The purpose of this classification system is to provide a method of adequately identifying poly(methyl methacrylate) (PMMA) molding and extrusion compounds. These compounds are polymers based on methyl methacrylate, and at least 70 % of the polymer shall be polymerized from methyl methacrylate. Poly(methyl methacrylate) molding and extrusion compounds are classified into groups in accordance with their composition. These groups are subdivided into classes and grades: class 1, 2, 3, and 4; grade 1 - materials used where special ultraviolet transmission, filtering, or stabilization characteristics are not required, grade 2 - materials used for those specialized applications in which the greatest amount of transmission of UV light is required, and grade 3 - materials (transparent UV stabilized or transparent UV absorbing) used when either special resistance to slight color change over long exposure times or high-intensity UV radiation is required, or when the material is required to filter out ultraviolet light. The plastics composition shall be uniform and shall conform to the requirements specified.
1.1 The purpose of this classification system is to provide a method of adequately identifying PMMA materials using a system consistent with that of Classification System D4000. It further provides a means for specifying these materials by the use of a simple line callout designation.
1.2 This classification system covers poly(methyl methacrylate) molding and extrusion compounds. These compounds are polymers based on methyl methacrylate, and at least 70 % of the polymer shall be polymerized from methyl methacrylate.
1.3 The properties in this classification system are those required to identify the compositions covered. Other requirements necessary to identify particular characteristics important to specific applications shall be described by using the suffixes as given in Section 5.
1.4 Acrylic molding and extrusion compounds are used frequently in applications where extreme clarity and the ability to retain that clarity and color under severe weathering and other environmental exposures are of primary significance. While the test specimen properties of this document extend to the evaluation of nonvirgin materials, the user must take precautions to ensure that parts made from these materials meet the desired end-use requirements. Accordingly, this specification allows for the use of those acrylic plastic materials that can be recycled, reconstituted, and reground provided the following:
1.5 This classification system and subsequent line callout (specification) are not intended for the selection of materials, but only as a means to call out plastic materials to be used for the manufacture of parts. The selection of these materials is to be made by personnel with expertise in the plastics field in which the environment, inherent properties of the materials, performance of the parts, part design, manufacturing process, and economics are considered.