PlyableTangible

CTE SCALING CALCULATOR FOR COMPOSITE TOOLING

Calculate a shrink factor to apply to your tooling design.

How CTE scaling works

During the cure cycle of a composite lay-up both the tool and the lay-up expand during the heat cycle.

The tool will expand and contract at a specific rate determined by the material and construction techniques utilized. At the peak of the heat cycle the composite lay-up will cure and become rigid.

To produce a dimensionally accurate part a shrink factor can be used prior to tool fabrication. By estimating the tool size at its greatest expansion point the percentage difference between this calculation and the dimensions at ambient can be applied to the base design.

It is also possible to account for shrinkage of the composite as it cools back to ambient in a similar way.

Pick a material below to calculate a shrink factor for your tooling geometry.

Your estimated shrink factor

Shrink factor (linear in all axes)

0.99612

Overall expansion

0.390%

Inputs
Results
Linear CTE (10-6 K-1)
39
Linear expansion
0.390%
Shrink factor (linear in all axes)
0.99612

Example

A 1m long tool at ambient is estimated to be 1.00390m long at 120°C.

Applying a 0.99612 scaling factor means a 0.99612m long tool at ambient is estimated to be 1.00000m long at 120°C.

This tool uses the coefficient of thermal expansion (CTE) from the material datasheet to estimate how a material will expand.

The scaling factor is an estimate. Plyable does not guarantee or provide any warranty of the provided figures.

Need help applying this to a tool?

Talk to the Plyable team about tooling design, materials, and how this shrink factor should be applied to your geometry.

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