What is Thermoplastic Compounding?

As we all know, plastic is everywhere. It’s in millions of products performing millions of functions for billions of people. From laundry baskets, to artificial joints in the human body, plastic performs and infinite number of functions. Plastics are polymers and there are a surprisingly few distinct polymer materials in the world when compared to the vast number of end uses for plastic. So how does plastic work well in millions of applications when there are only a few dozen plastic polymers? The answer is thermoplastic compounding.

Thermoplastic compounding makes basic polymers work better. Thermoplastic compounding is a process in which base polymers are mixed with other materials to make the base material behave differently. Compounding enhances the properties of base polymers by adding other materials to them.

All this work of making polymers better takes place in an extrusion machine. Most compounding companies (including PolyVisions) use machines called twin screw extruders. These machines consist of two heated screws that melt, mix and propel plastic materials. The base polymer (usually in pellet form) is put in the extruder and melted and propelled forward inside what is called the barrel of the extruder. Other materials (generally referred to as additives) which modify the behavior of the base polymer are added along the length of the barrel and mixed in to the base polymer. By the time the materials reach the end of the barrel they are fully mixed and are then turned back into plastic pellets ready to be used to make end products.

Putting additives into thermoplastic polymers can enhance many properties including; color, impact strength, flexibility, heat and cold resistance, UV resistance, electrical conductivity, tensile strength, lubricity ad countless other characteristics. Additives may include; pigments, glass fibers, carbon nano particles, flame retardants, lubricants, other polymers, elastomers, nucleating agents, fillers, etc….

PolyVisions is a leader in reactive compounding. In this process we are able to create a chemical reaction in our twin screw extruders to produce what is called a grafted polymer. Grafted polymers are similar to co polymers in that the materials are not simply blended together, they are actually bonded to each other at the molecule level. This results in much more radical and unique property transformation of the base material. This reactive extrusion process creates a stable morphology that not only can act as an interfacial compatibilizer but also retains many of the inherent thermal and mechanical properties of the base polymers. Because the materials are molecularly bonded to each other they tend to behave with more consistency than simple blends in processing like film and sheet extrusion, thermoforming and injection molding. PolyVisions takes polyester, nylon, polyurethane, polyethylene and other materials and grafts other polymers to them to create unique new materials.

PolyVisions uses co rotating twin screw extruders to melt, mix, propel and pelletize thermoplastic materials. If you are using a thermoplastic material that needs enhanced properties, call us!