Extrusion Part Design

There are a few basic guidelines for designing extruded plastic parts. Most of the guidelines are in place so that designing an optimized extrusion die is possible.

Use Generous Radii

On all internal and external corners, use generous radii to aid flow and strengthen the part. Click here for the draft section for injection molding (it is not all relevant to extrusion, but the concept is explained). For extrusion, the minimum recommended radius is 0.020”.

Maintain Uniform Wall Thickness

In order to maintain a constant flow velocity throughout the entire die, uniform wall thickness is strongly recommended. To produce a quality extruded part, all sections of the die must output plastic at the same rate. Thick part sections will tend to output more plastic, greatly hampering optimized production. Click here for a discussion of uniform wall thickness in injection molding.

Avoid Very Thick Walls

For cooling and flow problems, very thick walls should be avoided. Most extruded parts are about 0.080” – 0.150” thick.

Minimize Hollow Sections

Minimize the use of hollow sections. Hollow sections are difficult to produce, and may require special procedures and equipment.