FOAMABLE YARNS, TEXTILES AND ARTICLES INCORPORATING FOAMABLE YARNS, AND THE PROCESS OF MANUFACTURING THE SAME
An article, such as an article of footwear includes, a textile component. The textile component includes a yarn. The yarn includes a thermoplastic material and a blowing agent with an activation condition. Upon triggering the activation condition of the blowing agent, the blowing agent introduces a plurality of cavities, i.e. cells, into the thermoplastic material, creating a multicellular foam area of the textile.
1 . A yarn comprising:
a core yarn comprising a plurality of fibers or filaments, each of the plurality of fibers or filaments comprising a core material; and
a first thermoplastic material forming an unfoamed coating at least partially surrounding the core yarn;
wherein the first thermoplastic material comprises at least one first thermoplastic polymer chosen from a thermoplastic polyurethane, a thermoplastic polyolefin, a thermoplastic polyester, a thermoplastic polyether, a thermoplastic polyamide, or any combination thereof; and a thermally-activated chemical blowing agent, wherein the thermally-activated chemical blowing agent is present in the first thermoplastic material in an amount effective to foam the unfoamed coating of the first thermoplastic material into a multicellular foam.
2 . The yarn of claim 1 , wherein the first thermoplastic material comprises the thermoplastic polyolefin, and the thermoplastic polyolefin comprises an ethylene-vinyl acetate copolymer.
3 . The yarn of claim 1 , wherein the first thermoplastic material further comprises a cross-linking agent.
4 . The yarn of claim 1 , wherein the core material comprises a second thermoplastic material, and the second thermoplastic material comprises one or more polymers chosen from a thermoplastic polyurethane; a thermoplastic polyolefin; a thermoplastic polyester; a thermoplastic polyether, a thermoplastic polyamide; or any combination thereof.
5 . The yarn of claim 4 , wherein the second thermoplastic material comprises the thermoplastic polyester.
6 . The yarn of claim 4 , wherein the second thermoplastic material has a softening temperature at least 20 degrees Celsius above a melting temperature of the first thermoplastic material.
7 . The yarn of claim 1 , wherein the core yarn has a percent elongation of from about 5 percent to about 25 percent.
8 . The yarn of claim 1 , wherein the core yarn has a breaking strength from about 1.5 to about 10 kilograms force per centimeter squared.
9 . The yarn of claim 1 , wherein the core yarn has a tenacity from about 1.5 to about 10.0 grams per denier.
10 . The yarn of claim 1 , wherein the core yarn is a twisted multi-filament yarn or an entangled multi-filament yarn.
11 . The yarn of claim 1 , wherein the first thermoplastic material at least partially surrounding the core yarn has an average thickness of from about 0.4 millimeters to about 3.0 millimeters.
12 . The yarn of claim 1 , wherein the yarn has an average cross-sectional diameter of less than 4 millimeters.
13 . The yarn of claim 1 , wherein the core yarn has a cross-sectional diameter, and the first thermoplastic material at least partially surrounding the core yarn is coaxial with the core yarn and has an average thickness at most 10 times larger than the cross-sectional diameter of the core yarn.
14 . A method for making a yarn, the method comprising:
applying a coating of a first thermoplastic material to a core yarn to at least partially surround the core yarn with an unfoamed coating of the first thermoplastic material;
wherein the core yarn comprises a plurality of fibers or filaments, and each of the plurality of fibers or filaments comprises a core material; and
wherein the first thermoplastic material comprises at least one first thermoplastic polymer chosen from a thermoplastic polyurethane, a thermoplastic polyolefin, a thermoplastic polyester, a thermoplastic polyether, a thermoplastic polyamide, or any combination thereof; and a thermally-activated chemical blowing agent, wherein the thermally-activated chemical blowing agent is present in the first thermoplastic material in an amount effective to foam the first thermoplastic material into a multicellular foam structure.
15 . The method of claim 14 , wherein, during the applying, the first thermoplastic material is at a first coating temperature at or above a melting temperature of the first thermoplastic material but at least 20 degrees Celsius below an activation temperature of the blowing agent and, when the core material is a second thermoplastic material, the first coating temperature is at least 20 degrees Celsius below a softening temperature of the core material.
16 . The method of claim 14 , wherein applying the coating of the first thermoplastic material to the core yarn comprises increasing a temperature of the first coating thermoplastic material to the first temperature to form molten first thermoplastic material; extruding the molten first thermoplastic material onto the core yarn; and decreasing a temperature of the molten first thermoplastic material on the core yarn to a second coating temperature below a softening temperature of the first thermoplastic material to solidify the first thermoplastic material into the unfoamed coating on the core yarn.
17 . The method of claim 16 , wherein applying the coating further comprises pulling the core yarn through the molten first thermoplastic material.
18 . A method for foaming a yarn, the method comprising the steps of:
expanding an unfoamed coating of a yarn into a multicellular foam by increasing a temperature of a yarn to a first processing temperature, thereby softening or melting the unfoamed coating, activating a thermally-activated chemical blowing agent in the unfoamed coating, and expanding the unfoamed coating into a multicellular foam; and
after expanding the coating into the multicellular foam, decreasing a temperature of the multicellular foam to a second processing temperature at which the multicellular foam adheres to the core yarn and solidifies while retaining its multicellular structure;
wherein the yarn comprises a core yarn and a first thermoplastic material forming the unfoamed coating, the first thermoplastic material at least partially surrounds the core yarn, the core yarn comprises a plurality of fibers or filaments, and each of the plurality of fibers or filaments comprising a core material;
wherein the first thermoplastic material comprises at least one first thermoplastic polymer chosen from a thermoplastic polyurethane, a thermoplastic polyolefin, a thermoplastic polyester, a thermoplastic polyether, a thermoplastic polyamide, or any combination thereof, the first thermoplastic material further comprises a thermally-activated chemical blowing agent, and the thermally-activated chemical blowing agent is present in the first thermoplastic material in an amount effective to foam the unfoamed coating of the first thermoplastic material into a multicellular foam; and
wherein the first processing temperature is a temperature at or above a softening temperature of the first thermoplastic material and at or above an activation temperature of the thermally-activated blowing agent of the first thermoplastic material.
19 . The method of claim 18 , wherein the multicellular foam is a cross-linked foam, the first thermoplastic material further comprises a thermally-activated cross-linking agent, and the first processing temperature is a temperature at or above the activation temperature of the thermally-activated cross-linking agent.
20 . The method of claim 18 , wherein the core material is a second thermoplastic material, and the first processing temperature is a temperature at least 20 degrees Celsius below a softening temperature of the second thermoplastic material.