DUSSELDORF, GERMANY — Krupp Werner & Pfleiderer GmbH, which has sold 63 of its ZSK Mega-brand, high-output compounding extruders since introducing the machine at K'95, unveiled a new size at K'98 — with a new design replacing the old, bolted-barrel sections with tie bars.
The ZSK 50, with screw diameters of 50 millimeters, fills a hole between Krupp W&P's ZSK 40 and ZSK 58 Mega compounding extruders. The company does not plan to put tie bars on extruders larger than 50mm.
Krupp W&P officials say the ZSK 50 is user-friendly. Tie bars make it easier to gain access to the barrel and screw than individually bolted, flanged barrels, said Eberhard Dieterich, business manager for engineering resins at Krupp Werner & Pfleiderer Corp. in Ramsey, N.J., the company's U.S. headquarters.
At K'98, Krupp W&P demonstrated a ZSK 50 making long-glass-fiber compounds. A patented device allows glass rovings to enter the extruder downstream from the main polymer feed port, where the plastic is in a molten stage. A patented screw element design ensures a minimum of glass breakage, so glass length is the same size as the finished pellet.
To get to the barrel sections using the previous design, a technician had to unscrew 32 bolts. The tie-bar design requires removing just four bolts. To exchange a barrel section, the upper tie bars are removed, the new barrel section is placed on the lower tie rods, the upper tie bars are reinstalled, and the barrel is tightened. A standard wrench is used to torque the tie bars.
Krupp W&P first showed the ZSK 50 in September, at a processing conference in at the Ramsey plant. Then the machine was shipped to Dusseldorf.
At the Ramsey conference, Steve Jackson, manager of the process laboratory, said Krupp W&P has sold 63 Mega compounders since K'95. Ninety percent of them have gone to resin compounding operations, he said. The other 10 percent were sold for chemical and food-processing applications.
``We wanted to make those machines more attractive to the small and medium-size production requirements that are out there,'' Dieterich said at the conference in Ramsey.
At K'98, Krupp W&P also showed a ZSK laboratory-sized extruder with a new touch-screen panel mounted on the base. It swivels 360 degrees. The machine also has new cartridge heaters and quick-disconnect manifold fittings.
On the opposite spectrum, the company introduced, but did not display, what it claims is the world's largest co-rotating, intermeshing compounder. The ZSK 380 Mega compounder can pump through 165,000 pounds of material an hour. Nova Chemicals Ltd. recently bought one of the giant machines to compound polyethylene at its new plant in Joffre, Alberta.
Krupp W&P also announced its owners manuals are now available on CD-ROM.