The PS material is used in ballpoint pen injection molding. The production process of the injection molding machine using PS material in the manufacturing process of the ballpoint pen is as follows 5 steps:
- Material preparation
- Drying
- Injection molding
- Molding process
- Post-processing
Material preparation:
First, the PS (polystyrene) raw materials are mixed into the mixer according to the proportion to ensure the uniformity of the raw materials.
Drying:
As PS material has a very low water absorption rate, it needs to be dried to avoid moisture absorption affecting the molding quality. The drying temperature is generally around 50°C.
The PS material is used in ballpoint pen injection molding:
Barrel temperature:
During injection molding, the barrel temperature is generally controlled between 160℃ and 180℃. This temperature range can ensure the full melting of the PS material.
Injection speed:
The injection speed should be as slow as possible to avoid the formation of weld lines, which can improve the transparency and strength of the product while reducing internal stress.
Injection pressure:
The injection pressure is generally between 30 and 150 MPa, and the specific pressure is adjusted according to the thickness and shape of the plastic product.
Mold temperature:
The mold temperature is usually below 70°C to ensure that the product can be demoulded smoothly.
Molding process:
Filling stage:
The molten PS material is injected into the mold through the nozzle of the plastic injection molding machine to fill the mold cavity.
Holding pressure stage:
After the filling is completed, the injection molding machine continues to apply pressure to ensure that the material fully fills the mold and eliminates internal stress.
Cooling stage:
After filling and holding pressure are completed, the mold closes and begins to cool. The cooling time is adjusted according to the thickness and shape of the plastic product.
Demolding stage:
After cooling is completed, the mold opens and the product is ejected from the mold.
Post-processing:
Trimming: Manually trim the injection molded PS products to remove excess scraps.
Inspection: The finished products are inspected and unqualified products will be crushed and reused in production.
Conclusion
Through the above steps, the PS material is processed into the shell of the ballpoint pen/gel pen in the plastic injection molding machine and finally assembled into a complete ballpoint pen.
