热熔粘合剂具有快速放置和快速硬化的工艺优势。当熔化温度与前照灯温度匹配时，它们可用作前照灯粘合剂/密封剂。已开发出用于将聚碳酸酯透镜组装到聚丙烯反射器的优质热熔粘合剂。不粘聚丙烯粘合良好。粘结强度和高温性能（120摄氏度）均符合该应用的要求。1000小时的气象计测试几乎没有效果。粘结强度（ASTM D1002）在200到360磅/平方英寸（1。 0.010粘结线的剪切拉伸达到0.3挠度。在一些配方中，120℃老化期间的交联是明显的。

HOT-MELT ADHESIVES HAVE PROCESS ADVANTAGES OF RAPID PLACEMENT AND FAST HARDENING. THEY CAN BE USEFUL AS HEADLAMP ADHESIVE/SEALANTS WHERE THE MELT TEMPERATURE IS MATCHED TO HEADLAMP TEMPERATURE. SUPERIOR HOT-MELT ADHESIVES HAVE BEEN DEVELOPED FOR ASSEMBLY OF POLYCARBONATE LENSES TO POLYPROPYLENE REFLECTORS. THE UNSTICKABLE POLYPROPYLENE WAS BONDED WELL. BOTH BOND STRENGTH AND HIGH-TEMPERATURE PERFORMANCE (120 DEGREES C) WERE SATISFACTORY FOR THIS APPLICATION. WEATHEROMETER TESTS FOR 1000 HOURS HAD LITTLE EFFECT. BOND STRENGTH (ASTM D1002) WAS IN THE REGION OF 200 TO 360 PSI (1.3 TO 2.5 MPA) AND SHEAR STRETCH OF 0.010 BOND LINES WAS UP TO 0.3 DEFLECTION. CROSSLINKING DURING AGING AT 120 DEGREES C WAS APPARENT IN SOME FORMULATIONS.