Indentation Hardness Test Machine: ISO 2439, DIN 53577, DIN 53579-1, ASTM D3574, ASTM D3579

Indentation Hardness:

ISO 2439, DIN 53577, DIN 53579-1, ASTM D3574, ASTM D3579

• For molded foam such as vehicle cushions and mattresses, indentation hardness is one of the most important characteristic values used to describe the quality of the product, for example, its comfort. These molded parts are typically tested to DIN 53579-1. When testing cushions, the specimens are placed in specially shaped molds.

• This type of test is important in materials testing as well. Standards such as ISO 2439 and ASTM D3574define the test sequence in detail.

• The method of measurement used is hardness measurement. A defined indenter is pressed into a surface area that is significantly larger and the required force to do so is continuously measured. The sequence consists of multiple preload cycles, in which cells break off and the foam is brought to a mechanically defined state. This is followed by a measuring cycle. The result is shown as force values, which have been captured on defined impressions after defined hold times have expired.

• One advantage to this method compared to compressive stress value measurement is the elimination of the impact of cut edges. The measured value obtained is a characteristic value that is independent of the dimensions and is comparable if the specimen is large enough. This value is sufficient for quality control purposes.