High-Precision FHG Series Plastic Injection Molding Machine - China Suppliers and Factory for Efficient Molding Solutions
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Injection Unit
Injection Unit
Injection Unit — 01
Injection Unit — 02
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Frequently Asked Questions
Q
What is an injection unit in an injection molding machine?
The injection unit is the core component responsible for melting plastic material and injecting it into the mold cavity under controlled pressure and speed. It typically consists of a hopper, barrel, screw, and nozzle.
Q
What are the main functions of the injection unit?
The injection unit performs three primary functions: plasticizing (melting the raw material), injecting (pushing the melt into the mold), and holding (maintaining pressure to compensate for material shrinkage during cooling).
Q
How does the screw design affect injection unit performance?
The screw geometry — including its length-to-diameter (L/D) ratio, compression ratio, and flight depth — directly affects plasticizing efficiency, melt homogeneity, and injection consistency. Different screw designs are optimized for specific resin types.
Q
What materials are compatible with a standard injection unit?
Standard injection units are compatible with a wide range of thermoplastics including PP, PE, ABS, PC, POM, and nylon. For engineering or high-temperature resins, specialized barrel and screw materials (such as bimetallic or nitrided steel) may be required.
Q
How do I maintain the injection unit for long-term reliability?
Regular maintenance includes purging the barrel when changing materials, inspecting and replacing worn screws or check rings, monitoring barrel temperature uniformity, and lubricating moving components according to the manufacturer's schedule.
Q
What factors should be considered when selecting an injection unit?
Key selection factors include shot size (injection volume), injection pressure and speed requirements, the type of plastic material to be processed, screw diameter, and compatibility with the mold and clamping unit specifications.