CTE Scaling Calculator for Composite Tooling

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.

Tooling Material

Ambient Temp °C

Resin Cure Temp °C

Linear CTE (10^-6 K^-1)

Linear Expansion

Component Material

Component CTE (10^-6 K^-1)

Component Expansion

Overall Expansion

Shrink Factor (linear in all axes)

Example

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

Applying a scaling factor means a m long tool at ambient is estimated to be m long at °C. The lay-up is estimated to then shrink to 1m long at °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.