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DESIGN HINTS FOR EXTRUSION |
MATERIALS: |
Material selection is an important factor for part functionality and extrudability. There is a wide range of thermoplastics available, each with different properties and characteristics. Detailed information of the application is essential to the proper choice. We then can offer our expertise to provide a truly custom solution |
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WALL THICKNESS:
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Common wall thicknesses are run between 0.7mm(0.030") and 3.175mm(0.125") thick. Maintain as even as possible. Make unavoidable changes as gradual as possible. Heavier wall thickness requires more material and therefore slower production rates. Details on the inside of tubes should be thinner than the tube walls. Rule of thumb: make detail thickness 70% of tube wall. |
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THROUGH HOLES:
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Avoid through holes if possible. For screw-hole locations, we prefer two legs that wrap around the screw. Tiny through holes are expensive to tool and produce. |
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RADII:
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Large radii in intersections create a larger mass of material versus the wall beside the intersections and will cool at a slower rate. This can cause stresses, bows and cambers. These need to be avoided as do sharp corners which are difficult to extrude and also provide stress risers. |
LENGTH: |
Length for most thermoplastics will vary approximately 0.2mm(0.008") in every linear foot length for every ten degree Fahrenheit temperature change. |
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TOLERANCES:
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Tight tolerances are possible for a few dimensions depending on the complexity of the part. The tighter the tolerances are, the more expensive the extrusion. Mating parts must fit within the tolerance range. |