Extrusion molding is to mold plastic or metal into the predetermined shape. During this process, the metal or plastic melts and then they are pushed through the mold to form a linear shape. The final shape, usually called a rod, although not necessarily cylindrical, is then cooled and then cut into various lengths according to the application.
If you cut a rod of material into thin slices, the plastic extrusion shapes are called cross-section. The shape of the extrusion molding machine is the same as the shape of this cross-section. It is uniform throughout the project until the material or mold is changed.
The size of the extrusion molding machine is different, but it is usually at least the size of a car. It is equipped with some methods of inserting the material into the machine and melting it into a liquid state, which can be pushed through the mold to form its shape then. As a professional extrusion line manufacturer, we can produce high-quality extrusion molding machines for the market.
The components used for plastic and metal extrusion molding are similar in function but different in operation. For plastic extrusion molding, a large funnel (called a hopper) is placed on the top of the machine. Pour small particles of material, such as high-density polyethylene or plastic. These particles melt into a liquid state easily and are pushed through a mold to form a plastic tube or rod of a certain shape. For metal extrusion molding, a preheated heavy metal rod called a blank is inserted into the machine and then pressurized to force it through a die to make a metal tube or rod.
Like the injection molding, there are many variables to consider when extruding the materials. The temperature of the material, the pressure the material is forced through the die, and the time it takes to extrude are all factors that can be adjusted to create the ideal material condition. Extrusion molding is similar to injection molding in that it melts plastic or metal materials and then forms them into a predetermined shape. However, through injection molding, plastic or metal will not be continuously extruded. When the mold or mold filling material is cooled, open the pre-formed shape and then put them into the container.
When designing the mold for the extrusion molding machine, the factors affecting the cooling of the finished material must be considered. For example, the shrinkage of plastics and metals is the percentage of the size that the material loses after cooling. When designing a mold, the shrinkage of various materials must be considered.