High-Efficiency FHG Servo Motor Injection Molding Machine 100-1680 Tons from China Suppliers and Factory
Injection Unit
Injection Unit
Injection Unit — View 01
Injection Unit — View 02
Frequently Asked Questions
Q
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 high pressure. It typically consists of a hopper, barrel, screw, and nozzle working together to deliver precise shot volumes.
Q
What are the main functions of the injection unit?
The injection unit performs three primary functions: plasticizing (melting the raw plastic), metering (measuring the exact amount of melt needed), and injecting (pushing the molten plastic into the mold at controlled speed and pressure).
Q
How does the screw design affect injection unit performance?
The screw geometry — including its length-to-diameter ratio, compression ratio, and flight design — directly influences plasticizing efficiency, melt homogeneity, and cycle time. Different screw designs are optimized for specific materials such as PVC, engineering resins, or high-temperature polymers.
Q
What materials can the injection unit process?
Modern injection units are capable of processing a wide range of thermoplastic materials, including commodity plastics such as PP, PE, and ABS, as well as engineering-grade resins like PA, PC, POM, and high-performance polymers such as PEEK and PPS, depending on the barrel and screw configuration.
Q
How is injection pressure controlled in the injection unit?
Injection pressure is precisely controlled through the machine's hydraulic or electric drive system. Operators can set multi-stage injection pressure and speed profiles via the control panel, allowing fine-tuned filling of complex mold geometries while minimizing defects such as flash or short shots.
Q
How should the injection unit be maintained for optimal performance?
Regular maintenance of the injection unit includes routine inspection and cleaning of the screw and barrel, checking nozzle tip condition, monitoring barrel temperature zones for accuracy, lubricating moving components, and purging residual material between production runs to prevent degradation and contamination.