Stability of prevulcanised latex

The stability of latex is one of the key factors for many applications. With tests of different batches we can make a comparison and sometimes we see a deviation between old and more recent batches, where the recent batch has a much higher MST (Mechanical Stability Test) which is indicative of how stable the latex is. ZST is also another measurement of the chemical stability of the latex, and again some batches are a little more stable than others. The stability of the PVML may result in the latex not setting or drying as quickly when applied by brush or when a mould is dipped in the latex. This can result in the thickness of the rubber layer being less than you obtain when using a less stable product of the same type. This can be problematic when using no coagulant to gel or set rubber (i.e. straight dipping or applying latex by brush). Usually, high MST is preferred by customers as it makes product more stable during storage particularly, however it may not suit everyone’s application. For some customers we might need to look at a maximum MST for PVML.