(Plastics Today) -- With nine extruders that can be configured to provide numerous stripe and layer combinations, Welex (Blue Bell, PA) says its new five-layer sheet-extrusion system for multicolored food packaging sets a new mark for the number of extruders on one die. Built for a European custom-sheet manufacturer for use in thermoformed yogurt cups, the system has already been shipped and is expected to begin production in April.
The five-layer sheet construction includes a crystal PS gloss layer, a five-color custom-configurable stripe layer, a white layer, a scrap foam layer, and a white bottom layer. The scrap foam layer is produced via a proprietary gas-blown foam process. Welex notes that the system can also run polypropylene with no equipment changes.
Each mobile-mounted extruder includes a slide-plate screen changer and gear pump for high-precision output. The machines feed into a valve-distribution block before the multi-manifold and feed-block-equipped die for easy control of the individual component's destinations.
The sheet extrusion line's Welex Evolution individual roll drive sheet take-off system also has automatic roll-gap controls and a set of water-flow-driven secondary cooling rolls to promote uniform sheet temperature at the end of the line prior to winding onto jumbo rolls.