WO2023004321A1

WO2023004321A1 - Dissolvable footwear

Info

Publication number: WO2023004321A1
Application number: PCT/US2022/073897
Authority: WO
Inventors: Jesse MILLIKEN; Simon QUAY; Susanna HOHMANN
Original assignee: Woolybubs Llc
Priority date: 2021-07-20
Filing date: 2022-07-19
Publication date: 2023-01-26

Abstract

Footwear and methods of fabrication of the footwear are described. In some embodiments, footwear includes at least a portion of the footwear being dissolvable in heated solvent.

Description

DISSOLVABLE FOOTWEAR

CRO S S -REFEREN CE( S) TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application No. 63/223794, filed July 20, 2021; the content of which is hereby incorporated by reference in its entirety.

BACKGROUND

Footwear, such as shoes, sandals, slippers, or boots, including footwear for infants, is typically manufactured using a combination of natural and synthetic materials that are persistent in the environment after disposal. Materials such as rubber, leather, cotton, polyester, poly-vinyl chloride, enter waste streams after the end of life of the footwear, ending up in landfills or watercourses/oceans. In some cases, material from footwear, such as rubber or plastic fabrics and soles, are consumed by animals and lead to fatalities. While repurposing, reusing, or incinerating the footwear are alternative disposal approaches, each present different issues associated with expense, logistical complexity, and/or environmental impact that limit their broad adoption in place of landfilling or dumping.

For example, infant footwear is rapidly used and disposed of as a child grows through infancy and into toddler years. In addition, infants tend to be sensitive to heavy or un- breathable materials used in footwear and donning or doffing infant footwear can be challenging for caregivers.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to Reference No. 4998-P1WO identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

Footwear and methods of fabrication of the footwear are described. In some embodiments, footwear includes at least a portion of the footwear being dissolvable in heated solvent. At least a portion of the footwear may be dissolvable in heated water. In some embodiments, the entire footwear is dissolvable in the heated water.

In some embodiments, the footwear is formed essentially from polyvinyl acetate and/or polyvinyl alcohol (PVA). The footwear may be made from PVA in four forms: woven, non- woven, knit, and adhesive. The footwear may have a sole that is formed from non-woven PVA. The footwear may further include a non-woven PVA cushioning layer. The PVA may be in the weight range of 25 GSM to 80 GSM. The PVA may be in the weight range of 25 GSM to 65 GSM.

In some embodiments, the PVA is dissolvable in water heated to 75°C or above. The PVA may be dissolvable in water heated to 90°C or above. The footwear may further include a printed layer disposed on the PVA that is dissolvable in water heated to 75°C or above. The footwear may further include a printed layer disposed on the PVA that is dissolvable in water heated to 90°C or above.

In some embodiments, the footwear is in a form selected from: infant shoes, youth shoes, adult shoes, slippers, boots, slides, or flip flops. Only a portion of the footwear may be dissolvable in heated water. The footwear may include an upper that is dissolvable in heated water, with the remainder of the footwear not dissolvable in heated water.

In some embodiments, the footwear includes a lighter weight non-woven material in gusset panels on each side of the footwear, so as to allow the footwear to open longitudinally to accept a foot and then close around the foot upon insertion. The footwear may further include a lower portion having a longitudinal arc when the footwear is empty and an upper portion coupled with the lower portion the includes non-woven material in gusset panels on Reference No. 4998-P1WO each side of the footwear. The gusset panels may together define an opening of the footwear. The longitudinal arc may expand the opening of the footwear when the footwear is empty. The footwear may further include an upper portion that includes non-woven material in gusset panels on each side of the footwear, wherein the gusset panels together define an opening of the footwear and a lower portion, coupled with the upper portion, that widens the opening when flexed along a longitudinal axis of the footwear. The footwear may be configured to widen the opening by an action of a single hand when donning or doffing the footwear.

In some embodiments, the footwear further includes an elastic cord integrated into the footwear to enclose the footwear around a foot. The footwear may further include an elastic cord integrated into the footwear, and a cord lock configured to tighten around the elastic cord in order to enclose the footwear around a foot in a locked position and release the footwear from around the foot in an unlocked position.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 illustrates footwear including at least a portion that is dissolvable in heated solvent, in accordance with various embodiments.

FIGURE 2A illustrates a nonwoven PVA sole for incorporation into footwear, in accordance with various embodiments.

FIGURE 2B illustrates a nonwoven PVA cushioning layer for incorporation into footwear, in accordance with various embodiments.

FIGURE 3 illustrates footwear including at an upper portion formed from PVA, in accordance with various embodiments.

FIGURE 4 illustrates a footwear pattern formed from PVA, in accordance with various embodiments. Reference No. 4998-P1WO

FIGURE 5 illustrates footwear including at gusset panels defining an opening in the upper portion that widen when the lower portion is flexed, in accordance with various embodiments.

FIGURE 6A illustrates footwear including at gusset panels defining an opening in the upper portion that widen when the lower portion is flexed, in accordance with various embodiments.

FIGURE 6B illustrates footwear including at gusset panels defining an opening in the upper portion that widen when the lower portion is flexed, in accordance with various embodiments. FIGURE 7 illustrates a chord, chord lock, and shrink tubing for enclosing the footwear around a foot, in accordance with various embodiments.

FIGURE 8 illustrates a chord sewn into a rear gusset panel of the footwear, in accordance with various embodiments.

FIGURE 9A illustrates a composite street shoe with a patterned PVA upper, in accordance with various embodiments.

FIGURE 9B illustrates a composite athletic shoe with a patterned PVA upper and elastic closure, in accordance with various embodiments.

FIGURE 9C illustrates a composite athletic shoe with a dyed PVA upper and cord, in accordance with various embodiments.

DETAILED DESCRIPTION

While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. Examples described below focus on footwear formed from poly-vinyl alcohol nonwoven fabric, it is understood that other materials are also contemplated. For example, footwear may be or include other materials to be at least partially dissolvable in a solvent.

Materials and Dissolution Reference No. 4998-P1WO

Woven, non-woven, knit, stitched, and/or adhesive materials are formed into footwear 100, shown in FIG. 1. The footwear 100 shown includes a nonwoven molded lower portion 105 and a nonwoven upper 110 that are both formed from one or more pieces of polyvinyl acetate (PVAc) and/or polyvinyl alcohol (PVOH) fabric(s) and/or adhesives. PVAc may also be a liquid at standard temperature and pressure, which may be reversibly cured to a solid and may be used as a dissolvable adhesive. PVOH resin may be produced by hydrolyzing PVAc to PVOH. PVOH fabrics may be formed by spinning PVOH fibers that are then formed into nonwoven fabric. The footwear 100 shown also includes one or more components 115 for securing the footwear 100 onto and/or around a wearer.

While PVAc and PVOH are distinct materials, both are compatible with assembly into dissolvable footwear. As such, the materials from which the footwear 100 may be constructed, including but not limited to PVAc and/or PVOH, are referred to individually or together as PVA for the purposes of the following description. In general, the footwear 100 may be in a form selected from: infant shoes, youth shoes, adult shoes, slippers, boots, slides, or flip flops.

PVA fibers tend to be wear resistant and resistant to ultraviolet and chemical exposure (alkali, acid, oil, etc.). Fabrics made from PVA have a cotton-like feel, good affinity to water, do not emit toxic gases when burned, and may be washed and dried as is done with other fabrics. PVA has excellent adhesive properties. It is also resistant to oil, grease and solvents. It has high tensile strength and flexibility, as well as high oxygen and aroma barrier properties.

As implemented in the footwear 100 of FIG. 1, nonwoven PVA fabric is dissolvable in a heated solvent. Solvents may include but are not limited to polar solvents such as water, DMF, DMSO, or the like. Solubility is temperature dependent, with water tending to dissolve PVA at relatively higher temperatures than other solvents. For example, DMSO can dissolve PVA at ambient conditions of temperature and pressure, while water is typically heated above ambient temperature to dissolve PVA. Advantageously, use of water as a solvent improves compatibility with domestic disposal, where volatile or flammable solvents represent excess risk of fire and where safety equipment are typically unavailable. In some embodiments, the footwear 100 is dissolvable in heated water at about 70 °C or more, about 75 °C or more, about Reference No. 4998-P1WO

80 °C or more, about 85 °C or more, about 90 °C or more, about 95 °C or more, about 100 °C or more, including interpolations thereof.

PVA materials used in the footwear 100 may include, but are not limited to, woven, non-woven, knit, and/or adhesive 410 (in reference to FIG. 4) materials. In this way, the panels, sole, liners, reinforcement layers, cushions, and other components of the footwear may be or include PVA and may be dissolvable. In that different parts of the footwear 100 face different forces during use, different weights of the PVA material may be used for different components, as measured in grams per square meter, abbreviated "GSM." For example, a heavier weight material is typically stronger, more resistant to fraying, and less susceptible to abrasion failure or tearing. Conversely, lighter weight material is typically more flexible, more breathable, and feels lighter to a wearer.

In some embodiments, the PVA is in the weight range from 25 GSM to 100 GSM, from 25 GSM to 95 GSM, from 25 GSM to 90 GSM, from 25 GSM to 85 GSM, from 25 GSM to 80 GSM, from 25 GSM to from 75 GSM, from 25 GSM to 70 GSM, from 25 GSM to 65 GSM, from 25 GSM to 60 GSM, from 25 GSM to 55 GSM, from 25 GSM to 50 GSM, 25 GSM to 45 GSM, from 25 GSM to 40 GSM, from 25 GSM to 35 GSM, or from 25 GSM to 30 GSM. In some embodiments, the PVA is less than 25 GSM weight or more than 100 GSM weight. In some embodiments, the upper portion 110 of the footwear is made from lighter- weight PVA while the lower portion is made from heavier-weight PVA 105. In some embodiments, some portions of the footwear 100 use 60 GSM PVA, while other portions of the footwear 100 use 25 GSM PVA.

In some embodiments, the footwear 100 includes a knit liner 405 (in reference to FIG. 4) formed from a single yam size or multiple yarn or thread sizes. The knit liner 405 improves the stability and durability of the footwear 100 by spreading strain during wear and reduces the likelihood of sudden tearing or bursting. The knit liner 405 may include, but is not limited to, a PVA material made from a 62/18 filament yam, or other PVA yarns. Advantageously, using different threads for warp and weft with a heavier filament in one direction provides improved strength-to-weight properties for portions of the footwear expected to experience unilateral forces. Similarly, multiple different knit liners 405 can be used in different portions Reference No. 4998-P1WO of the footwear 100. For example, a toe cap 120 can include a heavier filament and/or higher thread count can reinforce the toe portion of the footwear 100, reducing wear and improving the durability of the footwear 100.

In some embodiments, the footwear 100 is entirely dissolvable in heated water. In some embodiments, at least a portion of the footwear 100 is dissolvable in heated water, as described in more detail in reference to FIGs. 9A-9C. In some embodiments, the footwear 100 is formed essentially from PVA. In this context, "essentially" is used to refer to a footwear includes discrete components 115 that are not formed from PVA but where as much as 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, of the material making up the footwear may be or include PVA, including interpolations thereof. For example, the footwear may have a sole 200 that is formed from non-woven PVA (FIG. 2A) and may include a non-woven PVA cushioning layer 210 (FIG. 2B). In some cases, the footwear 100 includes a polyester blend cushioning layer 210 that is not dissolvable in the solvent.

The upper portion 110 of the footwear 100, illustrated in FIG. 3, can be formed from multiple pieces, for example, according to a footwear pattern, as shown in FIG. 4, that are subsequently sewn together using PVA spun-fiber thread. In the example shown in FIG. 3, the upper portion 110 of the footwear 100 includes a toe cap piece 120, a front gusset panel 305 near the toe cap piece, and a rear gusset panel 310 near the heel of the footwear. As illustrated in FIGs. 6A-6B and FIGs. 9A-9B, the footwear 100 can include printed, dyed, or embossed materials that provide functional improvements or capabilities to the footwear. Embossing, for example, can impart a three-dimensional patterned surface that improves breathability of the footwear 100 and can improve water-resistance. Pigments or dyes used to color or pattern the footwear 100 can include PVA-derived materials that are similarly dissolvable and can improve visibility of the footwear 100 as a safety feature. For example, printed patterns 610 may include reflective materials or bright colors that can make the footwear 100 visible in low- light environments.

Donning and Doffing Reference No. 4998-P1WO

In some embodiments, the gusset panels 305-310 described in reference to FIG. 3 can together define a longitudinal opening 315 for receiving a foot. The gusset panels 305-310 can be coupled with the lower portion 105 such that a lateral folding of the lower portion can widen the opening 315 in the longitudinal direction. As illustrated in FIG. 4, in this context, "longitudinal" is used to refer to an axis 415 drawn from the toe to the heel of the footwear 100. In contrast, "lateral" is used to refer to an axis 420 drawn perpendicular to the longitudinal axis 415.

This approach to widening the opening 315 facilitates donning or doffing the footwear 100 by permitting the footwear 100 to be slipped on and off with only one hand, for example, by pressing the foot into the toe and pulling the rear gusset panel 310 over the heel of the wearer .

In some embodiments, the lower portion 105 can be pre-flexed, as illustrated in FIG. 35 and FIG. 6A, such that the opening 315 is wide when the footwear 100 is empty. In this context, "pre-flexed" is used to refer to the lower portion having a longitudinal arc 605 (in reference to FIG. 6A) from heel to toe when the footwear 100 is empty. Advantageously, the pre-flexed lower portion 105 eases donning and doffing with only one hand, as previously described. In an illustrative example, infant footwear that is pre-flexed permits a caregiver to hold an infant in one arm and to don the footwear 100 with the other, rather than putting the infant down to use both hands.

In some embodiments, the footwear 100 includes an elastic cord 705 (in reference to FIG. 7) integrated into the footwear 100 to enclose the footwear 100 around a foot of a wearer, as illustrated in FIGs. 1-6B. As shown in FIG. 6B, the elastic chord 705 can include a cord lock 710 configured to tighten around the elastic cord 705 in order to enclose the footwear 100 around a foot in a locked position and to release the footwear 100 from around the foot in an unlocked position. Examples of chord 705 and chord lock 710 are shown in FIG. 7. As illustrated in FIG. 6B, the chord 705 may be an open length of rubber or polymer-wrapped elastic chord. Including an open length of chord permits the cord to be fed through the front gusset panel 305 and rear gusset panel 310 after the footwear 100 is assembled. In some cases, shrink tubing 715 is used to hold the open ends of the chord 705 together and to prevent the Reference No. 4998-P1WO chord 705 from being pulled free of the footwear 700. Alternatively, a closed loop of chord can be sewn into the footwear, as illustrated in FIG. 8, using one or more cover portions 805, in which case the footwear 100 may omit the shrink tubing.

Composite Footwear:

In some embodiments, the footwear includes an upper that is dissolvable in heated water, with the remainder of the footwear not dissolvable in heated water. As illustrated in FIG. 9A, FIG. 9B, and FIG. 9C, the lower portion 105 of the footwear may be or include a rubber, foam, elastic, or composite sole 905 that is typically used for conventional shoes, on which a dissolvable upper portion 910 is disposed. In this way, the footwear 100 can include a robust bottom that protects the wearer from rough, sharp, wet, or slippery surfaces, while also exhibiting the dissolution properties of the materials described in reference to FIGs. 1-8. Advantageously, rubber and foam used in soles of conventional footwear tend to be more suitable for reuse or repurposing than the upper portion materials. Consequently, replacing the upper portion with the dissolvable materials reduces the quantity of material ending up in landfills or watercourses and improves sustainability of footwear products.

While the present disclosure focuses on footwear of various shapes, sizes, and structures, embodiments of the present disclosure include dissolvable garments and/or accessories other than the footwear 100 described. For example gloves, headwear, socks, garments for the upper and/or lower body, are included. In an illustrative example, a glove can be formed from a dissolvable knitted material 405 with an upper portion 110 and a lower portion 105, corresponding to the back of the hand and the palm of the hand, respectively, formed from a nonwoven material to provide added protection. The components 115 can be included to assist in fastening the dissolvable glove about the wrist. Accordingly, the disclosure can encompass other embodiments not expressly shown or described herein. Unless otherwise noted, in the context of this disclosure, the word “approximately” indicates a difference of +/- 5% of the stated value.

Claims

Reference No. 4998-P1WO CLAIMS The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Footwear, wherein at least a portion of the footwear is dissolvable in heated solvent.

2. The footwear of Claim 1, wherein at least a portion of the footwear is dissolvable in heated water.

3. The footwear of Claim 1, wherein the entire footwear is dissolvable in the heated water.

4. The footwear of Claim 1, wherein the footwear is formed essentially from polyvinyl acetate (PVA).

5. The footwear of Claim 1, wherein the footwear is made from PVA in four forms: woven, non-woven, knit, and adhesive.

6. The footwear of any of the preceding claims, wherein the footwear has a sole that is formed from non-woven PVA.

7. The footwear of any of the preceding claims, further comprising a non-woven PVA cushioning layer.

8. The footwear of any of the preceding claims, wherein the PVA is in the weight range of 25 GSM to 80 GSM.

9. The footwear of any of the preceding claims, wherein the PVA is in the weight range of 25 GSM to 65 GSM. Reference No. 4998-P1WO

10. The footwear of any of the preceding claims, wherein the PVA is dissolvable in water heated to 75°C or above.

11. The footwear of any of the preceding claims, wherein the PVA is dissolvable in water heated to 90°C or above.

12. The footwear of any of the preceding claims, further comprising a printed layer disposed on the PVA that is dissolvable in water heated to 75°C or above.

13. The footwear of any of the preceding claims, further comprising a printed layer disposed on the PVA that is dissolvable in water heated to 90°C or above.

14. The footwear of any of the preceding claims, wherein the footwear is in a form selected from: infant shoes, youth shoes, adult shoes, slippers, boots, slides, or flip flops.

15. The footwear of claim 1, wherein only a portion of the footwear is dissolvable in heated water.

16. The footwear of Claim 15, wherein the footwear includes an upper portion that is dissolvable in heated water, and wherein the remainder of the footwear is not dissolvable in heated water.

17. The footwear of any of the preceding claims, wherein the footwear includes a lighter weight non-woven material in gusset panels, so as to allow the footwear to open longitudinally to accept a foot and then close around the foot upon insertion.

18. The footwear of any of the preceding claims, further comprising: a lower portion having a longitudinal arc when the footwear is empty; and an upper portion coupled with the lower portion the includes non-woven material in gusset panels, wherein the gusset panels together define an opening of the footwear; wherein the longitudinal arc expands the opening of the footwear when the footwear is empty. Reference No. 4998-P1WO

19. The footwear of any of the preceding claims, further comprising: an upper portion that includes non-woven material in gusset panels, wherein the gusset panels together define an opening of the footwear; and a lower portion, coupled with the upper portion, that widens the opening when flexed along a longitudinal axis of the footwear.

20. The footwear of any of the preceding claims, wherein the footwear is configured to widen the opening by an action of a single hand when donning or doffing the footwear.

21. The footwear of any of the preceding claims, further comprising an elastic cord integrated into the footwear to enclose the footwear around a foot.

22. The footwear of any of the preceding claims, further comprising an elastic cord integrated into the footwear, and a cord lock configured to tighten around the elastic cord in order to enclose the footwear around a foot in a locked position and release the footwear from around the foot in an unlocked position.