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Which is better, blow molding chair or injection molding chair?

July 08,2022

Today, let’s discuss which one is better, blow molding chair or injection molding chair.

Blow-molded chairs use the principle of gas pressure to inflate the hot tire stored in the mold into a chair-shaped product.

extrusion blow molding is to first make plastic into a bottomed parison by extrusion, and then move the parison to a blow mold to blow it into a product. In addition to injection machines and extruders, blow molding equipment is mainly used for blow molding. The blow mold is usually composed of two parts, which are provided with coolant channels, and the small holes on the parting surface can be inserted into the air blowing pipe.

Injection molding chair is a method in which thermoplastic or thermosetting plastic raw materials are first heated in a heating barrel and uniformly plasticized, and then pushed into a closed mold by a plunger or moving screw to form a chair. Injection-molded chairs can be made from almost any thermoplastic. Injection-molded chairs have also been successful with certain thermosets. The molding cycle of the injection molding chair is short, from a few seconds to a few minutes, the molding chair varies from large to small, and the mass can range from a few grams to tens of kilograms. finished product.

Compared with chairs produced by injection molding, extrusion blow molded chairs have the following advantages:

1. The cost of blow molding machines, especially blow molding molds, is low. When molding similar products, the cost of blow molding machines is about 1/3 of that of injection machines, and the production cost of products is also low.
2. In the process of blow molding the chair, the chair parison is formed by the machine head under low pressure to form the plastic chair, and inflated under low pressure, the residual stress of the product is small, and it is resistant to stretching, impact, and environmental The performance of various strains is high, and it has better performance. During injection molding of the injection molding chair, the melt must pass through the mold runner and gate under high pressure, which will cause uneven stress distribution.
3. The relative molecular mass of blow-molding plastic raw materials is much higher than that of injection-grade plastics. Therefore, the chair made by blow molding has high impact toughness and high resistance to environmental stress cracking.
4. Since the blow mold is only composed of female molds, the wall thickness of the product can be changed by simply adjusting the die gap or extrusion conditions, which is beneficial for products that cannot accurately calculate the required wall thickness in advance. The cost of changing the wall thickness of the product for injection molding is much higher.
5. Blow-molded chairs can produce complex, irregular and integral chairs. When injection molding is used, two or more products are first produced and then combined by snap fit, solvent bonding or ultrasonic welding.

The precision of blow-molded chairs is generally not as high as that of injection-molded products; the appearance of injection-molded chairs is often rough, which is determined by their different processes. As for which blow molding chair or injection molding chair is better, I think it should be decided according to specific needs.
Bekwell is a manufacturer of large-scale blow molding machines, which can produce blow molding chairs of various models and colors. Welcome to buy.