All-electric roto feeder facilitates silicone, BMC processing

With the development of the Engel roto feeder—a new rotary conveyor for continuous feeding of solid silicone or BMC materials to the plasticizing unit—avoiding inclusions and maintaining constant pressure during processing of these materials could become significantly easier and more economical.

This development opens the use of solid silicone and BMC materials to applications where these materials were previously not cost-effective due to high material and processing costs. The lack of automatic process engineering capabilities, particularly for small batch sizes (up to 50,000 parts), often made the use of solid silicone or BMC materials unfeasible. Continuous, air-free material feeding through the Engel roto feeder dispenses with the cost-intensive, problematic engineering process of rolling the silicone, and therefore allows for an economical molding process.

Processing is kept consistent via closed loop pressure control, which regulates the speed of the feed-screw, and the all-electric design provides energy efficiency and a cleaner process than found with the typical hydraulic stuffer unit. The new roto feeder also eliminates material leakage, again supporting a cleaner more cost efficient process.

New fields of application are now technologically and economically feasible according to Engel, such as seals in the automotive industry and medical technology, due to the low investment cost of this system. The new Engel roto feeder was featured, processing solid silicone gaskets, on an Engel Victory 330/100 US machine at the recent K 2010 show. Production of the 6-mm diameter gasket was fully automatic, and post-processing-free, using a 64-cavity mold with cold runner technology. The Engel roto feeder is available on machines with injection units of 310 cc and larger. —[email protected]