Compressive creep test rig for thermoplastic samples

Creep occurs when a material is subjected to a constant load resulting in deformation. Thermoplastics are prone to creep and understanding creep behavior is important for predicting the long-term performance of thermoplastic parts that must bear load. Creep is a slow process and measuring it can take days, weeks, months, or longer. Accelerated methods to estimate creep behavior exist, but long-term testing produces the most accurate results. We have developed a creep test rig made from off-the-shelf parts that require minimal machining and is easy to operate. The instrument can provide students at the high school, community college, and university level with a simple entry point to materials research. The long run time means that multiple students can collaborate to acquire the data. The instrument helps expand the overall capacity of the scientific community to generate compressive creep data while simultaneously offering a low-cost way to engage students in research. The instrument can be used for traditional university, government, and industry research. Users may wish to operate the instrument in an air-conditioned space with minimal change in temperature and humidity, but some of the authors have recently published work demonstrating that creep measurement under changing ambient temperature and humidity can provide useful data as well (Vaezzadeh et al., 2025).