Compression Molding: Facts & General Information

Where Does Compression Molding Really Shine?

• When you need parts stronger than "plastic"

• Because some materials are as strong and as stiff as aluminum

• If your part contains highly complex geometry with a lot of detail, changing thickness, and different features

• If you want your part to be made with 2 or more different materials, called hybridizing

• When you take advantage of the low CTE (0–6 ppmoF) offered with all of our Carbon Fiber moldings

• If you want to co-mold in inserts, bushings, or other features

• Sometimes, we can even make the part from prototype tooling

What Compression Molding Does Not Do Very Well?

• It does not compete well with traditional layup / laminate composites

• It might not the best choice if you only need one or two parts. However, we sometimes can consider "soft" prototype tooling!

Here are Some Good Design & General Use Rules of Thumb

• Tolerancing:

  • General Tolerances:+/- 0.008-0.012 in. 

  • Select Features:+/- 0.005-0.007 in. 

  • Iterative Tool Modifications:+/- 0.003-0.005 in.

• Routine Minimum Wall Thickness(s) of ~ 0.040 - 0.050 inch (Thinner Requirements Are Geometry & Material Dependent)

• CTE Values Range From 0-6 ppm°F For Carbon Fiber Moldings

• Provide for a design update to match the attributes of compression molding