Trexel Inc. (Wilmington, MA) has introduced a device that, it says, will make it easier and less expensive for manufacturers to adopt its microcellular foaming technology, called MuCell. The Screw Tip Dosing Module (TDM) is designed to replace the traditional screw tip/non-return valve; in combination with Trexel's new high-pressure MuCell SCF injector, it provides significant benefits especially for high-performance molding applications, increasing output and reducing wear, according to Trexel.
The new TDM is described as an optimized wiping/mixing module with reduced space requirements. It is especially beneficial in applications such as thin-walled packaging or for gentle treatment of long-fiber-filled materials.
The TDM works with many different screw and barrel configurations currently used by processors. It is compatible with standard three-zone screws as well as specific barrier screws and others. Eliminating the middle non-return valve and extending the plasticizing zone of the screw allows more gentle plasticizing and reduces wear. This is important because market requirements are changing, as foam molding becomes a more standard process globally, said Trexel President Brian Bechard. “The trend is moving toward more high-performance, application-specific solutions.”
Modular and flexible to facilitate retrofits, the TDM also is easily reversible for users who want to do conventional molding. There's a suitable solution for any specific case depending on what screws and barrels are available or being used, said Trexel. The TDM module can be used with short screws and enlarged barrels and even with a barrel extension.
Microcellular foaming technology reduces production cost while increasing environmental sustainability, said Trexel. It allows design engineers to break some of the rules of thermoplastic part design, resulting in design for function instead of design for manufacturability. The technology enables lighter, more dimensionally stable products that can be produced faster on smaller, more energy-efficient equipment, added Trexel.