Label is primarily information appended to a product or its packaging giving the brand name, information on the product, its usage, safety instructions, manufacturer’s details, statutory information, prices and now bar codes that provide a system for track & trace, price information, inventory control and logistic support. How the label or the required information has been attached to the product has varied over the ages. The earliest form of labeling was done by etching, embossing or stamping brands and information directly on glass or metal containers. Labels have been in use for hundreds of years but labels as we know today have evolved largely after the 17th century. Printing originated in China in the 11th century and was further developed in Korea in the 12th century but a wooden block printing press for mass printing was invented by a German Johannes Gutenberg in the mid-15th century. It was only in the earlier part of 18th century that printed paper labels surfaced as a possibility but since adhesives to affix these labels were not available, their usage started later. By then lithography had developed, so directly metal printed containers started being used for packing and canning. Many products are still packed with modern canning processes using metal cans printed with the lithographic printing process. It was only in the 19th century that printed paper based labels started being used for labeling and packaging using natural gum based adhesive to stick the paper labels to glass, metal or paper based containers and packaging. These labels in an evolving label scenario are now referred to as Wet Glue Labels.
With increasing levels of literacy, growing population and growth of packaged products, mass production in factories has become an imperative. New glass, paper, metal and plastic based packages are being developed to catch the eye of demanding consumers. The aesthetics are enhanced by affixing colourful and attractive labels. Faster labeling and packaging methods evolved as also the need to have highly decorated labels to service the need of consumers. Driven by this demand labels have evolved into different tangents. Diverse and technical labeling technologies have emerged. Listed below are some of the prominent technologies that labels have presently evolved into;
- Pre printed labels on metal container
- Wet Glue Labels
- Self Adhesive Labels
- Self adhesive Liner less Labels
- Heat Transfer Labels
- Direct on product screen printed labels
- Contact printing and stenciling
- Laser engraved labels
- Metal anodized labels
- Shrink Sleeves
- In Mould Label
- Digital: Direct on product Labels
- 3D Printed labels
Pre printed labels on metal containers: Metal containers or cans are made from tin plate (steel
covered in a thin tin layer) or of Aluminum and steel coated with a lacquer. The labeling is done in any of the three different ways listed below;
- Metal tinplate sheets are printed by offset process and then converted into containers.
- Preformed round metal containers are printed using a curved surface printing machine. Each color of ink is placed on a different (plastic letterpress) plate, and then transferred to a single rubber blanket which re-transfers the inked image to a can allowing all colors to be printed at a time followed by ink curing and varnishing.
- Preprinted labels of paper, film or foil are laminated to preformed cans. These labels can be printed by, flexo, offset, gravure, or digital printing processes. These can be highly decorated on high end hybrid narrow web presses having advanced finishing capabilities. These labels can be applied as full wrap around labels or part labels with the balance surface left coated to show a metallic lustrous effect.
Wet Glue Labels: These labels are also referred to as glue applied labels. These formed the mainstay
of product labeling until well into the middle of last century. Labels initially printed on letter press machines and later on offset presses, were gummed manually and applied to the bottles or containers. In 1880 De La Rue came up with a machine for gumming labels but this had a problem as paper labels would curl as soon as they would come out with gum applied on it making it difficult to handle. From my personal experience I can cite example of how our company adapted to manual gumming of labels. Our parent company was established in 1939 to produce fountain pen inks and office adhesive that were packed in glass bottles. To achieve optimum level of production we devised an interesting method of applying glue and labeling. Those days the final packing was done in wooden cases, corrugated boxes came much later. We took a wooden crate and turned it upside down, spread a full roll of surgical cotton on it and then covered it with a thick cotton cloth that was tightly fixed by nailing it all around. This was then dipped into water overnight with its face downwards. In the morning we would squeeze out the water and our gumming pad was ready. A thin solution in water of natural gum (Gum Acacia) that grows on trees was applied on the pad and then labels spread on it. We would have the unlabelled bottles on one side of this pad and with a little gum on the finger, which made it a little tacky, lift the evenly gummed label off the pad and place it on the bottle without any curl and put on the other side for further packaging. Subsequently with development of high solid faster drying Dextrin based adhesive automatic machines to apply gum and dispense labels to the bottles were developed. This made large scale production on automated production lines possible.
Direct on product screen printed labels: Screen printing saw growth in the Indian label scenario in the middle of last century. A lot of consumer product that shifted from glass to plastic packaging also opted for screen printed containers. However this did not last for many years as self adhesive labels with the high end decoration they offered soon became the preferred option. However screen printing on container is still in use but has limited application.
Self Adhesive Labels: In 1935 “Ray Stanton Avery” developed the self adhesive label also referred
to as Sticker or Pressure Sensitive Label. This label revolutionized the way how the world branded and labeled their products. The label basically consists of a face stock which could be paper film or foil, coated with a tacky non drying adhesive and protected with a backing also referred to as release liner. The label after printing and die cutting just needs to be lifted off the release liner and placed on the product achieving instant bond on applying pressure, unlike the wet glue labels that need drying after application otherwise they would shift and look bad. The self adhesive label industry has over the years evolved to offer a diverse range of labels catering to various industries and applications that include fmcg products, lubricants, cosmetics, food, Pharmaceuticals, variable information, logistics, brand protection, etc. In the initial years these labels were printed and die-cut on slow flat bed letterpress presses and with time they are now printed on high speed flexo rotary or combination label presses with capability to decorate and finish the labels in line in a single pass delivering finished labels at the end of the line. These labels are used on high speed label dispensing machines adding to production volumes for end user.
Self adhesive Liner less Labels: Self adhesive labels as described above have an issue as regards the
environment. The release liner and waste matrix after die cutting is not generally recyclable, though efforts are being made in this direction. This waste goes either to the landfills or is incinerated impacting the environment adversely in both cases. Moreover if the liner can be done away with while converting this type of label, it will amount to cost saving and become eco friendly. Considerable amount of work has been done in this direction and various options are now available. The simplest one being to make a tape like product printed, and siliconised on one side and adhesive coated on the reverse and self wound. However these labels that can be cut with sharp corners, cannot be die cut and dispensed in regular labeling equipment. Many European and US based food companies are already using such liner less labels. There is development being done to overcome the challenges of die-cutting complex shapes and dispensing cost effectively.
Heat Transfer Labels: PET film that is precoated with special release lacquer is reverse printed by flexo, offset or gravure to form labels in roll form. The image is transferred onto the container or product using heat and pressure. The labels are a composition of inks and lacquers selected so as to perform to customer’s specific needs. On transfer these labels are just the image and no substrate is transferred. Many years ago Mumbai headquartered Paper Products Limited (now Huhtamaki PPL) commissioned this technology known as “Therimage” with help of Avery Dennison. Later with self adhesive label emerging as very decorative in presentation, this technology lost its popularity. In recent times it has resurfaced. It is extensively being used by the pen industry.It is now being extended to garments and other product segments.
Contact printing and stenciling: In present times even the corrugated shipper cartons bear self
adhesive labels needed for identification, inventory control and logistic requirements. In earlier days as I mentioned, wooden cases were used as shipper cartons. People would write on them using marker pens but when need for aesthetics became important stencils were made of tin plate. They were placed on the wooden cases and ink brushed over them to imprint the required information. Later when corrugated boxes started to be used for final packaging, roller contact printers with changeable rubber types and foam ink rolls were available to print the information that could be changed by changing the type faces as per need. Once corrugated cartons replaced the bulk of outer packaging, these cartons started to be printed and self adhesive labels applied, if needed. Stenciling is still used where wooden crates are required for final packaging.
Laser engraved labels: Steel or other metal auto components, like bearings need to be branded, they cannot be labeled with paper or film labels. Only the secondary packaging can be branded, this can amount to duplication and counterfeits. For this reason laser engraved branding is preferred. A laser beam which is a very small, focused point of laser power effectively superheats a tiny point of a surface and removes part of the surface, creating a permanent engraving. This beam of light is controlled and moved to create a brand name or permanent design.
Metal anodized labels: These labels are used in applications where permanent product identification
is critical such as equipment nameplates, signage, safety/warning plates, machine control panels, etc. Abrasion and corrosion resistance anodized aluminum labels are produced by chemical etching on photo sensitive anodized Aluminum. These are mostly riveted on to the equipment or panels as they are required to last most of the life time of the equipment.
Shrink Sleeves: Shrink sleeves offer 360 degrees space for decoration and product information. They are made of either of these materials; Polyester, PE, PVC or PP. Pre printed film is welded to form a tube, cut to desired size of the bottle or container and applied over it. It is then exposed to a heat gun or passed through a heated shrink tunnel for the tube to shrink and attain the form of the bottle or container providing all around decoration. Shrink sleeve labels originated in 1965 and invented by Fuji Carpentry shop that were later named as Fuji Seal. The actual large scale usage of these sleeve labels commenced in the mid 1980s. According to Suresh Gupta Chairman of Huhtamaki PPL, shrink sleeves were brought to the Indian market in 1991 when Paper Products Limited (now Huhtamaki PPL), set up the plant with help from Fuji Film to make these in India. This segment continues to register a steady growth rate. Global growth is 6-7% but in India it is slightly more, given the size of the market. In India these are largely printed on gravure printing presses. However in recent times, in an effort to cater to short run customers who maybe large customers doing special editions or small and medium enterprises, printing is also being done on flexo presses and in some cases on digital label presses.
In Mould Labels: Paper or film printed labels (mostly filmic) are placed inside the moulds during
the molding process. After placing the label, molten plastic is injected into the mould. On cooling the label is fused with the resin, takes the shape of the so molded container and becomes an integral part of it. The labels referred to as IML can be printed and decorated by any of the processes i.e. Offset, Flexo Gravure or digital. The end result is a highly decorated container. These IML applied containers are used for Ice cream, butter, paints, food packaging, etc. According to research firm MarketsandMarkets, the global in-mold label (IML) market is projected to grow from $2.58 Billion in 2015 to $3.23 Billion by 2020, at an estimated CAGR of 4.54%. It is the fastest growing segment amongst the various label segments.
Digital, direct on product Labels: Digital printing has made its presence in all variants of label
printing and converting. From wet glue to self adhesive and in mould labels, digital printing is making inroads everywhere. Some years ago when I was interviewing Helmut Schreiner, the former Chairman of Schreiner Group, I asked him, “What do you see as the biggest threat to self adhesive label industry?” He became pensive and after deep thinking said, “It will be digital printing direct on the product”! It makes a lot of sense as we see the market slowly evolving in that direction. This will open up a whole lot of opportunities for the brand owners. No paper, no silicone, no adhesive, no dies, no tooling and yet the option to indulge in personalization and creativity! According to AlexanderWatson Associates, “It may, indeed, be a disruptive technology”. Direct to digital has been around for some time printing on textiles and ceramics. It is commonplace to see digitally printed fabrics and ceramic tiles. It has started to make inroads into the consumer product market and we need to wait and watch where it leads to.
3D Printed labels: This is another technology which may see computer controlled 3D characters and images on products and labels. It will make the imagination go wild on what all can be created. It is a process in which layers of material are formed under computer control process to create an object that can be of almost any shape formed by deposits of binder material onto a powder bed with inkjet printer heads layer by layer.
The evolution of labels has created a whole bouquet of technologies which still keep coming up in new avatars. No one technology can become the predominant one for label production. With labels diversifying into different tangents, label printers need to select the way forward so as to stay innovative and ahead of time. It is surely time to emerge out of the crowd and create a separate visible entity.
Written Exclusively for Label and Narrow Web magazine USA by Harveer Sahni, Chairman Weldon Celloplast Limited, New Delhi November 2017. The article may not be reproduced without the magazine's or the author's permission.