High Volume Manufacture and Inspection Processes for Composite Pipes

Thermoplastic composites are gaining favour in place of traditional thermoset versions for their toughness, ease of recycling and ability to be manufactured in high volume without autoclaves. The High Volume Manufacture and Inspection Processes for Composite Pipes project aims to develop novel manufacturing and inspection processes for production of cost-effective thermoplastic composite tube, and to fully qualify the material.

The consortium comprises Sigma Precision Components (lead), Pultrex, Laser Optical Engineering and University of Manchester. The project will develop a pultrusion process to make high-quality thermoplastic composite tube and a semi-automatic laser shearography inspection system to check for flaws. The carbon /thermoplastic material will also be one of the first to be fully characterised for aerospace use. The partners will need to ensure the processes are capable of achieving cost and productivity targets while maintaining product quality.

Sigma is a manufacturer of metallic aerospace pipe assemblies and has developed thermoplastic composite tube technology that can be used for lightweight pipe assemblies and torque shafts. To fully capitalise on market opportunities, Sigma will perform a work package to fully qualify the thermoplastic composite material (overseen and published by NCAMP) through a series of coupon tests. Currently there are very few thermoplastic composites published in the industry's Composite Materials Handbook 17. In addition, the manufacturing costs for the tube need to be reduced, addressed by the two other work packages

Although pultrusion is an established technology for making various thermoset composite sections, Pultrex (a UK based manufacturer of pultrusion equipment) will develop innovative solutions to adapt the process for thermoplastic tubes, in particular the heating and cooling systems and consolidation die design. University of Manchester will assist by transferring knowledge from their laboratory pilot process, and maintain close academic interest for teaching purposes. Pultrex also anticipates potential sales of this equipment in other sectors such as automotive.

For the third work package, Laser Optical Engineering will adapt one of their existing laser shearography systems to inspect composite tubes for flaws such as inclusions, porosity and delamination. The system will use special lasers, cameras and semi automatic image analysis to inspect the tube more quickly than traditional C scanning techniques. Their innovation will focus on miniaturising a rugged system for both industrial use and for inspecting composite structures on aircraft during maintenance, or even wind turbine blades.