1.1 本试验方法测量粘附在塑料颗粒或颗粒上的微粒数量，这些颗粒通常是在塑料颗粒中生产和供应的。该测试方法的下限仅受用于捕获被量化颗粒尺寸的过滤盘的孔隙率的限制。 1.2 湿式分析技术允许通过液体清洗和过滤方法分离和收集带静电的颗粒。这必须在标准实验室条件下进行。 1.3 以国际单位制表示的值应视为标准值。 1.4 本试验方法描述了一种基本实践，即在生产周期结束后检查塑料的质量，并评估颗粒清洁系统或专用气动输送系统的性能，仅适用于小于500微米的不同粒级。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 注1: 没有已知的ISO等同于本标准。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 模塑和挤出塑料颗粒需要无尘、干燥的颗粒，以防止加工问题。塑料生产商试图在包装和装载之前用除尘系统清除灰尘和拖缆。 如何准确测量塑料颗粒中的粉尘和流光含量是一个重要的质量控制问题。 5.2 粒度分析用于确定整个代表性样品的粒度分布百分比。就塑料颗粒的尺寸分析而言，筛分用于确定500至2000微米范围内的粉尘含量。试验方法 921年 ，试验方法B，用于确定这种类型的粒度。 5.3 干筛分析后，小于500微米的颗粒需要通过湿法进行分析。 应使用新样品进行湿分析。该测试方法允许通过静电力冲洗附着在颗粒上的细粉。 5.4 湿式分析可精确定量少量到大量的细粉，消除静态影响，并消除机械搅拌的有害影响。必须采用湿法分析来准确量化塑料颗粒中较低的PPM粉尘水平。

1.1 This test method measures the amount of fine particles adhered on plastic pellets or granules in which they are commonly produced and supplied. The lower limit of this test method is restricted only by the porosity of the filter disc used to capture the particle size being quantified. 1.2 The wet analysis technique allows for separation and collection of statically charged particles by liquid wash and filtration methods. This must be performed under standard laboratory conditions. 1.3 The values stated in SI units are to be regarded as standard. 1.4 This test method describes an essential practice to check the quality of plastics once the production cycle is terminated and to evaluate the performance of pellet cleaning systems or of the special pneumatic conveying systems for the distinct size fractions below 500 micron only. 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. Note 1: There is no known ISO equivalent to this standard. 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. ====== Significance And Use ====== 5.1 Molding and extruding plastic pellets require dust free, dry pellets to prevent processing problems. Plastic producers try to remove the dust and streamers with dust removal systems prior to packaging and loading. How to accurately measure dust and streamer content in plastic pellets is an important quality control issue. 5.2 Particle size analysis is used to determine a percentage of particle size distribution from a representative sample of the whole. In terms of size analysis concerning plastic pellets, sieving is used to determine the dust content in the range of 500 to 2000 micron. Test Method D1921 , Test Method B, is used to determine this type of particle sizing. 5.3 After dry sieve analysis, particles smaller than 500 microns need to be analyzed by wet method. A fresh sample shall be used for wet analysis. This test method allows washing down the fines attached to the pellets by electrostatic forces. 5.4 The wet analysis provides accurate quantification of small to large amounts of fines, negating static effects, and eliminating detrimental effects of mechanical agitation. A wet analysis must be employed to accurately quantify lower PPM dust levels in plastic pellets.