Developing the Epson SurePress L-4033A Digital Label Press

SurePress L-4033A

The SurePress L-4033A digital label press announced in June 2010 was developed to print industrial labels, the paper or film "face" of myriad products, from groceries and consumer goods to jars, packages, and much, much more. This month we take a close-up look at the story behind the development of this small lot* label press (*10,000 labels/job or less).

Voice of the customer

Epson first gained experience in industrial label* printing in 2002, the year we commercially developed the PL-1000 (pictured at right), the world's first on-demand industrial inkjet label press. What we learned at the time from customers is that they had several overarching needs:

  • (1) They needed water-fastness. Sometimes labels are exposed to condensation, and the moisture from condensation caused the PL-1000's water-based dye inks to bleed.
  • (2) They needed to lower label cost. The inkjet specialty paper we had been recommending for the best print quality was pre-coated with an ink-eceiving layer for soaking up the ink and cost three times more than uncoated paper substrate (standard printing paper).
  • (3) They needed higher productivity. The print speed on narrow (150-mm) roll paper was a sluggish 0.8 meters/minute (at 720 x 720 dpi).

*Label: A type of sticker that consists of three layers: (1) a surface material (either a paper type made of bond paper, cast-coated paper, or art paper, or a film type made of synthetic paper, PET or PP); (2) an adhesive layer; and (3) a separator.

The SurePress development project got underway with an eye toward meeting these three needs. The first need was met by using water-resistant pigment ink. The second need was met by enabling label converters* to use uncoated paper substrate ? the same paper used for their analog presses. To meet the need for higher productivity, the development team first sought to strike a balance between print quality and print speed by providing the SurePress with an array of 15 high-performance print heads, each capable of exceptional accuracy in depositing ink droplets on substrates.

*Label converter: An enterprise that actually prints and processes roll paper or film to create finished labels.

The SurePress is engineered specifically for short-run jobs with fast turnaround times because these are the types of jobs where digital printing shines. (Digital presses do not require time-consuming plate production or plate swapping, so set-up times are only a fraction of those of analog presses.) As for applications, the SurePress is designed to take advantage of Epson's strengths and produce full-color labels that will serve as the "face" of our customers' products. Obviously, in addition to high print quality, all three of the needs summarized above had to be met.

The challenge: Inkjet printing on conventional analog print media

The key to enabling inkjet printing on uncoated paper substrates lies in a pair of heaters. The first heater is in the platen and is called the "platen heater." To print a label, the SurePress print heads pass back and forth over the platen as they deposit the multiple layers of ink needed to obtain good image quality. However, the ink droplets from one pass must be dry before the ink droplets from the next pass are deposited, otherwise the droplets will attract one another, forming a single lump. This is called the "agglutination." When this happens, the colors mix and blur. The role of the platen heater is to prevent agglutination by blasting the first ink droplets with heat and air to vaporize the moisture content and temporarily fuse them to the substrate before the next ink droplets arrive. Next, since the resin in the ink has to be completely bonded to the substrate in order to ensure resistance to rubbing, an air drying system equipped with a second heater is used to vaporize the solvent components to ensure optimum ink adhesion.

SurePress L-4033A

Compatibility with a variety of labels

The various types of substrates used for labels have different drying times and thus call for different printing setup and parameters. With plastic film substrates, for example, the ink is susceptible to agglutination because the substrates repel ink, and large ink droplets deposited on these substrates will not dry sufficiently in time to prevent agglutination and color mixing. For this reason, smaller ink droplets, rapid moisture vaporization, and more passes are used to obtain the desired image quality. Supporting a variety of label substrates thus requires adjustments to optimize the print mode for the substrate and the number of passes. With the SurePress, the best print mode and parameters are set automatically when the paper type is selected, so label converters and other printers can get the optimal prints without worrying about troublesome setup.

Heat Assist System

Newly developed ink and maintenance unit

We developed a new type of ink for this label press. The new ink, called "AQ ink,"was developed to improve image quality, waterfastness, resistance to rubbing, and bonding characteristics. The ink was also engineered to dry fast, to increase productivity. On the other hand, this ink does make inkjet head maintenance more difficult. If the maintenance unit, which is provided to absorb ink during the cleaning cycle, is left as is, it will dry and the unit will cease working. To get around this problem and ensure both productivity and ease of maintenance, the maintenance unit was placed in a moisture-retaining container so that the maintenance unit does not lock up. The SurePress development team, refusing to compromise when it came to meeting the needs of customers, overcame one hurdle at a time to improve usability and deliver outstanding print quality. The product is fully market-ready.

SurePress AQink

Details, including videos, of the Epson SurePress L-4033A

Read the news release;
Epson Launches the SurePress L-4033A Digital Label Press