Results of the September SimTech™ 2023 Injection Molding Challenge First Place goes to Dainius Staniulis of…
There are two main categories of plastic materials used in injection molding and extrusion (and other processes as well). These are Hygroscopic and Non-hygroscopic.
Hygroscopic materials absorb moisture from the outside air. To efficiently injection mold or extrude these materials requires that they be first dried. Some common hygroscopic materials include Nylon, ABS, Acrylic, Polyurethane, Polycarbonate, PET and PBT. Both types need plastic drying procedures.
Non-hygroscopic materials, on the other hand, do not actually absorb moisture, But moisture can accumulate on the surface of the pellets through condensation when there is a change in room temperature, for example. Moving a non-hygroscopic material from storage into the production area can cause condensation to form on the material. This moisture accumulation needs to be removed before processing the material through injection molding and/or extrusion. This type of moisture formation is primarily a material handling problem. Some common non-hygoscopic materials include Polyethylene, Polypropylene, Polystyrene and PVC.
You plant should have specific, step-by-step guidelines for how to handle all of the materials you process. Failure to have these rules in place will cause needless waste and expense.
Always try to minimize the amount of time that you dry any plastic material. Also, make sure that you always have fully dried plastic ready for each injection molding or extrusion job running on your production floor. Waiting for plastic to be dried is something that you should try to avoid at all costs.
So, to summarize… proper plastic drying procedures save time and energy, both important compbnents of your profit. Have systems in place to make sure that your plastic material handlers know the differences between plastic types and the drying requirements of each. You’ll save time, energy and ultimately make more profit.