THE RESEARCH OF CHANGE IN HARDNESS OF THE PRESS ROLL COATINGS OF POLYURETANE UNDER CHANGES IN TEMPERATURE
Polyurethane coatings are widely used on the rolls of papermaking machines. In the process of roll coatings are exposed to high temperatures.Exposure to high temperatures, even for a short period of time reduces the strength properties of coatings and compound "metal-polymer", as well as to change in process parameters of papermaking - the change of the contact area of rolls. In the making and operation of the coating is important to know how it behaves in these conditions. To the manufacturing take this fact into account and select a material with excellent physical and mechanical properties and assign the required parameters in the operation mode. For this, necessary to study, how change hardness with increasing temperature.In the article describes experimental studies determine the hardness in the range of temperatures from +20 0C to +120 0C, the analysis of the data, provide guidelines for the choice of coatings.