DALLAS - The growth in gravimetric blenders to feed extruders in blown film production has prompted Dayton, Ohio-based Comet Automation Systems Inc. to form a joint venture with a German company, Vollmar-AG. The companies began talking at NPE '94. An agreement was finalized in January, and Comet showed one of the weigh blenders, called Gramix E, during Plastics Fair Dallas at Dallas Convention Center Feb. 13-15. That unit was made by Vollmar in K”nigswinter-Oberpleis, near Bonn, Germany.
The blenders are used for film and sheet extrusion.
Vollmar is building the first few units and shipping them to Comet.
The licensing agreement calls for Comet to build the blenders in Dayton, according to Comet President Tom Rajkovich.
Rajkovich said the move will help Comet regain strength in blenders for extrusion. The market has been changing.
``We've been doing volumetric feeders for years, but in the last six or seven years we've seen our business in volumetric feeders for extrusion drop off. The main reason is people are going to gravimetric feeders.''
Hartmut Vollmar, president of the German company, said European film producers have turned to gravimetric feeders - which measure materials by weight, not by volume - because thegravimetrics make it easier to track and document production and change ingredients such as colorants and additives.
``This can be fully integrated into the production system,'' he said.
The Gramix blender continuously weighs the materials, and it can automatically slow down the extruder if needed when something runs low. The blender also features simultaneous setting of haul-off speed using pre-set values.
Another feature: the Gramix blender has no mixer. Rajkovich said that eliminates a component that can malfunction.
The compact Gramix E blender is the smallest in Vollmar's Gramix line. It can process up to 600 pounds of material an hour and handle up to four materials. Gramix S, for up to seven materials, can process a maximum of 1,400 pounds an hour. The Gramix Maxi can move more than 2,000 pounds an hour and handle as many as nine components.