The injection molding process creates rubber and plastic parts by melting the polymer material into a liquid, then filling a detailed mold with the melted material. Once the polymer cools, the removal cycle begins leaving a fully formed component. Injection molding is well-suited to the high-volume production of parts with complex design shapes.


Injection Molding Process Cycle

The injection molding cycle typically encompasses four steps:

  1. Clamping. Injection molds consist of two pieces that attach to the injection molding equipment. A hydraulic clamp forces the two mold halves together with a high level of force to keep them from leaking molten polymer material that gets injected.
  2. Injecting. Polymer pellets are fed into a hopper, where they are heated into a liquid form. From there, the molten material travels along a series of heated runners and/or sprues from the hopper into the mold. The mold is filled at sufficient speed to create enough pressure to fill the various crevices and complex design elements within the mold cavity. 
  3. Cooling. The melted polymer cools inside the mold and hardens into the mold shape. The cooling process is usually the longest portion of the injection molding cycle.
  4. Removal. Once the injection-molded part has cooled inside the mold, it is ejected from the mold using a built-in ejection mechanism in the rear of the mold that pushes the part free. Once the part has cleared the mold, the mold can be clamped shut to begin the next cycle.


Our Injection Molding Capabilities

The Plasticoid Company uses our injection molding capabilities to create standard and custom thermoplastic injection molded parts. We primarily use domestically sourced low-density polyethylene (LDPE) or polypropylene in our injection molding processes. We have supported numerous industries with our contract injection molding services, including:

  • Cosmetics
  • Medical equipment/devices
  • Personal care
  • Pharmaceuticals
  • Plastic pipes

We follow the FDA’s CRF 21 guidelines when producing food processing and pharmaceutical components. 


About The Plasticoid Company

The Plasticoid Company is an ideal partner for your rubber and plastic components. With more than 75 years of experience in rubber and plastic molding, we are the best choice for sourcing high-quality molded parts. To see how our injection molding services can support your project, please contact us today.