The term ‘catalin phenolic resin’ refers to a generic class of thermo-setting polymeric materials which are widely used in industry. Unlike the chemically similar plastic polymers all resins have a rigid structure suitable for making moulded products. The manufacturing process starts with one or more low molecular weight (MW) precursor chemicals known as ‘monomers’. Such molecules have two or more chemically active bonding sites that can link them together into larger ‘polymer’ structures. With only one chemically active group only simple ‘dimers’ are generated. If the relevant monomer has two or more active sites an on-going repetitive linking process known as polymerization may occur which generates large high MW structures. Monomers with two active sites tend to generate long chain molecules with plastic or rubber type properties. In contrast in phenolic resin polymerization the monomers have at least three active sites and the product of polymerization is a highly cross-linked three-dimensional chemical structure ideally suited to the manufacture thermosetting moulded products. In this case the low MW monomers in granular form are typically melted and cross linked within the mould. By contrast plastic polymers such a nylon are typically pre-polymerized, melted and then extruded under pressure in perhaps fibre or rod form.