High-Precision FHG Series Plastic Injection Molding Machine from China Suppliers | FUHONG Factory
Injection Unit
Injection Unit
Injection Unit – View 01
Injection Unit – View 02
Frequently Asked Questions
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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 under high pressure into a mold cavity. It typically consists of a hopper, barrel, screw, and nozzle working together to plasticize and deliver the molten material.
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Q What are the key performance parameters of an injection unit?Key parameters include injection capacity (shot size), injection pressure, injection speed, screw diameter, screw L/D ratio, and plasticizing rate. These parameters determine the range of materials that can be processed and the quality of the final molded parts.
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Q How does the screw design affect injection unit performance?The screw geometry — including flight depth, compression ratio, and L/D ratio — directly impacts melt homogeneity, plasticizing efficiency, and shear heat generation. Different screw designs are optimized for specific material types such as general-purpose resins, engineering plastics, or rubber compounds.
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Q What maintenance is required for an injection unit?Regular maintenance includes inspecting and replacing the screw and barrel for wear, cleaning the nozzle and check ring, lubricating moving components, verifying temperature sensor accuracy, and purging the barrel when changing materials or after extended downtime to prevent degradation.
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Q Can the injection unit process different types of plastic materials?Yes, injection units can be configured to process a wide range of thermoplastic and thermosetting materials. However, the barrel, screw, and nozzle materials and geometry must be matched to the specific resin being processed to ensure optimal performance, longevity, and part quality.
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Q What causes inconsistent shot weight in the injection unit?Inconsistent shot weight can result from worn check rings or screws, unstable back pressure settings, improper melt temperature, screw slippage due to poor feed zone conditions, or variations in raw material bulk density. Regular calibration and maintenance of the injection unit are essential to maintain consistent shot-to-shot repeatability.