VACUUM HEAT INSULATOR COMPRISING GLASS FIBER NOT CONTAINING ORGANIC BINDER

摘要

A vacuum thermal insulator having glass fibers that do not contain an organic binder is provided to keep a vacuum state for a long time by preventing outgassing during a vacuum process by excluding organic matters from the glass fiber. A vacuum thermal insulator is composed of a glass fiber which is a core material and a ventilation resistant envelope member for enveloping the glass fiber. The glass fiber is treated by needling, and binderless type. During a needling process, one surface of the binderless glass fiber with unit weight of 2.5~3.5kg/m^2 is firstly needled and then both surfaces of the binderless glass fiber are secondly needled. The glass fiber has thickness of 65~100mm and density of 30~50kg/m^3 after a first needling process, and thickness of 30~50mm and density of 65~100kg/m^3 after a second needling process.