Belong to. Paper-making, sugar-making, brick and tile industry, power plants, boiler rooms and diving cabins of trains and ships. All belong to high temperature operation. The pipe bender in paper mill belongs to the paper industry and also belongs to high temperature operation. All industries of industrial production have high-temperature operations, such as steelmaking and ironmaking. Paper mills produce paper products. There are many kinds of paper mills. The first type of sanitary paper factory specializes in producing toilet paper, paper pumping and other toilet paper. The second type is specialized in producing cartons and cartons for packaging goods.