To provide a void filler capable of better filling voids.
This void filler 1 has an expansion layer 3 expandable about 8-30 times by heating, an application layer 5 expandable about 1-5 times by heating and a bag 10 separating the expansion layer 3 and the application layer 5. The bag 10 is formed of a nylon, and an agent which evolves a gas by heating at about 100°C or higher is encapsulated in the bag 10. Further, tucked-in portions 11 in the form of bellows are formed in the bag 10. The void filler 1 can be made by placing the bag 10 on the application layer 5 and superposing the expansion layer 3 on the bag 10. When the side 5 of the application surface of the void filling material 1 is applied to a site to be fixed and heated, the expansion layer 3 and application layer 5 expand and, at the same time, the agent encapsulated in the bag 10 evolves a gas to stretch the tucked-in portions 11 of the bag 10 and to allow the bag 10 to slowly expand.
OKABE MASAYA
TOMOTA AKIRA
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