Faygo Plast

Plastic pipe extrusion line can be complicated to operate, but the overall process is relatively straightforward. The heart of the machine is the screw, which sometimes is referred to as an auger. The twin screw extruder is turned by a gearbox, which is powered by a motor. It is enclosed in a tight, heated barrel, which helps to provide friction.
The thermoplastic pellets are delivered into the machine through a hopper. The hopper is located at the rear of the barrel/screw assembly and the pellets drop into the barrel from there. As the screw turns, it slowly drags the thermoplastic pellets forward. The heat from the friction of the screw turning inside the barrel--along with external heating--melts the plastic as it moves forward in the barrel. The melted plastic is pushed into a section designed to meter the plastic for the next stage in the process. It also may be subjected to pressurized pumping at this phase of the process.
Now, however, improvements have been developed in plastics extrusion apparatus which reduce or substantially overcome the aforementioned prior art shortcomings.
Accordingly, it is a principal object of this invention to provide an improved screw extruder member of novel construction for use in extrusion apparatus which is capable of self-regulating a feed of particulate material from the extruder inlet to the downstream zone of the extruder.Another object is to provide such a screw member which permits operation of the extruder hopper in the flood feed mode while achieving the metered-starved state with respect to the screw without the use of apparatus external to the extruder.