Z-pinning

It is designed for use within pre-preg technology; there is extensive experimental evidence that Z-pinning dramatically improves the resistance of the composite structure to delamination.

The pin spreads the fibres and creates an oval shaped gap that is filled with resin.

[3] Z-pinning is a versatile technique that can be applied to many materials that will benefit from added strength and durability.

One process consists of pulling a continuous-fibre tow through a bath of liquid resin using a pultrusion machine.

This process is one of the more efficient and cost effective ways of producing Z-pins because it can be easily adapted to different pin sizes.

The vibrating chamfered tip of the Z-pins locally heats up and softens the resin allowing the Z-fibre to penetrate the preform with minimal disruption of the long fibres.

[3] A hand-held ultrasonic gun can also be used to insert Z-pins on a small scale production.