Calcium carbonate (CaCO3) and talc are two widely used mineral fillers in the plastics industry, and their use in rigid packaging has increased significantly over the years. Once thought of simply as resin extenders, the addition of these mineral fillers to materials such as polypropylene, has been shown to contribute to increased performance, improved processing, and improved sustainability of the finished part - properties which can be further influence by loading level.
But if you're new to the world of mineral fillers, or considering using them in an application for the first time, you might be asking yourself, how do I determine the proper loading level for my application? To shed some light on the subject our friends at Heritage Plastics have contributed the following guest post discussing methods to help determine the optimum loading level for thermoforming applications:
Working with polypropylene sheet for the first time often presents new challenges for thermoformers including shrinkage, low rigidity, and low stiffness. The addition talc or calcium carbonate mineral fillers can help remedy these problems while contributing added benefits compared to resin-only formulations. But while talc and calcium carbonate both offer benefits, we often find our customers asking, “what’s the difference?”