Common Plastic Processing & Molding Methods

Common Plastic Molding Methods，From Basics to Advanced Applications

In modern manufacturing, plastic products are widely used in packaging, automotive, home appliances, construction, and medical fields. Choosing the right molding process is critical to ensuring product quality and production efficiency.

Below are several mainstream plastic molding technologies and their industry applications:

 

1. Blow Molding

Among plastic molding technologies, hollow blow molding is one of the most important. It is particularly suitable for producing bottles, containers, and other hollow structures. The process combines air pressure with molten plastic extrusion or injection, expanding the parison against the mold cavity to form the product. It offers high efficiency, lightweight advantages, and cost-effectiveness, making it ideal for mass production of hollow plastic products.

• Typical Products: Large-volume hollow containers, complex hollow items, plastic bottles, fuel cans, water jugs, and other containers.
• Industries: Beverage and food packaging, household products, cleaning supplies, cosmetics, chemical containers.

2. Extrusion Molding

Also known as extrusion forming, plastic materials are melted at high temperature and continuously extruded through a die to form long strips, tubes, or sheets.

• Typical Products: Plastic pipes, wire coatings, building trims, sealing strips.
• Industries: Construction, electrical engineering, transportation, interior finishing.

3. Injection Molding

Plastic pellets are melted and injected into a mold cavity, then cooled and solidified into the final product. This method is suitable for high-precision plastic parts.

• Typical Products: Electronic housings, appliance parts, toys, daily necessities.
• Industries: 3C electronics, automotive components, home appliances, industrial parts.

4. Thermoforming

Heated and softened plastic sheets are stretched over a mold using vacuum or pressure, then cooled to form the product.

• Typical Products: Food trays, blister packaging, medical trays, bathtubs.
• Industries: Food packaging, medical devices, sanitary ware, retail display packaging.
  
  

5. Compression Molding

Preheated plastic material is placed in a mold, then shaped by heat and pressure, commonly used for thermosetting plastics.

• Typical Products: Electrical switch housings, heat-resistant parts, sealing gaskets.
• Industries: Electronics, automotive, aerospace, electrical appliances.

 

6. Rotational Molding

Plastic powder or liquid is placed inside a mold, which rotates and heats, allowing the material to evenly coat the mold walls. After cooling, a hollow product is formed.

• Typical Products: Large water tanks, plastic drums, toy balls, toolboxes.
• Industries: Agriculture, water management, sporting goods, toys

 

7. Foaming (Foam Molding)

Using foaming agents, plastic materials form pores, producing lightweight products with cushioning or thermal insulation properties.

• Typical Products: EPS packaging, soundproofing materials, foam cushions.
• Industries: Packaging, construction, shock-proof transport, furniture.

 

8. Casting

Liquid plastics (e.g., epoxy resin, polyurethane) are poured directly into a mold and naturally cured. This method is suitable for producing transparent or special-performance products. 

• Typical Products: Resin ornaments, transparent lampshades, small-batch models.
• Industries: Art and design, decoration, industrial prototypes.

 

Dih Hong Plastic ，One-Stop Blow Molding Solutions

Dih Hong Plastic specializes in hollow blow molding technology, with extensive experience from blow mold development, product design, to mass production optimization.

We focus on industries such as beverage packaging, daily chemical products, and industrial containers, helping clients develop high-quality, cost-effective, and efficient blow-molded products.

 

Whether you need mass production of hollow containers or the development of innovative blow-molded structures, we provide a complete one-stop service from mold design and trial runs to final manufacturing.