The influence of hygrothermal aging on disbonding performance of heat shrinkable sleeves in field coating for welded joint

In the light of the failure problem produced in heat shrinkable sleeves (HSS) in field coating for welded joint at pipel joint, five representative HSS used in field coating for welded joint are taken as research object, HSS installation system is manufactured, , and the influence of hygrothermal aging on disbonding performance of installation system with methods in CSA Z245.21-10 is studied. Results show that after an accelerated hygrothermal aging is made on different HSS, the difference in their disbonding strength and change trend vary. Combined with the analysis results of chemical composition of hot melt adhesives for HSS, it is pointed out that the chemical composition and structure of hot melt adhesives for HSS are important influencing factors on the stripping strength. The suggestions in performance improvements and continuous research of hot melt adhesive for HSS are proposed.