PVC Type1 Sheet
Polyvinyl chloride (PVC) is one of the most versatile thermoplastics in use today. It is used extensively in all walks of life, from food packaging, to home construction. Its excellent strength-to-weight ratio and superior flame resistance, coupled with its low cost, make it the material of choice for the most demanding applications. Polyvinyl chloride (PVC) or “vinyl” is usually an amorphous thermoplastic material with 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 PVC is 140°F (60°C). The physical properties of PVC can be readily altered by the addition of plasticizers, impact modifiers and other ingredients to develop and enhance specific properties.
Generally, there are many types of PVC with specific physical and mechanical properties. They are available in rigid and/or flexible and in formulations in between. Additional subcategories of rigid and flexible PVC, with desirable physical properties for specific applications, can be developed by mixing additives with the base resin (e.g., the addition of UV stabilizers to enhance weatherability of rigid vinyl siding used in outdoor applications). PVC is available in a wide spectrum of colors as well as transparent variations.
PVC is manufactured into products by the injection molding process (e.g., pipe fittings), extrusion (e.g., pipe, shapes, siding, etc.), blow molding (e.g., bottles, etc.) and calendering (e.g., sheet). Joining and fabrication of PVC can be easily accomplished by using standard metal and woodworking equipment with tools specifically prepared for PVC. Fabrication includes joining by solvent cementing process, hot gas welding, machining, vacuum forming, thermoforming, milling and drilling. The wide range of formulations, processing characteristics, fabrication capabilities, durability and relatively stable cost provide an economical material for a broad range of applications. Rigid PVC is the most common type of PVC used in the manufacture of pipe, fittings, valves, machining shapes, sheet and duct.
Rigid PVC offers advantages for piping and related applications due to its low cost, high strength to weight ratio, pressure bearing capability, corrosion and chemical resistance and low friction loss characteristics. Rigid PVC is used for siding, window lineals, pipes, fittings, profiles and sheets in areas demanding extreme durability, weatherability, corrosion and flame resistance.
Physical properties of rigid PVC generally conform to ASTM-D-1784 (ISO 1163) with an accompanying cell classification consisting of five numbers. The first number is for base resin, the second is impact strength, the third is tensile strength, the fourth for modulus of elasticity, and the fifth is for deflection under load. The cell classification is followed by letters ranging from A to D. This suffix denotes chemical resistance. Altering the amount of a specific ingredient to improve one desirable property can affect other properties. For example, adding plasticizers to improve flexibility and impact resistance can result in a finished product with less rigidity and lower chemical resistance. The cell classification called out within this standard helps define and establish a basis for selecting and identifying various grades of rigid PVC compounds for correlation to specific applications.
Type I rigid PVC is a high corrosion resistant material with normal impact properties and is used where chemical attack is the major concern. Type II is an impact modified formula, which increases the ability of the material to withstand shock or impact, but will have lower chemical resistance relative to Type I.
Flexible (plasticized) PVC is vinyl which has been heavily plasticized and is used to produce tubing, liners, film, packaging, wire and cable insulation jackets and many other products which require flexibility and resistance to tear, puncture and abrasion. As with rigid PVC, flexible PVC can be formulated with additives to achieve desirable physical characteristics for specific applications and can be easily fabricated.
Technology has created the ability to foam both flexible and rigid PVC. The most significant growth has been in the lines of foamed rigid PVC. The process of foaming reduces the density of the PVC by 50 percent or more, which significantly impacts weight and cost, while still maintaining good physical properties. This class of products has seen significant growth in a relatively short period of time. It has replaced materials such as wood, metal, acrylic and styrene. It is used in many of the same applications as traditional PVC, but because of its lower cost, it is now the material of choice for point-of-purchase applications, signage and building construction. (See property table for PVC on page 121.)
RIGID PVC APPLICATIONS
Industrial Piping Applications (Pipe, Valves, Fittings, Sheet)
• Chemical processing
• High purity applications
• Water and waste water treatment
• Corrosive fume handling (duct)
• Food contact applications
• Drain, waste and vent (plumbing)
Sheet, Rod and Tube
• Corrosive resistant tanks and vessels
• Corrosive resistant workstations and equipment
• Nuts, bolts and fasteners
• Pump and valve components
• Spacers, hangers, stiffeners, hubs and other mechanical
• Semiconductor equipment
• Vinyl siding
• Credit cards
• Decorative applications
• Window lineals