Polymer Breakthrough Solves A Sticky Problem

The revolutionary SICOR technology will also help the plastics and paints industries to attain higher environmental standards by eliminating the need for damaging solvents and ozone-depleting chemicals, while at the same time reducing costs.

In another major application, SICOR will for the first time enable waste polyethylene, which normally clogs up city landfills, to be efficiently recycled for new uses - lowering both the energy use and greenhouse emissions involved in plastics production.

The Chief of CSIRO Building Construction and Engineering, Mr Larry Little, says that SICOR is already being introduced in the Australian automotive industry, to bond paint to the surface of moulded polymer vehicle parts, and plastics mouldings to metal panels.

“SICOR is a revolutionary technique for engineering the surface of polymers, especially substances like polypropylene and polyethylene, which have traditionally been difficult to bond,” Mr Little says.

“Tests show that it bonds automotive paints to moulded polymer parts like bumper bars so strongly that the polymer itself will break before the paint can be pulled from the surface.

“In one trial SICOR was used to stick plastic mouldings to the sides of a Holden Carprice which then underwent 40,000 kilometres of road testing, much of it on very rough terrain. At the end of the test, it proved impossible to remove the mouldings without damaging the door panels.”

Mr Little says that the potential uses for SICOR are very wide, and include building products, defence equipment, the vehicle industry, packaging and biomedical uses.

“We are confident this technology will bring hundreds of millions of dollars worth of export revenue to Australia,” he says.

Already, a $16 million licencing agreement has recently been signed with a US building products company.

“One of SICOR’s most important features, in addition to adhesion strength and environmental benefit, is the fact that it reduces cost by allowing the use of cheaper materials, more efficient processes compared to plasma treatment and increased shelf-life of treated products,” Mr Little says.

The SICOR technique can easily be integrated into existing manufacturing systems, treating polymeric products at speeds up to 300 metres a minute. Once a product has been treated, any future bond with paint or plastic will be equally strong whether the adhesive or paint is applied at once - or 12 months later.

Project leader Dr Voytek Gutowski explains that what makes SICOR so attractive is the way it modifies the surface characteristics of the product without affecting the bulk properites of the material in a simple continuous process.

A CSIRO pilot plant to prove the effectiveness of SICOR for the automotive industry was established in Melbourne in January 1997. Its results support a successful trial of the technology by General Motors Holden, which included the 40,000 km road test.

Validation tests also proved the ability of SICOR to significantly exceed the bodyside moulding adhesion specifications of Ford Australia.

More information:
Mr Damien Thomas, CSIRO
email : Damien.Thomas@dbce.csiro.au