Vacuum heat insulator
The present invention provides a heat insulator that is extremely low in environmental load during production and recycling, is superior in handleability and workability, and shows favorable heat-insulating properties over an extended period of time. The present invention relates to vacuum heat insulator, comprising at least a core member and an external packaging member that stores the core member and can keep inside under reduced pressure, wherein the core member is a sheet-shaped fiber aggregate containing a polyester fiber having fiber size of 1 to 6 deniers in an amount of 50 wt % or more.
1. A vacuum heat insulator, comprising at least a core member and an external packaging member that stores the core member, with the and can keep inside kept under reduced pressure, wherein the core member is a sheet-shaped fiber aggregate processed into a sheet by a needle-punching method, and containing a polyethylene terephthalate fiber, having a fiber size of 1 to 3 deniers and a diameter of 9 to 17 μm, in an amount of 100 wt %, and has a density of 100 to 450 kg/m 3 .
2. The vacuum heat insulator according to claim 1 , wherein the thickness of the core member under vacuum is 0.1 to 5 mm.
3. The vacuum heat insulator according to claim 2 , further comprising a gas-adsorbing member containing a gas-adsorbing substance in a soft bag.
4. The vacuum heal insulator according to claim 3 , wherein the bag of the gas adsorbing member comprises a nonwoven fabric of polyester fiber.
5. The vacuum heat insulator according to claim 3 , wherein the bag of the gas adsorbing member is a nonwoven fabric made of polyethylene terephthalate fiber.
6. The vacuum heat insulator according to claim 4 or 5 , wherein the weight per unit area of the nonwoven fabric is 30 to 200 g/m 2 .
7. The vacuum heat insulator according to claim 1 , wherein the core member is a sheet-shaped fiber aggregate containing at least two kinds of polyethylene terephthalate fibers having different melting points.
8. The vacuum heat insulator according to claim 7 , wherein the fiber aggregate is processed into sheet by a needle-punching method and additionally followed by a thermal-bonding method.
9. The vacuum heat insulator according to claim 7 , wherein the low-melting-point polyethylene terephthalate fiber has a low melting point of 110 to 170° C. and the high-melting-point polyethylene terephthalate fiber has a high-melting-point higher by 20° C. or more than the melting point of the low melting point fiber.
10. The vacuum heat insulator according to claim 9 , wherein the low-melting-point polyethylene terephthalate fiber has a core/shell structure, the shell region is made of a low-melting-point polyethylene terephthalate, and the core region is made of a high-melting-point polyethylene terephthalate.
11. The vacuum heat insulator according to claim 9 , wherein the blending ratio of the low-melting-point polyethylene terephthalate fiber to the high-melting-point polyethylene terephthalate fiber is 10:90 to 30:70 by weight.
12. The vacuum heat insulator according to claim 1 , wherein the external packaging member has a sealed region formed by fusion at a peripheral edge area and an area inside the peripheral edge area in the external packaging member.
13. The vacuum heat insulator according to claim 1 , wherein the vacuum heat insulator has a through-hole area and/or a notched area, and a sealed region formed by fusion at a peripheral area of the through-hole area and/or the notched area.
14. The vacuum heat insulator according to claim 1 , wherein the external packaging member contains two or more core members and has sealed regions formed by fusion at a peripheral edge area of the external packaging member and an external periphery area of the core members in the external packaging member.
15. The vacuum heat insulator according to claim 1 , wherein an internal packaging member containing the core member is contained in the external packaging member under reduced pressure.
16. The vacuum heat insulator according to claim 15 , wherein the internal packaging member comprises polyethylene terephthalate.