ASTM D4976-12a(R2020) pdf free download

ASTM D4976-12a(R2020) pdf free download.Standard Specification for Polyethylene Plastics Molding and Extrusion Materials
1. Scope
1.1 This specification provides for the identification of polyethylene plastics molding and extrusion materials in such a manner that the supplier and the user can agree on the acceptability of different commercial lots or shipments. The tests involved in this specification are intended to provide information for identifying materials in accordance with the groups, classes, and grades covered. It is not the function of this specification to provide specific engineering data for design purposes. 1.2 Other requirements necessary to identify particular char- acteristics important to specialized applications shall be agreed upon between the user and the supplier, by using the suffixes given in Section 1.3. 1.3 Ethylene plastic materials, being thermoplastic, are reprocessable and recyclable (see Note 1). This specification allows for the use of those ethylene plastic materials, provided that any specific requirements as governed by the producer and the end user are met. N OTE 1—See Guide D7209 for information and definitions related to recycled plastics. 1.4 The values stated in SI units are regarded as standard. 1.5 The following precautionary caveat pertains to the test method portion only, Section 12, of this specification. This standard does not purport to address all ofthe safety concerns, ifany, associated with its use. It is the responsibility ofthe user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 For information regarding plastic pipe materials see Specification D3350. For information regarding wire and cable materials, see Specification D1248. N OTE 2—There is no known ISO equivalent to this standard. 1.7 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
11. Conditioning
11.1 Conditioning—Once specimens are molded, they shall be moved to a standard laboratory atmosphere or a controlled laboratory atmosphere. For natural unfilled polyethylene plas- tics the controlled laboratory atmosphere shall be 23 6 2°C. Test specimens, 7 mm or under in thickness, shall be condi- tioned for a minimum of 40 h immediately prior to testing. For filled and reinforced polyethylene plastics or polyethylene plastic blends, which contain a hydrophilic co-monomer, pigment, or modifier the specimens shall be conditioned in a standard laboratory atmosphere of 23 6 2°C and 50 6 10 % relative humidity (see Practice D618, Procedure A). For all materials to be conditioned for electrical testing, conditioning shall comply with the requirements of the standard test methods for electrical testing. In all cases the laboratory shall report both the temperature and humidity conditions during the conditioning period. 11.2 Test Conditions—Natural unfilled polyethylene plastics shall be tested in a controlled laboratory atmosphere of 23 6 2°C. For filled and reinforced polyethylene plastics and polyethylene plastic blends, which contain a hydrophilic co- monomer, pigment, or modifier the specimens shall be condi- tioned in a standard laboratory atmosphere of 23 6 2°C and 50 6 10 % relative humidity. For all materials to be tested for electrical properties, the laboratory shall comply with the requirements of the standard test methods for electrical testing. In all cases the laboratory shall report both the temperature and humidity conditions during testing. 11.3 Dispute—In cases of dispute, conditioning and testing shall be conducted in accordance with Procedure A of Practice D618.
12. Test Methods
12.1 Determine the properties enumerated in this specifica- tion in accordance with the ASTM methods as they apply, unless otherwise stated in this specification. 12.1.1 Flow Rate—Test Method D1238, using Condition 190°C/2.16 kg unless otherwise directed, (see Note 8). Make duplicate determinations on the material in the form ofpowder, granules, or pellets. No conditioning is required. N OTE 8—Although the flow rate of polyethylene plastics can be measured under any ofthe conditions listed for it under 6.2 ofTest Method D1238, only measurements made at Condition 190°C/2.16 kg are identi- fied as “melt index.” This method of test serves to indicate the degree of uniformity of the flow rate ofthe polymer ofa single manufacturer as made by an individual process and is not, by itself, indicative ofthe degree ofuniformity ofother properties.