Extrusion blow molding process principle, advantages and influencing factors
DATE：2021/2/27 8:42:51 / READ： / SOURCE：This station
Extrusion blow molding process principle, advantages and influencing factors
Plastic sheet production line
1. The principle of extrusion blow molding process
To put it simply, a semi-molten tubular preform is obtained by extrusion, compressed air is injected into the pipe preform to expand it, close to the inner wall of the mold cavity, and then cooled and demolded. Obtain various hollow products. The whole process is divided into two parts: the manufacture of plastic preforms and blow molding. Daily containers such as bottles, pots and barrels of different calibers and capacities are obtained by extrusion blow molding. Plastic sheet production line www.handern.com
Second, the advantages of extrusion blow molding process
1. In the blow molding process, the parison is formed by the die and inflated under a relatively low pressure, which determines that the blow molding product has less residues and has higher strain resistance such as stretching, bending, and impact. Better service life.
2. The raw material (PE) used in the extrusion blow molding machine has excellent low temperature resistance, good chemical stability, and good crack resistance.
3. The molding equipment is simple and easy to operate, and the choice of raw materials is more extensive.
4. After the parison flows out through the extruder head, it directly enters the blow mold for molding without secondary heating, and the production efficiency is high.
Third, the factors affecting the extrusion blow molding process
1. Screw speed. It is another important factor that affects the extrusion blow molding parison. The extrusion speed determines the quality of the product and reduces the surface sagging of the parison.
2. Temperature control. The extrusion temperature depends on the nature of the resin. Too low a temperature will cause the surface of the parison to be rough, and too high a temperature will result in uneven wall thickness of the parison.
3. Die size and quality. The size of the die determines the size of the preform, so the inner surface of the die is required to be smooth, which is conducive to obtaining a smooth preform on the surface of the product.
4. Selection of raw materials. It is very important in the blow molding process. Generally, HDPE is used, according to its fluidity characteristics
It can prevent the parison from sagging and the wall thickness is uniform. This is particularly important for the production of large hollow blow molded products. The reasons for choosing HDPE as the raw material for blow molding can be found if you are interested. Plastic sheet production line www.handern.com
Extrusion blow molding technology is becoming more and more mature, and the products produced have a wide range of uses. Through the above points, I have introduced in detail the related issues of the extrusion blow molding process. I believe everyone has already understood it. I will continue to share the relevant issues in the future. Let’s talk about issues related to blow molding machines and blow molding products today!
Author：admin