Backflush Screen Changers Meet Direct Recycling Demands
Maag’s CSC-BFX backflush screen changer meets the demands of direct recycling, such as rPET bottle flakes to films, with just two screen pistons. Conventional backflush screen changers utilize the filtered melt stream to clean the screens and are used primarily on pelletizing lines where the resultant fluctuations in throughput have little effect.
For commercial reasons, the recycling industry is increasingly demanding suitable backflush filters for direct processing of recycling material into 1A products (film, fiber, sections, etc.) without the intermediate step of pelletizing. The Maag CSC-BFX backflush screen changer meets those requirements by storing the backflush material in rheologically optimized conditions in an integrated melt accumulator. As a result, the CSC-BFX cleans the contaminated screen surfaces with no impact on the end-product.
The backflush filter incorporates two turn/lift cylinders for the complete filter function as opposed to other designs with as many as eight hydraulic cylinders. In addition, the diverter valve function, installed as standard feature, purges the startup melt to the floor when the line starts up. The backflush screen changer is fully automatic. Its controller, the maaxBFX, provides user-friendly control, monitoring and visualization of operating parameters when handling highly contaminated polymer melt. Extensive practical trials have been completed, and the backflush screen changer is available now in the standard extrusion sizes with active filter areas from 250cm2 to 3,250 cm2.