3M Flexible Adhesives

Contact adhesives require coating both surfaces, allowing the adhesive to dry until tacky, then pressing surfaces together. Bonding occurs instantly on contact—no clamping or cure time required, but repositioning is impossible once surfaces meet. Regular adhesives (wet bonding) are applied to one or both surfaces while still wet, allowing positioning and adjustment before the adhesive sets. Contact bonding is faster for production but less forgiving; wet bonding provides adjustment time but requires clamping or holding during cure. Choose based on whether immediate handling strength or positioning flexibility matters more.

Hold the spray can 6-8 inches from the surface, moving at steady speed with overlapping passes for even coverage. Apply in light coats rather than heavy wet application—multiple light coats build better than one heavy coat. Spray in well-ventilated areas; overspray and vapors require air movement. For large areas, work systematically to ensure complete coverage without missing spots or double-coating areas. Temperature affects spray pattern—warm cans spray more evenly than cold ones. Clear nozzle after use by turning can upside down and spraying until only propellant emerges, preventing clogging.

Consider VOC regulations, ventilation availability, worker exposure concerns, and performance requirements. Solvent-based adhesives often provide faster drying, more aggressive tack, and better performance on challenging substrates—but create VOC emissions requiring ventilation and may pose health concerns with prolonged exposure. Water-based adhesives reduce VOC emissions, improve workplace air quality, and clean up with water—but may dry slower and provide less aggressive bonding on some substrates. Where performance is comparable, water-based is often preferred for environmental and health reasons. Where solvent-based performance is clearly superior, proper ventilation and PPE address health concerns.

Hot melt adhesives excel when: fast set speed enables production efficiency, moderate bond strength is adequate, gap-filling capability is needed, and heat application during use isn't problematic. They're not appropriate when: maximum bond strength is required, bonded assemblies will experience high temperatures, or substrates are heat-sensitive. Hot melts are widely used in packaging, product assembly, and applications where fast line speeds demand near-instant bonding. They require applicator equipment (glue guns) but eliminate dry time waiting, VOC emissions, and cleanup challenges of liquid adhesives.h—using them as adhesives results in weak bonds that fail under load. Adhesives are formulated for strength and may be too rigid to accommodate joint movement or may not provide adequate environmental sealing. Some products are designed as adhesive-sealants that perform both functions, but these are specific formulations, not interchangeable use of separate products. Match the product to the primary function required and don't assume one can substitute for the other.