Curtain call for locally developed clearcoat

Compared with a van-style trailer, a ‘curtain-sider’ throws up a lot of challenges for the coatings necessary to protect it. Where a conventional refinish clearcoat (as used on cars and trucks) is fine for the rigid sides of a van trailer, the characteristics required for use on PVC curtains are quite different. The clearcoat must not only adhere to the woven curtain structure and provide a glossy finish and sufficient UV protection, more importantly it must be flexible enough to allow the curtain to be rolled and unrolled day-in, day-out over long periods. As the world’s largest manufacturer of transportation coatings and the leading supplier of coatings to curtain manufacturers across the region, PPG swung into action to develop a solution, with its Research and Development team at the company’s Clayton, Melbourne headquarters taking the lead. First on the agenda was to explore PPG’s global technology storehouse, says PPG Senior Technical Officer, Paul Finn.

“We were able to access an excellent High Solids clearcoat resin system which gave a fantastic foundation to build on. In basic terms, we added a flexibilising resin to the formulation to make the whole coating flexible after it’s cured. The result is F4977 DELFLEET® HS Ultra Flex Clear and our customers love it. In fact, the vast majority of new curtains in Australia and New Zealand are manufactured using this next generation clearcoat technology.”

“Another beauty of this product is that it comes flexibilised and ready to go – I don’t know of another brand that has a clearcoat like that. With other brands, the user may have to put an additive into a conventional clearcoat to flexibilise it and then add hardener and thinner. With Ultra Flex Clear, you just take it off the shelf, add hardener and thinner and it’s ready to spray. Regular clearcoats are not designed to be flexible enough to cope with curtain-sider applications but Ultra Flex Clear has been thoroughly tested to prove it can. For example, during its lifetime a curtain will be constantly rolled up and down, as well as being tightened and stretched, so to replicate this it had to survive a machine that performed 10,000 cycles of bending and stretching.”

“Using global High Solids technology gave us other terrific advantages. Firstly, it dramatically reduces application time because it has the ability to achieve the required film-build in just one visit. That means it effectively cuts application labour time in half and, when you’re talking about something as big as a typical semi-trailer curtain, that is a huge labour cost saving! Not only that, because it requires only one pass over the job, it actually uses considerably less material which further reduces costs. And that is not all – there is none of the gloss ‘sink-back’ that can affect conventional products.”

“In this part of the world, one key consideration for curtain manufacturers and vehicle operators is UV protection. Particularly in Australia where some of the highest UV readings in the world are recorded. To counteract this, we added a high ratio of UV absorbers into the formulation. It’s something the local R&D team also does when we finetune car-type clearcoats for the local market. Much like sunscreen does for humans, the UV absorbers are designed to block UV rays from damaging the clearcoat so it can continue to do its job of protecting the curtain material and any graphics. PPG uses exposure testing sites all over the world and, arguably, the highest UV readings are from the Allunga Exposure Facility, in Townsville, where we test local coatings. Products from other parts of the world can fail under our conditions but we know that Ultra Flex Clear is up to the job. Having been in the market for a number of years, it has proven itself. Everyone has a reason to be happy. Painters are impressed with the way the high film-build fills the weave of the vinyl material and provides excellent ‘melt-in’, while owner / managers are pleased with the reduced application time and material usage. Even vehicle operators enjoy the easy clean characteristics and the long service life.”

As well as being locally developed as a specific solution for a specific local need, F4977 Delfleet HS Ultra Flex Clear also keeps manufacturing local by being made at PPG’s Clayton production plant. Although local users may not always realise it, it’s another example of PPG’s Clayton R&D laboratory constantly working to ensure that products offered locally are tuned to meet the needs of consumers across this region.

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