Adhering to principles

During 2007-2008, the converting market saw the unfolding of the quest for sustainability. This is still a major concern within the industry, but the economic crisis has also concentrated the market’s focus on the need for improved processing and cost effective adhesive solutions and materials. The current market climate has acted as a catalyst driving forward innovation in adhesive products and equipment which provide greater mileage without compromising on quality or progress in sustainability.

New adhesive solutions are also continuing to come on the market to support applications which are evolving in complexity, such as the high end cartons for consumer products or the necessity for food packaging to safeguard against food contamination.

Adhesive aeration in box laminating is a good example of how new systems are helping to speed up production processes and improve bond integrity whilst also cutting adhesive spend and carbon emissions.

While the concept of aerating adhesives isn’t new, the provision of an integrated package combining the right dispensing equipment, compatible adhesive, training and technical back-up, like Henkel’s Aerobond system, is an innovation that is working well.

Aerobond is being used globally in sheet-to-sheet and in-line lamination, helping box manufacturers save between 20-30 per cent on adhesive consumption. It combines a specially developed laminating adhesive with a foaming device – the Glue-Mix – which introduces controlled quantities of air into the adhesive, increasing the volume and reducing the amount used for the same application volume.

The system also allows for rapid drying times, speeding up production as well as optimised initial tack. Also, with less adhesive needed, it cuts down on storage and transportation, reducing related costs and carbon emissions.

For many aspects of box converting, production managers have approached OEMs for better systems to improve processing times, to satisfy customer demand for quick turnaround times. Higher speed folding box equipment is one example, and as a consequence the worldwide leading supplier of packaging equipment recently introduced the fastest folder/gluer system, at up to 700 m/min.

For the new system, a cleaner running adhesive was sought that enabled minimal downtime to maintain optimised processing times and bond security of the end product.

Advances in consumer packaging are also stimulating new developments in adhesives. For example, clear box manufacturing is becoming increasingly popular for high end consumer products, and with it the requirement in versatile polyurethane (PUR) reactive hotmelt adhesives and equipment.

PUR hotmelts are delivered in solid blocks and, regardless of the amount needed for a run of clear boxes, a full block is melted, wasting whatever is not used. To overcome this, the leading adhesive dispensing equipment specialist has developed a melt-on-demand system for PUR application, reducing wastage in materials and energy consumed.

PUR hotmelts come in varying levels of quality, but for clear plastics presentation boxes designed for products such as lingerie, champagne or perfume, a high performing adhesive is demanded to ensure the aesthetics of the entire product are sustained. Some PUR hotmelts possess a milky quality, or yellow and disintegrate when exposed to UV light, letting down the overall appearance of the product on the shelf. However, adhesive companies are now producing better PUR hotmelts, with transparent films that are unaffected by UV light and maintain bond integrity.

Adhesives used in food packaging are another area of development. Recently, a number of industry leaders entered into a voluntary commitment to ban the use of plasticizer based glues in food packaging such as board sandwich cartons. These glues were effective at bonding, but the plasticizer particles could migrate beyond the substrates with the potential of food contact.

Henkel has responded by developing Adhesin A 78, a range of water based products with bonding results better than plasticizer based adhesives. It has formulations for applications from folding box bonding to envelope production, and offers high performance and trouble-free processing on existing machines.

Envelope conversion is yet another area where innovations are improving the processing and quality of the end product. Henkel has launched Envagum ES 3000, a front flap adhesive for high security envelopes. It has been trialled on a high speed inserter at 12,000 envelopes/hour with gusset flap envelopes for thick inserts. It proved to be excellent at long run manufacturing and sealed better than most other adhesives. It also reduces drying temperatures by up to 50 per cent, again saving on energy costs and carbon emissions.

Gilles Lendormy is Henkel’s paper converting sales manager for the EMEA region