Mar 31 2008
After being in the market for 60 years, PVC is a well proven thermoplastic. Don't let its long history of successful use be a disincentive, however, because PVC's well balanced physical properties can result in considerable cost savings in many applications.
Available in sheet, rod and tube forms, PVC remains a highly rigid, strong and versatile material for uses such as corrosion-resistant tanks, ducts, fume hoods and pipes. Various shapes produced from PVC provide excellent machining and fabrication characteristics for components used in corrosive environments.
Before designing with PVC, however, it is useful to understand the differences among its most frequently used varieties, including flexible plasticised PVC, rigid PVC (most typically Trovidur EN), and Chlorinated PVC, or CPVC.
Flexible (plasticised) PVC is vinyl that has been heavily plasticised and is used to produce liners, film, packaging and many other products that require flexibility.
Trovidur EN PVC is the name given to Dotmar EPP's extruded sheets made from rigid PVC that contains no plasticisers or fillers. Rigid PVC, as in Trovidur EN, is the most common type of PVC used in the manufacture of pipe, fittings, valves, fume extraction, acid tanks, ducting, templates, machining shapes, sheet and duct. Rigid PVC offers advantages owing to its low cost and high strength-to-weight ratio.
Trovidur EN possesses excellent chemical resistance and dielectric properties, good tensile, flexural and mechanical strength, low moisture absorption, exceptional dimensional stability and good flammability characteristics. The maximum service temperature for Trovidur is 60 deg C (140 F).
Joining and fabrication of PVC such as Trovidur EN is readily accomplished by hot air welding, machining and thermoforming. The wide range of formulations, processing characteristics, fabrication capabilities, durability and relatively stable cost provide an economical material for a broad range of applications.
Chlorinated PVC (CPVC) provides advantages in elevated temperature environments because of its high heat distortion temperatures.
CPVC is created when PVC homopolymer undergoes a chlorination reaction. The result is a polymer similar to PVC but with a higher heat distortion temperature. This provides a material with high temperature strength and excellent flammability properties that also exhibits many of the desirable physical characteristics of PVC, such as exceptional corrosion resistant and good mechanical properties.
CPVC has an upper working temperature limit of about 93 deg C (200 F), or 33 deg C (60 F) above that of PVC, which greatly increases the product application range and makes it advantageous for many aggressive high temperature processing applications.
In addition to chemical inertness and mechanical strength, CPVC product have excellent flammability properties when compared with other plastics. It will not support combustion and rated as self-extinguishing.
Conclusion: Although PVC and CPVC are similar in nature, they are not the same. Care should be used when comparing their characteristics, fabrication techniques and applications. Dotmar EPP can assist in selecting the correct material for particular applications.
..Products available ex stock include:..
Rod Outside Diameter: 6 - 400 mm
Sheet Thickness: 3 - 25mm Sizes: 2440 x 1220 mm
Sheet Thickness: 30 - 50 mm Sizes: 2000 x 1000 mm
Available • White Trovidur EC UV stabilised (upon request) Clear Trovidor ET
• Hi temp CPVC (upon request)