For a plastic extrusion process to be complete thermoplastic resins must be present. Thermoplastic resins are a form of plastic that can be melted, manufactured, and then re-dissolved. The resins used in a plastic extrusion machine are delivered in bead or pellet form.
Some plastic resin beads come in a pure form. Such beads have never been manufactured in the past and come with a purity certification. These beads are bought for specific uses and come in various grades of quality.
Machinery and Melting
The components of plastic extrusion machinery are quite simple. The machine has an auger or screw. A motor-operated gearbox turns the screw. The enclosed device is in a heated in a tight barrel to enhance friction.
Once the plastic enters the metering section, it is extruded through a die. The die is connected to the barrel and determines how the finished plastic will look like. A mandrel in the middle of the extrusion channel separates the plastic during the die assembly process
Pressurized air gets pushed through the device to prevent the plastic from collapsing. Once the plastic separates from the die, it goes to a vacuum environment. Sizing rings in the open environment help to shape the plastic. The vacuum is the filled with water to help cool the extruded plastic. Once the plastic has been cooled, it is spooled or cut into the desired shape. The remaining plastic from the extrusion process can be reprocessed into pellets and reused.
Parts of the Plastic Extrusion Machines
Engineers use the plastic extrusion machine to convert raw plastic granules into manufactured pieces. This tool is suitable for making long plastic tubes or sheets. An extrusion machine enables the mass manufacture of various plastic products with minimal waste.
It resembles a huge funnel and it keeps the raw product in a granular state. Its function is to transport the raw plastic into the heating barrel.
Once the plastic goes through the barrel of the extrusion machine, friction and heat cause it to melt. A rotating auger at the center of the machine helps to mix the molten plastic. At the end of the barrel is a water-cooled die that cools the plastic before it can be moved to the mandrel to produce the hollow shape.