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Technology Focus

Lamination-Taking on a New Face

by staff

November-December, 1999
Laminating has continued to become the finish of choice for an ever-increasing amount of products, including bookcovers, dust jackets, folding cartons, gift bags, menus, posters, trading cards, buttons, and ID cards, to name a few. Users of laminating film are generally defined by application and range from book manufacturers, commercial printers, and trade binderies/graphic finishers to specialty advertisers and in-house printing facilities for corporations and schools.

Film lamination is an excellent choice for protecting the printed sheet, presentation folder, or carton from abrasion, chemicals, and fingerprinting. The protection and enhancement that thermal lamination offers simply cannot be matched by UV or water-based coatings. And with this continued growth for laminating films, more and more choices are now available, and laminating equipment is running faster with less set-up time than ever before.

Film Types

There are three base films used in the thermal laminating industry. They are polyester, polypropylene, and nylon. Polyester (PET) is an outstanding film for most applications. It features excellent scuff and scratch resistance, durability, and good folding characteristics. It is the industry’s most popular film. Applications include book covers and dust jackets, presentation folders, and video cartons. PET has high tensile, tear and impact strength, and retains these outstanding properties, remaining tough and flexible once applied. Since PET doesn’t contain any plasticizers, it doesn’t become brittle with age under normal conditions; it provides toughness, durability, and heat resistance. In addition, being free of plasticizers makes PET an excellent choice for foil stamping over the lamination film. Film with plasticizers will attack the hot stamping foil over time and the foil will eventually fall off the laminated surface.

Polypropylene (OPP) has a good overall balance of properties and is a favorite choice in the industry due to its combination of price and good overall characteristics. It is the clearest and brightest of all films. Applications include write-on/wipe-off calendars, posters, presentation folders, and labels. Because of its softness, OPP also folds extremely well.

Nylon laminating film is very popular, particularly for book covers and dust jackets, due to its uniquely stable and non-curling properties. Compared to polyester and polypropylene, nylon provides the best solution for the traditional moisture-related curl often found in softcover books and dust jackets. Success when using nylon film will depend on understanding the intricacies of the film and the paper being laminated. Nylon features excellent abrasion resistance and exceptional optical properties (clarity, glossiness) as well.

There are many different types of choices available for laminating today. One of the more popular new technologies is the availability of textured films with textured patterns that add a unique look to the finished product and provide additional scratch resistance in most applications. These films are offered in many different textures by several of the major film suppliers.

Protect-all Inc., of Darien, WI, is now offering thermal laminating films with a metalized surface that can be applied through conventional laminating equipment. These metalized films can be laminated to plain stock and then overprinted or overstamped with hot stamping foil. The metalized films are available in a bright or dull silver, gold, brushed silver, holographic rainbow, and a holographic “cracked ice” finish. This can be an alternative to foil stamping when a customer is looking for an extremely large coverage of foil, which may be hard to achieve with conventional foil stamping equipment. You can then overprint the metalized film with an opaque white in some areas and leave others reversed out to provide a unique look for short to medium run folders, video boxes, etc.

Another recent development with thermal laminating films is semitone thermal films offered by D&K International. This film is an extremely stable, micro-embossed film that imparts a low-gloss, semi-matte appearance. The unique manufacturing process creates an appealing textured surface with outstanding scratch-resistant properties. Semitone has excellent processing characteristics as well, and will accept foil stamping, printing, and UV coating without the need of corona treating the surface. “We see a great opportunity for semitone thermal laminating film,” stated Dennis Kuta, National Sales Manager for D&K International. “Potential applications for acetate would include menus, high-end cosmetic packaging, book covers, and literature packaging that require a new, refreshing, elegant appearance.”

The Evolution of Thermal Laminating Equipment

Water-based lamination is not conducive to the new printing demands (such as short runs) and special post processing (such as gluing and foil stamping). New methods, state-of-the-art equipment, and more versatile films have allowed users to turn jobs much quicker with better quality.

Two-sided thermal laminating equipment is now achieving running speeds as high as 100 feet per minute, and one-sided machines are running well over 200 feet per minute. Equipment has evolved from cumbersome oil/water heated machines to advanced electrically heated roller technology-critical to run at the speeds demanded in today’s market. The newest heated roller technology, segmented electric heat, is the most efficient and precise method available. Instruments are mounted just off the surface of the heated roller to provide true temperature readings of the surface across the entire roller to help maintain consistent heat at high running speeds.

Thermal laminating films, where a heat-activated adhesive is pre-applied, have become extremely common for many applications in recent years. However, thermal films are more expensive than applying raw film, and may not provide the flexibility of a wet laminating system. The Steinemann Lotus Lamination machines, recently introduced by Schmid Corporation here in North America, incorporate a new wet lamination technology. It offers an alternative to thermal laminating equipment by using raw film with a solvent-free adhesive or a UV adhesive. This new system applies the laminate to the sheet with minimal temperature and pressure, achieving high gloss results at very high speeds. In addition, there is little sheet distortion because of the low pressure used, and thermal plasticity is eliminated, which is what takes place when a thermal film is applied. This can help reduce problems when running the sheets through other processes (after laminating) that may apply heat, such as foil stamping and UV coating.

Another recent innovation for laminating equipment was introduced during the Graph Expo trade show by Ecosystem s.r.l., of Rovereto, Italy. An affordable delivery system, similar to a stacking and jogging system found on commercial printing and foil stamping/die cutting presses, was built into the laminating machine. This feature promotes the need for only one operator. The laminated sheets are then ready for the next finishing process without additional handling required.

Advances in laminating equipment better serve the current market demands because the equipment can run more efficiently with faster speeds, less downtime, and with no messy clean-up and maintenance. In today’s market, new equipment is designed to increase job turnaround because runs are typically becoming smaller.

The emergence of new films and the faster, state-of-the-art equipment will continue to push the laminating market forward. Increased competition on the supplier level is adding to the excitement of the industry, and pushing suppliers to be innovative and contemporary with their manufacturing techniques and new product developments. To ensure enhanced end-product quality, it is important to utilize appropriate high-quality film products and choose the right equipment for your end application. Look to your film and equipment supplier as a “counselor” that can offer solutions to the ever-growing uses for laminating films for a variety of product applications.

InsideFinishing would like to give a special thanks to Jennifer Cantwell of D&K International (800-632-2314) for her assistance with this article, and also to Randall Isaacs of Protect-all, Inc. (888-HEAT-LAM), and Claude Schmid of Schmid Corporation (864-595-0087) for their contributions.