Search results
Results from the WOW.Com Content Network
Plastics extrusion is a high-volume manufacturing process in which raw plastic is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weatherstripping , fencing, deck railings , window frames , plastic films and sheeting, thermoplastic coatings, and wire insulation.
Hot extrusion is a hot working process, which means it is done above the material's recrystallization temperature to keep the material from work hardening and to make it easier to push the material through the die. Most hot extrusions are done on horizontal hydraulic presses that range from 230 to 11,000 metric tons (250 to 12,130 short tons ...
Wet spinning is the oldest of the five processes. The polymer is dissolved in a spinning solvent where it is extruded out through a spinneret submerged in a coagulation bath composed of nonsolvents. The coagulation bath causes the polymer to precipitate in fiber form. Acrylic, rayon, aramid, modacrylic, and spandex are produced via this process ...
Cast – Plastics extrusion can cast film which is cooled or quenched then wound up on a roll. Extruded film can be stretched, thinned, or oriented in one or two directions. Blown or tubular process forces air into an extruded ring to expand the film. Flat tenter frames stretch the extruded film before annealing. [3] [4]
In fluid dynamics, the die swell, extrudate swell or Barus effect, is a common phenomenon in polymer processing. Die swell occurs in instances of polymer extrusion, in which a stream of polymeric material is forced through a die, a specialized tool in manufacturing to shape or cut polymeric materials. Die swell is an instance where a polymer ...
The term is a portmanteau word, combining "pull" and "extrusion". As opposed to extrusion, which pushes the material, pultrusion pulls the material. A very early pultrusions type patent was filed by J.H. Watson in 1944. This was followed by M.J. Meek's filing of 1950.
Compounding is usually done by extrusion. The hopper feeds the begin of the screw which will gradually transport the resins towards the die. The screw itself is confined in a barrel that has different zones that can be heated according to the resins properties.
Melt Extrusion: The process begins with a polymer resin being melted and extruded through a spinneret, which is a device with tiny holes. High-Speed Airflow : Simultaneously, high-speed hot air or gas is blown onto the extruded polymer streams.