Barry Hunt researches how sustainability issues can increase interest in bottomless paper labels
The bottomless paper label has a release coating on the front and an adhesive on the back. When rolled into a roll, the coating prevents labels from sticking to each other, just like industrial tape. As an alternative to traditional laminates, their most obvious advantage is that they do not require paper or film lining or backing, which greatly reduces the cost of raw materials as a percentage of the total label production cost. There are more finished labels per roll to reduce overall handling and shipping costs. Waste reduction is also important as an environmental issue. After all, once the label is affixed to the package or container, the liner is no longer used, and an unlined label uses all materials throughout its life cycle.
Preventing this waste has always been the main goal of the early plans to introduce linerless technology-and it was largely unsuccessful. Today, fortunately, the improved technology of current products coincides with a higher understanding of the so-called "sustainability". In terms of packaging, they reflect that retail chains and brand owners are increasingly aware of the need to take environmental and social issues more seriously. There are now many initiatives around the world aimed at encouraging more packaging recycling programs, thereby reducing waste in landfills. Voice support from consumers and environmental lobby groups also supports these initiatives, aimed at minimizing the environmental impact of packaging.
While renewed interest in linerless technology, it also tried to persuade processors to sign the launch of the liner recycling program. As one might expect, we are unlikely to see the demise of the release liner in the short term. The liner plays a useful role as a protective carrier for the pressure-sensitive adhesive and at the same time acts as an anvil to facilitate accurate die-cutting or perforation. However, from a broader perspective, dumping billions of tons of used silicone-coated paper or film release paper into holes in the ground every year runs counter to good environmental practices. This is especially true considering that the siliconized cellophane and kraft paper linings are made of high-quality wood fibers that are commercially suitable for recycling.
The label trade organization Finat supports a number of European recycling programs. They first collect used linings from the processor’s premises for free, and then transport them to a repulp plant where they use chemical-containing water to release silicone from the fibers. The flotation process follows the type commonly used for deinking/cleaning and repulping printing paper fibers. The same process removes the released small silicone particles, and the resulting pulp is suitable for the manufacture of new products, such as fine and specialty papers-including release papers and facestocks.
Most siliconized film liners are made of polyester (PET) or polypropylene (PP) polymers and are suitable for many major label applications. The used lining is reground and granulated into plastic raw materials, which are used in a wide range of industrial and consumer products, as well as new silicone films.
More prominent recycling programs include the partnership between Avery Dennison and Morssinkhof Rymoplast to recycle PET lining in Europe; film and paper recycling programs operated by Channeled Resources in Europe and the United States; Cycle4green (C4G) and Lenzing Papier as Austria Paper partners recycle paper liners throughout Europe; and the RafCycle program for recycling UPM Raflatac paper and PP liners.
Interestingly, in the United States, Mitsubishi Polyester Films developed Reprocess as a sustainable technology for recycling PET liners. It was beta tested as part of Spear's global enterprise program called Spear Earth. Release paper accounts for about 30% of Spear's products. The new technology is not to be landfilled, but to allow the recycling of used linings from cradle to cradle to new grades. Mitsubishi said it hopes that Reprocess will eventually become an industry standard.
Whether these and similar recycling programs will affect the use of unlined paper is still inconclusive, but we do know where the current impetus is coming from. Yves Lafontaine, vice president of marketing at ETI Converting Canada, said: “The pressure to adopt unlined paper technology must come from The end user, not the converter. Initially, due to the limitation of format size and die-cut shape, the linerless paper did not start, but this has been overcome.
ETI's technology was developed after many years of development of the bottomless paper version of its established Cohesio coating production line, ostensibly developed for the converter to manufacture label materials in-house. The new bottomless paper model includes one unwinder (instead of two), UV flexographic printing unit, traditional die-cutting module, and a separate coating unit for water-based silicone and hot melt adhesive. Printing webs can be paper grade or biaxially oriented polypropylene (BOPP) grade.
Lafontaine said that after several years of development, the company is making every effort to build a non-backed paper business. ETI has signed confidentiality contracts with at least 10 major brand owners in North America. Interestingly, when researching the market, the company found that approximately 36% of labels are manually applied. This is a common practice of international soft fruit packers. Manually attaching linerless labels on site can eliminate the problem of disposing of unsightly and useless waste liner paper.
Manufacturers of other processing and finishing equipment have begun to notice the potential of unlined paper technology. These include Prati, which recently launched a linerless version of the Saturn slitter/rewinder, equipped with die-cutting equipment and a large unwinding diameter. On the front side of the substrate, Gruppo Irplast, a manufacturer of coated BOPP film, provides a 60-micron matte film to ensure bar code readability. Innovia Films, a major UK manufacturer of BOPP and cellulose labels and packaging films, has recently launched two Rayoface NB without liner paper grades. The 92-micron version can replace cardboard sleeves for food packaging, while the 60-micron version is suitable for traditional film labels and wrapping paper.
The collaboration between Innovia and Ravenwood Packaging provides some insights for large-scale unlined paper operations. Founded in 2004, it is located in Bury St Edmunds, England, with a US subsidiary in Georgia. The main products include Comac 500 coating machine and slitter/rewinder. It can convert pre-printed webs for use with Ravenwood's Nobac bottomless label labeler. These include Nobac 500 sleeves, which are used to package refrigerated foods and convenience meals in five forms (such as C-wrap and full-wrap). Its processing speed is up to 180 packs/min. The user can specify an optional thermal transfer printer. Allegedly, its wide-sided label display on the packaging can provide more labels for each reel while reducing downtime.
"Unlined is ideal for this kind of food packaging," said Paul Beamish, founder and managing director. 'We also see the growing potential of linerless packaging for bottling applications. By targeting brand owners, we intend to slowly enter other areas. Ultimately, our business is based on developing dedicated coaters, which must be as good as or better than traditional online coaters, and connect them with commercially viable online coaters.
Comac 500 uses a specific glue head to apply a precisely monitored hot melt glue line on the back of the label, from 3 mm to 25 mm. The small amount of water-based silicone used on the front of the coating is nitrogen inert, which means that harmful oxygen has been washed away from it. The pre-printed labels are slit and rewinded on a three-core turret rewinder. A narrower 300mm wide version was introduced at the food trade show in March.
Ravenwood's European customers include Paragon Print & Packaging in Spalding, Lincolnshire, which is one of the largest label processors in the UK and its expertise includes food packaging. It uses two Comac 500 coaters in its bottomless paper department and uses traditional UV flexographic printing presses to print face materials. Reflex Labels is another large British label processor/packer that also uses Ravenwood equipment for linerless label labeling of small cans, beverage bottles and refrigerated food packaging.
Generally speaking, water-based silicone release coatings can also prevent exposure to ultraviolet light, and resist moisture and chemicals, thereby extending the life of the label. In addition, bottomless paper labels can be printed on both sides because the release coating and adhesive are applied after the label is printed. Without matrix scrap stripping, flexographic printing presses can usually run faster, and only one substrate can improve the overall printing quality.
One of the fastest growing bottomless paper industries is related to various printing and application applications. There are a variety of systems to choose from, each with high productivity, fast reel change and a choice of ribbon-based thermal transfer printers from OEM suppliers. The main requirements are bottomless pallet labels, automatic identification labels and price tags, with measuring equipment as part of the system. They usually run with MS Windows operating software. Thermal transfer paper or film materials can include metallized grades to achieve special effects, possibly with corresponding metal ribbons.
Recent examples include the new TT-PA Evo 150 from Transfer Trade, a subsidiary of Italy's TT Trade group. The machine emphasizes ease of reel handling, runs on reels with a diameter of 400 mm, and distributes three times as many labels as pressure-sensitive labels of similar size. In addition, the system allows the label length to be changed on the fly. ALtech offers the new Alcode LL printing and labeling machine with decoiler, cutter and thermal transfer printer; labels are applied using air or contact methods. The speed varies from 20 to 80 labels/minute, depending on the label size.
Tamper Technologies, based in Derbyshire, UK, provides linerless technology for a series of tamper-resistant labels. Users can apply them to cardboard boxes, plastic containers and flexible packaging. Once the label is affixed, a clearly visible warning message "VOID OPENED" will be left to quickly detect theft or attack attempts. 'The increase in roll capacity and the reduction in transportation, transportation and storage costs make bottomless paper labels an excellent choice for our distributors and their customers. We are very satisfied with this product series because it makes a lot of sense. It’s cheaper and it’s good for the environment,” said General Manager Chris Chilis. He added that standard and customized bottomless paper labels now account for nearly 60% of its global tamper-proof business. Current uses Including industries ranging from logistics and transportation, food, retail to pharmaceuticals and asset protection.
The professionalism of the linerless technology and its requirement for a dedicated applicator have led to a number of licensing arrangements. For protected trademarks and patents, they are similar to those in extended text, leaflet label applications. One example is the Catchpoint linerless system based on microperforations, which is now widely used in various primer and printing applications.
Catchpoint is headquartered near Leeds, England, and has a US subsidiary in New Jersey. Its partners include vacuum system manufacturer Label Aire and global supplier AEW Delford of weighing machines with variable data overprinting. One of its largest projects for global brand owners is the establishment of a partnership with WS Packaging Group, a founding licensor with 17 manufacturing locations in North America and Mexico. Catchpoint is also in contact with ILTI, an Italian manufacturer of high-speed rotary applicators.
When it was launched in 2005, Catchpoint claimed that its technology would help save costs and the environment in a wide range of solutions without adversely affecting production efficiency or shelf attractiveness. In addition, creative brand managers can also use this change to meet consumer demand for reducing packaging waste. As the company’s publicity points out, no other packaging component wastes more than 50% of the input material.
Seven years later, FMCG manufacturers seem to be catching up in the name of sustainable development. Many have introduced packaging designs with a smaller environmental footprint. The international beverage giant Diageo (Diageo) is a striking example of what happened in this rapidly changing situation. Its sustainable packaging guidelines cover all aspects of its huge packaging expenditure. Its ambitious goal is to ensure by 2015 that its packaging design is 100% reusable, recyclable, or applicable to waste management practices in various countries/regions.
The linerless technology seems to meet many sustainability standards. With improved coating technology and advanced labeling equipment, it can have a significant impact in several key major labeling areas, especially food packaging. It is also preparing to further enter the labeling field of glass bottles and cans, while establishing existing thermal transfer printing and application growth in the field of logistics and data labels. Combined with any expansion of various waste liner paper recycling programs, the latest linerless technology can make a huge contribution to helping self-adhesive labels clean up their behavior.
Pictured: A linerless version of ETI's Cohesio coating line
This article was published in the second issue of L&L 2012
Barry Hunt is a former staff writer, technical editor and guest editor of Labels & Labeling.
Tarsus Exhibition Publishing Co., Ltd.
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