【国外标准】 Standard Test Method for Environmental Stress-Crack Resistance of Blow-Molded Polyethylene Containers

5.1 When properly used, these procedures serve to isolate such factors as material, blow-molding conditions, post-treatment, and so forth, on the stress-crack resistance of the container.5.2 Environmental stress cracking of blow-molded containers is governed by many factors. Since variance of any of these factors can change the environmental stress-crack resistance of the container, the test results are representative only of a given test performed under defined conditions in the laboratory. The reproducibility of results between laboratories on containers made on more than one machine from more than one mold has not been established.5.3 Results can be used for estimating the shelf life of blow-molded containers in terms of their resistance to environmental stress cracking provided this is done against a rigorous background of practical field experience and reproducible test data.1.1 Under certain conditions of stress, and in the presence of environments such as soaps, wetting agents, oils, or detergents, blow-molded polyethylene containers exhibit mechanical failure by cracking at stresses appreciably below those that would cause cracking in the absence of these environments.1.2 This test method measures the environmental stress crack resistance of blow-molded containers, which is the summation of the influence of container design, resin, blow-molding conditions, post treatment, or other factors that can affect this property. Three procedures are provided as follows:1.2.1 Procedure A, Stress-Crack Resistance of Containers to Potential Stress-cracking Liquids—This procedure is particularly useful for determining the effect of container design on stress-crack resistance or the stress-crack resistance of a proposed container that contains a liquid product.1.2.2 Procedure B, Stress-Crack Resistance of a Specific Container to Polyoxyethylated Nonylphenol (CAS 68412-54-4), a Stress-Cracking Agent—The conditions of test described in this procedure are designed for testing containers made from Class 3 polyethylene Specification D4976. Therefore, this procedure is recommended for containers made from Class 3 polyethylene only. This procedure is particularly useful for determining the effect of resin on the stress-crack resistance of the container.1.2.3 Procedure C, Controlled Elevated Pressure Stress-Crack Resistance of a Specific Container to Polyoxyethylated Nonylphenol (CAS 68412-54-4), a Stress-Cracking Agent—The internal pressure is controlled at a constant elevated level.NOTE 1: There are environmental concerns regarding the disposal of Polyoxyethylated Nonylphenol (Nonylphenoxy poly(ethyleneoxy) ethanol (CAS 68412-54-4), for example, Igepal CO-630). Users are advised to consult their supplier or local environmental office and follow the guidelines provided for the proper disposal of this chemical.1.3 These procedures are not designed to test the propensity for environmental stress cracking in the neck of containers, such as when the neck is subjected to a controlled strain by inserting a plug.1.4 The values stated in SI units are to be regarded as standard.NOTE 2: There is no known ISO equivalent to this standard.1.5 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. Specific precautionary statements are given in Section 8 and Note 1.1.6 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.