Continuous Screen Changer for Polymer Melt Filtration in BIAX Extrusion
NO WEB BREAKS ASSOCIATED WITH SCREEN MOVEMENT
When the film is lost from the chains of a biax line, it takes considerable time and wasted material to thread the line up again. This type of event can occur right after a shift to a fresh screen pack in a slide-plate or other discontinuous type screen changer. By contrast, with a HITECH™ screen changer, the 120’ roll of filter screen is equivalent to several hundred screen packs and lasts for several months in non-stop operation.
- The elimination of pressure fluctuations due to screen clogging results in uniform melt temperatures and flow rates, thereby significantly improving gauge control.
- The continuous movement of the filter ribbon prevents contaminants from building up and degrading. By contrast, the operating mode of slide-plate screen changers can dislodge decomposed polymer particles and other contaminants, resulting in scrap film being produced for some time after each screen change.
HITECH™ fully automatic, continuous belt type screen changers are used in BIAX extrusion lines applications world-wide for polymer melt filtration.
HITECH™ continuous ribbon screen changers have no moving parts to wear, no hydraulics. Sophisticated PLC based controls continuously monitor the extrusion process and automatically adjust the rate at which the 120’ roll of filter ribbon advances. Uniform head pressure and melt temperatures are maintained indefinitely resulting in tight gage control for months of non-stop operation. HITECH™ continuous polymer filters are used in Biax lines from all the world’s leading extruder equipment manufactures. Whether a retrofit of existing BIAX extrusion equipment or the purchase of a new BIAX extrusion line, HITECH™ screen changers have been the leading solution for polymer melt filtration equipment for more than 50 years.