If you're not familiar with the plastic extrusion process, here's what you should know: it is a continuous forming procedure that takes place in an extruder barrel. There are two types of extruders: the single screw and the twin screw. The single screw design has advantages like ease of manufacture, simplicity of operation, low capital cost, and good mechanical properties. Twin-screw designs have higher output rates than single-screw designs but they're also more expensive to produce and operate.
Extrusion profiles are always identical, which is desirable for a homogeneous end product. In addition, the process is easily modified to produce different products. Achieving good extrusion profiles means that the final product will be uniform, without gaps or air pockets that could affect the metallurgical properties of the end product.
A plastic extrusion profile consists of four basic criteria:
- The width of an extrusion ogive (the widest point),
- the thickness at an ogive (measured in two dimensions),
- the arc length in one direction,
- and the height in another dimension (measured using a gage block).
The process of production often starts with the preparation of the material. This can be in the form of pellets, scraps or flakes which are processed into a film by compounding and pelletizing. The materials are then measured out for each roll width (typically 3 to 18 inches) and placed onto a core. This sheet is then formed onto a round tube called an extrusion mandrel, which controls the shape of the final profile as it passes through the die and also helps determine how much plastic is wasted to formation. The mandrel also helps compensate for any further drawing that may occur during cooling.
Profile extrusion is a common process and is used in a variety of applications. For more information on this it's best to ask the experts.
