The process of grinding of rubber, or turning post-consumer rubber into a valuable new resource, can be a difficult application. Recyclers who are considering a grinder purchase should first identify the end product that they are after. The market offers plenty of grinders to choose from, with a variety of options to match buyer needs.

John Farney is the national sales manager at Cumberland Engineering. He said the firm and its subsidiary, Cumberland Recycling, offer the most extensive array of granulators, shredders and reclamation systems available in the industry.

“From specialty units for specific applications such as tire recycling, and wire/cable reclaim, to systems for PET and HDPE bottles, we develop solutions for any budget,” Farney said. As a pioneer in the recycling industry since 1939, Farney said Cumberland always strives to remain at the forefront of product and solution development.

“Our annual sales are approximately $25,000,000, but vary depending on the market sectors that are active at any given time. We serve the recycling, extrusion, injection molding, blow molding and rotational molding markets. In the last 18 months, demands and needs have risen at a surprising but welcome rate. Market increase is expected to total at 80 percent for fiscal 2010. Our biggest sellers are our X Series granulators, our 3200 Series granulators, and our shredder units,” Farney noted.

He added, “In the specific area of rubber reclamation, quite a few of our models have been employed to achieve high volumes of ground material, at exceptionally high rates, with the lowest possible consumed energy. For end products used as mulch-alternatives, molding compounds, crumb rubber and alternative fuels, we achieve high quality. Incorporating the highest level of safety, and ease of operation, our products are developed to minimize maintenance time, and optimize safety levels. Tilting hoppers, drop down screen cradles, hydraulic systems to minimize manual labor and sound suppression measures are just a few of our developments. From positive mechanical restraints engaged during maintenance, to the most secure and strongest knife mounting systems, our units are easy to clean, maintain and operate.”

Farney said most Cumberland units are delivered ready-to-install. Tall units require component mounting or stacking, and evacuation systems require physical assembly. Unless any wiring is needed, most units can be operational in hours. Intricate systems involving wash lines, classification systems, and other ancillary devices do require a bit more setup. “In today’s market, the biggest challenge to processors is high volume at low operating costs. We offer energy saving drive and operating systems, low maintenance knives and screens, and strong, long-lasting knife designs.

“We strive for minimal down time, and work to reach the highest output per hour of operation. Current limiting controls on start-up help control energy consumption and cost. For operations, each pound is profit, and the more pounds per hour, the higher the profits. But quality finished material is crucial as well. Our long-lasting knives cut more efficiently and require less sharpening than other formulations/designs. Capabilities include tires, carpet, bottles, automotive scrap, pallets and many other materials,” he said.

UNTHA shredding technology has been manufacturing shredders for a wide range of applications since 1982. “UNTHA invented and patented the original four-shaft shredder and continues to be the world’s expert on low speed shear shredding, said Peter Dion, regional sales manager.

“Because of high-torque, advanced cutting systems, UNTHA two- and four-shaft shredders are ideal for tire shredding. Our model S120 two-shaft shredder is used for pre-shredding and for applications where exact particle size control isn’t needed. The RS50, RS100 and RS150 four-shaft shredders add the capability to provide controlled particle size and, using our exclusive tire cutting system, of removing tire wire from the rubber during shredding,” Dion said. He also reported that from an operations standpoint, UNTHA’s shear shredders are well-suited for shredding operations with production requirements up to 5 tons per hour.

“Tires represent the largest source of rubber for reutilization and recycling in America. Over 300 million scrap tires are generated annually. In recent years there has been a lot of consolidation in the tire recycling industry, with a migration to larger and larger machines. Still, there is a need for smaller machines where tires are a secondary market or where densification is required for efficient transport or to add value. Production waste is also an interesting market. A common application for a 4-shaft shredder is in a facility where rubber products such as mats are manufactured. Cut-offs, setup pieces and defective product can all be shredded and used again, so nothing goes into a landfill. The UNTHA RS45 and RS50 machines are good machine choices due to their compact size and rugged design,” said Dion.

He said his company has extensive experience with four-shaft shredders, pioneered by the firm with many UNTHA-exclusive features, such as the tire cutting system and dynamically-loaded cutters with pneumatic shaft flushing, which are designed to extend machine life and ease maintenance by keeping debris from working its way under the cutters.

“The Austrian company’s attention to design and detail ensures shredder longevity and economical operation. UNTHA America provides sales, application, spare parts and service for our United States and Canadian customers. Our service technicians have worked for UNTHA in Austria for many years, and so they have excellent experience in keeping our shredders performing at their best. We recently unveiled redesigned versions of the reliable RS30 and RS40 universal four-shaft shredders. These small shredders have features which previously were seen only on larger units, and several enhancements make the machines easier to maintain and more versatile than ever,” Dion said.

“Weima is a manufacturer of single-shaft shredders, which are used for primary breakdown of bulky vulcanized rubber materials like tire tread, trimmings and other various rubber scrap,” said Madison Burt, vice president, sales and marketing. Weima has manufactured single-shaft shredders for more than 25 years to many markets, including plastic, rubber, wood, paper and more.

“Weima’s shredder design includes a unique access door that allows full access to the shredding chamber for both maintenance and cleanout purposes. The single-shaft shredder allows for batch feeding of bulky materials without having to precut or separate the load. Weima America recently received an order for a model WLK10-60HP shredder. It will be used to process 1,500 pounds per hour of various vulcanized rubber scrap prior to granulating. Our customer is thrilled with the ability to load gaylord containers full of material into the shredder without the need to separate the load or precut the pieces,” Burt explained.