Extrusion Dies For Plastics And Rubber Pdf Download
The resulting sheet of plastic is normally then coiled, or formed into a roll using a winder, before being cut into any desired shape and taken to another station for processing. A common method of cutting the film is by a so-called knife or \"knife and die\" cutting system. This is a method used to cut a large diameter tube into sections or pieces by passing the material over a stationary knife that runs at a fixed speed and angle. The characteristics of this system depend upon the type of material you are using and the speed at which you are working.
There are several operational methods available for mechanical handling of a plastic film, and this is one common method. The simplest method is to run the film between a pair of rotating rolls, usually nip rolls. As the film travels through the nip rolls, it is broken down into shorter lengths called \"flats\". This process takes place fairly quickly, and speed is determined on the properties of the film, the viscosity and the temperature at which the film is extruded.
The plast of all sorts of products are placed in the tube or pipe. The tube is vacuum sealed and the air inside is compressed by a pneumatic breaker, which turns the material inside out and then the plastic is forced through the filler head. Several methods of creating a vacuum are used. The simplest is to apply a vacuum to the lip of the tube; this compression causes the tube to seal by blowing outward and the lip is sealed by the vacuum (a tube is considered sealed if the tube is dry to the touch). With the tube sealed, the filler head pushing it down the aisle of the tube is used to exert the vacuum on the inside of the tube. For a distributor line, the vacuum may be created across the entire length of the tube; this is called multi-pouch vacuum. 7211a4ac4a