Compounding machinery development news at K 2007 focuses on:
More torque or more output, and sometimes both for kneaders, mixers and twin-screw extruders
New productivity enhancements for multi-screw and planetary extruders
Improved dispersion and degassing for specialty compounds and masterbatches.

1. Kokneader
Switzerland's Buss AG is introducing a new four-flight, single-screw kneader to compound polyolefin wire and cable compounds and masterbatches. The MX Kneader adds a fourth flight and a fourth row of pins in the barrel to those of the traditional kneader. The deeper flights provide more free volume and have longer flanks for better conveying. The MX will use a 4 motor CMG drive from K&A Knoedler GmbH in Germany or screw speeds up to 800 rpm vs. about 300 rpm for the standard kneader. The result is upto two and a half times higher output on an equivalent size machine. The first MX Kneader being built for the show is with 105 mm dia. Both smaller and larger sizes are planned.

2. Continuous Mixer
Farrel Corp will show its latest 9UM continuous mixer, designed for higher throughputs of low-bulk-density materials. Farrell also developed a high-torque version of its size 9 continuous mixer (9CM-HT) for rigid PVC, with 20% more available torque for higher rates and lower temperatures. For smaller throughputs, Farrell will introduce a new model of its compact processor model CP125 (2 in. dia), coupled with a single-screw discharge extruder for output of 125 kg/hr (275 lb/hr) of color concentrates and other masterbatches. For nano-compounding, Drais-werke will show a 5-liter Gelimat mixer modified to disperse nano-fillers.

3. Twin-screw and multi-screws
Coperion will introduce its ZSK Megavolume Plus, which combines large free volume (screws have a 1.8:1 OD/ID ratio) with significantly higher specific torque (now up to 11.3 Nm/cm3 vs. 8.7). Flights are deeper, so there is less shear. Screw speed also can be raised to yield 40% higher throughput of rigid and flexible PVC compounds. Leistriz in Germany is showing upgraded ZSE Maxx co-rotating twin-screws that combine high torque and high volume. They have an OD/ID ratio of 1.66:1, due to patented asymmetrical splined shafts. Addition of new gearbox will add over 30% more torque.
Leistritz is also building its largest Maxx machine yet, with 135-mm screw dia. Krauss Maffei Berstoff in Germany will display a complete �plug-and-play� twin-screw extrusion system on a skid sized to fit in a standard shipping container. It includes a ZE 50 UTX twin-screw extruder, material-handling auxiliaries, vacuum pump, control cabinet, and underwater pelletizer. The company has offered complete systems on skids for several years, but this is the first time one has been displayed. They are available for ZE twin-screw extruders from 25 through 130 mm.
Entex Rust & Mitschke GmbH will display photos of two new large planetary-ring extruders. Model 280 has 8 large spindles; Model 400 has 14. Entex has built three 280s for compounding and direct extrusion of wood-plastic composites with up to 75% wood. The bigger 400 model is compounding recycled tire rubber for compression molding of mats for cows to sleep on. Entex will also show a TP/WE 70 planetary-ring extruder combined with a gear pump and an underwater pelletizer. This system will be used to demonstrate colour changes in 15 to 20 min.
Extricom in Germany will show a new generation of its 12-screw ring extruder with higher throughput capacity. Extricom will also present a new counter-rotating twin-screw vent-port stuffer that is more compact than its previous co-rotating stuffers.