The PVC pipe fittings ( accessories ) injection molding process

At present, PVC processing requires precise control of various stages (such as a variety of raw materials mixing ratio, injection time, etc.). Pipes directly use the mixture extrusion molding, and pipe fittings need granulation machine made of granular materials, and then injection molding. This article is mainly about the introduction of PVC pipe fittings injection molding process.

PVC material is a white powder, need to add stabilizer and processing aids. One of the most important stage is the formula and mix, the selection of raw materials and ingredients, mixing are to maintain strict norms. Pipes directly use the mixture extrusion molding, and pipe fittings need granulation machine made of granular materials, and then injection molding.

     In summary, the two main processes used in the manufacture are the injection molding of the fitting and the extrusion of the pipe. Basically, PVC finished by the raw material PVC powder mixing auxiliary raw materials, through the extrusion and injection molding. This article is mainly about the introduction of PVC pipe fittings injection molding process. You must be know better about the PVC pipe fittings after reading this article.

Production of PVC pipe fittings need to injection molding machine and mold two conditions, and then by heating and melting raw materials, high pressure injection molding. And pipe manufacturing is different from the injection molding is repeated cycle process, each cycle will be "high pressure injection" of the material into the mold, cooling molding. Injection molding process has the following four stages, and these four stages is a complete continuous cycle process.

(1)High pressure filling stage:

Filling is the first step in the entire injection cycle, starting from the mold closure and filling the mold cavity to about 95%.

(2)Packing stage

The role of the holding stage is to continue to exert pressure, compaction of the melt, increase the plastic density (density) to compensate for the shrinkage of plastic behavior.

(3)Cooling stage 

In the injection molding die, the design of the cooling system is very important. This is because the molding of plastic products only cooling and curing to a certain rigidity, stripping to avoid plastic products due to external forces and deformation. As the cooling time of the entire molding cycle of about 70% to 80%, so a well-designed cooling system can significantly shorten the molding time and improve the injection molding productivity.

(4)From the mold stage

Stripping is the last part of an injection molding cycle. Although the product has been cold forming, but the mold is still on the quality of the product has a very important impact, to choose a reasonable way off.