1.1 本试验方法涵盖了塑料木材及其“制造”形状的堆积密度和比重的测定。因此，这是一种评估塑料木材或形状作为产品性能的试验方法，而不是材料性能试验方法。 1.2 该试验方法适用于通过将整个物品或代表性横截面浸入水中来确定体积比重或体积密度。该试验方法包括使用比水轻的塑料沉降片在水中对一块试样进行称重。该试验方法适用于被水浸湿但在试验期间不受水影响的产品。 注1: 该试验方法是为应用于塑料木材而开发的，但它足够通用，同样适用于其他塑料复合材料，包括木材- 塑料复合材料。 1.3 塑料木材和塑料型材目前主要由回收塑料制成。然而，该试验方法也适用于由原始树脂制成的类似塑料制品，其中产品的横截面不均匀。 1.4 以国际单位制表示的数值应视为标准。 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制定适当的安全、健康和环境实践，并确定监管限制的适用性。 注2: 目前还没有与此测试方法等效的ISO。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 固体的比重或密度是一种特性，可以方便地测量，以跟踪样品的物理变化，指示不同采样单位或样品之间的均匀度，或指示大型物品的平均密度。 5.2 特定塑料木材或形状试样的密度变化可能是由于结晶度的变化、增塑剂/溶剂含量的损失、发泡程度的差异或其他原因造成的。由于结晶度、热历史、孔隙率和成分（树脂、增塑剂、颜料或填料的类型或比例）的差异，样品的部分密度可能会有所不同。 注3: 参考试验方法 D1622/D1622米 . 5.3 密度对于计算强度重量比和成本重量比非常有用。 5.4 如果未来对特定样品进行测试需要样品的横截面积，可以通过比重测量来确定，请参见 Eq 4 .

1.1 This test method covers the determination of the bulk density and specific gravity of plastic lumber and shapes in their “as manufactured” form. As such, this is a test method for evaluating the properties of plastic lumber or shapes as a product and not a material property test method. 1.2 This test method is suitable for determining the bulk specific gravity or bulk density by immersion of the entire item or a representative cross section in water. This test method involves the weighing of a one piece specimen in water, using a sinker with plastics that are lighter than water. This test method is suitable for products that are wet by, but otherwise not affected by water for the duration of the test. Note 1: This test method was developed for application to plastic lumber materials, but it is generic enough that it would be equally applicable to other plastic composite materials, including wood-plastic composite materials. 1.3 Plastic lumber and plastic shapes are currently made predominately from recycled plastics. However, this test method would also be applicable to similar manufactured plastic products made from virgin resins where the product is non-homogeneous in the cross-section. 1.4 The values stated in SI units are to be regarded as 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. Note 2: There is no known ISO equivalent to this test method. 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 The specific gravity or density of a solid is a property that can be measured conveniently to follow physical changes in a sample, to indicate degree of uniformity among different sampling units or specimens, or to indicate the average density of a large item. 5.2 It is possible that variations in density of a particular plastic lumber or shapes specimen will be due to changes in crystallinity, loss of plasticizer/solvent content, differences in degree of foaming, or to other causes. It is possible that portions of a sample will differ in density because of difference in crystallinity, thermal history, porosity, and composition (types or proportions of resin, plasticizer, pigment, or filler). Note 3: Reference is made to Test Method D1622/D1622M . 5.3 Density is useful for calculating strength to weight and cost to weight ratios. 5.4 If the cross-sectional area of the specimen is required for future testing on a particular sample, it is acceptable to determine it from a specific gravity measurement, see Eq 4 .