Made in China News

Pneumatic butterfly valves are the most widely used universal valves. Used in many pneumatic pipes. Therefore, rational maintenance not only improves work efficiency, but also reduces maintenance time and saves replacement costs. In order to stabilize the performance and long life of the pneumatic butterfly valve, it is recommended to pay attention to the following factors. Prior to use, the pipe and valve body overflow is washed with water to prevent residual iron powder and other debris from entering the valve body cavity. Second, when the butterfly valve is closed, some medium remains in the valve body and a certain pressure is applied. Before repairing the butterfly valve, first close the shut-off valve in front of the butterfly valve, open the butterfly valve that requires repair, and completely release the internal pressure of the valve body. For electric butterfly valves or pneumatic butterfly valves, you must first disconnect the power and air supply. Third, ordinary s...

The core foam chemistry principles can be divided into two categories. A chemical blowing agent that releases gas upon heating is used. Common chemical foaming agents such as azodicarbonamide, azobisisobutyronitrile, N,N'-dinitrosopentamethylenetetramine, sodium hydrogencarbonate. Many thermoplastics can be made into foam in this way. For example, PVC foam shoes are made from resins, plasticizers, foaming agents and other additives for use in injection molding machines. The blowing agent ruptures in the barrel and the material foams in the mold. . The foamed artificial leather is mixed with a foaming agent to prepare a polyvinyl chloride paste. Scratching or calendering on the fabric, continuously passing through the tunnel furnace, the material is plasticized and melted, the blowing agent is decomposed and foamed, cooled and the surface finish is made from foamed artificial leather. Forming rigid PVC low foam sheets, tubes or profiles by extrusion. The blowing agent decomposes...