Our extrusion process is very similar to what many food processors work with in that we utilize a rotating screw in a heated barrel. In our case we melt plastic pellets, also called resin, in these extruders and push the molten plastics through a die. There are two ways to produce film, blown film and cast film, and at Multifilm we produce cast film. The process of creating cast film consists of a flat die. The molten plastic falls down like a waterfall onto a large chill roller. The plastic is quenched and solidified with the help of a cold surface, and is stretched over several additional rollers. The speed the film is run determines the thickness of the extruded film. The advantage of a cast film over blown film is the very high output.
We have two extrusion lines with multi-layer capabilities that allow us to better control stiffness, friction, seal range, and tensile strength. The gauge is automatically adjusted in the die, giving the final products extremely fine tolerances and high quality. Our in-house extrusion lab line allows our research and development department to constantly experiment with process improvements and packaging solutions by testing new resins and new resin combinations. The lab line helps optimize our films by continuously improving our existing product line.
Scrap is an inevitable part of any manufacturing process, but at Multifilm we make sure our extrusion scrap does not go to waste. As part of our commitment to sustainability, and as part of our Zero Waste program, we have been sending a portion of our scrap to a local injection molder to be reprocessed into consumer goods since 2009. In 2012, Multifilm acquired a repelletizing extruder to turn clean, useable scrap from extrusion back into virgin resin to be used internally again. Read more about our repelletizer and our Zero Waste-to-Landfill program in our sustainability section.