Fiber fleece cushioning - determination of the compressive strength
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Our test laboratory performs testing in accordance with the Volkswagen standard PV 3919 using an accredited procedure. This internal specification describes a test method for determining the compression hardness (indentation force deflection) of flexible cellular materials. The aim of the test is to characterize the mechanical resistance of a material to compressive loading, particularly with regard to its force–deformation behavior under defined compression.
The method is primarily applied to polymer-based foams, such as polyurethane foams, which are used in seating systems, upholstery, armrests, and other comfort and damping components in vehicle interiors. Compression hardness is a key parameter for evaluating seating comfort, support characteristics, and long-term load-bearing performance.
During testing according to PV 3919, standardized foam specimens are conditioned under defined climatic conditions and then placed in a testing machine between two parallel compression plates. The specimen is compressed at a defined rate to a specified relative deformation (typically expressed as a percentage of the original specimen height). During compression, the required force is continuously recorded.
The compression hardness is reported as the force value at a defined degree of deformation (e.g. 40% compression). Depending on the test specification, multiple deformation levels may also be evaluated to describe the nonlinear deformation behavior of the material in more detail.
The resulting parameters provide a reliable basis for assessing the mechanical properties of foam materials and are important for material selection, component design, and quality assurance in the automotive sector.