Plasma treatment solves sticky problem
6 Jul 2001
Replacing metal car parts with plastic gives automotive manufacturers a host of benefits but getting such components to from a strong adhesive bond to the frame of a vehicle has been a major challenge.
Now a collaborative research team led by the University of Warwick's Warwick Manufacturing Group have found a simple plasma pre-treatment process that solves that problem.
Until now one of the most effective ways of solving this problem has been to use friction welding but that process can leave unacceptable amounts of unsightly weld swarf marks which are difficult and expensive to remove from the surface of plastic components.
The research team considered a number of other processes that might prove more acceptable and finally hit upon a plasma treatment that was already being used in the US to apply paints and labels to plastic products.
Rebecca Cain, a research fellow with the University of Warwick's Warwick Manufacturing Group, worked with Hamilton machinery sales Ltd, adhesive suppliers Gurit-Essex and Dow Automotive, polymer supplier Solvay Engineered Polymers, car component manufacturer Linpac Automotive, and Bristol University.
They developed a process that allowed large plastic components to be easily applied to automotive bodies.
They devised a simple method that fixed a plasma spraying tool to a robot arm.
This was used to rapidly treat / oxidise the mating surfaces of plastic car components. The mechanism deposits oxygen based 'hand holds' onto the surfaces.
These handholds are said to greatly increase the performance of the adhesives used to bond the components. The bonds created by adhesives used on the surfaces treated with this technique have passed all the standard automotive impact tests.
A further advantage of this method is that once treated by the plasma the component stays treated for up to a month allowing significant flexibility in the manufacturing process.
