Recycling Plastics and Polymers

There can be life after death, especially if you are a car tire, plastic bottle, or polymeric casing of a cable. Senior Business Editor Melody Bomgardener of Chemical & Engineering News explains in her cover story that the business of recycling and repurposing materials from discarded items is growing.

The business is rising because of several factors. Those factors include increasing consumer demands that products be sustainable and not wind up in landfills, and companies wanting to take advantage of the price benefit of recycling materials, like metals and some polymers, that still work well despite coming from a discarded item.

Americans are recycling more these days. In 1980, 10% of municipal solid waste was recycled. In 2009, that number was 34%, according to the Environmental protection agency.

The upshot? Material manufacturers now must change to help consumer goods firms meet the goals of product stewardship for the simple reason that the products people use every day were not designed with any end-of-life destination in mind.

Bomgardner writes:

The marketplace is showing signs that this shortsightedness will change: Sustainability initiatives of both retailers and consumer products manufacturers increasingly include goals for product stewardship whereby companies plan, and oftentimes pay for, the recycling or appropriate disposal of a product after its useful life. Chemical and material suppliers are being warned by their customers to prepare for the day when these initiatives encompass their products, as well.

Companies committed to taking back merchandise for recycling arrange for their products to flow through a supply chain that they refer to as the ‘back end.’ It’s similar to the forward supply chain that creates products for consumers, only it runs in reverse. And just like in the forward supply chain, which links raw material maker, product manufacturer, and retailer, each of the partners in the reverse supply chain must make a profit for the system to function.

There is a profitable business model in reclaiming and reselling valuable materials or managing hazardous ones. But if material makers understood from the get-go how their products were going to be reclaimed and recycled after the product’s lifetime was up, they could design their materials more appropriately for disassembly.

Bomgardner gives the example of PVC, or polymers that contain brominated flame retardants. These materials help the plastics resist fire but, unfortunately, they can release hazardous air pollutants when melted or burned during processing to recover the metals in electronic consumer goods. Manufacturers do need flame retardants for the original product, so what to do?

Bomgardner says the company, DSM, for instance, offers a range of halogen-free engineering plastics (ones that lack bromine in the flame-retardant molecules and chlorine in PVC) as alternatives to conventional plastics that are aimed at the electronics market, and others where recycling is common.

She writes:

‘Engineering plastics end up in critical technical applications, whether in automotive, electronics, or food packaging,’ says Fredric Petit, director of sustainability at DSM Engineering Plastics.

The company has been working to certify its products as recyclable through the Cradle to Cradle designation developed by McDonough Braungart Design Chemistry, a product design consultancy. The effort ‘is a newer expansion of our sustainability concept,’ Petit says. ‘We take end of life into account. Then you start to think, ‘Should there be an end of life, or can it be reused and recycled in a closed loop?’’

By closed loop, Petit refers to continual reuse and recycling of a material in the same product type, an attribute of raw materials that many customers of chemical and material suppliers increasingly desire. DSM’s Cradle to Cradle products include polyamide, copolyester, and polybutylene terephthalate resins marketed under names such as Akulon, Arnitel, and EcoPaXX.

The video above shows McDough, whose brainchild was Cradle to cradle.

There is a drawback with recycling plastics and polymers, Bomgardner points out, that doesn’t exist as much with steel and glass. Polymers tend to be restricted in the amounts that can be reclaimed from the original product and in the number of times they can be recycled without degrading.

So recyclers often take a different tack with the polymers and plastics for their next life. Bomgardner gives the example of Lehigh Technologies, a company that recycles rubber from discarded tires and from the waste material of tire makers.

Bomgardner explains:

Lehigh takes in rubber chunks from firms that recover used tires. It then uses a proprietary milling process to create what it calls micronized rubber powder, with grain sizes as small as 50 μm in diameter. The different powders are sold in various markets including tire making, coatings, sealants, and plastics. Yokohama Rubber, one of Lehigh’s clients, also buys back the powder for use in new tires.

Finally, it should be noted though that just because a product has recycled material in it, the product itself may not be amenable to recycling. Sometimes, a good thing must come to an end.