New applications are pushing the limits of low-temperature performance in standard rubber compounds. In most cases, formulation changes must be made to meet these new criteria. As temperatures drop, many rubber materials begin to increase in hardness and resistance to deformation, which can result in leakage. Apple Rubber engineers took a closer look at three common polymers, Nitrile Rubber (NBR), Silicone (SL) and Fluorocarbon (FKM) to find ways to improve their performance at low temperatures.