WO1992016119A1

WO1992016119A1 - Seamless waterproof article

Info

Publication number: WO1992016119A1
Application number: PCT/CA1992/000106
Authority: WO
Inventors: Kevin G. Parkinson
Original assignee: Parkinson Kevin G
Priority date: 1991-03-12
Filing date: 1992-03-12
Publication date: 1992-10-01
Also published as: AU1368792A

Abstract

This invention pertains to a seamless resilient waterproof article which can be worn by a human being. More particularly, this invention relates in one aspect to a resilient waterproof boot, or glove which is formed in one piece, can be fitted over a human foot or hand without a zipper and is useful for aquatic activities. A process of manufacturing a seamless resilient article which comprises: (a) heating a mold in the shape of the article to an elevated temperature; (b) immersing the mold in a first elastomer dispersion and partially curing the coating of the elastomer; (c) immersing the mold and the first elastomer coating in a second elastomer dispersion and partially curing the coatings of the elastomer; and (d) removing the article from the mold.

Description

SEAMLESS WATERPROOF ARTICLE

This invention pertains to a seamless resilient waterproof article which can be worn by a human being. More particularly, this invention relates in one aspect to a resilient waterproof boot or glove which can be fitted over a human foot or hand without a zipper and is useful for aquatic activities.

Aqua boots and gloves are widely used for various aquatic activities, and notably sports activities such as water-skiing, windsurfing, surfing, scuba diving, and the like. The boots and gloves are usually formed of shaped rubber-cloth pieces which are sewn together. The seams are then covered by flexible sealant, to waterproof them. Notwithstanding, it is common for aqua boots, in particu¬ lar, to develop leaks after use and become water absorbent. The seams represent weak points in the boot and can develop leaks, particularly after stretching. The seams can also be abrasive to the foot. Such boots, under hard use, expand with water intake, do not conform closely to the foot and often require zippers in order to enable the boot to be put on or removed from the foot, yet contour to the ankle. The zippers are also a leak source. Also, wet surface is slippery and tread on boot sole does not always effectively increase coefficient of friction.

The invention pertains to a seamless one-piece, elastomeric, waterproof boot having an ankle, foot and sole, comprising: (a) a first layer having an ankle, foot and sole formed of a pliable, resilient, highly stretchable material; (b) a second layer overlying the foot and sole area of the first layer, the second layer being formed of a flexible material, stiffer than the material of the first layer; and (c) a third layer overlying the sole of the second layer, the third layer being constructed of an anti- slip foamed wear-resistant material. The third layer can be^■ formed of a porous open- cell elastomer and a cushioned anti-slip sole can be bonded to the exterior of the third layer. The first layer, second layer and third layers can be formed of different formulations with the same type of elastomer or different compatible elastomers systems.

Polyvinylchloride plastisol may form a suitable elastomer dispersion for manufacturing the above-mentioned wares. The first layer may cover only the foot and sole and a woven fabric inner liner can be located within the first layer. A pattern can be embossed into the exterior of the third layer of the boot while the third layer is still moldable.

The plastisols can be formed of a vinylchloride polymer, a pthalate ester plasticizer, an adipate ester plasticizer, a borium cadmium zinc stabilizer, an organic phosphite and an organic pigment. The difference between the formulation plastisol used in the first and second layers may be in the amount of incorporated plasticizer and possible different grade of PVC polymer. The third layer can be formed of a vinylchloride polymer, a pthalate ester plasticizer, a zinc stabilizer, an organic phosphite, an azobisdicarbonamide foaming agent, a molecular sieve, and an organic pigment.

The plastisol dispersion for the first dip can be formulated to provide a stretchy resilient coating which can be readily stretched over a human foot. The plastisol dispersion for the second dip can be formulated to provide a relatively tough, rigid intermediate layer over the sole area to provide dimensional stability and to resist stretching at the sole of the boot. The plastisol for the third dip can be formulated to produce a resilient, wear resistant open cell foam which can absorb water and provide gripping action even on wet surfaces. The mold can be dipped in the first, second or third plastisol dispersions one or more times as required to form the type of article that is required.

The mold can be heated to about 380"F and can be in the shape of a foot or an ankle and foot. The mold can be the shape of any other part of the human anatomy, for example, the hand.

Figure 1 illustrates a side view of a three layer high top waterproof boot according to the invention;

Figure 2 illustrates a side view of an alterna¬ tive construction of a three layer ankle cut waterproof shoe according to the invention.

Figure 3 illustrates a side view of a mold which can be used to form the waterproof footwear according to the invention.

Figure 4 illustrates a side sequential view of the process of forming a high top waterproof boot by dipping a heated mandrel in the shape of an ankle and foot in a series of liquid elastomer dispersion, and curing the boot. The mold is inverted after each dipping operation to reduce possible sagging of uncured elastomer and improve product thickness uniformity.

Figure 5 illustrates a side section view of a mold with a three layer plastisol waterproof high top boot formed thereon.

Figure 6 illustrates a side section view of the mold with a neoprene inner boot and elastomeric upper and lower sole. Figures 1, 2, 3, 4, 5 and 6 illustrate specific embodiments of the invention. As seen in Figure 1, the high top boot 2, well above ankle height, is constructed to have a resilient throat 10, a resilient body 12, a dimen- sionally stable upper sole 14, and an open-cell resilient walking sole 16.

Figure 2 illustrates a side view of a shoe type boot 20 with a low resilient throat 22, resilient foot body 24, upper dimensionally stable sole 26 and cushion open- cell resilient walking sole 28.

Figure 3 illustrates a side view of a hollow aluminum mold 30 (the hollow being indicated by dotted lines) which is used to form the inner part of the water¬ proof footwear such as the boot 2 illustrated in Figure 1 or the boot 20 illustrated in Figure 2. Aluminum is preferred because it has high heat conductivity, it is neutral to most elastomeric dispersions and it is free to air absorption. In the mold shown in Figure 3, the thickness of the mold is uniform. However, if desired or preferred, the thickness of the mold walls can be varied to provide areas having different heat absorption capacities.

The seamless aqua boot can be formed by a batch process or it can be formed in a continuous process by staged dips of a heated mold to regulated depths into one or more liquid elastomeric dispersions of the same or different formulations, with intermediate partial cure stages, to provide a boot with layers with different specified properties. The process is schematically illus¬ trated in Figure 4 in relation to the high top boot 2 illustrated in Figure 1. The contour support and thickness of the throat 10, the body 12, the upper sole 14, and the sole 16 of the boot 2 are created according to the depth and time the mold is dipped in the elastomer liquid disper¬ sion. Referring to Figure 4, the mold 30, which is preferably of hollow aluminum, is heated in an oven 32 until the required temperature (usually about 200-380°F depending on elastomeric dispersion formulation) is reached (usually in about 15 to 20 minutes) . The heated mold 30 is then submerged by holding rod 31 in a tank 34 of specified liquid elastomer dispersion 36 up to the top of throat 10 (see Figure 1) for a specified length of time (usually 3 to 45 seconds) to provide a resilient waterproof coating of a specified thickness. The throat 10 and body 12 are then removed, inverted and allowed to partially cure on the heated mold 30, or in the oven 32, for a specified length of time (usually for 1 to 5 minutes) . Inversion increases uniformity in product thickness. The mold 30 is then removed from the oven 32, uprighted and dipped in the second liquid elastomer dispersion 37 (which can be the same or a different formulation than the first dispersion 36) up to the upper sole 14 for a further specified time (30 to 180 seconds) , thus creating a contour line between the body 12 and the top of the bottom sole which is formed in part by the upper sole 14. The second coating can be a relatively tough dimensionally stable but flexible coating which resists stretching and thus provides dimensional stability to the boot. The mold 30 is then withdrawn from the second plastisol dispersion 37, inverted, and heated in the oven 32 to partially cure the boot 2, including the first and second coatings. The lower walking sole 16 is formed by removing the mold from the oven, uprighting the mold 30 and dipping the mold 30 and boot 12 into the same, or another liquid elastomeric dispersion formulation 39, up to the top of lower sole 16 to create a thick walking sole 16 for the boot (see process step (g) in Figure 4) . Alternatively, lower sole 16 can be formed in a separate mold and laid on top of upper sole 14, and bonded to it by glue or heat. In one preferred version of the boot, the first dispersion 36, second dispersion 37 and third dispersion 39 can be different formulations to form a specific design of boot. The first dispersion 36 is formulated to provide a resilient soft elastomeric coating which can be readily stretched so that the boot 2 can be pulled on or off a foot. The second dispersion 37 is formulated to provide a relatively rigid durable, but flexible, elastomeric, coating to provide dimensional stability to the sole area of the boot. The third dispersion 39 is formulated to provide an open cell resilient coating which withstands scuffing, absorbs water, and provides traction and long wear. It will be recognized, however, that any suitable combination of formulations can be used. Also, further dipping dispersions can be included in the process to form as many layers, or as thick layers, as required.

The mold 30, after the body 12, sole 14 and sole

16 are formed, is withdrawn and inverted (step (h) in Figure 4) and placed in the oven 32 (step (i) in Figure 4)

(usually 10 to 20 minutes) to partially cure the boot 2 with the various formed parts, that is, the throat 10, the body 12, the upper sole 14 and the lower sole 16.

After the respective dippings, and between dippings, the boot and mold 30 are inverted by holding rod 31 and placed in an oven (typically at 200°F to 380°F and typically for 1 to 5 minutes) and the plastisol dispersion 36 is allowed to at least partially cure until lower sole 16 is bonded to upper sole 14. Satisfactory partial cure times are governed by oven efficiency, elastomeric dispersion formulations, required process temperatures, and other relevant process parameters. The boot 2 is then removed from the oven 32 and is left on the mold 30 in the air until it has cooled to room temperature. Cooling can be accelerated by immersing the mold 30 and boot 2 in a water tank 38 as seen in step (k) of Figure 4. Before peeling from the mold, powder release agent (for example talcum powder) may be applied to the product surface to avoid surface damage. Once peeled from the mold 30, the boot 2 may be allowed to cure for a further twenty-four hours at room temperature to ensure full cure and strength of the boot.

Figure 4, step (j), illustrates an optional additional intermediate step that can be conducted to form a grid or tread pattern, with or without a logo, embossed in the lower sole 16 of the boot. A female mold 40, which can have formed thereon in inverse pattern a traction, tread or grid pattern, with or without a logo, is pressed against the bottom of lower sole 16 while it is still moldable in order to emboss the pattern into lower sole 16 before dipping the boot 2 in the water tank 38.

Figure 5 illustrates a side section view of a boot 2 with the throat 10, body 12, upper sole 14 and walking lower sole 16 formed on the hollow mold 30. Figure 5 illustrates readily the different thicknesses of the components, for instance, the flexible but dimensionally stable upper sole 14 is thicker than the resilient body 12, but the lower absorbent scuff resistant sole 16 is even thicker than the upper sole 14.

The body 12 should be formed of a stretchable resilient elastomeric dispersion coating to permit the boot to be readily pulled on or off the foot. The upper sole 14 should be formed of a more durable dimensionally stable but flexible cured elastomer dispersion coating to provide good support for the arch and foot of the wearer and to stand up to wear and tear. The lower sole 16 should be formed of a cured elastomer dispersion coating which provides traction and wear resistance. The lower sole 16 can be formed of a foam or porous cured liquid elastomer dispersion formulation. The pores enhance traction and enable the lower sole 16 to absorb water, thereby reducing slipperiness on wet surfaces, which is a characteristic of smooth plastic materials on smooth wet surfaces. Figure 5 also illustrates a rim 42 which can be formed at the top of throat 10, by a corresponding groove 44 in mold 30. The rim 42 retards ripping of the throat 10 when pulled over the foot of a wearer.

Figure 6 illustrates a side section view of a boot 2 which is formed with a neoprene and nylon ankle sock 46, with elastomer dispersion upper sole 14 and elastomer dispersion lower sole 16. The ankle sock 46 can be adhered to the interior of the boot body 12 or can be removable. The ankle sock 46 is pulled over the mold 30 and the sock 46 is then dipped in the elastomer dispersion to a specified depth to form sole 14 and then later with a second dipping to form lower sole 16. This process produces a sock 46 which is adhered to the boot body 12.

The molded seamless resilient waterproof boot is formed by a continuous staged dipping process. A hollow mold in the shape of a foot is formed of cast aluminum. As a general rule, the thickness of the walls of the mold is uniform. However, if need be, the walls can vary in thick- ness. The mold can be formed according to conventional aluminum molding technology using plaster of paris or sandcast molds. Mold can be hollow or solid depending on process heat requirements.

Example 1

A hollow aluminum mold of about 1/4 inch (0.6 cm) wall thickness in the shape of a foot was tested and found to work well under the following conditions. A mixture of four gallons PVC plastisol disper¬ sion (batch No. BN 09110) prepared by QCM Manufacturing Inc., of 930 So. Central, Kent, Washington 98032, was used. The plastisol mixture, prior to use, was degreased to remove any undesirable entrained air bubbles. Prior to use, the PVC plastisol dispersion was stirred carefully without undue agitation to ensure a homogeneous dispersion.

The mold was heated in an oven for about 18 minutes to achieve metal temperature of 380^βF. The mold was then dipped in an upright manner into the first plastisol PVC dispersion. The formulation was tailored to provide a tough resilient waterproof boot which was sufficiently elastic that it could be pulled readily on or off a foot.

In preliminary experimentation, utilizing PVC plastisol dispersions (No. 5520) , it was found that the boot that was formed was impractical because the boot had little or no stretch. It was therefore not possible to pull the boot on the foot after it had been formed and stripped from the mold.

Initially, to make an ankle high top boot, the heated mold was dipped into the 4 gal. plastisol dispersion up to the ankle for about 3 to 5 seconds. The mold and plastisol coating were then raised or lifted out of the solution, inverted, and allowed to partially cure due to the heat contained in the mold. Curing could be accelerated in an oven, if required. If a thick sole was to be formed on the bottom of the boot, from the same plastisol formulation, the mold with the first coating would be either redipped into the same solution/ or a second solution, or raised so that only the upper sole of the boot remained in the plastisol dispersion. The mandrel would be held at that elevation for about 1 to 2 minutes.

The result would be that the lower foot area and sole portion of the boot would have a thicker coating of PVC plastisol. This would form a boot which had a sole which was thicker than the ankle portion of the boot, thereby providing support to the foot of the wearer, and increasing the life of the boot. This type of boot would have the same plastisol formulation throughout.

The mold with the plastisol coated thereon was removed from the plastisol-plasticizer dispersion, in- verted, and held in an oven at 380°F for a period of time to partially cure the body and sole of the boot.

An upper sole and/or a lower sole could be formed on the boot by successively immersing the boot to the lower sole line into the same or a different PVC plastisol dispersion, and allowing the sole to build up on the boot to a partial cure state. The formulation for the upper sole and/or the lower sole could be tailored to provide a tough, traction providing, bottom sole.

Following curing, the mold and the plastisol boot molded thereon were removed from the oven and the mold and plastisol-molded boot were dipped in a cooling tank of water held at 50°F, to cool the mold and formed boot. The mold and the plastisol boot were cooled quickly by this process. The mold and plastisol boot were then removed from the cooling tank of water and the boot was peeled off the mold.

In the process described, the oven used was an

1800 cu. ft. oven maintained at 380"F. Optionally, the lower sole could be formed separately and bonded to the bottom of the upper sole to form a tough durable sole. Example 2

In this process, the hollow mold described in Example 1 above was varied by first fitting a sock formed of neoprene coated nylon fabric over the foot and ankle of the mold. The mold and sock were then heated to 380^βF for about 18 minutes. However, if 380"F was found to be too hot, lower temperatures could be used to preserve the integrity of the neoprene and nylon fabric sock.

The mold and the neoprene and nylon fabric sock were dipped into the PVC plastisol-plasticizer dispersion bath for specified period of time up to the height of the upper sole of the sock. Three 30 second dips were used, the first to provide an initial sheen coating, the second to provide an intermediate layer, and the third to provide an outer layer, so that the overall desired thickness of the sole was achieved. The mold was placed in the oven for about 1 to 5 minutes in between dips to accelerate partial curing. The mold and sock, with triple PVC plastisol coated on the sock, were then removed from the plastisol- plasticizer bath, inverted, and placed in an oven at 380^βF for about 5 minutes. Inversion prevented drips forming on the sole.

Subsequently, after the first layer of plastisol had completely cured to form the upper sole of the boot, the mold, intermediate sock and exterior plastisol upper sole coating were dipped a second time in the plastisol dispersion (or, if desired, a different dispersion formu¬ lation) for about 3 minutes up to the height of the lower sole. The depth that the mold was dipped into the bath the second time was governed by the extent that the lower region of the boot, for example, the sole and heel portion of the boot, should have a thicker elastomeric layer. After the second dip, the mold, sock and plastisol coating were removed, inverted and again placed in the 380"F oven for curing of all layers of plastisol.

Optionally, the mold, sock and plastisol could be dipped into the plastisol dispersion bath or a different plastisol bath a second or third time to form the lower sole, according to desired thicknesses. In another option, the combination could be dipped into the bath up to the ankle, if a second layer of plastisol up to the ankle was required, or the combination could be dipped in the plasti¬ sol-plasticizer bath to a lesser depth, depending upon whether thicker regions were required for the upper sole or the lower sole of the boot.

By using this process, it was possible to form a boot having a neoprene and nylon fabric inner liner for the ankle area, and one or more outer coatings of cured plasti¬ sol, of the same or different formulations and characteris¬ tics, according to graded thicknesses, covering the upper sole and the walking sole of the boot, according to either of the boot configurations illustrated in Figures 1 and 2. Alternatively, by complete immersion(s) the neoprene and nylon fabric could be coated entirely with plastisol.

Example 3

This process was used to form the boot illus¬ trated in Figure 2. The mold was placed in an oven heated to 380°F for 18 minutes. The mold was then removed from the oven and submerged up to the top of ankle 22 in the PVC . plastisol dispersion mentioned in Example 1. The mold was left in the PVC plastisol dispersion for about 4 to 8 sec¬ onds. This time was dependent upon the thickness of the plastisol coating that was to be obtained.

The mold was then raised from the plastisol dispersion to the point where the top of the upper sole 26 was submerged and the thickness at the sole was allowed to build in that area for 35 seconds.

The mold and plastisol coating thereon were then inverted and placed in the oven for about 5 minutes to reheat the plastisol on the mold.

The mold with plastisol coating 22 and 24 thereon was then removed from the oven and submerged into a second plastisol formulation designed to provide a stronger and thicker plastisol coating, for 1-1/2 minutes. This formu¬ lation had considerably less plasticizer than the first plastisol formulation. A thicker wall up to top of the upper sole 26 was thereby formed.

The mold and coated plastisol were placed in the 380^βF oven for 4 minutes to provide a partial cure. The mold and plastisol coating were then removed from the oven and submerged up to the top of the lower sole 28 for about one minute in an anti-slip formulated foamed plastisol plasticizer dispersion. This procedure produced a foamed cushioned anti-slip bottom sole 28. A grid traction pattern was embossed on the sole 28 of the boot while the bottom sole 28 was still moldable.

The mold and multiple plastisol coatings were then removed from the plastisol bath, inverted and placed in the oven for a final cure time of about 11 minutes. After curing, the mold and coatings were removed from the oven and submerged immediately into a cold water bath. When the mold cooled to room temperature, the formed plastisol boot was peeled from the mold and left at room temperature for 24 hours before use. Table 1

Formulations of QCM PVC plastisol that were used by the inventor for forming the seamless aqua boot are set out below. Properties of QCM PVC plastisols are discussed in the Appendix.

A. Plastisol formulation for upper sole 14: 1. Vinyl chloride polymer; 2. Phtalate ester type of plasticizer;

3. Adipate ester type of plasticizer;

4. Borium/cadmium/zinc stabilizer;

5. Organic phosphite; and

6. Organic pigment.

B. A higher level of adipate ester type of plasti¬ cizer than that shown in A was used to make the top part of the boot 12.

C. Plastisol foam formulation for bottom sole 16:

1. Vinyl chloride polymer;

2. Phtalate ester type of plasticizer;

3. Zinc stabilizer;

4. Organic phosphite; 5. Azobisdicarbonamide;

6. Molecular sieve; and

7. Organic pigment.

Tables 2 and 3 summarize the plastisol properties and property limits for producing aqua boots according to the invention. The results in Table 2 were determined experimentally while the results in Table 3 are estimates based on literature information. Table 2 Measured Properties of Vinyl Plastisols

Plastisol Type

Test Description Soft Hard Foam (P6685) (P6420) (F5957) (boot 12) (sole 14) (sole 16)

Tensile strength (psi) 683 1330 405 (ASTM D 882)

Elongation at break (%) 550 365 440 (ASTM D 882)

Modulus at 100% Elongation (psi) 174 370 134 (ASTM D 882)

Compression Set (ASTM D 395) 22°C - 22 hrs. (%) 12 27 22^βC - 70 hrs. (%) 35 43

Hardness (D2240 - Shore A) at 22 ° C 45 78 40

Abrasion (ASTM C 957 — 500 g - H22 wheel, 20,000 cycles)

Weight loss (g) 2.253

Loss in height (mm) 0.813

Table 3 Estimated Property Limits

Soft Hard Foam (boot 12) (sole 14) (sole 16)

Tensile strength (psi) mm 300 min 500 min 200 (ASTM D882)

Elongation at break (%) min 200 (short) min 50 min 100

(ASTM D882) min 250 (long)

Modulus § 100% Elong (Psi) max 250 (long) max 1100

(ASTM D882) mzx 400 (short) Compression set (70 hrs. - 22°C) max 65 (ASTM D395)

Hardness (Shore A @ 22°C) max 55 (long) max 95

(ASTM D2240) max 70 (short)

Abrasion *

(ASTM C957 - H22 wheel, 500 g, 20,000 cycles) Weight loss (g) max 5.0

Long - long boots Short - short boots

♦Tested as described in Table 2

Claims

WHAT IS CLAIMED IS:

1. A seamless one-piece, elastomeric waterproof boot (2) having an ankle, foot and sole, characterized by: (a) a first layer (12) having an ankle, foot and sole formed of a pliable, resilient, stretchable elastomer; (b) a second layer (14) overlying the foot and sole area of the first layer, the second layer being formed of a flexible, shape retaining elastomer; and (c) a third layer (16) overlying the sole of the second layer, the third layer being constructed of a flexible anti-slip wear-resistant elastomer.

2. A boot as claimed in claim 1 wherein the third layer is formed of a porous open-cell elastomer.

3. A boot as claimed in claim 2 wherein a cushioned anti-slip sole is bonded to the exterior of the third layer.

4. A boot as claimed in claim 1 wherein the first layer, second layer and third layers are formed of differ¬ ent formulations of cured elastomers.

5. A boot as claimed in claim 4 wherein the elastomers are selected from the group consisting of polyvinylchloride and latex.

6. A boot as claimed in claim 1 wherein the first layer covers only the foot and sole.

7. A boot as claimed in claim 1 wherein a woven fabric inner liner is located within of the first layer.

8. A boot as claimed in claim 1 wherein a pattern is embossed into the exterior of the third layer of the boot while the third layer is moldable.

9. A boot as claimed in claim 1 wherein the elastomer is formed of a vinylchloride polymer, a pthalate ester plasticizer, an adipate ester plasticizer, a borium cadmium zinc stabilizer, an organic phosphite and an organic pigment.

10. A boot as claimed in claim 1 wherein the third layer is formed of a vinylchloride polymer, a phtalate ester plasticizer, a zinc stabilizer, an organic phosphite, an azobisdicarbonamide foaming agent, a molecular sieve, and an organic pigment.

11. A process of manufacturing a seamless resilient article which comprises:

(a) heating a mold in the shape of the article to an elevated temperature;

(b) immersing the mold in a first elastomer liquid dispersion to permit a first elastomer coating to form on the mold;

(c) partially curing the coating of the elastomer on the mold;

(d) immersing the mold and the first coating in a second elastomer liquid dispersion to permit a second elastomer coating to form on the mold;

(e) partially curing the second coating on the mold; and

(f) removing the article from the mold.

12. A process as claimed in claim 11 wherein the mold and the elastomer coatings thereon are placed in an oven maintained at an elevated temperature to cure the elastomer coating on the mold.

13. A process as claimed in claim 11 wherein the first coating of elastomer is permitted to partially cure on the mold while it is submerged in the elastomer solution and the mold is then partially elevated in the elastomer solution to thereby enable the elastomer coating to thicken in the area where the mold and elastomer coating are still submerged in the elastomer solution.

14. A process as claimed in claim 11 wherein after the first and second elastomer coatings have been partially cured, the mold and elastomer coating are immersed in a third elastomer dispersion for sufficient time to enable a coating of the third elastomer dispersion to at least par¬ tially cure over at least a portion of the first and second elastomer coatings.

15. A process as claimed in claim 14 wherein after the first, second and third elastomer coatings have par¬ tially cured, the mold and the first, second and third elastomer coatings are placed in an oven at an elevated temperature for sufficient time to enable the three elasto¬ mer coatings to further cure.

16. A process as claimed in claim 15 wherein after the elastomer coatings have been partially cured, the mold and elastomer coatings are immersed in a fourth elastomer liquid dispersion for sufficient time to enable a coating of the fourth elastomer dispersion to at least partially cure over at least a portion of the third elastomer coating.

17. A process as claimed in claim 16 wherein after the fourth elastomer coating has partially cured, the mold and the first, second, third and fourth elastomer coatings are placed in an oven at an elevated temperature for sufficient time to enable the elastomer coatings to further cure.

18. A process as claimed in claim 11 wherein the mold is heated to about 200°F to 380°F.

19. A process as claimed in claim 11 wherein the mold is in the shape of a foot.

20. A process as claimed in claim 19 wherein the elastomer is a plastisol and the mold is heated to about 380"F and is immersed in the plastisol solution for about 3 to 45 seconds.

21. A process as claimed in claim 20 wherein the mold and first plastisol coating are placed in an oven at about 380^βF for about 1 to 5 minutes before reimmersing the mold and first plastisol coating in the second plastisol disper¬ sion.

22. A process as claimed in claim 11 wherein a fabric is placed over the mold and at least a portion of the fabric and the mold are immersed in the first elastomer dispersion so that the first elastomer coating forms over at least a portion of the fabric.

23. A process as claimed in claim 11 wherein the elastomer liquid dispersion is a polyvinylchloride liquid dispersion or a liquid latex dispersion.