ASTM D1621 Compression Test of Expanded Spray Foam

ASTM D1621 maps out test conditions for compression testing of rigid cellular materials, specifically expanded plastics or foams. These materials are used by a broad range of industries and applications. One example of their use is for sound and thermal insulation in the construction industry.

Plastics and foams must be flexible enough to withstand wall installations and sometimes strong enough to support entire roofing systems. Testing these products provide the necessary results to ensure safety and performance. ASTM D1621, similar to ISO 844, can be a guideline for testing the compression strength of a new or improved expanded plastic or foam.

Testing procedure

This test should be performed on a minimum of five specimens for each sample at a minimum height of 1 inch each. Start the crosshead with a rate of displacement of 2.5 to 0.25 mm [0.1 to 0.01 in.]/min for each 25.4 mm [1 in.] of specimen thickness. Continue until the specimen hits a yield point or until it has been compressed approximately 13% of the original thickness, whichever occurs first.

It is important to research:

  • Load deflection curve
  • Determine zero strain or load point
  • Measure 10% deformation point
  • Determine yield point
  • Compressive strength (psi)
  • Compressive modulus (optional)
  • Averages and standard deviations

A testing machine for compression testing of plastics or foams must be versatile and accurate. ASTM D1621 requires results within 1 % accuracy. The machine should include both a stationary and movable member and include compression platens. The plates should be larger than the specimen with a drive system for imparting a controlled velocity to the movable crosshead with a spherical upper platen.

By means of our expertise and product inventory, we guarantee to help find the testing solution that is right for you. Give one of our experienced engineers a call today for assistance with your testing plan and budget according to ASTM D1621.

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