Eprotec Extrusion Technology: coated melt pumps for product quality

Whether uniform colouring in sheet and profile extrusion or transparency in film extrusion, there is a rising demand toward the quality of products in plastics processing. Homogeneity of the melt and dimensional stability of the final product are of high importance. In this context, the even and constant delivery of the melt pump plays an important role. To ensure optimum product quality, the Swiss company Eprotec Extrusion Technology AG has introduced a novel melt pump to the market. Amorphous surfaces of the pump prevent possible material build-up, allow faster colour changes and reduce wear to a minimum.

Deposits can significantly reduce product quality

 Deposits within the melt pump, caused by dwell time, chemical reactions or dead zones, can significantly reduce product quality and lead to higher reject rates and longer down times. In addition, colour pigments in masterbatches, fillers or contaminated recycling materials increase wear and thus shorten the service life.

 Peter Fischer, co-owner of Eprotec Extrusion Technology, confirms: “During the extrusion of sheets made of PC, PMMA or the compounding of TPE, our pumps must meet the highest standards. The manufacturer expects process stability from us. Already 15 years ago, we introduced smaller diameter flow channels (product holes) in our melt-X melt pumps. The goal
was to achieve a higher flow velocity and thus to prevent melt adhesion. The transitional areas between the housing
bore and the bushings have also been optimized to avoid dead zones. A high level of self-cleaning was the main focus
in our development. In particular, the gentle and complete squeezing of each individual tooth gap guarantees success and process stability. “

Eprotec is breaking new ground 

With Dreistegen GmbH in Monschau, Germany, a specialist for surface treatment in plastics processing, Eprotec has found a competent partner. Dreistegen assists in finding solutions for even higher customer demands and for the continuous development of new products. An oxide hard coating applied by means of PVD / CVD technology offers decisive advantages: The amorphous, non-polar surface prevents chemical build-up and deposit formation. The wall adhesion is reduced which in turn results in improved flow properties. An almost dense surface reduces the tendency to corrosion. The high hardness
of more than 2,300 HV offers very good wear protection for demanding melt pump applications.

Cleaning time reduced by 1/3

Customers of Eprotec confirm that the cleaning time, thanks to the new coating of the of melt-X melt pumps, is reduced
by 1/3. Polymers are easy to wipe off. Colour change times are again significantly reduced, thus reducing polymer loss. In addition, the maintenance intervals are extended for applications which are subject to significant wear.