Chances are you bought at least one plastic bottle of water or soda this week: after all, about one million of them per minute are bought by people around the world. If you’re an environmentally-conscious person, you might toss bottles in the blue bin when you’re finished. Where does it go from there?
Sustainability is becoming increasingly important within construction in general, and in the nonwovens space in particular.
Marketing Manager of Cellulosics and Composites at BASF
Studies show only nine percent of plastic is recycled. Thanks to many manufacturers, some of your plastic products make it from the bin to a new application in roofing or construction.
Here’s how manufacturers recycle plastic, glass and other types of waste by transforming them into nonwoven materials for use in specific applications.
The vicious cycle of plastic waste
The ever-increasing production of plastic bottles and similar products has overwhelmed recycling systems worldwide. Many nations, including the United States, began shipping recycled plastic to China and other developing Asian countries in 1992, only to have China close its doors to imported plastic waste in 2016.
As a result, “recycling has become a growing area of interest,” says Matt Cloward, Marketing Manager of Cellulosics and Composites at BASF. He notes many American recycling facilities lack the ability to process plastic packaging from beginning to end. “The U.S. used to send millions of tons of plastic bottles to China.”
In 2016, for instance, China imported over 693 million metric tons of plastic waste from the United States.
“Since they stopped accepting it, we have all this plastic waste that has nowhere to go,” Cloward adds.
Thanks to a new approach in manufacturing, bottles that might otherwise end up in landfills, incinerators and oceans are being used to build something new.
Freudenberg Performance Materials recycles approximately 2.5 billion plastic bottles per year at its European facilities. The bottles are delivered by truck, separated from their caps and labels, washed and chopped into plastic flakes. The flakes are then melted down, spun into yarn and extruded into fibers, creating a polyester nonwoven material used to manufacture “waterproof roofs, thermal insulation, furniture upholstery and geotextiles,” according to the company’s website.
Similarly, manufacturer Johns Manville uses post-industrial recycled glass to create glass fiber nonwovens for insulation and other applications.
Handling the heat with a water-based binder
Besides sustainability, recycled plastic brings its own benefits to the manufacture of roof shingles and similar products. Cloward says polyester nonwovens used as roofing mat or membranes have certain advantages when compared to other types of roofing material.
“Polyester provides high elongation and tensile strength,” he notes. “Polyester mats exhibit high puncture resistance and durability against tears. Contractors can roll out long sections of the roof at a time, which means it can be installed quickly. The roof is able to withstand foot traffic and the possibility of punctures over its lifespan.”
The material must also be strong enough to withstand the elements, like UV rays and weather events.
With those factors in mind, manufacturers look closely at the type of binder used to hold the nonwoven together. Acronal 4888, a water-based product with self-crosslinking capabilities, has a range of properties that make it particularly well suited to the task.
“It has a very unique set of properties,” says Cloward. “It has high heat resistance and adheres to polyester and glass fibers very well, which is important to give the matting the strength it needs.”
The high heat resistance is especially crucial when working with asphalt shingles and build up roof (BUR) membranes, which involves coating the polyester fibers with hot asphalt. The binder protects fibers from those high temperatures, preventing the plastic from melting and helping the material hold its structure.
Recycled plastic mat is here to stay
When it comes to using recycled materials to create nonwovens, Cloward believes the trend will continue to gain traction among manufacturers globally.
“Sustainability has not always been top of mind in construction, but it is becoming increasingly important within construction in general, and in the nonwovens space in particular,” he explains. “By utilizing recycled plastics to produce nonwoven mat for roofing and various other applications, we can take an existing problem — excesses of plastic waste — and find a way to give it an additional use.”
Rather than piling up in landfills or oceans, taking upwards of 450 years to decompose, recyclable plastics have the potential to find new purpose as construction materials. Cloward says that philosophy is important for manufacturers to keep in mind.
“The plastic doesn’t just go into a landfill. It’s not floating around in the ocean. It’s being used to build a roof, to solve other problems, and it has a long lifespan. It’s going to stay there for a very long time.”