Extrusion is a continuous process through which parts of a fixed cross-sectional profile are made. Material is fed through a hopper into an extruder, essentially a rotating screw surrounded by a heated barrel, where it is mixed, melted and pumped through a die. The die gives the part its shape. Types include film extrusion, sheet extrusion, pipe, profile and tubing extrusion.
Film extrusion is divided into two subcategories: cast film (flat film) and blown film. In cast film extrusion, hot plastic is extruded through a flat, slit die onto a polished chill roll where it is quenched, pulled to a second set of rolls to cool the other side, then wound. In blown film extrusion, plastic is extruded into a cylindrical die, then inflated to form a bubble, which is cooled ...
Extrusion is nothing without in-process measurements. But what you do with those measurements can mean everything to transforming yields and profitability.
Custom processor GaMra Composites has developed new profile extrusion technology for producing siding, window lineals, fencing and other products for the construction market. The new patent-pending technology consists of 40% (by weight) long-glass fiber extruded with 60% PP copolymer, which is ...
Understanding Viscosity in Extrusion Both the power-law coefficient and the consistency index must be considered to calculate viscosity.
Plastics Extrusion Expert Jim Frankland, President of Franklin Plastics Consulting, delves into solutions and troubleshooting for film extrusion, sheet extrusion, pipe, profile and tubing extrusion.
Plastics Technology covers technical and business Information for Plastics Processors in Injection Molding, Extrusion, Blow Molding, Plastic Additives, Compounding, Plastic Materials, and Resin Pricing
EXTRUSION: Venerable Maddock Mixer Still an Extrusion Workhorse Variations to this decades-old mixing section are widely used, but processors should carefully analyze these designs and not assume they will perform better.