Vinyl Tubing
Vinyl tubing are hollow cylinders that are constructed from polyvinyl chloride, or PVC, and are used to convey fluids or gases or as structural components. Vinyl tubing is chemically resistant to acids and alkalies as well as many chemicals, solvents and abrasions; it is even sometimes used to transfer hydrocarbons, although not certain aromatic hydrocarbons. Vinyl tubing is the best choice for transferring air, oxygen, water, and many other liquids. Since vinyl is a naturally crystal clear material, vinyl tubing is particularly useful for applications that require visible fluid movement. Offering many advantages, such as a high corrosion resistance, electrically non-conductive, naturally resistant to combustion, odorless, non-toxic and tasteless, vinyl tubing can be sterilized and thus used for applications requiring food and beverage grade tubing. Industries that utilize vinyl tubing include medical, brewery, cosmetic, pharmaceutical, commercial pools, food processing, waste water and petroleum. Vinyl tubing is commonly used for air conditioning, heating, dispensing beer, water distillation lines, ice making machines, furnace drainage and deionized water systems.
Made through the extrusion process, vinyl pellets are first fed into a hopper placed atop a closed extruding channel. Gravity feeds the raw vinyl down into the extruding channel; inside the channel is a screw conveyor which moves the pellets towards the opposite end, softening the pellets through friction and heat. Electric heaters built into the extruding channel ensure that the vinyl is completely molten by the time it reaches the die at the end of the channel. The die works by forming the molten vinyl into a specific profile as it is pushed through by the screw conveyor. In order to create the hollow inside of the tubing, a pin or mandrel must be placed inside of the die and a positive pressure is applied to the internal cavities through the pin. The newly formed tubing is instantly cooled with cold water, pulled through by a series of conveyors and cut to length. There are two main types of vinyl tubing: clear vinyl tubing and black vinyl tubing. Clear vinyl tubing is the natural form of vinyl tubing. Black vinyl tubing, however, requires a dye to achieve the desired color. Since pellets are pre-fabricated before undergoing the extrusion process, if the tubing is to be colored, the dye will be typically be added while the pellets are being fabricated and will begin the extrusion process already dyed.