Traditionally in the film industry, film scrap has almost always been landfilled. However, more progressive companies like Multifilm have sought optimal homes for their scrap. In early 2012, Multifilm took the next logical step and invested in a Plasmac Omega 60 recycling extruder for the recyclable plastic scrap from the plant. The Omega 60 transforms plastic trim and scrap into valuable, high purity resin that can be reused in the films.
The process is relatively similar to a regular extrusion line, but done in reverse. The clean scrap that has been segregated by material type is loaded onto a conveyor belt. The material passes through a metal detector that automatically turns the machine off if metal is detected. Then the scrap feeds into a shredder and the material is conveyed into a 60mm extruder, similar to our cast extruders.
The liquid plastic is then extruded through a die with 1/10” holes with a rotating knife that slices the extruded plastic into pellets. The pellets are quenched in cool water to solidify and sent through a centrifugal sift to keep the fresh pellets from clumping together. The pellets cycle through a dryer and are finally deposited into a container to be used as virgin material again. The repro extruder has a capacity to recycle about 250 lbs/hr of production scrap.
Months of testing in Multifilm’s quality control lab and on the in-house lab line have ensured the quality and safety of reintroducing material back into the recipes. Segregation has been the key to success and no product scraps mix with others; UltraWrap only goes back into UltraWrap, TwistWrap only goes back into TwistWrap and so on. Also, the repelletized material is only used in the core of the film. No repelletized material is used in the skin layers, so there is never any risk of material-food contact. Finally, after numerous trials, we established the max safe load for putting material back into the recipes.
Repelletizing production scrap is a profitable way of being greener, reducing resin purchases, reducing the company’s environmental footprint and partially reducing the volatility on the resin market; a win-win for all.