Thermally insulating products for footwear and other apparel
The present invention is directed to articles of apparel comprising insulating components having insulating structures with low thermal conductivity. Preferred insulating components for use in apparel have an insulating structure comprising a gas impermeable envelope and a porous material contained within the envelope where the insulating structure has a thermal conductivity of less than 25 mW/m K.
1 . A method for making an insulated article of apparel comprising
providing an article of apparel,
forming a pliable insulating structure comprising
a) a gas impermeable envelope, and
b) a porous material contained within the envelope,
evacuating and sealing the insulting structure at reduced pressure;
shaping the pliable sealed insulating structure into a form;
incorporating the insulating structure into the article of apparel;
wherein the insulating structure is at least partially evacuated and has thermal conductivity less than 25 mW/m K at 25° C.
2 . The method of claim 1 , wherein apparel comprises headwear, footwear or handwear.
3 . The method of claim 1 , wherein apparel comprises a boot.
4 . The method of claim 1 , wherein the insulating structure has a thickness of 10 mm or less.
5 . The method of claim 1 , wherein the insulating structure has a thickness of 3 mm or less.
6 . The method of claim 1 , wherein the insulating structure has a thermal conductivity less than 20 mW/m K.
7 . The method of claim 1 , wherein the insulating structure has a thermal conductivity less than 10 mW/m K.
8 . (canceled)
9 . The method of claim 1 , wherein the envelope is under a vacuum pressure of less than about 10,000 Pa.
10 . The method of claim 1 , wherein the insulating structure has a thermal conductivity of about 15 mW/m K or less.
11 . The method of claim 1 , wherein the insulating structure has a thermal conductivity of about 2-10 mW/m K or less.
12 . The method of claim 1 wherein the envelope comprises at least one layer of a material selected from metallized polyester, nylon or polyethylene.
13 . The method of claim 1 , wherein the envelope is a multilayer laminate.
14 . The method of claim 1 , wherein the porous material has a pore size of <100 nm.
15 . The method of claim 1 , wherein the porous material has a pore size of <10 nm.
16 . The method of claim 1 , wherein the porous material is selected from metal oxides.
17 . The method of claim 1 , wherein the porous material is fumed silica.
18 . The method of claim 1 , wherein the porous material is an aerogel.
19 . The method of claim 18 , wherein the aerogel comprises silica.
20 . The method of claim 1 , wherein the insulating structure further comprises a binder.
21 . The method of claim 20 , wherein the binder is selected from an organic or inorganic fiber.
22 . The method of claim 1 , wherein the insulating structure further comprises carbon or titanium dioxide.
23 . The method of claim 1 , wherein the envelope comprises a gas having a molecular weight greater than that of air.
24 . The method of claim 1 , wherein the gas has a molecular weight of 100 or greater, and a boiling point of 25° C. or less.
25 . The method of claim 23 , wherein the gas is selected from carbon dioxide, fluorocarbons, chlorocarbons, and chlorofluorocarbons.
26 . The method of claim 23 , wherein the gas is selected from heptafluoro-1-nitrosopropane and 1,1,1,2,2,3-hexafluoropropane.
27 . The method of claim 23 , wherein the insulating structure has a thermal conductivity of about 10 mW/m K to about 25 mW/m K.
28 . The method of claim 23 , wherein the insulating structure has a thermal conductivity of about 10 mW/m K to about 20 mW/m K.
29 . The method of claim 1 , wherein the insulating structure is substantially incompressible under pressure equal to the weight of a human body.
30 . The method of claim 1 , wherein the insulating structure has a loss of thickness of 20% or less at a pressure of 1 atmosphere.
31 . The method of claim 1 , wherein the insulating component does not alter the fit of the apparel.
32 . The method of claim 3 , wherein the sealed insulating structure is shaped into a toe cap.
33 . The method of claim 1 , wherein the method further comprises sealing the envelope between sections of the structure material.
34 . The method of claim 1 , wherein the pliable insulating structure is formed as a flat component prior to the steps of sealing and shaping.