Plastic Products Making from Blow Moulding

Polyethylene (PE) Blow Molding is a plastic manufacturing process used to create hollow, cylindrical containers from thermoplastic polymers like high-density polyethylene (HDPE) or low-density polyethylene (LDPE). The term "blow molding" refers to the technique where molten plastic is injected into a mold that has a pre-formed inner cavity. As the mold closes, air or another gas is introduced, forcing the plastic to expand and fill the mold. Once the mold cools and solidifies, the part is removed, resulting in a seamless, hollow container.

 

Here's a step-by-step breakdown of the process:

 

1. Material preparation: The PE pellets are melted in an extruder and then heated to a suitable temperature for Injection Molding.

 

2. Injection molding: The molten PE is injected into a closed mold, which consists of two parts – an outer mold and an inner mold cavity. The inner mold cavity has the shape and size of the final product.

 

3. Blowing stage: Before the mold closes, a small opening is made, through which a pressurized gas (usually air or nitrogen) is introduced. This gas expands rapidly, pushing the plastic against the mold walls, causing it to take on the desired shape.

 

4. Cooling and solidification: The mold halves are then separated, and the part is allowed to cool down until it becomes rigid. The internal pressure from the gas is released, and the part is removed from the mold.

 

5. Post-processing: Any burrs or flash material is trimmed, and the part may be subjected to additional treatments such as surface coating, printing, or trimming to achieve the final product.

 

Applications of PE blow molded products include bottles, jugs, tanks, fuel containers, and various industrial packaging items due to their lightweight, durable, and cost-effective nature. The process is widely used in the food and beverage, chemical, and consumer goods industries.