Because PVC is a vinyl derivative, it can be engineered to be either clear or opaque. The word vinyl describes any material that belongs to the vinyl group of chemicals, and PVC is one of the most commonly produced and used vinyl-based plastic products.
PVC is versatile, strong, durable and can be formed into many shapes and used for many purposes. It is a particularly appropriate plastic for the fabrication of tubes and pipes because of its resistance to abrasives and many corrosive solvents; it is even sometimes used to transport hydrocarbon products, which are often volatile.
PVC tubing can be an excellent choice for transferring gasses and liquids at variable volumes and pressures because of its high tolerance for pressure changes. PVC’s electrical non-conductivity combined with its corrosion resistance, non-toxicity and natural combustion-resistance make it a good choice for transportation of demanding materials.
PVC tubing is also used in pharmaceutical products development, brewing, food processing, waste water management, pool operation and in many other applications.
Plastic tubing products can be produced through a variety of thermoforming processes, but the most effective, efficient and common method is plastic extrusion. Plastic extrusion is the process by which raw plastic material is shaped into a usable product. In the case of plastic tubing extrusion, the process begins with a collection of raw plastic material called stock.
The stock is loaded into a hopper suspended above a conveyance channel. Inside the channel, a long, turning screw forces the stock toward a die at the end of the channel. A die is any industrial tool designed to shape a raw material into something useful. A plastic tubing extrusion die is a metal plate with a specially designed hole and pin through which molten plastic is forced.
The plastic becomes molten because of the friction caused by the turning screw and heat from electric heating elements along the length of the channel. Once molten, it is forced through the die. When it emerges on the other side of the die, the plastic has become newly extruded tubing, at which point it is allowed to cool and harden. Then the tubing is cut to length and prepared for shipment or additional processing.