Granulator Knife Designs Improve Cutting for Efficient Recycling

New press-side granulators

The chevron-shaped bed- and rotor-knife design on New Herbold's new LMV granulators is said to raise throughput of film, hollow parts, and bottles by 10-20% over its similarly sized LM straight-cut units. The chevron arrangement reportedly distributes material better while still providing a double scissors cut. The four models in the new line have five rotor knives and a new drop-down screen cradle. They process up to 2000 lb/hr.

The first two units in Rapid Granulator's new Rage series of machines fill out the medium-to-large end of its press-side line. They come with three rotor knives and two bed knives. The R18 has a 14 x 18 in. opening and output rate up to 990 lb/hr. The R24 has a 14 x 24 in. chamber and processes up to 1320 lb/hr.

Hosokawa Polymer Systems puts a sound enclosure around its new PL-QS series press-side machines. The first of the top-feed models is the 28/50. It uses two rotor blades, which turn at 450 rpm against one bed knife. Output ranges up to 550 lb/hr. Models 16/20, 22/30 and 28/40 are being developed for production rates of 220-550 lb/hr.

Cumberland Engineering introduced its new 25 Series general-purpose granulator. It replaces the 15 and 20 Series. Two sizes are offered: a 2530 unit with 250 x 300 mm throat, and the 2545 with 250 x 450 mm throat. Throughput rates are 308 and 440 lb/hr, respectively. The rotor operates at 340 rpm.

Cumberland also added the model 1745 to its 17 Series of ultra-low-speed beside-the-press units. The tangential-feed unit has a 170 x 450 mm feed opening, six rotor knives, rotor speed of 210 rpm, and output of 242 lb/hr.

Heavy-duty central grinders

New Herbold came out with the new heavy-duty SMV series granulators that process abrasive materials, purgings, film, fiber, or bottles at rates from 2000 lb/hr on up. The tangential-feed units have seven rotor blades and replaceable steel wear plates in the housing. The largest model is 32 x 72 in. The bed knives are mounted on modular blocks so they can be replaced by the user. A new feature allows rotor or bed knife adjustment from outside the machine.

The latest addition to Cumberland's 18 Series central granulators is also the largest. The high-shear model 1842 is targeted for thick-walled molded parts, purgings, and rigid PVC pipe. It has an output rate of 1800 lb/hr.

Ram it through faster

Weima Maschinenbau (represented here by Size Reduction Specialists) rolled out seven new models for processing tough films in bales, rolls, or webs. The new Weima Terminator, or WT, line uses a new top-mounted ram to push the material into an 80-rpm closed rotor. Throughput range is from 550 to 10,000 lb/hr.

Wash and spin dry

New TW 850 B/10 turbowasher from Officine Costarelli processes up to 3300 lb/hr of ground film and up to 4400 lb/hr of stiff materials. After washing, a rotating screen barrel separates the water from the product. The Dinamic Centrifuge dryer (CA 850 B/10) is a high-speed (1800-rpm) version of the washer.

Cold cuts

Munchy Ltd. (represented by Action Industries) brought out the new CoolCut system for reprocessing heat-sensitive resins at up to 2640 lb/hr. It quickly removes residual heat after pelletizing in order to prevent degradation. After the die-face cutter, pellets fall into a turbulent cascade of chilled water. The water is recirculated and re-chilled, which minimizes tank-volume requirements while improving cooling efficiency.