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Technology Focus

Film Laminating - Moving into the Automated Age

by Jeff Peterson

August-September, 2000
As with many different graphic finishing technologies, lamination has seen many changes over the past few years. There is a continuing trend for shorter print runs, the emergence of new digital on-demand printing, and the continuation of faster turnaround times wanted by everyone. ‘In today and out tomorrow’ has become the norm for many short to medium-sized runs for laminating, as well as other finishing processes.

Laminating equipment and adhesive manufacturers have recognized these trends and have tailored equipment and processes to meet the demands of this new fast-pace century in which we all live. Equipment has evolved from cumbersome oil/water heated machines to advanced electrically heated roller technology, allowing for more consistent laminated products, faster speeds, less downtime, and no messy clean-up and maintenance. In addition, adhesives have become more user-friendly, more versatile, and better for our environment. Let us explore some of the emerging trends with laminating equipment and adhesives that are helping make life better and easier for the graphic finishing trade.

Adhesives

Laminating adhesives have more demands put upon them than ever. Applications require very low quantities while at the same time achieve an optimum interaction between film and printing ink and paper/board substrates. Adhesives must run at optimum temperatures for compatibility with a wide range of printing inks and the chemistry of the adhesives must insure visible gloss while still having the ability to be stored economically, conveniently, and without risk. And most importantly, adhesives should not require unnecessary or lengthy clean-up by the operator. Operators aren’t asking for much, are they?

Due to environmental constraints, the use of solvent-based adhesives has steadily declined since the 1980’s and true water-based adhesives have been somewhat problematic due to metering and handling. Thermal films with adhesives built-in have found applications that make sense, but are costly for runs of larger lengths and must be applied at very high temperatures. UV reactive adhesives have had success and are easy to use, however, have been found to be less versatile in regards to types of substrates and printing ink compatibility.

As with the emergence of hot melt glues in the folding/gluing arena, hot melt adhesives are now available for laminating, providing a universally appropriate adhesive, thereby meeting the demand in the laminating market. Billhöfer Maschinenfabrik, GmbH has been at the forefront of hot melt adhesive technology and has worked in cooperation with H.B. Fuller (in regards to the hot melt adhesive) and with Inatec (in regards to nozzle application technology) to develop a system for high-speed laminating. This new hot melt adhesive development is said to address the concerns of compatibility with film, printing inks, and paper, and still achieve high gloss with very low application quantities. The adhesive is supplied to the user in a solid bar form and is applied with a special nozzle technology that controls automatically the volume of adhesive being applied at very high production speeds.

Another adhesive becoming more and more common is being used with a new laminating system by Steinemann. The adhesives are polyurethane moisture curing adhesives or PURs. Currently, PURs are a lower cost alternative to water-based and solvent-based laminating systems in converting and web market applications. Steinemann has now developed a system to make use of this new adhesive technology in the sheet-fed market.

PURs are low cost, high tack adhesives that do not require heat or an oven for curing. Therefore, there is no heated calender necessary for application as is the case with thermal laminating. Graphic finishers can take advantage of significant cost savings, utilizing non-thermal films that can save the finisher as much as 50 percent verses thermal films.

Machinery Trends

For small to medium-sized graphic finishers, shorter printing runs and high demands on turnaround times have prompted many of them to look at mid-sized laminating equipment. Many have purchased two or three mid-sized machines, providing the versatility to run multiple jobs at the same time, or to customize jobs with an embossing roller. This has decreased overall set-up times and improved production speeds, thereby, increasing profits.

D&K has recently introduced the Dual Kote 1 and 2-sided laminating machine to meet the needs of mid-sized applications. The Dual Kote is a thermal laminating system that provides the flexibility to apply one-sided laminating or two-sided lamination on one machine. This is possible through D&K’s patented de-curling brake. In addition, this new technology has heated, turning rollers, which are excellent for running polypropylene film.

Manufacturers are also offering feeding systems and/or sheet separator systems with mid-sized laminators that have traditionally been hand-fed. Protect-all is now marketing a new auto feeder and cutter manufactured by Italian-based L.S.M. to automate existing, hand-fed laminating machines. In addition, the new auto feeder can work with other stand-alone equipment, including mounting, gluing, and stamping machines. The new feeder/cutter uses much different technology than the trade is now familiar with in design and material. It is extremely easy to operate and requires very little set-up time.

Although there are trends towards smaller, mid-sized laminators, this does not inhibit the market for high-speed lamination for larger applications. The market continues to see growth in high-end, large run laminating applications as well. With the development of the hot melt adhesive system discussed earlier, Billhöfer has introduced the KC-Coat 2000 Laminating System for high-speed, high volume laminating. Billhöfer claims that this new system with the hot melt adhesive revolutionizes the film laminating of printed products not only from environmental and economic aspects, but also from the standpoint of product quality. The KC-Coat 2000 has taken the adhesive application unit in combination with a film draw-off calender and release roller to help insure a crease-free film run, as well as absolute flatness of the laminated printed sheet. In addition, the new system includes a computerized operator panel for programming size width, quantity of adhesive, laminating temperature, production speed, as well as sheet overlapping.

As with many graphic finishing processes, the world of lamination is constantly changing. Market demands such as print lengths, expected turnaround times, printing inks and substrates, as well as many other influences, will dictate how machinery, adhesives, and films will evolve and change. One thing is for sure, laminating will continue to become a growing area for finishing operations as the demand for quality, laminated printed products continues to increase at its current pace.

InsideFinishing would like to thank Walter Dean of Dean Machinery – representing Billhöfer Machines (678-947-8550), Claude Schmid of Schmid Corporation – representing Steinemann (864-595-0087), Jennifer Cantwell of D&K Group (800-632-2314), and Randy Isaacs of Protect-all Inc. (888-HEAT-LAM) for their assistance with this article.