Shore Hardness is nothing but a measure of the hardness of a given material or how resistant it will be to permanent indentation. It is measured by the depth of indentation that is created on the material with a specified force. The measuring instrument is actually a durometer, but Shore Hardness is named after its inventor Albert Shore.
Accordingly, there are different Shore Hardness scales for measuring the solidity of different materials with varying properties, like rubbers, polymers and elastomers. In fact, there are as many as 12 different scales depending on the intended use, and each scale results in a value between 0 and 100. You can safely assume that higher values indicate higher hardness and vice versa.
However, you will find that only two of these scales are most commonly used for measuring the hardness of rubber compounds – A scale for softer ones and D scale for harder ones.
Shore A Hardness Scale is used for measuring the hardness of flexible mold rubbers. These can range in hardness from very soft and flexible, to medium and somewhat flexible, to hard with almost no flexibility at all. It follows that Shore A0 obviously denotes extremely soft and gel-like rubbers. While semi-rigid plastics will be measured at the highest end of the Shore A Scale.
In bonded cladding you need a durable and elastic connection on behalf of an optimal tension distribution due to weight, windloads and thermal extensions.
An adhesive having a Shore A 50/55 appears to be most suitable for the bonding of façade panels.