• Sika India Private Limited

Reactive Hotmelt Adhesive Technology

Sika India’s Reactive Hotmelts (RHM) are solid at room temperature and are based on polyurethane pre-polymers. This technology combines the properties of hotmelts with those of reactive polyurethanes. Sufficient early strength is attained when the material passes from the liquid to the solid state as it cools. By reaction with atmospheric moisture the adhesive is then transformed from a fusible thermoplastic to an infusible elastomer, making it more resistant to high temperatures than non-reactive hotmelts. How is it used Sika’s reactive hotmelt adhesives are heated to temperatures of 120-160ºC for application. Within this temperature range they exhibit a liquid or free-flowing consistency. They are applied by spray or roller or in extruded bead form at coverage rates determined by the specific application. Where is it used Reactive hotmelts adhere well to textiles, plastics and other porous substrates. Adhesion to metals is more limited. Typical applications include: heat-resistant interfacial bonding of textiles, e.g. door facings and parcel shelf linings in automobile assembly, decorative furniture facings, bonding of PUR foams as an alternative to flame laminating, fast structural bonding of interior trim components in automobile assembly, e.g. panel retaining clips for door panel trims. Technological benefits: faster production due to high early strength, significantly improved creep and heat resistance due to post-curing by means of atmospheric moisture, smaller investment in plant compared with emulsion-type or solvent-based laminating adhesives, as drying lines are not needed, high final strength, bonds well to a wide variety of substrates, very low fogging and emission levels. Product examples: Sika Melt-9630 (pseudoplastic), and Sika Melt-9670 (crystalline).