High-Precision FHG Series Plastic Injection Molding Machine - China Suppliers & Factory for Efficient Molding Solutions
Injection Unit
01Injection Unit
02Injection Unit — View 1
03Injection Unit — View 2
Frequently Asked Questions
What is an injection unit in an injection molding machine?
The injection unit is the core component of an injection molding machine responsible for melting plastic material and injecting it under high pressure into the mold cavity. It typically consists of a hopper, barrel, screw, and nozzle assembly.
What are the main functions of the injection unit?
The injection unit performs three primary functions: plasticizing (melting) the raw material, measuring the correct shot volume, and injecting the molten plastic into the mold at a controlled speed and pressure to ensure consistent part quality.
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 impacts melting efficiency, mixing quality, and plasticizing capacity. Selecting the right screw design for specific materials is critical for optimal performance.
What materials can be processed by the injection unit?
Modern injection units are capable of processing a wide range of thermoplastic and thermosetting materials, including PE, PP, ABS, PC, PVC, nylon, and engineering-grade polymers. Specialized screw and barrel configurations are available for abrasive or corrosive materials.
How is injection pressure controlled in the injection unit?
Injection pressure is precisely controlled through the machine's hydraulic or servo-electric drive system. Modern machines allow multi-stage pressure and speed profiles during injection, enabling fine-tuned control over filling, packing, and holding phases to minimize defects.
What routine maintenance does the injection unit require?
Regular maintenance of the injection unit includes purging and cleaning the barrel and screw between material changes, inspecting the check ring and nozzle for wear, monitoring barrel temperatures, and lubricating mechanical components according to the manufacturer's recommended schedule.