Polyvinyl-chloride (PVC) is a type of plastic common in construction and building materials. The various types of PVC components are manufactured on a PVC production line. Typical components of a PVC production line are the PVC mixing unit where the plastic formula is combined and an extruder that pushes the plastic out of the mixer in a liquid or softened form. Other components in a PVC production line are the mold and the vacuum molding machine. A cutoff machine and a stacker/sorter commonly round out the production line equipment in a PVC manufacturing plant.
Similar to many chemical components, PVC begins as chemicals that must first be mixed in the proper amount to produce the PVC plastic material that will be shaped into useful components for everything from plumbing to siding materials. The production of PVC begins with a mixing machine or unit that heads the PVC production line and combines the various chemical ingredients into a liquid mixture. Equipped with scales that weigh the different components and a temperature gauge to monitor the required temperature setting for the PVC mixture to activate, the mixing unit is the first step in the production of a PVC plastic product.
The machine following the mixer on a typical PVC production line is the extruder. An extruder is the part of the machine that pushes the PVC plastic out of the mixing machine and into the forms or dies. Commonly designed with screw-type components known as conical screws, the PVC production line often uses more than one extruder machine to empty the mixing machine of plastic. As the screws turn, the liquid plastic is pulled between the spiral twists of the extruder and travels along the screw to the next stage in the production line, the moulding machine.
Moulding machines are used to cast the soft PVC plastic into a desired shape or form. Round PVC plastic pipe, pipe fittings and flat panels are some of the more common PVC mold shapes used on a production line. The extruder pushes the plastic into the moulding machine, where a detailed mold or die is filled with the plastic until no space is left unfilled inside of the mold. Some production lines utilize a vacuum moulding machine to remove any trapped air from the mold before it hardens. One of the final steps on a PVC production line is the cutting and stacking machine that cuts the PVC to size and places the pieces on a pallet for shipping.