L-P-535E

Abstract

This specification covers rigid unsupported polyvinyl chloride) and poly(vinyl chloride-vinyl acetate) sheets (sheeting) and strip (see <a>6.4</a>) <br>Plastic sheet and sheeting covered by this specification shall be of the following compositions, types, classes, and grades as specified (see <a>6.2</a>). <br>Composition A - Poly(Vinyl Chloride) <br>Type I - Normal impact strength, high stiffness and chemical resistance <br>Class 1 - Maximum stiffness and maximum chemical resistance. <br>Class 2 - Maximum stiffness and high chemical resistance. <br>Class 3 - High stiffness and maximum chemical resistance. <br>Type II - High impact strength, moderate chemical resistance. <br>Grade NT - Nontoxic according to intended use. <br>Grade GU - General use. <br>Type III - Medium impact strength, low chemical resistance. <br>Type IV - Good embossing characteristics. <br>Composition B - Poly(Vinyl Chloride-Vinyl Acetate) <br>Type I - Unmodified. <br>Class 1 - Colored. <br>Class 2 - Colorless and transparent. <br>Class 3 - Optical quality. <br>Type II - Modified. <br>Class 1 - Medium impact strength. <br>Class 2 - Moderately high impact strength. <br>Class 3 - Very high impact strength. <b><u>Intended Use:</u></b> Composition A sheeting and strip is used because of its resistance to chemicals, moisture and oxidation, transparency or ease of coloring, mechanical strength, dimensional stability, and low cost. The values for these properties vary with type, class, and grade, the higher impact types being lower in strength and in resistance to chemicals and to weather. Type I, class 1 should be specified for applications which require the maximum chemical and temperature resistance but which do not require resistance to impact. Examples are linings for tanks for holding hot concentrated acids, and hoods, ducts and on blades for handling corrosive fumes. Since this class is rather difficult to fabricate, class 2 or 3 should be specified for less critical applications. Type II is used in thin gauges for blister packaging and as swimming pool liners, and in thicker gauges for vacuum forming into trays and drip pans for refrigerators and into military dummies and decoys. Type II may be used for opaque, white cartographic sheeting. Type II, grade NT is used for nontoxic applications (see <a>4.3.18</a>). Type III is used for applications in which the impact strength and chemical resistance of the material are relatively unimportant. Type IV material is used in applications such as credit cards which require maintenance of original embossing after exposure to summer temperature conditions. Composition B sheeting and strip is used where greater flexibility is desired that can be obtained with the sheetings of composition A. Composition B sheeting and strip normally is odorless, tasteless, water resistant, self-extinguishing, has good dielectric properties, and low toxicity. Examples of uses are given below: <pre> Type I: Class 1 Three-dimensional displays for educational purposes. Three-dimensional decorations. Class 2 - Recording discs. Class 3 Transparent cartographic sheeting. Type II: Class 1 - Luminous ceilings. Spiral book bindings. Class 2 - Decorative and structural wall panel laminates. Instrument dial covers. Class 3 - Bas-relief maps. Signs and charts. Navigation and computing charts. Slide rules. Identification cards. Instrument dial faces.</pre> <br>