Solvent-free powder coats heat-sensitive plastics

Dulux Powder Coatings and the CSIRO claimed that Customcoat QP solvent-free powder coating technology can be applied to heat-sensitive plastics and cured at low temperatures.

Dulux Powder Coatings and the CSIRO said their Customcoat QP technology is attracting world-wide interest It is claimed to be the world’s first solvent-free powder coating that can be applied to a wide range of heat-sensitive plastics and cured at low temperatures.

Customcoat QP won a Premier’s Sustainability Award in Victoria Customcoat QP can reduce the waste, CO2 emissions and damaging volatile organic compounds (VOCs) that result from solvent-based paint finishes.

CSIRO/Dulux said that discussions have already taken place with a major European furniture manufacturer, a German automobile manufacturer, Chinese furniture and automobile manufacturers and the aerospace sector.

Of the total VOCs released into the environment, over 70% is generated by vehicles and domestic sources, and up to 20% from industrial applications such as spray painting in the automotive industry.

Because the coating can be applied to plastics, it also allows many metal parts to be replaced with lighter, less expensive plastics parts, which generate less waste, emissions and VOC during the coating process.

* Research – Customcoat QP has involved more than a year’s research and development by half a dozen scientists from the CSIRO Division of Materials Science and Engineering and Dulux Powder and Industrial Coatings.

Dulux’s technical manager for Powder and Industrial Coatings, Bill Matthews, said: "The challenge in this project was to overcome the previous limitations of spray-on powder coatings.

This has involved the CSIRO’s patented new technology that allows plastic to become conductive to electricity, and Dulux’s development of a powder coating that can be applied to plastics and cured at low temperatures".

The electrostatic "Corona" spray process requires negatively-charged powder to be transferred on to an earthed metal object.

As plastics could not be earthed, industries have used metal substrates up until now.

* Makes plastics substrates conductive – the Customcoat QP not only makes the plastics conductive, but ensures better adhesion of the Customcoat QP powder coating, which is then cured.

The resulting product looks like a painted metal surface, which can then be used in a host of applications including car dashboards, consoles, and components found under the bonnet or in the car boot.

Development of this project has been supported by Sustainability Victoria, which provided a grant of A$440,000 for R and D.

Customcoat QP won a products award in the Premier’s Sustainability Awards in Victoria, during May 2008.

* Significant environmental benefits of Customcoat QP – when conventional liquid coatings are sprayed on to plastics parts, up to 70% is lost either as solvent or solid waste.

The solid waste is collected, treated and disposed of in landfill, with about 2.5 million kg being dumped each year.

The solvent waste is released to the atmosphere as VOCs, and the Australian Paint Manufacturers’ Federation estimates that in the automotive industry alone, the annual consumption of 10 million litres of paint releases up to 7000 tonnes of solvent into the atmosphere.

With Customcoat QP, powder that doesn’t land directly on the sprayed item can be recycled and reused, so waste is eliminated.

No VOCs are contained in the product, and because sprayed items are cured at low temperatures, there’s also a reduction in CO2 emissions.

"In conventional applications, baking temperatures would be at about 180 degrees Celsius," said Matthews.

"Because we are baking only at 130 to 140 degrees, about 50% less energy is required to heat the ovens.

By reducing the heat you’re reducing the environmental impact, not to the mention the cost savings in energy".

* Product costs – the price of Customcoat QP is very similar to that of conventional powder coatings.

While new plant will be required by manufacturers changing over to this product, it provides them with a new tool to reduce their carbon footprint and overall environmental impact, said CSIRO/Dulux.

Mathews told manufacturingtalk that the biggest issue is the culture of change.

He continued: "There are obviously issues with capital investment, but when new plants are required, that’s the time to do it." Later in 2008, Matthews, and the CSIRO’s team led by Dr Voytek Gutowski, will brief the automotive industry on this product, in conjunction with Sustainability Victoria.

There are significant benefits for the designers of many products, as the use of Customcoated plastics reduce weight and cost, as well as environmental impacts.

The product can be applied just to colour the surface of plastics, which is a far cheaper option than pigmenting the entire product.

A multi-million dollar market is emerging, and Matthews said Dulux and the CSIRO would jointly licence the technology around the world.

Dulux Powder Coatings is a member of the Green Building Council of Australia, and is opening a new plant in Melbourne’s Dandenong South area in mid 2008.