Phthalate-free flexible vinyl compounds that have bio-based plasticizers and reduce CO2 emissions by 41 percent have been developed by Teknor Apex Co. and are being incorporated into several commercial applications just now appearing on retail shelves.
The new BioVinyl compounds contain phthalate-free Dow Ecolibrium bio-based plasticizers made from nonfood plant byproducts by the Dow Electrical and Communications unit of Dow Chemical Co. Teknor Apex has the exclusive North American rights for certain applications to market those specific compounds.
“We have developed over 80 different compounds in the last eight months and tested [them] in many manufacturing areas with representative products,” said Lou Cappucci, vice president of the vinyl division of Teknor Apex, which introduced the compounds and unveiled the first product applications at NPE2012 in Orlando. “We have a dozen applications in the process of customer testing right now.”
The product has environmental benefits and better stability and color-hold than flexible vinyl compounds made with phthalate plasticizers, he said at NPE, held April 1-5.
Teknor Apex senior development chemist Nicole Marshall said the material displays an improvement in heat stability that allows extrusion processors to carry out longer product runs without prohibitive levels of polymer degradation.
“In addition, the compounds we developed for weatherstripping and gasketing showed significantly less color change than standard vinyl after accelerated weathering,” she said.
Teknor Apex and Dow credit the improved properties to the way they adjusted the formula for initial customers.
“You have to really look at the formulation [to explain] why the plasticizer performance is different” and better in several areas, said Cappucci. “Some of the other ingredients have been adjusted to get the needed viscosity and product flow. You have to learn how to formulate the compound so when the customer gets it, it behaves the same as the compound it had before.”
BioVinyl compounds are already being used in a line of flip-flops made in the U.S. by Okabashi Brands Inc. and a range of shoe welting — the strip of leather, rubber, or plastic that is stitched to the upper insole of a shoe as an attachment-point for the sole — by custom extruder Barbour Plastics Inc.
“The sandals are just now going to be available,” said Cappucci. “They made the ones here just for us to show them to people.”
Additionally, Dow Ecolibrium bio-based plasticizers are being used in a flooring product made by Chester, Va.-based Flooring Adventures LLC that is just now entering the market. The Tuff-Seal interlocking floor tile, first introduced in 2002, now will be 70 percent derived from natural resources without using phthalates or lead. The tile formulation was developed by Teknor Apex.
Typically, plasticizer accounts for one-third of the PVC polymer. The bio-based Dow plasticizer is made from naturally occurring vegetable substances that are not used for food. “They are seed-oil-based, derived materials,” said Dirk Zinkweg, marketing manager for new segments for Dow's electrical and telecommunications business.
Cappucci expects BioVinyl to be used initially by companies looking to avoid phthalates.
“A lot of our customers are looking to get away from a difficult issue and turn that into positive press,” said Cappucci. “This is a good compound for anyone with a vinyl product that is close to the consumer.”
He pointed to one company that discontinued a good-selling line of vinyl apparel because of concerns about phthalates. “We are in discussions with them,” said Cappucci. “They said they would introduce it back into the market if we can develop a bio-based phthalate-free plasticizer for them.
“The second group of companies that will be interested are those that have sustainability goals,” he said.
A life-cycle analysis conducted by Dow and reviewed by a third party indicates that every ton of vinyl compound made flexible with Dow Ecolibrium reduces CO2-equivalent emissions by 41 percent compared with phthalate-containing vinyl compounds.
“BioVinyl compounds possess a lower global-warming potential than conventional flexible vinyl, and their carbon footprint reduction is even greater in comparison with non-vinyl plastics,” said Cappucci.
“Many people want a better carbon footprint without a reduction in performance,” he said.
Teknor Apex said it can supply commercial quantities of BioVinyl for a number of applications including medical tubing, masks and collection bags; automotive window seals, interior and exterior trim and instrument panel skins; and consumer products such as footwear and toys.
In addition, the company said development work continues on applications such as blood bags and wire and cable jacketing.
“People want bio-based products, but don't want to pay extra,” said Zinkweg. “We hope that with this BioVinyl compound we have discovered the right balance in that equation.”
He added, “If you replace all the phthalates in products worldwide, you could have a huge effect globally on carbon footprint.”