Extension of Twin Screw Extruder
Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section. The two main advantages of this process over other manufacturing processes is its ability to create very complex cross-sections and work materials that are brittle, because the material only encounters compressive and shear stresses. It also forms finished parts with an excellent surface finish.
Extrusion may be continuous (theoretically producing indefinitely long material) or semi-continuous (producing many pieces). The extrusion process can be done with the material hot or cold.
Commonly extruded materials include metals, polymers, ceramics, concrete and foodstuffs.
Twin screw extruder transforms starch
More versatile and energy efficient than batch processing, the reactive extrusion process allows for a quick change of product with no shutdown time.
Today's powdery mountains of dry cornstarch could be tomorrow' s high-tech, economical, and environmentally friendly resins, adhesives, packing materials, and other goods--with some help from a machine called a twin-screw extruder.
Starch-based plastic products such as biodegradable cutlery and garbage bags have already made headlines. Now chemist Merle E. Carr at ARS' National Center for Agricultural Utilization Research (NCAUR) in Peoria, Illinois, is using a pilot-scale twin-screw extruder to explore further the potential of cornstarch for industrial uses. Twin screw extrusion technology for production of RTE snack food
Extrusion technology has offered food manufacturers exciting new opportunities in markets where consumers clamour to try new exciting eating experiences. Snack and breakfast cereals created using twin screw extrusion technology are already massively produced in U.K and America and has very vast potential in India and other developing countries. Confectionery and petfood are also equally common products of this process. The extrusion process is continous- the materials fed to extruder inlet constantly being conveyed, compacted & sheared to carry out cooking/gelatinisation of the ingredients and being extruded out though suitably shaped die fitted at the outlet of extruder, a constantly rotating knive cutting the extruded product into small beads for further treatment ahead.
Process in which metal or other material is forced through a series of dies to create desired shapes. Many ceramics are manufactured by extrusion, because the process allows efficient, continuous production. In a commercial screw-type extruder, a screw auger continuously forces the plastic feed material through an orifice or die, resulting in simple shapes such as cylindrical rods and pipes, rectangular solid and hollow bars, and long plates. In metalworking, extrusion converts a billet of metal into a length of uniform cross-section by forcing the billet through the orifice of a die; aluminum is easily extruded. Formed sheet aluminum is used for opaque curtain-wall panels and window frames.
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by Xiangsu