Method of manufacturing a sole assembly formed from a plurality of preforms

Abstract

The present invention relates to a method for manufacturing a sole assembly formed from a plurality of preforms. The method includes: arranging a plurality of preforms of different colors together to form a sole assembly preform; and placing the sole assembly preform in a recessed portion of a first portion of a mold assembly. The sole assembly preform is then heated for a predetermined amount of time so that the plurality of preforms bond to each other to form the sole assembly.

Description

[0001] This application is a divisional application of an application filed on April 1, 2015, with application number 201580018491.5 and invention name “Method for manufacturing a sole assembly formed of multiple preforms”.

[0002] Relevant application materials

[0003] This application claims priority to U.S. Utility Application No. 14 / 252,045, filed April 14, 2014, which is hereby incorporated by reference herein in its entirety for all purposes. Technical Field

[0004] Aspects of the present invention generally relate to methods of making a sole assembly, and more particularly, to methods of making a sole assembly formed from a plurality of preforms of different colors. Background Art

[0005] Conventional athletic footwear consists of two main components: an upper and a sole assembly. The upper provides a covering for the foot, comfortably receiving the foot and securely positioning the foot relative to the sole assembly. Additionally, the upper may have a construction that protects the foot and provides breathability, thereby keeping the foot cool and removing perspiration. The sole assembly is secured to the lower portion of the upper and is typically positioned between the foot and the ground. In addition to attenuating ground reaction forces, the sole assembly may, for example, provide traction, control foot motion (e.g., by resisting eversion), and impart stability. Thus, the upper and sole assembly work together to provide a comfortable structure suitable for a wide variety of activities, such as walking and running. The insole may be positioned within the upper and adjacent to the sole (i.e., lower) surface of the foot to enhance the comfort of the shoe and is typically a thin, compressible member.

[0006] The sole assembly may incorporate multiple layers. Some shoes include only a midsole, while others may also include an outsole secured to the bottom surface of the midsole. The midsole is traditionally secured to the shoe upper along its length and is primarily responsible for attenuating ground reaction forces. The midsole may also form the ground-contacting element of the shoe. In such embodiments, the midsole may include textures, such as protrusions and recesses or grooves, to improve traction. The outsole, when present, forms the ground-contacting element and may be made of a durable, wear-resistant material.

[0007] The midsole may be formed primarily of a resilient polymer foam material, such as ethylene vinyl acetate (EVA), that extends the entire length of the shoe. The properties of the polymer foam material of the midsole depend primarily on factors including the spatial configuration of the midsole and the specific characteristics of the material selected for the polymer foam, including the density of the polymer foam material. By varying these factors across the midsole, the relative stiffness and degree of ground reaction force attenuation can be varied to meet the specific requirements of the activity for which the shoe is intended to be used. In addition to the polymer foam material, a conventional midsole may include, for example, one or more fluid-filled bladders and buffers.

[0008] The sole assembly may be formed from multiple parts, some or all of which have different colors. When the EVA is formed in the mold assembly, the boundaries between the different colored parts may become blurred, thereby reducing the aesthetics of the shoe.

[0009] It is desirable to provide a method for manufacturing a sole assembly for an article of footwear that reduces or overcomes some or all of the difficulties inherent in the prior known processes. Specific objects and advantages will become apparent to those skilled in the art (i.e., those knowledgeable or experienced in the art) from the following disclosure of the invention and detailed description of certain embodiments. Summary of the Invention

[0010] The principles of the present invention can be used to advantageously provide a method of manufacturing a sole assembly formed from a plurality of preforms. According to some embodiments, the preforms are of different colors.

[0011] According to a first aspect, a method for forming a sole assembly includes: arranging a plurality of preforms of different colors together to form a sole assembly preform; and placing the sole assembly preform in a recessed portion of a first portion of a mold assembly. The sole assembly preform is heated for a predetermined amount of time so that the plurality of preforms are bonded to each other to form the sole assembly.

[0012] According to another aspect, a method for forming a sole assembly includes arranging a first preform having a first color, a second preform having a second color, and a third preform having a third color together to form a sole assembly preform. The sole assembly preform is placed in a recessed portion of a first portion of a heated mold assembly. The mold assembly is closed so that the second portion of the mold assembly is positioned above and in contact with the first portion. The sole assembly preform is heated for a predetermined amount of time so that the first, second, and third preforms bond to each other to form the sole assembly. The mold assembly is opened and the sole assembly is removed therefrom.

[0013] According to another aspect, a method for forming a sole assembly includes forming a first preform having a first color in a recess of a first mold assembly, the bottom surface of the recess including a plurality of surface irregularities. Forming a plurality of second preforms having a second color in the plurality of first recesses of a second mold assembly. Forming a third preform having a third color in the second recess of the second mold assembly. Arranging the first preform, the second preform, and the third preform together to form a sole assembly preform. Placing the sole assembly preform in the recess of the first portion of a heated third mold assembly. Closing the third mold assembly so that the second portion of the third mold assembly is located above and in contact with the first portion. Heating the sole assembly preform in the third mold assembly for a predetermined amount of time so that the first, second, and third preforms are bonded to each other to form the sole assembly. Opening the third mold assembly and removing the sole assembly therefrom. Allowing the sole assembly to cool and then trimming it.

[0014] This application also provides the following:

[0015] 1) A method for forming a sole component, comprising the following steps:

[0016] arranging a plurality of preforms of different colors together to form a sole component preform;

[0017] placing the sole component preform in a recess in a first portion of a mold assembly;

[0018] closing the mold assembly so that the second portion of the mold assembly is above and in contact with the first portion;

[0019] The sole component preforms are subjected to heat for a predetermined amount of time such that the plurality of preforms are bonded to one another to form a sole component.

[0020] opening the mold assembly; and

[0021] The sole assembly is removed from the mold assembly.

[0022] 2) The method according to 1), wherein the plurality of preforms include a first preform, a second preform, and a third preform.

[0023] 3) The method according to 2), wherein the plurality of preforms includes a plurality of second preforms.

[0024] 4) The method according to 1), wherein the plurality of preforms have different performance characteristics.

[0025] 5) The method of 1), wherein a first preform of the plurality of preforms is formed in a first preform mold assembly.

[0026] 6) The method of 5), wherein a bottom surface of the recess of the first preform mold assembly includes at least one surface irregularity.

[0027] 7) The method according to 6), wherein the at least one surface irregularity comprises one of a protrusion and a recess.

[0028] 8) The method of 1), wherein the second and third preforms of the plurality of preforms are formed in a second preforming mold assembly.

[0029] 9) The method according to 8), wherein the second and third preforms have different colors.

[0030] 10) The method according to 8), wherein a bottom surface of each of the first recess and the second recess of the second preforming mold assembly includes at least one surface irregularity.

[0031] 11) The method according to 10), wherein the at least one surface irregularity on the bottom surface of each of the first recess and the second recess comprises one of a protrusion and a recess.

[0032] 12) A method of forming a sole component, comprising the steps of:

[0033] placing a first preform having a first color, a second preform having a second color, and a third preform having a third color together to form a sole component preform;

[0034] placing the sole component preform in a recess in a first portion of a heated mold assembly;

[0035] closing the mold assembly so that the second portion of the mold assembly is above and in contact with the first portion;

[0036] subjecting the sole component preforms to heat for a predetermined amount of time such that the first preform, the second preform, and the third preform are bonded to one another to form a sole component;

[0037] opening the mold assembly; and

[0038] The sole assembly is removed from the mold assembly.

[0039] 13) The method according to 12), wherein the sole component preform is formed using a plurality of second preforms having the second color.

[0040] 14) The method according to 12), wherein the first preform, the second preform and the third preform have different performance characteristics.

[0041] 15) The method according to 12), wherein the first preform is formed in a first preform mold assembly.

[0042] 16) The method according to 12), wherein the second preform and the third preform are formed in a second preform mold assembly.

[0043] 17) A method of forming a sole component, comprising the steps of:

[0044] forming a first preform having a first color in a recessed portion of a first mold assembly, a bottom surface of the recessed portion including a plurality of surface irregularities;

[0045] forming a second plurality of preforms having a second color in the first plurality of recesses of the second mold assembly;

[0046] forming a third preform having a third color in a second recess of the second mold assembly;

[0047] placing the first preform, the second preform, and the third preform together to form a sole component preform;

[0048] placing the sole component preform in a recess in the first portion of a heated third mold assembly;

[0049] closing the third mold assembly so that the second portion of the third mold assembly is above and in contact with the first portion;

[0050] subjecting the sole assembly preforms in the third mold assembly to heat for a predetermined amount of time such that the first, second, and third preforms bond to one another to form a sole assembly;

[0051] opening the third mold assembly;

[0052] removing the sole assembly from the third mold assembly;

[0053] allowing the sole assembly to cool; and

[0054] The sole assembly is trimmed.

[0055] The reader will further understand the features and advantages of manufacturing sole assemblies for shoes disclosed herein based on the following detailed description of certain embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a front view of an article of footwear including an upper and a sole assembly.

[0057] Figure 2 yes Figure 1 A top view of the bottom of the sole assembly.

[0058] Figure 3 yes Figure 1 A perspective view of a sole assembly in exploded form.

[0059] Figure 4 is used to form Figure 3 A perspective view of a first mold assembly for a core portion of a sole component.

[0060] Figure 5 is used to form Figure 3 A perspective view of a second mold assembly of an insert and perimeter portion of a sole assembly.

[0061] Figure 6 is in a closed position and adjacency Figure 5 Cross-section of the base plate, side wall plate and core plate of the mold assembly.

[0062] Figure 7 is in a closed position and adjacency Figure 5 Cross-section of the bottom plate, side wall plate, core plate and top plate of the mold assembly.

[0063] Figure 8 is a front view of a third mold assembly having a top plate and a bottom plate, shown in exploded form, and also showing the preform before being positioned in the bottom plate.

[0064] Figure 9 yes Figure 8 FIG. 1 is a front view of the third mold assembly showing the preform in the recess of the base plate.

[0065] Figure 10 yes Figure 8 A front view of a third mold assembly shown in a closed state.

[0066] The foregoing drawings are not necessarily drawn to scale and should be understood as providing schematic diagrams of specific embodiments of the present invention and are essentially conceptual diagrams and illustrations of the principles involved. Some features of the mold assembly used to manufacture the sole assembly have been enlarged or distorted relative to other features to facilitate illustration and understanding. In the drawings, the same reference numerals are used for similar or identical components and features shown in various alternative embodiments. The mold assembly for the sole assembly and the method of manufacturing the sole assembly disclosed herein will have a configuration and components determined in part by the intended application and environment in which they will be used. DETAILED DESCRIPTION

[0067] Shoes 10 Figure 1 1 and 14. For ease of reference in the following description, shoe 10 can be divided into three general regions: a forefoot region 16, a midfoot region 18, and a heel region 20. Regions 16-20 are not intended to define precise demarcations between regions of shoe 10. Rather, regions 16-20 are intended to represent general areas of shoe 10 and serve as a reference point during the following discussion. While regions 16-20 apply generally to shoe 10, reference to regions 16-20 may also apply specifically to upper 12, sole assembly 14, or individual components within upper 12 or sole assembly 14.

[0068] Upper 12 defines a void or chamber for receiving a foot. For ease of reference, upper 12 includes a lateral side 22, an opposite medial side 24, and a vamp or instep area 26. Lateral side 22 is configured to extend along the lateral side (i.e., the outside) of the foot and generally pass through each of zones 16 to 20. Similarly, medial side 24 is configured to extend along the opposite medial side (i.e., the inside) of the foot and generally pass through each of zones 16 to 20. Upper 12 may also include a closure mechanism, such as a lace 28. Upper 12 also includes an ankle opening 30 that allows the foot to access the void within upper 12.

[0069] The upper 12 may also include an insole (or sockliner, not shown), which is typically a thin, compressible member disposed within the void that receives the foot and adjacent to the lower surface of the foot. Typically, the insole, which is configured to enhance the comfort of the shoe, may be formed of foam, and optionally, the foam may be covered with a moisture-wicking fabric or textile material. Furthermore, the insole or sockliner may be glued or otherwise attached to the other components of the shoe 10, if desired, although it need not be attached.

[0070] For example, the sole assembly 14 may be secured directly to the upper 12 using an adhesive. Suitable adhesives are well known in the art and need not be discussed in detail herein. Any other suitable fastening means may be used to secure the sole assembly 14 to the upper 12, and those skilled in the art will readily appreciate other suitable means of securing the sole assembly 14 to the upper 12 after reading this disclosure.

[0071] It should be understood that in some embodiments, sole assembly 14 can function as a midsole, with an outsole (not shown) secured to the bottom surface of the midsole. In other embodiments, as shown herein, the bottom surface of sole assembly 14 functions as the ground-engaging portion (or portion that engages other contact surfaces) of shoe 10.

[0072] The sole assembly 14 is responsible for attenuating the reaction forces of the ground (or other contact surface) to reduce stress on the foot and leg and absorb energy. The sole assembly 14 can also beneficially transfer such ground reaction forces to achieve a more efficient toe-off maneuver and control potentially harmful foot movements, such as eversion. The sole assembly 14 also forms the portion of the sole assembly 10 that engages the ground (or other contact surface). As described above, in some embodiments, there is a separate outsole member attached to the bottom surface of the midsole of the sole assembly 14, while in other embodiments, there is no separate outsole member of the sole assembly. The bottom surface of the sole assembly 14 may include texture to improve traction.

[0073] The sole assembly 14 is formed from multiple components of different colors. The method for forming the sole assembly from multiple preforms of different colors can reduce color bleeding between the different colored parts, thereby enhancing the aesthetics of the sole assembly 14. In addition to different colors, the multiple components can also have different physical properties or performance characteristics. For example, the hardness of various components can be different. It should be understood that any known physical property or performance characteristic of the sole assembly can be different for different components of the sole assembly 14, thereby changing, for example, the support, cushioning, load-bearing capacity, wear characteristics, and tread life of the sole assembly 14. Other suitable physical properties or performance characteristics will become apparent to those skilled in the art after reading this disclosure.

[0074] like Figure 2 , sole assembly 14 includes a first core portion 32, one or more inserts 34, and a perimeter portion 36. Core portion 32 is formed of a first color, inserts 34 are formed of a second color, and perimeter portion 36 is formed of a third color. While three colors are used in this embodiment, it should be understood that any number of different colors may be used for the various components of sole assembly 14, depending on the manufacturing method described below.

[0075] In certain embodiments, the core portion 32, the insert 34, and the perimeter portion 36 may be formed from injection phylon (ethylene vinyl acetate or "EVA"). The EVA may have a vinyl acetate (VA) content of between about 9% and about 40%. For example, suitable EVA resins include those provided by DuPont. and Engage, provided by Dow Chemical Company. In certain embodiments, the EVA can be formed from a combination of a high melt index material and a low melt index material. For example, the EVA can have a melt index between about 1 and about 50.

[0076] The EVA may also contain various components, including a blowing agent. The blowing agent may have a weight percentage between about 10% and about 20%. For example, a suitable blowing agent includes azodicarbonamide. In certain embodiments, a peroxide-based curing agent, such as dicumyl peroxide, may be used. The amount of curing agent may be between about 0.6% and about 1.5%. The EVA may also contain a leveling agent, a processing aid, and a wax. For example, a mixture of light aliphatic hydrocarbons, such as 60NS. EVA may also contain other components such as mold release agents (eg, stearic acid), activators (eg, zinc oxide), fillers (eg, magnesium carbonate), pigments, and clay.

[0077] like Figure 2 As shown, perimeter portion 36 can form the entire outer perimeter 38 of sole assembly 14. In other embodiments, perimeter portion 36 can form only a portion of outer perimeter 38. As shown here, perimeter portion 36 can also completely surround outer perimeter 40 of core portion 32. As shown here, insert 34 can be completely surrounded by and contained within core portion 32.

[0078] The preforms of the components of the sole assembly 14 are Figure 3 . As shown therein, the core preform 32' includes ribs 42 that extend downwardly from a lower surface 44 and define a plurality of internal recesses 46. Each insert preform 34' is configured to be positioned or received in one of the internal recesses 46. The ribs 42 also define a shoulder 48 that extends around at least a portion of the core preform 32'.

[0079] An aperture 50 extending through the perimeter portion preform 36' defines an inner lip 52 that is positioned on the shoulder 48 of the core portion preform 32'. Figure 2 As shown, in the finished product of the sole assembly 14 , the surface of the aperture 50 abuts the outer perimeter of the rib 42 .

[0080] As here Figure 3 As shown, surface irregularities 53 may be formed in the lower surfaces of the core portion preform 32', the insert preform 34', and the perimeter portion preform 36'. The surface irregularities 53 may take any desired shape. In the illustrated embodiment, the surface irregularities 53 include a plurality of grooves 55 and lugs or protrusions 57, which form a grid of hexagonal protrusions 57 with corresponding grooves 55 surrounding the protrusions, as shown in FIG. Figure 2 1 and 2. This is more clearly shown in the sole assembly 14 of FIG. Surface irregularities 53 may serve both aesthetic and performance purposes.

[0081] A method of forming a sole assembly 14 that reduces color bleeding between the colors of the core portion preform 32', the insert preform 34', and the perimeter portion preform 36' will now be described. Figure 4 As shown, a first preform mold assembly 54 for forming a core portion preform 32' includes an upper plate 56 and a lower plate 58. The upper plate 56 and the lower plate 58 can be rotatably fixed to each other by a hinge 60. A protrusion 61 extending downward from the upper plate 56 and a lower recess 62 formed in the lower plate 58 cooperate to define a core recess 63. As shown here, the first preform mold assembly 54 includes two core recesses 63 so that the core portion preform 32' can be formed for both the left and right sole assemblies at the same time.

[0082] When the core portion preform 32' is formed in the first preform mold assembly 54, the recess 64 formed in the bottom of the core recess 63 is used to form the rib 42. The recess 64 may include surface irregularities 66 that are used to form the mating surface irregularities 53 in the lower surface of the rib 42, as described above in conjunction with Figure 2 As stated.

[0083] A core portion preform 32' is formed in a known manner in the core recess 63 of the first preform mold assembly 54 while heated EVA is inserted into the core recess 63. The resulting EVA core portion preform 32' is later combined with the insert preform 34' and the perimeter preform 36' to form the sole assembly 14, as described in more detail below.

[0084] Figure 5 The second preforming mold assembly 68 is shown for forming the insert preform 34' and the perimeter portion preform 36'. The second preforming mold assembly 68 includes a bottom plate 70, a top plate 72, a core plate 73 disposed below the top plate 72, and a sidewall plate 74 disposed between the bottom plate 70 and the core plate 73. The plates of the second preforming mold assembly 68 are connected by hinges 76. A protrusion 78 extending downwardly from the core plate 73, an aperture 80 extending through the sidewall plate 74, and a recess 82 formed in the top surface of the bottom plate 70 cooperate to define a first or insert recess 84 and a second or perimeter recess 86, as shown. Figure 6 and Figure 7 As shown there, the second preform mold assembly 68 includes two sets of insert recesses 84 and two perimeter recesses 63 to simultaneously form the insert preform 34' and perimeter portion preform 36' for both the left and right sole assemblies.

[0085] The surface irregularities 88 formed in the bottom surface of the recess 82 serve to form the mating surface irregularities 53 in the lower surfaces of the insert 34 and the perimeter portion 36, as described above with respect to the core portion 32 and the combined portion. Figure 2As stated.

[0086] For illustrative purposes, the perimeter portion preform 36' is shown here in the right side recess 82 of the base plate 70 with the insert preform 34' positioned therein and formed in the second preforming mold assembly 68. It should be understood that any number of insert preforms 34' may be formed in the second preforming mold assembly 68. In the illustrated embodiment, there are three insert preforms 34' used to form the sole assembly 14. It should be understood that a single insert preform 34' or any number of insert preforms 34' may be used to form the sole assembly 14.

[0087] like Figure 6 As shown, the side wall panels 74 and the core panel 73 are pivoted downward onto the bottom panel 70 into a closed position. The heated EVA for forming the perimeter portion preform 36' is then injected through the first door 90 formed in the core panel 73, as shown by arrow A. The EVA for the perimeter portion preform 36' is thereby disposed within the perimeter recess 63.

[0088] After the heated EVA is injected into the perimeter recess 63, the top panel 72 is then pivoted downward onto the core panel 73 into a closed position. The heated EVA for forming the insert portion 34' is then injected into the insert recess 84 through the second door 92 formed in the top panel 72 and the core panel 73. Thus, the configuration of the second preform mold assembly 68 allows for the simultaneous formation of two different colors of injected EVA material to form both the insert preform 34' and the perimeter portion preform 36'.

[0089] All preforms (ie, core portion preform 32', insert preform 34', and perimeter portion preform 36'), each having a different color, are then preassembled into a single sole assembly preform 94. Figures 8 to 10 As shown, this one-piece sole assembly preform 94 formed of all three colors of material is then placed in a single step into a recess 96 formed in a heated bottom plate 98 of a third mold assembly 100, as indicated by arrow C. Once the sole assembly preform 94 is positioned in the recess 96, the top plate 102 of the third mold assembly 100 is placed on the bottom plate 98, thereby closing the third mold assembly 100. The sole assembly preform 94 is then heated within the third mold assembly 100 for a predetermined duration to bond the core portion preform 32', the insert preform 34', and the perimeter portion preform 36' to one another, thereby forming the sole assembly 14.

[0090] In some embodiments, third mold assembly 100 is maintained at a temperature between approximately 170° C. and 180° C. for approximately 10 minutes. The specific temperature and duration used to form sole assembly 14 in third mold assembly 100 may vary in a known manner, depending on the specific EVA used.

[0091] In a known manner, the sole assembly 14 will expand after being removed from the third mold assembly 100. The sole assembly 14 is then subjected to typical stabilization steps, including cooling and finishing, as required.

[0092] By inserting the entire unitary preform 94 into recess 96 simultaneously, all of the material begins to melt simultaneously upon insertion into third mold assembly 100 , so that bleeding between different colored portions of preform 94 is reduced when forming sole assembly 14 .

[0093] In certain embodiments, as Figure 2 As shown and described above, the surface irregularities 53 can form a defined pattern. As shown in the embodiment illustrated here, the surface irregularities 53 form a grid of hexagonal protrusions 57 with corresponding grooves 55 formed around the protrusions 57. In this embodiment, it may be advantageous to have boundaries between the different colors, that is, the color lines between the core portion 32, insert 34, and perimeter portion 36 do not exactly match or coincide along the edges of the protrusions 57 or grooves 55. If an attempt is made to align the color lines with the edges of the protrusions 57 or grooves 55, any bleed between the different colors will be more noticeable. If the color lines span the protrusions 57, rather than just along the perimeter of the protrusions 57, the user's eye will be less likely to notice the bleed.

[0094] Thus, while the essential novel features of various embodiments have been shown, described, and pointed out, it will be understood that various omissions, substitutions, and modifications in the form and details of the illustrated apparatus, as well as in its operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, the present invention expressly contemplates that all combinations of those elements and / or steps which perform substantially the same function in substantially the same manner to achieve the same results are within the scope of the present invention. The present invention also fully contemplates and contemplates the substitution of elements from one described embodiment to another. It is therefore intended that the present invention be limited only as indicated by the scope of the appended claims.

Claims

1. A method of forming a sole assembly, comprising the steps of: Arranging a plurality of preforms together to form a single sole component preform, the plurality of preforms having different colors from one another, wherein the plurality of preforms include a first preform, a second preform, and a third preform; wherein in the sole component preform: (a) the first preform is formed of ethylene vinyl acetate, wherein a lower surface of the first preform includes: (i) a first internal recess, wherein an outer periphery of the first internal recess is surrounded by a rib formed as part of the first preform, and (ii) a shoulder extending around at least a portion of the rib and positioned on a side of the rib opposite the first internal recess, (b) the second preform is formed of ethylene vinyl acetate and is received in the first interior recess on the lower surface of the first preform, and (c) the third preform is formed of ethylene vinyl acetate and includes: (i) an aperture extending through the third preform, the rib of the first preform being received in the aperture, and (ii) an inner lip positioned on the shoulder of the first preform, wherein the shoulder of the first preform is surrounded by the aperture; placing the sole component preform in a recess in a first portion of a mold assembly; closing the mold assembly so that the second portion of the mold assembly is above and in contact with the first portion; subjecting the sole component preforms to heat for a predetermined amount of time such that the plurality of preforms bond to one another to form a sole component; opening the mold assembly; and The sole assembly is removed from the mold assembly. The method of claim 1 , wherein the plurality of preforms have different performance characteristics. 3 . The method of claim 1 , wherein the first preform of the plurality of preforms is formed in a first preform mold assembly. 4 . The method of claim 3 , wherein a bottom surface of the recess of the first preform mold assembly includes at least one surface irregularity. The method of claim 4 , wherein the at least one surface irregularity comprises one of a protrusion and a recess. 6 . The method of claim 1 , wherein the second preform and the third preform of the plurality of preforms are formed in a second preform mold assembly. 7 . The method of claim 6 , wherein a bottom surface of each of the first recess and the second recess of the second preform mold assembly includes at least one surface irregularity. 8 . The method of claim 7 , wherein the at least one surface irregularity on the bottom surface of each of the first recess and the second recess comprises one of a protrusion and a recess.

9. A method of forming a sole component, comprising the steps of: placing a first preform having a first color, a second preform having a second color, and a third preform having a third color together to form a sole component preform; Wherein in the sole component preform: (a) the first preform is formed of ethylene vinyl acetate, wherein a lower surface of the first preform includes: (i) a first internal recess, wherein an outer periphery of the first internal recess is surrounded by a rib formed as part of the first preform, and (ii) a shoulder extending around at least a portion of the rib and positioned on a side of the rib opposite the first internal recess, (b) the second preform is formed of ethylene vinyl acetate and is received in the first interior recess on the lower surface of the first preform, and (c) the third preform is formed of ethylene vinyl acetate and includes: (i) an aperture extending through the third preform, the rib of the first preform being received in the aperture, and (ii) an inner lip positioned on the shoulder of the first preform, wherein the shoulder of the first preform is surrounded by the aperture; placing the sole component preform in a recess in a first portion of a heated mold assembly; closing the mold assembly so that the second portion of the mold assembly is above and in contact with the first portion; subjecting the sole component preforms to heat for a predetermined amount of time such that the first preform, the second preform, and the third preform are bonded to one another to form a sole component; opening the mold assembly; and The sole assembly is removed from the mold assembly.

10. The method of claim 9, wherein the sole component preform is formed using a plurality of second preforms having the second color.

11. The method of claim 9, wherein the first preform, the second preform, and the third preform have different performance characteristics.

12. The method of claim 9, wherein the first preform is formed in a first preform mold assembly.

13. The method of claim 9, wherein the second preform and the third preform are formed in a second preform mold assembly.

14. A method of forming a sole component, comprising the steps of: forming a first preform having a first color in a recess of a first mold assembly, the bottom surface of the recess including a plurality of surface irregularities, wherein the step of forming the first preform includes forming the first preform to include a lower surface having: (a) a plurality of internal recesses, wherein an outer periphery of each of the plurality of internal recesses is surrounded by a rib formed as part of the first preform, and (b) a shoulder extending around at least a portion of the rib and positioned on a side of the rib opposite the plurality of internal recesses; forming a second plurality of preforms having a second color in the first plurality of recesses of the second mold assembly; forming a third preform having a third color in a second recess of the second mold assembly, wherein the step of forming the third preform includes forming an aperture extending through the third preform; disposing the plurality of second preforms in the plurality of interior recesses on the lower surface of the first preform, and disposing the third preform relative to the first preform such that the apertures of the third preform abut and surround an outer periphery of the ribs of the first preform, wherein the disposing step places the first preform, the plurality of second preforms, and the third preform together to form a sole assembly preform; placing the sole component preform in a recess in the first portion of a heated third mold assembly; closing the third mold assembly so that the second portion of the third mold assembly is above and in contact with the first portion; subjecting the sole assembly preform in the third mold assembly to heat for a predetermined amount of time such that the first preform, the second preform, and the third preform bond to one another to form a sole assembly; opening the third mold assembly; removing the sole assembly from the third mold assembly; allowing the sole assembly to cool; as well as The sole assembly is trimmed.

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