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About the influencing factors of preform mold forming

Update:18-09-2020
Summary:

1. The conveying, melting, mixing and pumping of the po […]

1. The conveying, melting, mixing and pumping of the polymer in the extruder into the formation stage of the parison; at this stage, the factors affecting the wall thickness distribution are: 1. The molecular weight distribution and average molecular weight of the material; 2. The temperature control system and screw speed of the blow molding machineChina Plastic Pail Moulds Manufacturers. The temperature control system includes the temperature of the hopper, the temperature of the barrel 1, zone 2, zone 3, and zone 4, the flange temperature and the storage die zone 1 and 2 , Zone 3 and Zone 4 temperature.

 

 

2. The stage where the parison is extruded from the gap between the die lip and the core is called the blanking stage. At this time, the common phenomenon is the expansion of the parison and the parison sag. The factors that affect these two phenomena are: the die diameter and wall thickness control system of the blow molding machine. The control system includes the axial wall thickness control system and the circumferential wall thickness control system, which are used to adjust the gap between the die lip and the core. of.

3. In the pre-blowing stage of the parison, in order to avoid the contact and adhesion of the inner surface of the parison, and to improve the uniformity of the product wall thickness, the parison should be pre-bloated. In the pre-blowing stage of the parison, blow air from below the parison into the parison to protect the parison and reduce its sag. At this stage, the factors that affect the wall thickness distribution are: pre-blowing pressure and pre-blowing time.

4. In the high-pressure blowing stage of the parison, the parison is inflated under high pressure to make it close to the mold cavity to achieve plastic molding of the product. At this stage, the common phenomenon is that the parison is deformed by high pressure inflation, and the parison deforms in contact with the mold cavity. The factors affecting this situation are: shrinkage of the material; blowing pressure and time; mold material and structure; mold exhaust system and mold cooling system, such as cooling water distribution, cooling water inlet temperature, etc.

Although there are many factors that affect the quality of blow molding products, when the production conditions and product requirements are determined, adjusting the blow molding process factors can effectively improve the quality of the products. After all, optimized process factors can increase production efficiency, reduce raw material consumption, and optimize product overall performance.