Vacuum heat insulator and its manufacturing method

A method of manufacturing a vacuum heat insulator comprising the steps of:

• heat fusing heat seal layers of first and second enveloping members, wherein heat is applied to every portion of the first and second enveloping members including portions of the first and second enveloping members in which a flat core member is present between the first and second enveloping members;
• and
• pressing, every portion of the first and second enveloping members, including the portions in which the flat core member is present between the first and second enveloping members, by applying a force of 1 kg/m2 or more at the same time as the fusing step,
• wherein the vacuum heat insulator comprises the first and second enveloping members and the flat core member and each of the first and second enveloping members comprises the heat seal layers,
• wherein the flat core member is sealed under reduced pressure between the first and second enveloping members, and the heat seal layers of the first and second enveloping members face each other, and
• wherein the first and second enveloping members are heat sealed at every portion of the first and second enveloping members that are in contact with each other.

A method of manufacturing a vacuum heat insulator comprising the steps of:

• heat fusing heat seal layers of first and second enveloping members, wherein heat is applied to every portion of the first and second enveloping members including portions of the first and second enveloping members in which a flat core member is present between the first and second enveloping members, and peripheral portions of the flat core member where the flat core member is not present between the first and second enveloping members;
• and
• pressing, every portion of the first and second enveloping members, including the portions in which the flat core member is present between the first and second enveloping members and the peripheral portions of the flat core member where the core member is not present between the first and second enveloping members, by applying a force of 1 kg/m2 or more at the same time as the fusing step,
• wherein the vacuum heat insulator comprises the first and second enveloping members and the flat core member and each of the first and second enveloping members comprise the heat seal layers,
• wherein the flat core member is sealed under reduced pressure between the first and second enveloping members, and the heat seal layers of the first and second enveloping members face each other,
• wherein a heat-sealed portion is formed at a periphery of the flat core member by heat-sealing the heat seal layers of the first and second enveloping members with each other, and
• wherein no non-heat-sealed portion is present between the core member and the heat sealed portion at the periphery of the core member.