Cold Extrusion
Cold extrusion is an extrusion process during which the plastic material is processed below the recrystallization temperature, around room temperature. Aside from this, the cold extrusion line runs about the same the hot extrusion line.

Coextrusion
During coextrusion, manufacturers use multiple extruders on the extrusion line to make one piece. In doing so, they are able to mix two or more layers of different plastic resin types together and create a product with qualities from both. The different extruders melt their respective resins at the same time, then deliver them to a forked conveyance channel, where they all meet and mingle. They are extruded using a single die.

Blow Film Extrusion
Blow film extrusion, similar to blow molding, is the method used to make plastic films like shopping bags. This extrusion process makes use of a cylindrical die with an annular opening and an air outlet. Molten plastic exits the extruder barrel, where it encounters sets of rolls. The rolls pull the material, thereby changing its thickness. After this, the resin enters the die, where the air outlet blows air into it until the material spreads out and takes on the die’s cylindrical profile. After this, the plastic is cooled, usually by a cooling ring.

Plastic Injection Molding
Plastic injection molding is quite similar to plastic extrusion. In fact, plastic extrusion is considered a subtype of injection molding. During this process, manufacturers melt plastic pellets in a hopper, then inject them into two hollow cavities. These hollow cavities are then clamped together and held there under pressure. This helps join the molten plastic. Then, manufacturers allow the plastic shape to cool and harden. Once it’s solid, they separate the two halves of the mold and eject the new plastic part. Plastic injection molding is useful when you want to create tight tolerances. It is also great for high volume runs.