METHOD OF SHAFT COATING WITH POLYURETHANE Russian patent published in 1998 - IPC

FIELD: chemical technology. SUBSTANCE: suction shaft for paper- and cardboard-making machines is covered with the 1-st layer containing epoxyresin (epoxy-group content is 20-30%), urethane prepolumer (NCO-groups content is 5-7%), aromatic diamine (NH₂-groups content is 8-12%), finely dispersed mica and organic solvent on metallic surface of a perforated shaft. Then after 30 min sealing layer is applied which consists of reinforcing filling agent as a band and composition of the first layer but without mica in organic solvent followed by 30-70% subpolymerization of total hardening and composition of the first layer is applied. Shaft is kept at 15-35 C for 2 h, poured with polyurethane, hardened and put out from the form. Method provides high safety degree of polyurethane coating fastening with metallic surface of the suction shaft. EFFECT: improved method of coating, improved quality. 1 tbl