Has the technology of reactivating the reversely applied functional layers of edgebands become established? Is it replacing the conventional, direct bonding method on large scale in edgebanding? The standard edgebanding process, where all kind of edgebands are bonded directly to various wood-based panels, is still the most common method of edgebanding. While other adhesive systems are pushing through, EVA-based adhesives are still the established technology and the most widely used adhesives.
Additionally to EVA hot melt adhesives, there are the PO-based hot melt adhesives, whose use has increased since the mid-90s. The success story of PO adhesives began in the kitchen industry, where adhesives with a heat resistance of more than 70 – 80 °C were required. PO hot melt adhesives can be processed like the related EVA hot melt adhesives without any technical modifications to the equipment and became an efficient solution. The use of hot melt adhesives based on polyolefin increased especially in recent years due to higher quality requirements in edgebanding, and this trend continues.
There are various adhesive systems available today to obtain a “zero-bondline” at a high quality, provided that the edgebanding process was conducted correct and error-free. For the end consumer it is almost impossible to distinguish between the different products.
When it comes to highest quality in edgebanding and perfect bondlines, PUR hot melt adhesives are currently the first choice. Today, top-quality edgebanded furniture components demonstrate heat resistance values above 120°C and a high resistance to water and chemicals, as well as a superior, almost invisible bondline.
Post-curing hot melt adhesives based on polyurethane (PUR) require more caution during processing. These adhesives are supplied in moisture-proof packaging and are processed in special melting units to avoid contact with the moisture in the air.
The continuously increasing acceptance of PUR hot melt adhesives in edgebanding is proven by the steadily rising sales numbers of edgebanders adapted to the PUR processing technology and by the growing demand for PUR upgrades of standard edgebanding machines.
The newly available PUR in granulate form, enables an easy introduction to these kind of adhesives. The granulate form is not only of interest for processors new to the PUR hot melt technology, but above all, also for small industrial companies that absolutely require PUR edgebanding for specific objects.
Processors who only have melt and applicator units for non-reactive hot melt adhesives, had to make expensive modifications to the applicator equipment, to process the high-quality, moisturecuring PUR adhesives as well. Especially these companies are now able to utilise the existing application technology without any investments for processing reactive PUR hot melt adhesives in the granulate form as well (taking into account some precautionary measures).
The common view at the beginning of this millennium was still that moisture-curing one-component moisturecuring hot melt adhesives cannot be granulated because of their high sensitivity to water. Meanwhile, several patented methods are available on the market for this technology.
Exhibitor: Jowat Adhesives India Pvt. Ltd.