Car manufacturers utilize foam materials primarily for seating purposes. The consumer is continuously interacting with the material and it's material properties can directly affect the consumer's ownership experience. As such, manufacturers perform rigorous testing of foam materials to ensure their safety, durability, and comfort. Various tests are performed in order to characterize the material's properties as they relate to the support profile and long-term consumer comfort.
Simple compression testing is not adequate in quantifying the material properties of foam materials. Car manufacturers often require cyclic testing in order to better analyze the performance of foam materials.
The two most common tests performed are indentation force deflection (IFD) and hysteresis testing. IFD is defined as the amount of force required to indent a platen of a specified thickness into the material. This test is often performed repeatedly on various sections of the material to best characterize its support profile. Hysteresis testing measures the difference between loading and unloading energy of the material. This helps car manufacturers understand the comfort and support provided to consumers when getting in and out of the seat.
Offered as an add-on to Bluehill® Universal software, TestProfiler allows the user to create advanced multi-step tests with unprecedented flexibility. Within the powerful yet easy-to-use architecture, cyclic tests can quickly be created to perform both IFD and hysteresis tests.
The required calculations can be easily implemented within the software, and graphical displays can be filtered to only show relevant loading cycles. This gives the user the control to view information most important to them, and more easily gain insight into their product.
Most foam compression tests performed by automotive manufacturers are based off ASTM D3574, which has very specific fixture requirements. Most automotive companies internal standards share the same requirements.
The standards require the support plate to be perforated with 6.5 mm diameter holes and 20 mm spacing. The holes allow for the rapid escape of air during the test. The standard also dictates the use of a swivel indenter foot which ensures proper alignment when axial loading is applied to the specimen, ensuring the most accurate and repeatable results.
The design utilizes a spherically seated compression platen and an aluminum support base. The support base can be set up in minutes, using the Instron bolt pattern on the base of the frame. The compression platen can attach directly to the load cell.