Compression Molding

We review your component specifications and CAD drawings, as well as your required volume to see if injection molding would be suitable.

We help you choose the right material for your performance and cost goals.

Polymer granules are heated until molten, then pressed into a precisely engineered mold. The polymer cools and solidifies into the required shape, after which the mold opens and the finished component is ejected.

Your component(s) are then fully inspected and sent to you with a CoC.

You’d choose compression molding when the part’s material and shape suit pressing in a mold—especially for relatively simple, large, or flat parts, such as a rubber gasket or panel. It can be attractive for low- to medium-volume production when you want to keep tooling costs down.

Compression molding is very dependent on the plastic and its glass fiber-reinforced composites being used. Here are some examples of components created by this process: 

• Rubber seals, gaskets, O-rings and pads, especially larger or simpler shapes. 
  
• Large plastic parts with fairly simple shapes, such as trays, covers and panels. 
  
• Fiber-reinforced composite parts, including lightweight structural components where strength and stiffness matter. 
  

Compression molding is useful for making repeated polymer or composite parts, particularly those with relatively simple or large shapes. It can offer an economical way to produce consistent parts when the material and design are well suited to being pressed into a mold.

Compared with CNC machining, compression molding requires an upfront investment in a mold but can reduce the work needed to make each part. Compared with injection molding, it may have lower tooling costs for simpler parts, although injection molding is often better for intricate shapes, tight tolerances or very high production volumes.

• Can have lower tooling costs than injection molding for suitable parts.
  
• Works well for large, fairly simple shapes.
  
• Can produce parts from thermoset polymers and fiber-reinforced composites.
  
• Makes repeated parts with a consistent shape once the mold is set up.
  
• Can form strong, lightweight composite components.