moulding techniques that are suitable for use with the present invention make use of polymers which have a relatively low viscosity when introduced to the mould, and a relatively high viscosity after the process is complete. Suitable moulding processes therefore include: thermoplastic/reactive injection moulding, reactive/thermoplastic casting, and some forms of compression moulding. In other words any moulding process that involves using a material that starts in a plastic form and changes into an elastic form, will be suitable. The polymer forms a bond with the felt from which the insertion is formed primarily via a mechanical bond. In other words, the polymer advances (to a limited extent) into the felt and then solidifies. This causes a number of the fibres of the felt to become entangled in the solidified polymer. A fraction of these fibres is not fully entangled in the polymer, and they have a portion of their length which is outside the polymer. The portion which is outside of the polymer is, in most cases entangled with the other fibres forming the felt. As a result, the felt is substantially attached to the polymer.

In addition, some polymers form a chemical bond with some fibres when they are bought into contact with the fibres. This type of bond makes the entanglement of the fibres in the polymer much easier, but does not greatly influence the overall strength of the attachment between the felt and the polymer.

The overall strength of attachment is related to both the entanglement of the fibres in the polymer and the entanglement of these trapped fibres with the other fibres in the felt.

Preferably, the mould comprises an outer wall defining a cavity comprising the first chamber and the second chamber, and further characterised by an inner wall spaced apart from the outer wall which inner wall defines the first chamber, the inner wall comprising at least one aperture extending between the first chamber and the second chamber. The at least one aperture extending between the first chamber and the second chamber thus allows fluid communication between the two chambers.

Advantageously the mould comprises: a first mould portion having a first outer wall, and a first inner surface and defining a first recess; a second mould portion having a second outer wall and a second inner surface and defining a second recess; the two mould portions when brought together forming the mould, the two recesses together defining the cavity; characterised in that the first mould portion has an inner wall spaced apart from the first outer wall and defining an inner recess, and an outer recess such that when the two mould portions are brought together, the first chamber is defined between the inner wall and the first and second inner surfaces, and the second chamber is defined between the outer wall the inner wall and the first and second inner surfaces.

An advantage of forming the mould from two portions, is that the process of placing, for example, an insertion into the inner chamber is greatly simplified in that this may be carried out when the mould is open and the mould portions are not connected to one another. Further, once the moulding process has been completed, a finished product, such as a under-foot layer insertion may be removed from the mould by separating the two mould portions.

The second mould portion may also comprise an inner wall which in some embodiments may also comprise at least one aperture. The mould is formed so that the shape of the first chamber is substantially the same size and shape as the insertion. This means that when an insertion is placed in the mould and the mould is closed, the inner surface of the second mould portion will be in contact with or very closely adjacent to an upper surface of the insertion. Similarly, the inner surface of the first mould portion will be in contact with, or closely adjacent to a lower surface of the insertion.

This in turns means that when the polymer enters the first chamber via the one or more apertures in the inner wall, the extent to which it makes contact with either the upper or lower surfaces of the felt is limited.

In addition, the polymer is prevented from randomly seeping into the felt or from extending substantially over a top or bottom surface of the felt.

This may result in the polymer forming a "rim" around the insertion which provides strength to the insertion.

Advantageously, the inner wall comprises a plurality of apertures positioned at spaced apart intervals along the length of the wall.

This means that on injecting polymer into the second chamber via the inlet, the polymer will gain access to the first chamber via each of the plurality of apertures. By the time the polymer makes contact with the felt the temperature and pressure of the polymer will have fallen, and melting of the felt will be prevented or at least reduced. In addition, as the polymer makes contact with the felt, it is forced into the felt due to the pressure applied to the polymer through the injection moulding process. This results in a plurality of elongate portions of polymer in the form of arms extending from the polymer into the felt forming the insertion in the manner described hereinabove with reference to mechanical bonding.

It is to be understood, however, that different ways of effecting communication between the first and second chambers are possible.

In other embodiments of the invention, the interface between the felt forming the insertion and a polymer may be in the form of a continuous rim extending around at least some of the edge of the felt.

The outer wall defines the overall shape of the under-foot layer.

Advantageously, an insert is receivable within the first mould portion of the mould, and a piece of a second material is receivable within the second mould portion of the mould.

The second material advantageously comprises a sheet of leather which is attached to the second inner surface of the second mould portion.

When molten polymer is introduced into the inner chamber, it attaches to a surface of the leather sheet remote from the second inner surface. An under-foot layer formed in this manner comprises a leather cover which will come into contact with the wearer when an item of footwear is in use. An under-foot layer made in this way is stronger than conventional under foot layers. The surface of the layer which comes into contact with a wearer is flatter than when the leather cover is applied in conventional ways. This makes the under foot layer more comfortable for a wearer.

According to a second aspect of the present invention there is provided a method of manufacturing a composite structure comprising the steps of: determining a required shape and size of the structure; forming a mould having a first chamber having a lower surface and an upper surface and having substantially the required shape and size of the structure, and a second chamber, the first chamber being in fluid communication with the second chamber and the second chamber comprising an inlet; placing a first material within the first chamber of the mould; introducing a pourable material into the second chamber of the mould via the inlet, the pourable material flowing from the second chamber into the first chamber to bond with the material, to form the composite structure, characterised in that the method further comprises the step of controlling the flow the of pourable material into the inner chamber so that flow of the pourable material slows before entering the first chamber.

Preferably, the method comprises the further step of attaching a second material to the upper surface of the first chamber prior to injecting the pourable material into the second chamber of the mould. Preferably, the step of introducing the pourable material into the second chamber comprises injecting the pourable material into the second chamber.

Preferably, the pourable material comprises a material which is initially in a plastic form and evolves into an elastic form.

Conveniently, the pourable material comprises a polymer for example polyurethane.

Advantageously, the first chamber comprises an inner chamber, and the second chamber comprises an outer chamber.

Advantageously, the second material is a sheet of leather.

According to a third aspect of the present invention there is provided a footwear component having a predetermined shape, and having an outer portion formed from a pourable material, and an inner layer formed from a porous material, the inner and outer portions being bonded together by a moulding process.

Preferably the porous material is a non- woven material. Conveniently the non-woven material is felt.

Advantageously, the pourable material comprises an initially plastic material which evolves into an elastic material.

The porous material may also comprise woven or knitted materials. For example the porous material may comprise Poliyou (registered trademark of Jones and Nining) a porous foam or spacer knit fabrics (registered trademark of Heathcoats of Tiverton, UK), which are highly porous knitted fabrics. Another suitable material is synthetic weave article A904, containing antibacterial treatment 'Amicor'

(woven by Lenzi Egisto of Naiano, Italy) which is a woven textile with beneficial properties.

During the moulding process, the polymer bonds with the inner portion to form a rim which may be either continuous or discontinuous.

By means of the present invention it is possible therefore to form a under-foot layer in which the insertion is bonded to the outer portion of the under-foot layer by a rim of polymer extending substantially along the entire edge of the felt.

The invention will now be further described by way of example only with reference to the accompanying drawings in which:

FIG. 1 is a schematic representation of a portion of a known mould using a standard co-moulding technique to form a under-foot layer formed from polymer and a felt insertion;

FIG. 2 is a schematic representation of the known mould of Figure 1 showing the positioning of the felt insertion before the mould is closed; FIG. 3 is a cross-sectional representation of the mould of Figure 1 showing the mould in a closed position;

FIG. 4 is a cross-sectional representation showing the extent of polyurethane seepage into the felt insertion when a standard co- moulding technique is used;

FIG. 5 is a schematic representation of a part of a mould according to an embodiment of the invention;

FIG. 5a is a detail of the inner wall of the mould of Figure 5;

FIG. 6 is a schematic representation of a portion of the mould of Figure 5;

FIG. 7 is a cross-sectional representation of the mould of Figure 5 with the mould in an open position;

FIG. 8 is a cross-sectional representation of the mould of Figure 5 with the mould in a closed position.

FIG. 9 is a cross-sectional representation of part of the mould of Figure 5 showing the apertures formed in the inner wall of the bottom mould portion;

FIG. 10 is a schematic representation of part of the mould of Figure 5 showing the mould in the closed position; and FIG. 11 is a schematic representation of part of a under-foot layer formed from the mould of Figure 5 showing the way in which the PU bonds with the insertion.

FIG. 12a and 12b are schematic representations from above and below respectively of a under-foot layer according to an aspect of the present invention;

FIG. 13 is a schematic representation of a part of a under-foot layer of Figures 12a and 12b;

FIG. 14 is a plan view of an under-foot layer incorporating an insert formed by a mould according to the first aspect of the present invention;

FIG. 15 is a cross sectional representation along the line A- A of Figure 14 of the under-foot layer;

FIG. 16 is an under-foot layer for a right foot incorporating insert formed from a mould according to the first aspect of the present invention;

FIG. 17 is a plan view of a second embodiment of the present invention incorporating an upper leather layer covering the under- foot layer similar to that shown in Figure 14;

FIG. 18 is a cross sectional representation of a mould used to form the insert for the under-foot layer shown in Figure 17; FIG. 19 is a schematic representation of two halves of a mould according to the present invention in which an upper layer of leather is added to the mould;

FIG. 20 is a schematic representation of an under-foot layer incorporating an insertion formed from a mould according to the present invention; and

FIG. 21 is a second embodiment of an under-foot layer showing a different form of the insertion

A known mould will be described briefly with reference to Figures 1 to 4. As has been previously mentioned, a known under-foot layer would not be suitable for making a under-foot layer of the type herein described. However, there will now be described the method that would be used if a under-foot layer were formed using the known mould. The mould 1 comprises a lower mould portion 2 and an upper mould portion 3. The mould is formed by bringing the lower and upper mould portions into contact with one another to define a cavity 4 having a predetermined shape appropriate for a particular under-foot layer.

A felt insertion which has previously been cut out into an appropriate shape is positioned within the cavity 4. As can be seen particularly from Figure 1, the insertion 5 is smaller than the cavity 4, and thus the insertion does not make contact with the sides of the wall 6 defining the cavity in the bottom portion 2 of the mould. In order to make the under-foot layer, the upper portion 3 is brought into contact with the lower portion 2 as shown in Figure 3. When the two portions are in contact with one another, a molten polymer such as polyurethane (PU) is injected into the mould and flows through the entire cavity 4. Because of the force with which the PU enters the cavity 4, the PU seeps into the felt in a random manner as shown in Figure 4. This adversely effects the properties of the insertion.

Turning now to Figures 5 to 13, a mould according to the present invention will be described and is designated generally by the reference numeral 10. The mould 10 comprises two mould portions, a lower mould portion 11 and an upper mould portion 12.

The lower mould portion comprises an outer wall 13 and an inner wall 14. The outer wall 13 defines the shape of the under-foot layer.

The inner wall 14 defines a recess 15 having a predetermined shape. The recess 15 is shaped so that a piece of material 16 forming an insertion for a under-foot layer just fits within the recess 15. When the material 16 is positioned in the recess, a lower surface of the material is in contact with the surface 17 of the recess 15, and edges

18 of the material are in contact with inner surface 19 of the wall 14.

The inner wall 14 and the outer wall 13 are spaced apart from one another so that a channel 20 is defined between the two walls 13, 14. In order to close the mould, the upper mould portion 12 is brought into contact with the lower mould portion 11 as shown in Figure 8. The material 16 is thus completely confined within an inner chamber formed by the recess 15 and a surface 21 A (Figure 9) of the upper mould portion 12. The inner wall 14 is formed with apertures 22 positioned at spaced apart intervals along the length of the wall 14 thus forming a plurality of communication channels between the inner chamber 21 and the channel 20.

The inner wall 14 is dimensioned such that is extends to substantially the same height as the height of the material 16. This means that the apertures expose portions of the edge 18 of the material 16.

In use, a polymer such as polyurethane is injected into the mould via an input port 100 . The molten polymer is injected under pressure into the outer chamber defined between the outer wall 13 and an inner wall 14 of the lower mould portion 11. The molten polymer is able to gain access to the inner chamber 21 via the apertures 22. Due to the dimensions of the inner chamber 21, the polymer makes limited contact only with the material 16.

Due to the force under which the molten polymer is injected, a stream of polymer will be forced through each of the apertures and extend some distance into the material as shown in Figure 11. Once the polymer has solidified, a plurality of "arms" 24 will be formed.

Each of the arms 24 is formed by the polymer passing through a respective aperture. The bond formed between the polymer and the felt is primarily a mechanical bond as explained hereinabove. The bond between the polymer and felt is formed because the polymer forms small "puddles" in the felt as the polymer is forced through each of the apertures. The size of these "puddles" is limited and is related to the size of the apertures which causes the polymer to cool and cure, increasing its viscosity. Because the polymer has to travel some distance in the outer chamber, before it makes contact with the material 18, its temperature and pressure will have dropped before it makes contact with the material and so the material will not melt when the polymer makes contact with it.

In addition, the polymer cannot indiscriminately seep through the material, and so the properties of the material stay relatively intact.

In the illustrated embodiment the polyurethane is injected at a temperature of approximately 45°C. This results in a peak in-mould temperature of approximately 90°C, although peak temperatures of up to 100°C are feasible. The pressure under which the polyurethane is injected is between 0.5 and 2 bars. The mould clamping force is 5 to 10 tonnes, and the in-mould cure time is 2 to 3.5 minutes. The post mould cure time is 48 to 72 hours.

Referring to Figures 12a, 12b and 13, a under-foot layer according to the present invention is illustrated. The under-foot layer 110 has an overall shape which is defined by the outer wall 13 of the mould

(Figure 5). The under-foot layer comprises an outer portion 120 which is formed from a polymer which in this example is polyurethane. The under-foot layer further comprises an insertion 130, the shape of which is defined by the inner wall 14 (Figure 5).

The insertion 130 and the outer portion 110 are bonded together during the moulding process as described herein and in accordance with the method of the present invention. Whilst it is possible to form a under-foot layer from a single layer having an outer portion 120 and an insertion 130 as shown in Figure 1 lb, it is also possible to form an insertion by joining together two such layers to form a laminate in which the insertion is sandwiched between two layers of polymer 120.

Referring now to Figures 14, 15 and 16, an under-foot layer including an insertion according to the present invention is illustrated schematically. The under-foot layer comprises an insertion 140 and a plurality of air channels 142 which serve to ventilate the foot of a user during use. The under-foot layer further comprises apertures 144 which also form part of the ventilation system.

In the embodiment shown in these figures, an upper layer 146 made of leather forms part of the under-foot layer. The leather top cover

146 comprises a plurality of apertures 148 which form part of the ventilation system and some further markings 150 which are present for aesthetic reasons.

Referring particularly to Figure 15, it can be seen that the under-foot layer 140 comprises a non-woven layer in the form of for example felt 152 surrounded by polyurethane 154. The under-foot layer further comprises the leather top cover 146 which extends across the whole of the under-foot layer.

Turning now to Figure 18 a mould suitable for forming the underfoot layers in Figures 14 and 17 is shown. The mould 180 comprises an upper mould portion 182 and a lower mould portion 184. The upper and lower mould portions 182, 184 define a first chamber 186 and a second chamber 188. Positioned in the first chamber is a felt insert 190. Molten polymer is injected into the second chamber 188 from an injection piston 190. As described in detail herein above, communication between the first chamber and the second chamber is such that the flow of the polymer reduces substantially before the polymer enters the first chamber 186. The mould is shaped so that a sheet of leather may be positioned to cover a lower surface 194 of the upper mould portion and may be held in position by shoulders 196, 198 formed between the upper mould portion 182 and the lower mould potion 184.

Turning now to Figure 19, a sheet of leather 199 is shown just before attachment to the upper mould portion 182. In this embodiment the leather sheet 190 is attached to the upper mould portion by means of pegs 200.

Turning now to Figure 20 an insert formed by a mould according to the present invention is designated generally by the reference numeral 300. The insert comprises a non-woven portion 320 and a polymer portion 330.

Turning now to Figure 21 a further embodiment of an insert formed according to the present invention is designated generally by the reference numeral 340. In this embodiment the insert comprises two polymer portions 360, 380 each surrounded by a non-woven material

390. By means of the present invention it is possible to form inserts having a wide range of different shapes of porous material and pourable material portions.

Claims

1. A mould for forming an item of footwear, or a component thereof formed from a composite material comprising a porous material and a pourable material, the mould having a first chamber of a predetermined shape and size and adapted to receive the non- woven material, and a second chamber of predetermined shape and size, the first and second chambers being in fluid communication with one another, the second chamber comprising an inlet through which the pourable material may be injected or poured into the second chamber, the mould being shaped such that on passing from the second chamber to the first chamber the flow of the pourable material is reduced before entry into the first chamber.

2. A mould according to Claim 1 wherein the porous material comprises a non- woven material.

3. A mould according to Claim 2 wherein the non- woven material comprises felt.

4. A mould according to Claim 1 wherein the porous material comprises a knitted material.

5. A mould according to Claim 1 wherein the porous material comprises a woven material.

6. A mould according to any one of the preceding claims wherein the pourable material has an initial plastic state which evolves into a later elastic state.

7. A mould according to any one of the preceding claims wherein the pourable material comprises polymer.

8. A mould according to Claim 7 wherein the polymer comprises polyurethane.

9. A mould according to any one of the preceding claims wherein the first chamber comprises an inner chamber and a second chamber comprising an outer chamber.

10. A mould according to any one of the preceding claims comprising an outer wall defining a cavity comprising the inner chamber and the outer chamber, and further characterised by an inner wall spaced apart from the outer wall, which inner wall defines the inner chamber, the inner wall comprising at least one aperture extending between the inner chamber and the outer chamber.

11. A mould according to Claim 10 comprising: a first mould portion having a first outer wall, and a first inner surface and defining a first recess; a second mould portion having a second outer wall and a second inner surface, and defining a second recess; the two mould portions when brought together forming the mould, the two recesses together defining the cavity; characterised in that the first mould portion has an inner wall spaced apart from the first outer wall and defining an inner recess, and an outer recess such that when the first two mould portions are brought together, the inner chamber is defined between the inner wall and the first and second inner surfaces, and the outer chamber is defined between the outer wall, the inner wall and the first and second inner surfaces

12. A mould according to Claim 10 or Claim 11 wherein the inner wall comprises a plurality of apertures positioned at spaced apart intervals along the length of the wall.

13. A mould according to any one of the preceding claims further comprising a second material receivable within the second mould portion of the mould.

14. A mould according to Claim 13 wherein the second material comprises a sheet of leather which is attached to the second inner surface of the second mould portion.

15. A method of manufacturing a composite structure comprising the steps of: determining a required shape and size of the structure; forming a mould having a first chamber having a lower surface and an upper surface and having substantially the required shape and size of the structure, and a second chamber, the first chamber being in fluid communication with the second chamber and the second chamber comprising an inlet; placing a first material within the first chamber of the mould; introducing a pourable material into the second chamber of the mould via the inlet, the pourable material flowing from the second chamber into the first chamber to bond with the material, to form the composite structure, characterised in that the method further comprises the step of controlling the flow the of pourable material into the inner chamber so that flow of the pourable material slows before entering the first chamber.

16. A method according to Claim 15 comprising the further step of attaching a second material to the upper surface of the first chamber prior to injecting a pourable material into the second chamber of the mould.

17. A method according to Claim 15 or Claim 16 wherein the step of introducing the pourable material into the second chamber comprises injecting the pourable material into the second chamber.

18. A method according to any one of Claims 15 to 17 wherein the pourable material comprises a material which is initially in a plastic form and which evolves into an elastic form.

19. A method according to any one of Claims 15 to 18 wherein the pourable material comprises a polymer.

20. A method according to Claim 19 wherein the polymer comprises polyurethane.

21. A method according to any one of Claims 15 to 20 wherein the first chamber comprises an inner chamber and the second chamber comprises an outer chamber.

22. A method according to any one of Claims 15 to 21 wherein the second material comprises a sheet of leather.

23. A method according to any one of Claims 15 to 22 wherein the porous material comprises a non-woven material.

24. A method according to any one of Claims 15 to 23 wherein the non- woven material comprises felt.

25. A method according to any one of Claims 15 to 22 wherein the porous material comprises a knitted material.

26. A method according to any one of Claims 15 to 22 wherein the porous material comprises a woven material.

27. A footwear component having a predetermined shape, and having an outer portion formed from a pourable material, and an inner layer formed from a porous material, the inner and outer portions being bonded together by a moulding process.

28. A footwear component according to Claim 27 wherein the porous material is a non-woven material.

29. A footwear component according to Claim 28 wherein the non- woven material is felt.

30. A footwear component according to any one of Claims 27 to

29 wherein the porous material comprises a knitted material.

31. A footwear component according to any one of Claims 27 to 29 wherein the porous material comprises of woven material.

32. A footwear component according to any one of Claims 27 to

31 wherein the polymer is bonded to the porous material by means of arms of polymer extending into the porous material.

33. A footwear component according to any one of Claims 27 to

32 wherein the polymer is polyurethane.

34. A mould substantially as herein before described with reference to the accompanying drawings.

35. A method of manufacturing a under-foot layer substantially as hereinbefore described with reference to the accompanying drawings.

36. A footwear component substantially as hereinbefore described with reference to the accompanying drawings.