Plastic Injection Molding

What’s plastic injection molding?

Plastic injection molding technology uses an extruder to inject molten plastic material into a metal mold. The molten plastic is poured into this confined space and allowed to cool and solidify to obtain a plastic finished product with the same shape as the closed space. It is called injection molding. It is the most important and widely used technology in plastic molding.

How does injection moulding work?

The principle of injection molding is to pour plastic raw materials into the barrel of an extruder. Then, the raw materials are stirred by a rotating screw device and are heated and melted in the heating barrel of the extruder. Under the alternating operation of spiral rotation and oil pressure propulsion, liquid plastic is ejected from the cylinder under high pressure to fill the space in the metal mold, and then cold water is immediately sent into the metal mold to lower the temperature. After cooling and hardening, the molded products can be taken out of the mould.

These processes can be fully automated and can be produced continuously at high speed. The speed is very fast. On average, a cup can be completed in about 10 seconds, while a plastic tube of ballpoint pens can be produced in 1 second. Even large pieces, like car dashboards, can be completed in 3-4 minutes. Among all the molding methods, it is the fastest and suitable for mass production. Besides, the dimensional accuracy of molded products is high, and the quality is very stable.

From simple-shaped cups to complex-shaped car dashboards, from 0.01g of pinions for watches to large-scale products over 20Kg bathtubs, all can be produced by injection molding. The advantages of plastic molding and the reasons why it is popular in the industry include:

• ⇰ Less loss of raw materials
• ⇰ Easy completion and processing
• ⇰ High flexibility for materials and colors
• ⇰ Color during molding
• ⇰ Beautiful appearance

Also, costs can be greatly reduced during mass production.

• Plastic injection molding process:

• 1. Provide samples or design drawings (2D / 3D)
• 2. Confirm product material, weight, color, and specifications
• 3. CHANG YANG provides quotation according to demand
• 4. Material preparation & entering production schedule
• 5. Mold development
• 6. Mould test
• 7. Quality Control Inspection
• 8. Mold repair & trial molding mold completed
• 9. Mass production
• 10. Secondary processing (Pad printing, bronzing, plating)
• 11. Assembly
• 12. Ship

• Material

• ❚ ABS
• ❚ PP
• ❚ POM (Polyoxymethylene)
• ❚ nylon
• ❚ TPR
• ❚ AS
• ❚ CA (Cellulose acetate)