Thermally Bonded PET-basalt sandwich composites for Heat Pipeline protection: Preparation, stab resisting, and thermal-insulating properties

Abstract

In order to solve the cost and bulky problems of buried thermal pipeline insulating materials, this study adopts basalt fabric and low-melting PET nonwoven to construct low-cost and light-weight pipeline thermal-insulating composites after needle punching and thermal bonding processes. Research result shows that thermal-bonded temperature affected the stab resistance and burst energy more significantly. As thermal-bonded temperature increased, knife resistance and spike resistance presented the upward and then downward trends, but the burst energy gradually decreased. Yarn pull-out result shows that the enhancement of stab resistance of intra-/inter-thermal-bonded structure resulted from the increment in the coefficient of friction between yarns. When PET-basalt sandwich composites were thermal-bonded at 140 °C for 5 min, the maximum knife and spike resistance were 147.00N(1.99 J) and 196.30N(1.11 J), respectively, and burst energy was 4.79 J, thermal conductivity reduced to 0.0073 W/(m·K). The resultant thermally bonded sandwich composites can be used as thermal-insulating protection for buried thermal pipeline.