by Ben Chouchaoui, Windsor Industrial Development Laboratory
Part 1 of this contribution, published in the May 2021 edition of Rubber World, investigated a real manufacturer’s process that was set to produce medical tubing. It was found (through trials at the extruder, then through simulations) that the equipment available to the manufacturer was too large for the relatively low output that was required for this project, and consequently the polymer was degrading on the screw surface. It was ultimately determined through simulation that a smaller extruder, with a screw optimized for the low rate, would work better.
Extrusion simulations based on VEL (Virtual Extrusion Laboratory) software proved to be useful in anticipating issues and running “what if” scenarios to size extruders and designing associated dies for rubber extrusion projects, and should be used at early stages of any project to avoid manufacturering “trial and error” and the remaking of tooling.