Enough plastic is thrown away each year to circle the earth four times – and plastic in a landfill can take up to a thousand years to degrade.
According to the Recycling Coalition of Utah, only about 25 percent of the plastic produced in the U.S. is recycled even though the process requires 88 percent less energy than using raw material to make new plastic.
Granulators are used in recycling plastics because the machines rapidly reduce the plastic and other materials.
“At the Conair Group, we believe that key to the successful use of reclaimed plastics is pristine regrind,” explained Dave Miller, general manager, size reduction. “If you produce granules that are consistent in size, with minimal dust, fines or longs, you will experience better processing melt properties, fewer problems in material handling, less filter clogging and, ultimately, better part quality.” Conair is a global supplier of plastics-processing auxiliary equipment.
Conair offers a broad range of granulator configurations, from smaller units designed for recycling scrap on the processing plant floor, to large machines capable of handling even large, heavy-walled parts at rates that can exceed 1,000 lbs. per hour. Special purpose units, including some developed to process difficult materials such as large volumes of scrap plastics film and thin sheet, are also available. Regardless of size or configuration, every Conair granulator is designed with a “constant cutting diameter” feature that ensures the position of the rotor knives relative to the bed knives remains the same despite knife sharpening, adjustment or replacement. “This constant cutting diameter is key to consistently producing pristine regrind,” said Miller, “and it is key to generating maximum value for the recycler.”
Another factor in ensuring maximum profitability, according to Miller, is efficient scrap handling before and after granulation. Because staff members at Conair possess extensive experience in plastics material handling, they can supply tailored feeding solutions, including conveyors, film-unwinding equipment and specially designed feed hoppers to accommodate large, heavy or unusually shaped scrap. Downstream from the granulator, Conair’s material-handling expertise comes into play. A basic system might use a blower or vacuum pump to convey regrind from the granulator catch bin to storage bins. To separate lighter-weight materials (paper, for instance) from heavier plastics regrind, scrap passes first through an elutriator where plastic granulate falls out while paper and/or other lightweight materials are blown through to a second cyclone and bag filter.
For four generations, Herbold has been designing, manufacturing, installing and servicing a full line of high quality size reduction equipment, including granulators and shredders. U.S. operations began in 1996 and expanded in 2010 with a brand new warehouse increasing the number of available stock machines and parts. Herbold’s line of granulators – including heavy duty, general use, force fed, and compact machines – offer throughput capacities ranging from a few hundred pounds per hour to eight tons.
The popular SB Series delivers high throughput by means of a patented force feed system that conveys material to be granulated from the unit’s hopper to the grinding chamber via conveyor screws. This technique offers 30 to 50 percent greater throughput versus gravity feeding. Other benefits include less power consumption, quieter operation, no fly back, reduced wear to the cutting blades and reduced fines.
“Plastics processors are always looking for solutions that will allow them to process more materials faster and spend less money doing it,” Herbold USA president David Lefrancois, stated. Herbold’s ease of maintenance, service access and adjustable rotor/bed knives help meet that challenge. Both sets of knives are adjustable to provide a more efficient cutting action than fixed rotor knife machines. With Herbold’s knife adjustment fixture, knives are adjusted outside of the unit which allows for more precise alignment, higher throughput and reduced downtime. Another bonus of adjustable rotor knives is the additional amount of knife sharpenings, which is nearly double that of fixed rotor knife machines.
Hosokawa Polymer Systems (HPS) is a global manufacturer of granulators, shredders, dedusting and separation systems, washing lines and other plastic recycling equipment. “With over 50 years of experience and thousands of granulators and systems delivered worldwide, HPS has distinguished itself by supplying quality equipment and system solutions,” said Doug Ort, vice president/general manager. The HPS line of granulators range from 3 to 600 hp, for a variety of plastic recycling methods including: injection molding, blow molding, extrusion, film and post-consumer plastic recycling.
The majority of HPS systems manage plastics but other systems are available for materials such as paper, food, wire and cable. “Many of our granulators and systems are still operating after 40 plus years in production and the hallmark of our equipment is robust design and longevity. Key features in our granulator designs are high cutting efficiency, easy granulator knife access, fast screen changing, and a range of cutting technologies. These granulators deliver production capacities from several hundreds of pounds per hour to over 10,000 lbs. per hour,” noted Ort.
The HPS workhorse models for large volume recycling are the Alpine Rotoplex and CL granulators and their heavy duty line of granulators. The Rotoplex and CL products feature a patented cross scissor cutting technology which utilizes many short rotor knives, positioned side by side, compared to competitive models fitted with one or two knives per row. If damaged, not all knifes need to be replaced on the Rotoplex or CL.
Also, this cutting technology distributes recycled material evenly throughout the whole chamber instead of directing material in one direction or to one side, as is the case with some other cutting methods. Ort explained, “This cutting action minimizes wear and maximizes throughput. These granulators also keep a constant cutting circle and the rotor knives are adjusted outside the chamber for easier knife gap adjustment.” He commented that there is a growing trend in export restrictions for recycled plastics. This has caused U.S. market players to recycle difficult waste streams in a more economical manner. So, HPS continues in developing technology to meet those emerging market demands.
Published in the February 2017 Edition of American Recycler News