A typical label sandwich. Source: Weber Packaging
Anilox: A method used to provide a measured amount of ink to a flexographic printing plate.
Anilox roll: A hard steel or aluminum core cylinder, which is coated by an industrial ceramic whose surface is engraved with millions of very fine dimples (known as anilox cells) usually coated in a precise layer of ink that is then transferred to the raised portions of the printing plate. The number, size, and geometry of the anilox cells vary and will determine the amount of ink that the anilox roll delivers to the plate.
Doctor blade: Also known as ductor blade, removes the excess ink from the smooth non-engraved portions of the anilox roll and the land areas of the cell walls used in the flexo printing process. The name derives from the blades used in flatbed letterpress equipment for blades used to wipe ductor rolls.
Substrate: The base material that the image will be printed on such as a plastic film glass, paper, or other textile products. Direct to substrate printing provides durability, flexibility, etc.
TLMI is the Tag and Label Manufacturers Institute. It was founded in 1933 and is the premier association in North America for the web, tag, label, and packaging industry. The association facilitates an annual awards competition. The competition aims to stimulate innovative printing and to recognize technical achievement.
Winery owners. What do they want to achieve? Naturally, great wine, right? But they also want an excellent brand identity, high-quality printed images, outstanding label performance (will it withstand an ice bucket or a chilled cabinet?), and label flexibility. But wait, I think they also want to see or utilize something different that stands out on their wine bottles.
Located in San Luis Obispo County is one of the premier print companies of wine labels. You read that right. Right here. They utilize a flexographic printing process, on press equipment from an international company that has been around for 150 years, making use of pressure-sensitive label stock.
This article will briefly explain the processes, substrates, and adhesives used to print many of the wine bottle labels in San Luis Obispo County and across North America.
Flexographic Printing Press
Flexographic printing, also known as flexo, was first patented in the late nineteenth century and was originally rudimentary in quality. This was because of its limitations in ink control and rubber printing plates. As the consumer industry grew the packaging labels required high-quality prints and were commonly used in the food packaging industry. Since 1990, great advances have been made to the quality of flexographic printing presses, drying systems, inks, printing plates and printing units.
Flexographic printing machines offer efficiency and speed advantages over other label printing methods and the print on rolls of various materials occurs quickly and does not sacrifice quality. This makes it the ideal printing method for food, beverage and consumer products.
How This Process Works
This process generally takes three steps.
The first step is to design the artwork. Creating a design that fits the specifications needed to produce the final desired print can be challenging. Failure to thoroughly proof the artwork can result in costly mistakes because image carriers cannot be changed once they are produced. The image carrier is mounted to a printing cylinder which can either create flat, stretched, or distorted images.
Step two utilizes web-fed substrate materials. The rolling design of the flexographic printing press allows for continuous substrate materials, in a roll form, to be fed through the machine. It can achieve high speeds, maintain accuracy, and efficiently produce large print runs.
The third step is the flexographic printing press. A roll of substrate is fed into the printing press keeping the tension taught to prevent slack. The slack in the substrate can cause wrinkling, misregistration, web breaks, and other print defects. A continuous cycling pump fills the enclosed chamber with ink; the ink is transferred onto the anilox roll with any excess removed by the doctor blade. The ink cycles in and out of the enclosed system during printing.
Then the anilox roller is inked and the image carrier transfers the image to the substrate. The flexographic press pulls the substrate between the image carrier and the impression cylinder where the impression cylinder holds the exact right amount of pressure on the substrate for even ink distribution.
The drying process comes next as the substrate winds through roller-less and plate-less sections to dry the ink. The substrate might pass through multiple image carriers, impression cylinders, and drying sections depending on the number of colors used. In this type of process, the single print run happens for each color of ink used.
The final step on the flexo press is the outfeed and rewind, where the substrate needs to BE rolled up again in preparation for a cutting die to separate the individual prints.
Advantage of Flexo Press
- Flexo press has the capability to run at extremely high speed when compared to gravure and offset printing.
Gravure printing is used to print large volumes of magazines and catalogues.
The ink is transferred from carved micro cavities which are embedded in the printing cylinder.
Offset printing is where the inked image is transferred from a plate to a rubber blanket and then to the printing surface.
- Flexo press has the capability to print on a wide variety of substrates
- Flexo press has a shorter setup time, therefore, reducing waste when compared to gravure
- Flexo press that runs on water based ink or UV/UV-LED inks are much more environmental friendly when compared to gravure
- Flexo press is very suitable for medium to long-run jobs
Disadvantage of Flexo Press
- The operators of flexo press require higher technical skills when compared to the gravure printing process
- Flexo press is less suitable for short-run jobs when compared to digital printing as the job setup time and plate preparation time is much longer and much less flexible
Brief History of Heidelberg
Andreas Hamm at the age of 26, took over a foundry and machine factory from his older brother, Georg, in March 1850. He partnered with Andreas Albert who had completed his apprenticeship in the factory of Koenig and Bauer, where he had become well-acquainted with printing presses. They produced bells, metal castings and high-speed presses. By 1864 a German newspaper reported “In a remarkably short time, this business has established a reputation for itself extending far beyond Germany. The company will soon be dispatching presses to customers as far away as Odessa and Kherson.”
In October 1875, Andreas Hamm came up with a high-speed cylinder letterpress which he sold to clients as far off as Egypt for 2,400 marks. By June 1894, his son Carl Hamm sold the company and shortly thereafter it moved from Frankenthal to Heidelberg, Germany. Then in 1905, the company was renamed Schnellpressenfabrik AG Heidelberg.
Beginning after the end of World War I, the production of an automatic platen press, able to print 1,000 sheets per hour, virtually became a success overnight. A new Board member, Hubert H.A. Sternberg, was a marketing wizard and really pushed the company onto the world stage. Because demand grew so rapidly, the very first assembly line in a German printing press factory, permitting 100 presses to be assembled each month.
In 1934, with 60% of the company’s revenues coming from foreign sales, Heidelberg introduced a fully automatic high-speed cylinder press to the printing market. With the outbreak of World War II, production was cut back, but Heidelberg wanted to keep its skilled workers from being sent to the front, so the company accepted orders for precision lathes and hydraulic devices. When U.S. troops marched into Heidelberg during March 1945, the press factory could resume production even before the official end of the war.
The world’s largest printing press plant began production in 1957 in Wiesloch near Heidelberg. And, by 1959 over 100,000 presses were produced. Heidelberg also added building offset printing presses, a newly added technology in 1962. Around the year 1980, more printers were looking to print in color, and thereby a second factory was built in Amstetten by Heidelberg.
To handle the expansion of the product portfolio Heidelberg constructed a new international spare parts center (SPACE) in Wiesloch by 1999. 2000 was a very important year for several reasons. 400,000 Heidelberg presses existed globally in printing companies. Secondly, Heidelberg opened a Print Media Academy in Heidelberg which is an international communication and training center for the graphics industry. Thirdly, they also took over the office imaging business of the Eastman Kodak Company, Rochester, NY building on its leadership in digital printing. And finally, they acquired a 30 percent stake in Gallus Holding AG, Switzerland which strengthened its position in flexographic printing, both letterpress and screen printing technologies, with products aimed at label printers in the world.
Substrates have to handle the added value that they’ll eventually be adorned with, and they also have to withstand the environments a bottle of wine might be placed in. “Years ago, almost all wine labels were produced on coated paper of a similar type, in a limited range of shapes and sizes. And the labeling was fairly standardized,” says Andrew Oransky, director of sales and marketing for Roland DGA, an inkjet printer manufacturer based in Irvine, CA, USA. “Today we are seeing a lot more creative design work integrated into wine labels. Over the past 10 to 15 years, the industry has increasingly recognized that the label is an integral part of the product’s branding and shelf appeal. So the trend is moving toward more complex designs, more graphical elements, and a much broader range of materials for labels,” he says.
Flexographic printing also allows for printing on various substrates. The substrates can include paper, corrugated cardboard, non-woven fabric, plastic film, metallic surfaces and multilayered film composites. Because of this a range of products utilized with the printer equipment includes self-adhesive labels, cut and stack labels, food packaging, and plastic bags.
AWA Alexander Watson Associates estimates “the global market for wine labels in 2009 at 575 million square meters (nearly 6.2 billion square feet), with an annual growth rate to 2013 forecast as between 3 and 4 percent, depending upon production and consumption patterns”. “The global market share enjoyed by the pressure sensitive label formats continues to increase from the 55 percent share recorded in 2009. Glue applied label formats have lost their dominance in the market, and continue to lose share from the 45 percent level reported for 2009,” the firm reports.
The substrates utilized for printing can be absorbent, non-absorbent, porous, and non-porous materials. Offset printing only works with smooth and flat surfaces.
Self-Adhesive or Pressure-Sensitive Labels
When did wet-glue labels change to self-adhesive labels? The answer could be when it was possible. The old labels required heat, or a solvent, or water to adhere to the object. The messy process of applying glue to labels at the point of application, or of customers brushing on the glue by themselves possibilities all changed when R. Stanton Avery created a new substrate in the 1930s. But the equipment had to keep up with the labels.
But pressure-sensitive labels are an easy and straightforward label solution. They can use paper, film and foil as their primary label materials and can be used with a wide range of inks. They also come on rolls to be peeled off and pressed onto the wine bottle using a hand or machine-applied technique.
Each year, millions of bottles of wine around the world are being labeled. These labels are being printed on conventional or digital printing presses. There is a wide range of self-adhesive wine label materials. There are also print equipment and presses that can print in four, five, six or more colors. Third, the run capabilities on this print equipment can be long or short. Next, printers can utilize different substrate materials to the labels, including embossing, metallic foil, paper types. And lastly, different adhesives can make pressure-sensitive labels removable or permanent.
The global self-adhesive labels market size is projected to grow from USD 46.5 billion in 2020 to USD 59.2 billion by 2025. This is attributed in part to changing preferences of manufacturers for cost-efficient and effective labeling.
A pressure-sensitive label is made up of different layers and is sometimes referred to as the label sandwich.
A finish applied to the label to protect it and add visual effects. One of the last steps and can also protect from moisture, sunlight, temperature variations and chemicals. Matte, semi-gloss or gloss finish.
The base material with the printed design. Affects both the price and appearance of the label. Can choose from a variety of papers, films or metal foils.
The part that sticks to the wine bottle. The choice depends on the face stock material, the packaging material, and the environments the product must survive. Permanent, temporary (removable), and specialty adhesive.
Release Coating and Liner
The label peels off of a roll treated with a non-stick coating.
Printing in San Luis Obispo
Blake Printery, founded in the city of San Luis Obispo, established the business of producing and printing wine labels for the wine industry with a graphic design team and cutting-edge technology that has become one of the most famous and dynamic in the world. Read the full article, Richard Blake: Legendary Printer of Wine Labels.