Plastics packaging: Foaming process cut costs in rigid PS sheet

Matt's take: Polystyrene supplier Styron introduced its CO2RE foaming technology to great fanfare last fall. The process uses carbon dioxide as a physical foaming agent during extrusion of rigid PS sheet, the kind of sheet that often is then thermoformed for dairy and food service applications. PlasticsToday caught up with John Case, Styron's global marketing manager for packaging and consumer goods, to get an update on the process and to add some detail to the original announcement so you can decide if this is a technology you might consider licensing. Send any questions or comments you may have on the tech and we'll try to get those answered. If you want to know the exact price for a license, please contact Styron directly.

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Polystyrene supplier Styron introduced its CO2RE processing technology at last fall's K show in Düsseldorf, Germany, and now can point to some concrete commercial successes. The process involves injection of liquid carbon dioxide as a physical foaming agent into the polymer melt during extrusion of rigid PS sheet. The technology is available globally.

Target markets are dairy and food service applications where rigid PS is in use; figures vary from region to region but in Europe about 75% of these applications rely on rigid PS, according to John Case, global marketing manager for packaging and consumer goods at Styron.

Case says the company is licensing the technology, with the payback period for a license dependent on how a processor finances it, the volume of PS processed, and other variables. "Savings are several hundred Euros per tonne," he estimates, indicating that payback could be swift even for a mid-sized buyer of PS. "The technology is about delivering improved margins through cost reductions to us and to our customers," he adds. "(To cut costs) people have tried to mix more general purpose PS into high-impact PS, they've reduced wall thickness, but this technology brings the next dimension to that."

The CO2RE technology can be used with any grade of PS, not just those marketed by Styron. A processor using the processing technology can control the cell size, structure and other variables in the sheet. The density realized in the sheet can be as low as 0.6, "but we're not trying for low density," explains Case. Most products made with CO2RE will have a density ranging from 0.74 - 0.85, he says.

In a monolayer product, the cellular structure is revealed on a product's surface. One of the first licensees, REMA Industries and Services (RIS), an Australian packaging and food service company, successfully started up the first extrusion line equipped with the foaming technology on October 20, 2010. The company uses the foamed sheet in thermoformed rigid PS serving plates. Although these plates are formed from multi-layer sheet, RIS opted to have the outer layers thin enough to enable some of the foam structure to be revealed, as it decided this gives the plates a high-end appearance. One other early licensee of the technology is Intraplas, with signed a license late last year. The Portuguese plastic packaging processor extrudes sheet and supplies form/fill/seal (FFS) packaging to the dairy market.  

What makes this technology better than other foaming technologies availble? With CO2RE, the process is more cost efficient and the foaming is more controlled that others aimed at these applications, says Case. "It's not a low-density foaming technology," he explains. "This is to make high-density rigid PS sheet-rigid sheet for thin-walled containers," for example, and not for the low-density PS sheet formed into meat trays. 

Since the introduction of CO2RE processing technology at last fall's K show in Düsseldorf, Germany, Case says the response from the processing industry has been strong. "There has been a lot of interest, even beyond dairy and food service," he says, with that interest primarily from processors in North America, Europe and Japan. So far the response and interest has been especially high in developed regions where packaging markets are hyper-competitive, but big dairy companies want to leverage this technology globally, he adds.

The technology is especially interesting for processors operating in countries that require a waste disposal tax on all plastics processed, notes Case, citing France, Portugal and Germany as some examples. Also, as less material is required for an equivalent quantity of packaging, and less energy is used in transferring containers, the carbon dioxide footprint of the packaging is reduced.

 

 

 

 

 

 

 

 

 

 

 

 

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