Renault D45 1045 Cellular Materials Apparent Density

The purpose of the procedure described in the standard "Renault D45 1045 Cellular materials apparent density" developed by the French automobile company Renault is to evaluate the apparent density of cellular rubbers and plastics, cushioning polyurethane, the density and filling of box section foams and similar flexible or rigid cellular materials. This standard does not apply to lightweight thermoplastics.

This test method principally involves weighing a known volume of material.

The main equipment used in the tests are:

• Therasi: Accuracy up to 0,001 g
• Slide caliper: accuracy up to 1/10 mm
• Cutting equipment: For example, band saw (toothless blade)
• Conditioning room: Set to 23 degrees plus/minus 2 degrees temperature and 50 percent plus/minus 5 percent relative humidity

When preparing samples, three test pieces of simple geometric shape (for example, a rectangular parallelepiped) are taken using cutting equipment. The dimensions of the samples must comply with the instructions given in the relevant normative documents. If no such instructions are given, the following procedure must be followed:

• Cellular rubber and plastic: 2 to 5 g samples
• Foam with integrated skin: Test samples of 2 to 5 g are taken into the core, eliminating a thickness of 5 mm on the skin side
• Foam board: 100 mm x 100 mm samples and height equal to the thickness of the semi-product
• Cushioning foam: Samples with a carrying capacity of 100 mm x 100 mm and a height of between 30 mm and 60 mm.

Condition the test pieces in the chamber for at least 16 hours.

When performing the test, the edges of the sample are determined using a slide caliper. In the case of using a caliper or probe, pressure should not be applied to the sample due to the risk of distorting the measurement. The measured sample should slide effortlessly between the jaws of the caliper. The shape of the sample is rarely a perfectly flat plane geometry. For each side, the average value of six measurements (3 measurements are on opposite sides) is taken as shown in the appendix. In the case of cellular foam filling, the height can be determined by the method of the D41 1003 standard. The volume is calculated in mm3.

When calculating the results, the density expressed in kg/m3 for each sample is calculated using the formula given in the standard. The density of the material is the arithmetic average of the densities of the tested samples.

In addition to the results obtained, the test report should include:

• Reference for this test procedure
• Identity of the operator and machine used
• Test date
• Reference of the part from which the samples were taken
• Supplier name and material reference
• Sampling points, dimensions, any molding surfaces or heterogeneity of the samples
• Procedural details not specified in the test procedure and any events that could affect the results

Apparent density refers to the ratio between the mass and volume of the test specimen. Volume is the volume occupied by a solid material, including voids formed during production and all surface coatings. Apparent density depends on the shape of the particles, the composition of the material and the storage method. Another standard that is taken as a basis in this regard is “ASTM D1622/D1622M-14 Standard Test Method for Apparent Density of Rigid Cellular Plastics”. This test method covers the density of a cellular plastic. Density can be evaluated as apparent overall density (includes formed skins) or apparent core density (removed formed skins). If the material to be tested contains formed skins, apparent overall density or apparent core density or both should be determined. If the material does not have formed skins, the term overall density is not applicable. This test method is also applicable to spray foam materials.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the “Renault D45 1045 Cellular Materials Apparent Density” standard with its trained and expert staff and advanced technological equipment.