High-Precision FHG Series Plastic Injection Molding Machine from China Suppliers and Factory
Injection Unit
Injection Unit
Injection Unit – View 1
Injection Unit – View 2
Frequently Asked Questions
Q1
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 into the mold cavity under controlled pressure and speed. It typically consists of a barrel, screw, nozzle, and hopper assembly.
Q2
What are the main functions of the injection unit?
The injection unit performs three primary functions: plasticizing (melting) the raw polymer material, metering the precise shot volume required, and injecting the molten material into the mold at the correct pressure and velocity to fill the cavity completely.
Q3
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 melt quality, homogeneity, and output rate. Proper screw design ensures consistent plasticization and minimizes material degradation.
Q4
What materials can be processed by the injection unit?
Injection units are designed to process a wide range of thermoplastic and engineering polymers, including PP, PE, ABS, PC, POM, PA (Nylon), PET, and various glass-filled or reinforced compounds, depending on the screw and barrel material specifications.
Q5
How is injection pressure controlled in the injection unit?
Injection pressure is precisely controlled through the machine's hydraulic or electric drive system combined with the CNC/PLC control unit. Operators can program multi-stage injection profiles — adjusting speed, pressure, and position — to optimize part quality and reduce defects.
Q6
What maintenance is required for the injection unit?
Regular maintenance of the injection unit includes inspecting and cleaning the screw and barrel for wear or buildup, checking the non-return valve and nozzle for leaks or damage, lubricating moving components, and verifying temperature sensor calibration to ensure consistent processing performance and extended service life.