METHOD FOR PRODUCING COMPOSITE THERMAL INSULATOR, METHOD FOR PRODUCING WATER HEATER, AND COMPOSITE THERMAL INSULATOR

摘要

To provide a method for producing a composite thermal insulator (1), a method for producing a water heater (25), and the composite thermal insulator (1) which can limit degradation of thermal insulation performance of a vacuum thermal insulator (2) more efficiently than the conventional techniques, achieving improved integrity.;The present invention provides a method for producing a composite thermal insulator (1) including a vacuum thermal insulator (2), the vacuum thermal insulator (2) comprising a core (2a) and an enclosure (2b) configured to wrap the core (2a) and include a weld portion (5) which extends along an outer periphery of the core (2a) and at which portions of the enclosure (2b) are welded together, the vacuum thermal insulator(2) having vacuum-sealed inside, the method including: a first step of covering edges (7) of the vacuum thermal insulator (2) including the weld portion (5) with a first heat insulating foam (3) foamed in advance and placing the first heat insulating foam (3) along the outer periphery of the core; and a second step of forming a second heat insulating foam (4) configured to cover the first heat insulating foam (3) placed in the first step and at least part of the vacuum thermal insulator (2).