FHG Servo Motor Injection Molding Machine 100ton-1680ton | China Suppliers & Factory for High-Efficiency Production
Injection Unit
Injection Unit
Injection Unit — Detail 01
Injection Unit — Detail 02
Frequently Asked Questions
Q1
What is an injection unit in a 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 barrel, screw, heater bands, and nozzle working together to deliver precise shot volumes.
Q2
What are the key performance indicators of an injection unit?
Key performance indicators include injection pressure (bar/psi), injection speed (mm/s), shot weight (grams), screw diameter (mm), and plasticizing capacity (kg/hr). These parameters directly affect part quality, cycle time, and material compatibility.
Q3
How does the screw design affect injection unit performance?
The screw geometry — including L/D ratio, compression ratio, and flight depth — determines how efficiently the material is melted, mixed, and homogenized. Different screw designs are optimized for specific materials such as PVC, nylon, polypropylene, or engineering resins.
Q4
What maintenance is required for the injection unit?
Regular maintenance includes inspecting and replacing worn screws and barrels, checking heater bands and thermocouples, cleaning the nozzle tip, lubricating moving components, and monitoring back pressure settings. Preventive maintenance schedules help extend service life and ensure consistent output quality.
Q5
Can the injection unit handle multiple types of plastic materials?
Yes. Modern injection units are designed with interchangeable screws and barrel configurations to accommodate a wide range of thermoplastics and thermoplastic elastomers. Material-specific screws and corrosion-resistant barrel coatings are available for processing abrasive or corrosive resins.
Q6
How do I select the right injection unit size for my application?
Selecting the correct injection unit involves calculating the required shot weight, considering the material's melt flow index, evaluating the mold cavity volume, and matching the machine's injection pressure and speed capabilities to the part's geometry and wall thickness requirements. Consulting with an application engineer is recommended for complex parts.