ASTM D1622 Standard Test Method for Apparent Density of Rigid Cellular Plastics

The standard "ASTM D1622 Standard Test Method for Apparent Density of Rigid Cellular Plastics," developed by the American Society for Testing and Materials (ASTM), describes a test method covering the density of a cellular plastic. Density can be evaluated as either the apparent overall density (including formed skins) or the apparent core density (removed formed skins).

The apparent density of rigid cellular plastics refers to the measured density of the foam-like plastic material, taking into account both the solid portions of the plastic and the air-filled cells (or voids) within it.

Rigid cellular plastics are plastics with a foam structure, containing many small, closed air pockets (cells), making them lightweight yet rigid. Examples include rigid polyurethane foam, polystyrene foam, and rigid PVC foam.

Apparent density is the density calculated by dividing the total mass of the foam sample by its total volume, including the volume occupied by air cells. It is called apparent density because it reflects the bulk density of the material, not just the density of the solid polymer.

Apparent density is the ratio of the mass of the foam sample to the total volume of the foam sample (including air cells).

Apparent density is important for the following reasons:

• Material properties: Apparent density greatly affects the mechanical strength, thermal insulation and durability of rigid cellular plastics.
• Quality control: Helps manufacturers ensure consistent foam production.
• Design considerations: Engineers use apparent density to select the right foam for insulation, packaging, or structural components.

If the material to be tested contains forming skins, the apparent overall density or the apparent core density, or both, must be determined. If the material has no forming skins, the term overall density is not applicable.

This test method can also be applied to spray foam materials.

Before proceeding with this test method, the properties of the material to be tested must be consulted. Any test specimen preparation, conditioning, dimensions, or test parameters, or combination thereof, included in the relevant ASTM material specification take precedence over those specified in this test method. If no relevant ASTM material specification is available, the default conditions in this method apply.

The ASTM D1622 test method utilizes an analytical balance, a micrometer dial indicator, and two-component spray equipment. The sample is weighed on a scale, and its dimensions are measured using a measuring device. The sample's weight is checked to an accuracy of plus or minus 0,1 percent. The sample is measured using a caliper or dial gauge with a minimum area of ​​6,5 cm2. The dial foot pressure is maintained at 2,7 kPa plus or minus 0,7 kPa until the sample is indented. If any indentation occurs, the pressure is reduced. The tester must ensure that the caliper jaws do not compress the sample. Three measurements are taken for each dimension. To ensure there is no error, the measurement is performed three times.

Sample size and number must be as required by ASTM D1622. Three samples are taken, each with a volume that can be accurately calculated and is not less than 16,4 cm3.

Major applications of the ASTM D1622 standard include:

• Research and development: This standard provides fundamental information that facilitates research and development in cellular plastics. This information helps evaluate material properties for innovation in various applications and formulations.
• Quality control: The primary application of this testing method involves quality control processes. It helps manufacturers ensure that their products meet specific density requirements that are critical to performance and industry standard compliance.
• Material specification: Test results inform the material specification, which advises engineers and designers on the materials that should be used for a given application. Such specifications play a critical role in industries such as construction, automotive, and aerospace, where the properties of materials significantly contribute to performance and safety.
• Versatility in Applications: The methods covered in this standard can be applied to both skin-forming and non-skin-forming materials. Spray foam materials can also be tested using this method, increasing their usefulness across a variety of industries and applications.
• Interlaboratory comparisons: This method has also been used in interlaboratory studies to develop precision statements, further solidifying this method as one of the standard testing methods for multiple laboratories.

In short, ASTM D1622 covers the determination of density in rigid cellular plastics, both surface-coated and spray-foam materials. The process involves precise weighing and dimensional measurement to ensure accuracy in both overall apparent densities and core densities. It is an important method for research, development, and quality control, providing critical information for material properties and performance evaluation. Furthermore, thanks to the ASTM D1622 specifications, the industry is better positioned to improve product quality and consistency, make better decisions about appropriate material applications, and enhance overall product reliability.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with ASTM D1622 Standard Test Method for Apparent Density of Rigid Cellular Plastics.