Pull leads a push in high-tech materials.
A research team at the Warwick Manufacturing Group at the University of Warwick has developed a new technique for creating composite materials which had previously been thought impossible.
The research enables the new materials reinforced with glass fibre to find new ultra-lightweight uses in cars and construction instead of metal. It could even pave the way for making composites in space.
Composite materials, with their lightweight advantages, could have many uses but handling and assembly of materials with different properties to create composites brings drawbacks as well as benefits, particularly in processing techniques.
One obstacle with composites has been the difficulty of joining materials. This makes it hard to create complex shapes.
Warwick researchers Dr David Britnell and Dr Gordon Smith have developed a process which avoids this drawback with a technique that eliminates the need to use corner joints for complex shapes.
By adapting pultrusion techniques, the researchers can create fibre-reinforced components in complex shapes. Pultrusion is the opposite technique to extrusion and involves the pulling of fibres through a resin in a die.
Ultraviolet light rather than heat is applied to cure the resin coated fibres and the pultruded composite shape is manipulated by a computer controlled robot.
Dr Smith's first idea to was to heat the materials with a laser but found that a focused ultraviolet source provided the energy needed to cure the composite.
Pultrusion usually relies on pulling resin coated fibres through a long, heated die. The die shapes the material, creating continuous shapes, such as round bars, angles or rectangular hollow sections.
The heat from the die cures the resin as the composite forms - but by using pultrusion and UV light rather than heat from a die to cure the resin, they have increased the range of shapes that are open to composites.
"You can do extremely complicated shapes - for example, window frames without a joint," says Dr Smith.
As well as its ability to create new shapes, the technology also allows manipulation of the fibres emerging from a die, for example, twisting the fibres during the heating stage to strengthen the composite.
The researchers believe that their work could benefit many industries.
In car production, the composites could be an alternative to steel and aluminium in space frames like chassis.
Automotive companies are already using pultrusion techniques to form metal frames for car manufacture but this research would help along the substitution of lightweight composite materials.
The technique might also have an application in the manufacture of window frames.
In concrete, fibre composites could substitute for steel reinforcement where corrosion is a hazard.
In space, it might be possible to produce materials that could be processed in orbit - the sun might even provide the energy to cure the resins.