Materials handling & size reduction were stars of Dallas show.

The greatest concentration of news at the recent Plastics Fair in Dallas was in auxiliary equipment for size reduction and materials handling. New granulator entries ranged from what's said to be the smallest on the market up to mammoth central units. Two more shredder manufacturers introduced themselves to the plastics market for the first time. Also on hand were new entries in blending, hopper-loading, and drying equipment.

MINI AND MAXI GRANULATORS

The news in granulators is in very small and very large machines. Battenfeld Gloucester Engineering's Gloenco-Newport Div. in Newport, N.H., is developing the smallest granulator yet, one with a 4 x 4 in. feed opening for economical laboratory or small-press regrinding. The model will have two rotor knives and will be available in a low-rpm unit for glass-filled materials and a higher-speed version for films. Expected output is 3540 lb/hr, says William Crowder, product sales manager. Battenfeld plans to show a commercial model around September.

At the opposite end of the size range, a line of large central granulators from Europe is being introduced here by Rapid Granulator Inc., Rockford, Ill. The Rapid 80 line - the company's largest - are tangential-feed granulators that come with three- or nine-bladed open rotors and two bed knives (a third bed knife is optional). These models are designed for large purgings, film, injection or blow molded parts, and pipe. The first unit available is the 3250 (32 x 50 in. cutting chamber), which has an approximate throughput rate of 7700 lb/hr. It is priced around $200,000. Later this year, Rapid will offer models 3240 and 3260. These units will be assembled in Rockford from components manufactured in Sweden, where Rapid's parent company is located.

NEW NAMES IN SHREDDERS

Blower Application Co. (BloApCo) of Germantown, Wis., is one of two shredder manufacturers that are targeting the plastics market for the first time. The company has a new three- or five-shaft shredder that's marketed for plastics by Size Reduction Specialists Corp., East Lansing, Mich. The shafts are designed as a series of rings with spikes that pierce and tear. This unit was initially built for the paper and cardboard industry but is now available for regrinding plastic pallets, refrigerator liners, and other bulky, thin-walled parts. It comes in models of 3 to 20 hp with shafts that turn at different speeds between 2 and 70 rpm. The feed opening is typically 14 x 100 in., though custom sizes are available. Output rates range from 300 to 10,000 lb/hr. Price is approximately $18,000.

Another newcomer to plastics is Nordlab Systems, Inc., Thomasville, N.C., The company showed its Vortex line of grinders, which were originally used in the wood industry. The low-speed, high-torque machines range from 20 to 150 hp and 100 to 145 rpm. They have a four-point cutter blade mounted on a single rotor, plus one bed knife. A hydraulic ram pushes material into a 32 x 120 in. rotor. Screen sizes range from 5/8 in. to 2 in. and remove easily for clean-out or rotation of the cutting blades on the rotor. Electronic "Smart-Feed" controls monitor the ram and shaft speeds to prevent jams. Prices range from around $40,000 to $120,000.

There were also new shredder entries from more familiar suppliers. A new 80-rpm, 30-40 hp, low-noise, horizontal grinder for extruded products was introduced by All-Grind Inc., Sparta, N.J. The WLK 600/150, built by Weima Maschinenbau in Germany, has a 7-ft vibrating conveyor that transports strips of material to an in-feed roller. The toothed roller pulls the material into a rotor that has 20 hardened, square knives. The machine also has a fixed bed knife. The rotor is 24 in. wide x 14.5 in. diam. The system handles strips up to 24 in. wide and 6 in. thick. The conveyor operates at a fixed speed of 30 ft/min. Throughput ranges from 500 to 600 lb/hr and noise levels from 80 to 85 dbA. The unit costs $45,000.

SSI Shredding Systems, Wilsonville, Ore., showed off a new line of low-speed/high-torque shredders with an optional split-body design that can spread apart like wings for easy clean-out. The new M line has optional hydraulic arms that can swing the body of the shredder open or closed by pushbutton control. The cutter shafts remain in place even as the body is opened. The M line also has larger shafts than any previous SSI models. The first unit available will be the M85, a mid-range model with a 63 x 33 in. cutting chamber, 100-hp drive, and ability to shred six nested 1-cu-yd plastic canisters simultaneously. Throughput rates for the series will range from 2000 to 10,000 lb/hr. The shredders will cost from $115,000 to $140,000. Optional split-body "Quick-Clean" design costs an additional $30,000.

NEW BLENDERS, LOADERS, AND DRYERS

Marking its first new product for extrusion in years, Comet Automation Systems Inc., Dayton, Ohio, introduced a continuous weigh blender made by Vollmar Anlagentechnik of Germany. Vollmar's Gramix blenders feed all of the components in proportioned amounts directly to the feed throat of the extruder. The main resin component is gravity-fed through a tube in the center of the blending hopper. The other components are auger-fed into the hopper around the outside of the central tube. They fall directly into the extruder throat, where they mix with the main ingredient. Since the blending occurs inside the extruder, color changes are reportedly executed quickly.

Each component has a load cell on the bottom of its hopper for loss-in-weight feed control. Feed rates of the secondary components are slaved to the calculated feed rate of the main ingredient so they deliver the correct percentages. These percentages are entered by the operator at the touch-screen controller. The Gramix blender uses Texas Instruments controls and can generate hard-copy data as well as store and retrieve up to 500 recipes. Reported accuracy of the system is [+ or -]0.4% of maximum throughput.

In addition, the blender controller maintains uniform extruder throughput by means of a pressure transducer placed just before the screen changer. Screw speed is adjusted to maintain a constant head pressure. Also, extrudate thickness control is provided by automatic regulation of hauloff speed.

The first available model, Gramix-E, can handle up to four components at up to 550 lb/hr. Two larger models, Gramix-S (for up to seven components and 1540 lb/hr) and Gramix M (nine components, 2640 lb/hr), will be introduced later this year. Gramix-E costs $25,000-35,000.

Metering of liquid color into a gravimetric blender rather than directly into the throat of the processing machine provides greater feeding accuracy and improved color distribution, according to Maguire Products Inc., Media, Pa. The company now offers liquid-color metering as an optional add-on capability for its full line of gravimetric blenders. Color is fed into the weighing/blending chamber, where pellets are coated with the liquid before entering the processing machine. Precoating pellets with colorant does not occur in the normal method of liquid-color metering. Maguire says weighing the liquid provides color-feeding accuracy to [+ or -]1 gram per batch, regardless of batch size. This translates into roughly [+ or -]0.02% accuracy versus [+ or -]0.05% accuracy using the typical combination of a volumetric blender and separate liquid-color pump, Maguire claims. Maguire says color changes can be speeded by interchanging modular mixing chambers.

NEWS IN VACUUM LOADERS

MPG Service & Sales Inc., Hillsboro, Texas, a relatively new maker of granulators, unveiled its first line of vacuum loaders at the show. Four units in the Handy-Load line convey 40-780 lb/hr. The loaders have a standard microprocessor controller, blow-back filter, and overload shutdown switch. The units are constructed of stainless steel for easy cleaning. Options include a ratio loader and remote-control capability. The loaders cost from $600 to $1400.

New press-side loaders that reportedly convey more than three times as much material as typical loaders were introduced by Motan Inc., Plainwell, Mich. The PLS-15 and PLS-30 units convey up to 3000 lb/hr. Motan's line of press-side loaders until now could only handle up to 800 lb/hr. The system can be supplied as a single- or dual-station loader. It features a 2.5-hp motor and a new bag filter design.

The company also unveiled the PMD-30 press-side dryer, Motan's smallest unit, built for lab use or for small injection presses. Maximum throughput is 30 lb/hr. It has twin desiccant beds and a 1-kw heater. Competitive dryers of this size do not have an internal process heater, Motan says.

HEATING/COOLING NEWS

Walton/Stout Inc., Lithonia, Ga., brought out its first line of gas-powered dryers, which can be used for heating either process or regeneration air. WS business-area sales manager Michael Grant says processors who live in an area where gas is cheaper than electricity can save up to 60% in energy costs with a gas-fired dryer. The new WSD-G line comes in three sizes rated at 600 to 4000 cfm, all with the same small footprint of 36 x 44 in. The micro-processor-controlled dryers can reach temperatures up to 385 F and are able to hold process-air temperature to [+ or -]2 [degrees] F of setpoint.