WHAT IS EXTRUSION? - 1
Do you remember as a kid shoving play dough into the red and yellow toy to squeeze out a “rope” shaped like a star or a flower?
Well, that defines Extrusion: a process used to create objects of a fixed cross-sectional profile. Commonly extruded materials include metals, polymers, ceramics, concrete, modeling clay, and foods, such as macaroni and cheese puffs. Here we will focus on the high output use of plastic extrusion to form plastic parts that we use on an everyday basis and for industrial and medical processes.
Plastics Extrusion in advanced manufacturing is not simply choosing different colors to push through several basic shapes… Custom Plastic Extrusion can combine the properties of advanced materials to enable specific performance characteristics for plastic tubing or plastic parts, and can form multi-lumen tubing or complex profiles to fit a wide range of applications for commercial, industrial, food processing, filtration, automotive, military and medical/pharmaceutical industries.
The extrusion process starts by feeding plastic material (pellets, granules, flakes or powders) from a hopper into the barrel of the extruder. The material is gradually melted by the mechanical energy generated by turning screws and by heaters arranged along the barrel. The molten polymer is then forced into a die (typically a metal disc with cutouts or holes), which shapes the polymer into a continuous shape that hardens during cooling. Every step in the extrusion process is critical to defining the performance characteristics of the end product. The science and art of extrusion relies upon experience and extensive quality control using temperature, speed, force, tension and time factors to create a consistent product.