What are the requirements for materials used in plastic blow molding processing

Juxinchang believes that the development and application of plastic blow molding technology are complementary to the development of blow molding materials. Blow molding materials have gradually evolved from LDPE, PET, PP, and PVC products to blow molding engineering plastics, rubber, and some composite materials.

1) Special requirements for rubber materials in various plastic blow molding processing materials

A. Extrusion blow molding

Extrusion blow molding is carried out in a viscous flow state, so in order to reduce billet sagging and optimize wall thickness distribution, plastics with higher molecular weight are usually used.

B. Injection blow molding

Injection blow molding is carried out in a high elastic state, and in order to reduce the energy consumption of injection molded blanks, some easily flowable plastics (plastics with smaller molecular weights) are used.

C. Injection stretch blow molding

Non crystalline plastics are generally used because they have lower intermolecular entanglement forces and are easier to stretch. Although PET also crystallizes, it is still the main stretch blow molding material, and its crystallization rate is quite slow. In short, the vast majority of blow molded plastics have a medium to high molecular weight distribution.

2) Types of materials for plastic blow molding processing

A. Polyolefins

HDPE, LLDPE, LDPE, PP, EVA are generally used for blow molding industrial products, containers and toy accessories, storage containers for chemical drugs, etc.

B. Thermoplastic polyester

PETG and PETP are mainly used for blowing carbonated beverage packaging bottles, wine bottles, etc. They have gradually replaced PVC and are widely used. The disadvantage is that their cost is relatively high, mainly used for injection pull blow molding.

C. Engineering plastics (alloys)

ABS, SAN, PS, PA, POM, PMMA, PPO, etc. have gradually been applied in industries such as automotive, pharmaceutical, home appliances, and chemical, especially PC and its blended plastics, which can blow produce high-quality containers and automotive products (PC/ABS, etc.).

D. Thermoplastic elastomer

Usually, SBS, SEBS, TPU, TPE and other blow molded materials are used as rubber materials, while thermosetting plastics, vulcanized rubber and cross-linked PE cannot be blow molded.