Rubber Erasers - Consistency


Industry:

Materials

Attributes measured:

hardness

firmness

peak force

total area

resilience

Background

Our clients occasionally seek cheap, easily available products that might serve as firmness benchmarks for their test methods and which can be replicated across multiple locations. The gel industry occasionally uses metal Bloom strips which are typically deflected 4 mm with a ½” cylinder, but that technique does not translate very well to other test methods and Bloom strips can develop a history if not properly stored and used. Other industries use mounted springs, which can be as repeatable as Bloom strips, however, it is nearly impossible to get a set of springs that behave identically within an acceptable tolerance. The optimal benchmark would have to be extremely repeatable between products and must be insensitive to storage conditions and age. Our clients have considered using rubber erasers because of their highly uniform and consistent appearance. This study uses two test methods to evaluate whether rubber erasers are suitable to serve as a benchmark test product.