What are the specific technical means for optimizing the design of screw barrels in injection molding machines?

1. Material selection

High wear-resistant and corrosion-resistant materials: Screw barrels are usually made of nitrided alloy steels such as 40Cr, 45Cr, and 38CrMoAIA. These materials have high hardness (HV850 or above) and corrosion resistance, which can improve wear resistance and service life.

Double alloy screw: A double alloy screw containing tungsten carbide is used, with a hardness of up to HRC58-60 and high temperature resistance (below 550℃), suitable for high-wear processing products.

Special alloy steel: Such as GH113 material, which has excellent wear resistance and is suitable for high-temperature and high-pressure injection molding machines.

2. Structural design

Separation type, barrier type or diversion type screw: Different types of screws are selected according to the characteristics of the plastic to optimize the plasticizing effect. Separation type screws are suitable for crystalline plastics such as polyolefins, barrier type screws are suitable for plastics with poor thermal stability, and general-purpose screws are highly adaptable and can process a variety of plastics.

Mutation screw: suitable for crystalline plastics such as polyolefins and polycarbonates, with a long compression section and intense energy conversion.

New screw design: such as the screw structure mentioned in the patent of Terry Machinery, the design of annular resistance ring and check ring reduces the friction between the thread and the barrel and improves the material conveying efficiency.

3. Surface treatment

Hard chrome plating: The surface of the screw for corrosive materials is hard chrome plated to improve its corrosion resistance and wear resistance.

Nitriding treatment: The hardness and wear resistance of the screw are improved through the nitriding process to extend the service life.

4. Equipment maintenance

Regular inspection and cleaning: avoid metal fragments and debris from entering the barrel, ensure that the plastic is completely melted, clean the new residual plastic, and check the wear of the rubber head.

Preset temperature and pressure: ensure that the screw reaches the preset temperature and maintains a stable pressure to avoid poor plasticization due to unstable temperature or pressure.

Bimetallic repair technology: repair and refurbish the old screw, and make the old screw more durable through processes such as grinding, reaming, nitrogen treatment and alloy inlay.

5. Other optimization measures

Overall optimization of injection molding machine: combine other parts of the injection molding machine (such as nozzles, flanges, etc.) for overall optimization design to ensure the smoothness and plasticization effect of the material in the channel.

Intelligent monitoring: real-time monitoring of temperature, pressure and other parameters through sensors and PLC control systems to optimize the production process

6. Case analysis

Application of double alloy screw: suitable for processing plastics containing a large amount of glass fiber (such as PC, PPO, PP, PET, etc.). The design of double alloy screw significantly improves the processing efficiency and product quality.

Application of new screw structure: The patented design of Terry Machine solves the wear problem of traditional screws under high load by reducing the friction between the thread and the barrel, and improves the material conveying efficiency.