How Does Injection Molding Work?
During the injection molding process, resin powders or pellets are dispensed into a hydraulic press via a hopper, heated to their liquification point, and injected into the die via a pressurized screw or plunger. In the mold, the liquid resin is distributed into the various cavities via a main channel or sprue. Once the material cools and solidifies, the finished products and sprue are ejected. Hydraulic injection molding presses are often engineered in a horizontal configuration to allow for optimal material flow into the die cavities.
Reaction Injection Molding (RIM) is commonly used to manufacture polyurethane by combining two liquid polymers. Once pumped or injected into the heated mold, the liquids generate an exothermic reaction to create the desired polyurethane. The finished part could be rigid or flexible depending on the polymers. Presses used for RIM act as large clamps that hold the tooling closed while the substrate inside cools and hardens. RIM presses are often low tonnage (under 100 tons) and can have rotating and/or tilting bases to facilitate even coating of the liquids inside the die cavity.
Advantages of Beckwood Injection Molding Machines
Whether you’re performing traditional injection molding or reaction injection molding (RIM), Beckwood’s hydraulic and servo-electric injection molding presses offer accuracy and precision no competitor can match. Using the press’ fully-programmable controls system to collect, measure, and analyze various cycle parameters, you can save and recall optimal part recipes with ease. Additionally, Beckwood uses multiple electric heating rods within each platen to create heating “zones” which can be adjusted independently or together depending on the type of material being injected.
- Customizable plunger ram & bore cylinder sizes
- Swivel and tilt capabilities ensure even application of injected material & reduce air pockets
- Optional dispensing systems and automation equipment can be integrated into a turnkey package
- Optional booking ram for easy die maintenance and part extraction
- Capable of traditional injection molding, RIM, SRIM, and RRIM
- Multi-zone heated platens for ultimate temperature uniformity
- Press frame built for Infinite Life™