ASME NM.3.2:2018 pdf free download – Nonmetallic Materials Part 2 – Reinforced Thermoset Plastic Material Specifications
4.1.1 Type—In Roman numerals, shall designate the rein- forcement structure comprised of specific plies of glass fiber in specific sequences.
4.1.1.1 Type I—A standard all-mat or chopped-roving construction, or both, as shown in Table 1.
4.1.1.2 Type II—A standard mat or chopped-roving and woven-roving construction, or combination thereof, as shown in Table 2.
4.1.1.3 Other types, such as standard mat or chopped roving with alternating layers of nonwoven biaxial or unidirectional reinforcement in the structured plies. may be qualified in accordance with Appendix X2. 4.1.2 Class—In capital letters, shall designate the generic resin: “P” for polyester and “V” for vinyl ester. The letters “FS” followed by parenthesis, “FS( ),” shall designate fire retardancy, if specified, with maximum flame spread in the parentheses in accordance with Test Method E84. NOTE 4—Fire retardancy by Test Method E84 is determined for 0.125-in. (3.175-mm) thick, flat laminates with all-mat glass content of25 to 30 %. NOTE 5—Maximum flame spread designation by Test Method E84 relates to measurement and description of the properties of materials, products, or systems in response to heat and flame under controlled laboratory conditions and should not be considered or used for the description or appraisal of the fire hazard of materials, products, or systems under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment that takes into account all the factors that are pertinent to an assessment of the fire hazard or a particular end use.
4.1.4 Thickness—Nominal, shall be designated by Arabic number in decimal hundredths of an inch. (See Table 1 and Table 2 for standard thicknesses.) NOTE 7—Table 1 and Table 2 are for reference purposes and do not preclude other laminate-type constructions, such as nonwoven biaxial or unidirectional fabric, which may be agreed upon between the buyer and the seller, or may be added to this specification if they have been fully identified and characterized, as shown in Appendix X2.
4.1.5 Classification Requirements for Different Laminates— Laminate designation from Table 3 shall consist of the abbre- viation RTP followed by (1) type in Roman numerals; (2) class in capital letters followed by FS if required; (3) grade consisting offive Arabic numbers to designate minimum levels of physical properties and (4) thickness designated by Arabic number in decimal inches (or ALL, if properties apply to all thicknesses).
6.2 Apply resin and two plies of 1 1 ⁄ 2 -oz (42.6-g) mat. As an alternative, a minimum of two passes of chopped roving (minimum fiber length 1 in. (25.4 mm) and resin may be applied by the spray-up process equivalent in weight and thickness to 3 oz/ft 2 (918 g/m 2 ) of chopped mat. Each pass of chopped roving or ply of chopped-strand mat shall be thor- oughly rolled out. This section ofthe laminate shall be allowed to exotherm prior to application of subsequent plies of rein- forcement.
6.3 Continue lay-up in the sequence of plies, tabulated for the specified laminate type. Roll each ply for thorough wet-out and deaeration. 6.3.1 Interruption of laminate construction for exotherm shall follow instructions noted on Table 1 and Table 2 for the particular laminate type. The final ply of reinforcement before interruption for exotherm shall be 1 1 ⁄ 2 -oz/ft 2 (459-g/m 2 ) mat or chopped roving equivalent. The initial ply of the following lamination shall be 1 ⁄ 1 2 -oz/ft mat or chopped roving equiva- 2 lent.
6.4 The outer surface of the fabricated laminate shall be smooth and free of exposed glass fibers. The final ply shall be mat or chopped roving equivalent. A surfacing mat is not required unless specified. Surface resin may require the addi- tion ofparaffin or may be sealed with overlaid film, as required or approved by the resin producer, to ensure proper surface cure.