By Craig Boulton, managing director, Jowat UK
For decades, edgebanding of wood-based panels with a verity of edgebands has been an established practice in the furniture industry. The quality demands concerning visual appeal , the technological progress in engineering, and also the almost unlimited diversity of materials to be processed – all of these factors represent special challenges for the adhesive technology.
In modern, high-quality furniture manufacture, the quality of the edgebanding is increasingly becoming a key criterion for evaluating the quality of the entire furniture item. The end customer demands a glueline that is hardly visible and perfect.
Not least of all due to the development of ultra-modern manufacturing methods like laser, plasma or hot air technologies, the industry has been talking about the so-called zero bondline for a long time. These technologies are often using edgebands pre-coated witha reverse, co-extruded polymer material. The manufacture of these co-extruded edgebands, however, is limited to thermoplastic material, and these, due to the continuos and very involved manufacturing process, cannot be widely used.
Jowat AG has met these challenges and offers modern and innovative solutions for the new technologies, and also for the conventional bonding technologies – and they all lead to zero bondline.
A milestone was the development of unfilled EVA hot melt adhesives for edgebanding, and this makes Jowatherm 280.30 a real standard classic. An improvement of the recent generation is Jowatherm 280.50, which has become established due to the excellent adhesion properties and the very wide processing window as a very tolerant all-rounder. Higher demands with regards to heat-resistance can be met using holt-melts based on polyolefines.
Jowat-Toptherm 237.10 meets exactly this requirement, but can still be processed just like a conventional holt-melt based on EVA. Apart from hot melts for conventional bonding methods, Jowat also offered hot melts for the pre-coating of edgebands, which can then be processed later by laser, plasma or hot air technologies.
Jowat-Toptherm 237.2x (plasma, hot air) and Jowat-Toptherm 237.9x (laser, plasma, hot air) can be applied by nozzle or roller applicator onto primer-pre-coated edgebands. Due to the excellent adhesion characteristics, Jowat-Toptherm hot melt adhesives are suitable for all standard edgeband materials, such as resinated paper, veneer, and with plastic edgebands – with a respective primer pre-coating. The highest heat and moisture resistance levels can only be achieved by using hot melt adhesives based on polyurethane. Jowatherm-Reaktant 607.30 is a fast-setting PUR edgebanding hot melt with high initial strength, a good elasticity at low temperatures, and a good solvent resistance. The chemical crosslinking takes place within a few days, depending on the moisture content of the ambiant air.