Test Fixtures for ASTM D1621 Model: G-ASTM-D1621

The definitive standard for Compressive Properties of Rigid Cellular Plastics. This is critical for structural insulation and core materials. The technical nuance lies in the Yield Point determination. Since foams often exhibit a long plateau after initial cell wall collapse, the UTM must have high-resolution displacement encoders to capture the transition from elastic to plastic deformation. MTO recommends Self-Aligning upper platens to ensure full contact with the specimen faces, as even a 0.5-degree tilt can lead to edge-crushing and a significant underestimation of the compressive modulus.