Stress relaxation testing measures when a constant stress creates a physical and/or chemical change in a plastic or rubber material, thus reducing the force that the polymer compound can exert over a specified period of time.
The first observed effects generally include the relaxation of polymer chains and fillers. Because the changes that occur are generally chemical reactions, the effects tend to be long term and irreversible.
Accelerated environmental aging
can also be added to a stress relaxation test using a forced air oven and a wide variety of fluids that the material would normally come in contact with in service to better simulate real life conditions.
Our rubber and plastic testing experts have years of experience conducting accelerated aging testing to industry standards and custom specifications.
Common Standards for Stress Relaxation Testing
- ASTM D6147—Standard Test Method for Vulcanized Rubber and Thermoplastic Elastomer—Determination of Force Decay (Stress Relaxation) in Compression
- ISO 3384—Rubber, vulcanized or thermoplastic -- Determination of stress relaxation in compression -- Part 1: Testing at constant temperature