Advantages and disadvantages of blow molding machines

Hollowextrusion blow molding machines have advantages and disadvantages in blow molding. After all, everything has disadvantages and advantages. Today, I will share with you the advantages and disadvantages of MEPER blow molding machines.

Let's briefly introduce the principle of the blow molding machine. Using the wind blowing from the machine, the plastic body is blown to a certain shape of the mold cavity to make a product. This machine is called a blow molding machine. It is also a type of blow molding machine, that is, a hydraulic blow molding machine. The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in a split mold while it is hot (or heated to a softened state), and compressed air is introduced into the parison immediately after closing the mold to blow the plastic parison. It expands and sticks closely to the inner wall of the mold, and after cooling and demoulding, various hollow products are obtained.

I The advantages of hollow blow molding machine

The product produced by the blow molding machine has a uniform wall thickness and does not require post-modification processing, and the product has no stitching line, resulting in less waste.

II Disadvantages of hollow blow molding machine

The advantages and disadvantages are also the same. When blow molding products, two molds are used, an injection parison mold and an inflation molding mold. The injection parison mold must be able to withstand high pressure. The positioning tolerance of the two molds is high, and the cost of the mold increases. Large, the shape and size of the production container are limited, and it is not suitable to produce a container with a handle.

III Precautions for the operation of hollow blow molding machine

The parison of the hollow blow molding machine is completed in the injection mold, and the product is completed in the blow mold. Some precautions need to be paid during the operation.

1. Tube billet temperature and blowing temperature: Too high temperature: low melt viscosity and easy deformation, resulting in uneven thickness of the tube billet during transfer; too low temperature: there is often a lot of internal stress in the product, which is easy to use during use Deformation and stress cracking occur.

2. Resin for injection blow molding: it has high relative molecular weight and melt viscosity, while the specific melt viscosity is less affected by shear rate and processing temperature, and the product has good impact toughness and suitable melt elongation performance. .