Fix Bonding of Headlamp Assemblies by Reactive Warm Melts

Instant-Fix Bonding of Headlamp Assemblies by Reactive Warm Melts 

Headlamp assemblies (Figs. 95 and 96) made from different plastics can be bonded with a unique system consisting of plasma pre-treatment followed by application of a patented, warm melt adhesive using special adhesive pumping/delivery equipment. This section describes the advantages of this unique system over one or two-component conventional adhesives and butyl rubber containing hot melt sealants. 

Headlamp assemblies basically consist of two parts a transparent cover shield and body. The cover shield is generally made of polycarbonate (PC), which is scratch-protected by a hard coat e.g. by a UV-cured coating system. The body is generally polypropylene (PP) which is modified with fillers like talc. Headlamp 

Sealants or adhesives are traditionally used for producing headlamp assemblies. The most common techniques for bonding the two parts comprising the headlamp assembly are summarised below  

IC-silicone adhesives do not fulfill all customer wishes as these pasty adhesives do not keep the assembled headlights perfectly aligned and are tacky and easy to contaminate in the uncured state, which leads to additional expenses or delay in leakage quality control and the use of fixing aids such as clamps. 

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