Phenolic resin or phenol formaldehyde resins are synthetic polymers which are obtained by the reaction of phenol or their derivatives with formaldehyde in the presence of a catalyst and
according to the type of catalyst, they are classified into two categories of resul and novalac.
Phenolics whit acid catalyst basement call novalac and are used in manufacturing of wear resistant materials, brake pads, shoe glue, the casting industry and the manufacture of resinous sands.
The reason for using phenolic resin
Among all resins, phenolic resin because of its great thermal stability is used to manufacture brake pads. Phenolic resin is exposed to abrasion so friction has been arisen and the temperature of it rises to a great extent. According to this point phenolic resin heat resistance is so important. Zero water absorption, electrical properties and great chemical resistance are other advantages of phenolic resin.
What is the usage of phenolic resin?
It is used to attach composite section of brake pad to each other for manufacturing brake pad.
Phenolic resin (novalak) during braking because of high temperature of brake pad, in addition to great thermal stability, it has more friction even in high temperature of 350-420 C̊.
Quantity and also quality of phenolic resin formulation of brake pad have an important effect in function of brake pad, because the optimal amount of resin gives structural integrity to the brake pad without cancelling features.