【国外标准】 Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products

5.1 Flexural properties determined by these test methods are especially useful for research and development, quality control, acceptance or rejection under specifications, and special purposes.5.2 Specimen depth, temperature, atmospheric conditions, and the difference in rate of straining specified in Test Methods A and B are capable of influencing flexural property results.1.1 These test methods are suitable for determining the flexural properties for any solid or hollow manufactured plastic lumber product of square, rectangular, round, or other geometric cross section that shows viscoelastic behavior. The test specimens are whole “as manufactured” pieces without any altering or machining of surfaces beyond cutting to length. As such, this is a test method for evaluating the properties of plastic lumber as a product and not a material property test method. Flexural strength cannot be determined for those products that do not break or that do not fail in the extreme outer fiber.1.2 Test Method A, designed principally for products in the flat or “plank” position.1.3 Test Method B, designed principally for those products in the edgewise or “joist” position.1.4 Plastic lumber currently is produced using several different plastic manufacturing processes. These processes utilize a number of diverse plastic resin material systems that include fillers, fiber reinforcements, and other chemical additives. The test methods are applicable to plastic lumber products where the plastic resin is the continuous phase, regardless of its manufacturing process, type or weight percentage of plastic resin utilized, type or weight percentage of fillers utilized, type or weight percentage of reinforcements utilized, and type or weight percentage of other chemical additives.1.4.1 Alternative to a single resin material system, diverse and multiple combinations of both virgin and recycled thermoplastic material systems are permitted in the manufacture of plastic lumber products.1.4.2 Diverse types and combinations of inorganic and organic filler systems are permitted in the manufacturing of plastic lumber products. Inorganic fillers include such materials as talc, mica, silica, wollastonite, calcium carbonate, and so forth. Organic fillers include lignocellulosic materials made or derived from wood, wood flour, flax shive, rice hulls, wheat straw, and combinations thereof.1.4.3 Fiber reinforcements used in plastic lumber include manufactured materials such as fiberglass (chopped or continuous), carbon, aramid and other polymerics; or lignocellulosic-based fibers such as flax, jute, kenaf, and hemp.1.4.4 A wide variety of chemical additives are added to plastic lumber formulations to serve numerous different purposes. Examples include colorants, chemical foaming agents, ultraviolet stabilizers, flame retardants, lubricants, anti-static products, biocides, heat stabilizers, and coupling agents1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.NOTE 1: There is no known ISO equivalent to this standard.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.