Search results
Results from the WOW.Com Content Network
The polymer solution casting process utilizes a mandrel, or inner diameter mold, that is immersed in a tank of polymer solution or liquid plastic that has been specifically engineered for the process. Due to a combination of thermal and frictional properties, the polymer solution then forms a thin film around the mold. [1]
Blow extrusion of plastic film. The manufacture of plastic film for products such as food packages, shopping bags, and continuous sheeting is achieved using a blown film line. [5] This process is the same as a regular extrusion process up until the die. There are three main types of dies used in this process: annular (or crosshead), spider, and ...
Die swell is an expansion of the melt as the pressure is released, and is dependent on polymer chemistry and die design. After curing, the solid, continuous part is drawn onto a take-up roller or cut into transportable lengths, depending on the type of part. This process may vary significantly depending on the type of die and extrusion process. [1]
Melt blowing process Melt blowing is a conventional fabrication method of micro- and nanofibers where a polymer melt is extruded through small nozzles surrounded by high speed blowing gas. The randomly deposited fibers form a nonwoven sheet product applicable for filtration, sorbents, apparels and drug delivery systems.
In both types of extrusion the raw material must be plasticized to allow and induce the flow of the material in the process. Complex technical ceramic parts are commonly formed using either the injection moulding process or "hot wax moulding." Both rely on heat sensitive plasticizers to allow material flow into a die.
A process flow diagram (PFD) is a diagram commonly used in chemical and process engineering to indicate the general flow of plant processes and equipment. The PFD displays the relationship between major equipment of a plant facility and does not show minor details such as piping details and designations.
The distance from the die is called the height of the frost line. It depends on various factors, including the melt temperature, the speed of cooling, the extrusion speed, and the diameter of the bubble. The notion is important, since the higher the frost line, the more difficult to control the uniformity of the film thickness.
The melt flow rate (MFR) or melt flow index (MFI) is a measure of molecular weight of polypropylene. The measure helps to determine how easily the molten raw material will flow during processing. Polypropylene with higher MFR will fill the plastic mold more easily during the injection or blow-molding production process.