Making method of hot water bottle

The hot water bottle is literally a bag with hot water. The traditional hot water bottle is just a rubber made of empty bags, usually square, and one has a hot water entrance and exit, a plug seal, more spiral plug. It uses the way to get warm in the use of hot water. This traditional hot water bottle now is gradually replaced by the reservoir of electric heating bags and electric cakes. The water storage electric water bag is loaded with a heater, inserted with a liquid heating in a heating bag, thereby achieving the purpose of heating.