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September 1, 2003

7 Min Read
Size reduction

Cumberland?s 2000 Series large-capacity granulators come in three sizes and have a throughput range of 1800 to 2600 lb/hr.

The SJ Series low-speed, high-torque granulator from Wittmann uses trapezoid-shaped, helically aligned cutting knives that rotate at 27 rpm for consistent regrind.

Whether you want to reclaim material for production or break down parts and scrap to reasonable dimensions for disposal, size reduction equipment is a necessity for any processor, and many suppliers rolled out new lines in the hopes of enticing processors to try the latest technologies.

  • Screenless Granulators

    Low-speed screenless granulators are one such technology that is more widely available due to the expiration of a patent. Methodically breaking down scrap at very low rpms, these units use slower-moving rotors to reduce material. At higher speeds, some scrap simply bounces around the chamber, never getting a chance to fall through the screens, and getting smaller and smaller until it?s reduced to fines. At lower speeds the scrap is given more time to break down, and to the enthusiasm of operators, the units are much quieter.

    As part of the 14 new models introduced by Cumberland in the last six months, the S Series screenless granulators are beside-the-press units with three cutting chamber sizes ranging from 9 by 9 up to 9 by 18 inches. Motor sizes are 2 and 3 hp.

    Matsui brought two screenless grinders to NPE, the SMGL and the MGL. Both units are portable, to be placed beside machines as necessary, and they are said to have quiet, slow-speed designs with low energy usage. The unit can be cleaned out in minutes, thanks to a hinged chamber that flips open for access and a compressed air hose to blow out debris.

    Distributing the Moditec line of low-speed granulators, Plastec North America displayed 10 beside-the-press units that range in size from 4 by 6 to 29 by 33 inches. Plastec says the machines can handle large parts and thick cross sections; they can even take on cylindrical parts thanks to a patented dual-rotor design. A patented third axis, dubbed the Masher, precuts large parts for easier processing.

    The SJ Series screenless granulator from Wittmann treats scrap with a high-torque/low-speed motor. Engineering resins as well as styrenics, acrylics, and glass-fiber-reinforced materials are well suited for the SJ, which has three cutting chamber sizes ranging from 9 by 9 to 9 by 18 inches. The trapezoid-shaped, helically aligned cutting knives rotate at only 27 rpm for more consistent regrind.

    Rapid Granulator?s Multi-Cutter MC Series screenless low-speed unit is particularly suited to process engineered resins and filled materials. The design minimizes noise and frictional heat while virtually eliminating fines and longs. Tungsten tool steel is used for the crusher blades and cutter wheels. The Multi-Cutter Series is available in 9.5-by-10- and 14-by-18-inch chambers and up to 2.5 hp.

    Conair?s contribution to screenless granulators, the CM Series, offers a 25-rpm motor and has three sizes with throughputs up to 40 lb/hr. While the rotor turns, two large arms slide through blind slots in the cutting chamber to break up scrap.

  • Large Central Units

    On a much bigger scale, many size reduction suppliers also brought large units with high throughputs for central size reduction or large-part programs.

    Wittmann?s MC 2840 goes up to 150 hp, taking on large items like pallets without the need for precutting. The fabricated steel cutting chamber has a 28-by-40-inch opening, and the extended rotor shaft gives processors the option of a second flywheel for more inertia.

    Offering horsepower up to 100 and 16-by-16- or 16-by-32-inch throat sizes, the Transformer 1624 from Granutec has a new Duo Pak feature with removable cutting chambers. The tangential feed unit uses a double-scissors rotor-cutting action and a three-blade welded-steel rotor.

    Offering big performance in a (relatively speaking) smaller package, the redesigned Shuttle granulator was shown by Maguire Products. Maguire says the unit is one-fourth the size of a comparable rotary machine, but it still has high throughput. The design incorporates two size-reduction steps. In the first stage, material is planed and then ground using a radial granulator. Rotors spin knives at 1750 rpm to cut gravity-fed scrap and feed it into the radial hopper granulator located underneath.

    With production of all its largest units now stateside, Cumberland displayed new iterations of its Tangential and 2000 Series granulators. The Tangential comes in 20-by-24- or 20-by-36-inch models, and its 40° infeed at a height of 63 inches makes scrap loading easier. The 2000 Series comes in three sizes (20 by 42, 20 by 50, and 20 by 62 inches), with a throughput range of 1800 to 2600 lb/hr.

    A lowered feed height and unique swing-away design in lieu of a clamshell configuration give the CW Series from Conair accessibility in a large unit with 2200-lb/hr throughput.

    Extruders with scrap pipes and profiles can use the ESP from EconoGrind, which has automatic feeding that accepts longer parts.

    A removable deflector wedge and externally mounted, oversized pedestal rotor make Ball & Jewell?s SSH Series a versatile central granulating unit.

    One of the 11 new granulators that Ball & Jewell, a division of Sterling, brought to the show was the heavy-duty SSH Series. The SSH features a removable deflector wedge and externally mounted, oversized, pedestal rotor bearings to withstand wet granulate.

    Conair joined the chorus of central size reduction at NPE with its new CW Series. These heavy-duty granulators have throughputs up to 2200 lb/hr, and, in spite of this speed, some unique design elements allow for a lowered material feed and open-door access. Unlike many large units that feature a clamshell configuration, the CW has a swing-away front panel, which contains the screen cradle and catch bin for granulate.

  • Beside the Press

    Beside-the-press granulators are one link in a full-scale cell, as they reclaim materials for inline reintroduction of resin into the material stream.

    Ball & Jewell updated its 12 and 28 Series compact granulators to include built-in soundproofing and an accessible enclosure. Ball & Jewell?s ACS Group kin, AEC, added German-engineered I Series granulators to its auxiliary lineup. The 1200 and 2800 models also offer soundproofing, as well as a removable third bed knife and integrated blowers and cyclones to discharge the granulate.

    Conair?s new CLS and CHS Series beside-the-press granulators offer low-speed rotors for light parts and high-speed units for batch jobs. The CLS has a solid rotor with staggered knives that turn at 160 rpm for throughputs of 150 to 300 lb/hr. The high-speed CHS goes up to 800 lb/hr; it has a high-inertia flywheel, staggered rotor, and drop-in cassette knives.

    EconoGrind offered a new ESC Series beside-the-press unit featuring three sizes (20 by 20, 20 by 28, and 20 by 50 inches). The compact granulators are soundproofed and the enclosure allows access to the cutting chamber. Targeting extruders, EconoGrind also introduced the ESP granulator line, designed for pipe and profile. Ergonomic, automatic feeding is said to easily accept longer parts.

    Cumberland had several beside-the-press granulators on display, including the 6500 Series with three cutting chamber sizes ranging from 6.5 by 8 to 6.5 by 16 inches. The 6500 Series has vacuum discharge, an 1800-rpm motor, and a double-walled hopper for augmented sound insulation. The company also displayed its new 1200 Series available in 12-by-12- to 12-by-20-inch sizes. The 1200 uses a three-knife, open slant-cut rotor with scooped wings for positive feeding and cooler operation.

  • Shredders, Two-stage Units

    Herbold displayed its new HGM Series low-speed HOG-shredder, expanding its product range that includes pulverizers and granulators. The series has two sizes with a single-rotor design. The unit combines a granulator with a shredder to break up bottles or even metal-reinforced materials.

    Shred-Tech offers its Shred-Tech Series single-rotor shredder for size reduction. The units range in size from 10 to 200 hp and use bolt-on knives created from hardened D-2 tool steel or tungsten carbide.

    Vecoplan introduced its new ReTech RG62K rotary grinder with SureCut that is said to self-feed material. The two-stage reduction unit has a 63-by-80-inch hopper opening, a 15-inch-diameter rotor, and 150-hp drive motor for throughputs ranging from 1000 to 6000 lb/hr. For even bigger jobs, Vecoplan offers the RG78/200 and RG98/250 KNF grinders. These feature an 8-by-10-ft hopper with a volume of 15 cu yd and a solid rotor with diameters up to 25 inches. The 250-hp motor allows throughputs up to 5000 lb/hr.

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