Deinking: Multiple Environmental Tests for Inkjet Printing

The two most popular topics in the industry are probably environmental and digital printing. The deinking of digital printing is the intersection of these two topics. Improving the environmental reputation of printing is a key step in consolidating its important position in the media mix, but it is also important to increase the overall efficiency of printing through digital technology.

Whether digital printing's deinking problem will make printing companies feel headaches depends on the specific conditions of these printing companies. The International Deinking Industry Association (INGEDE) believes that this is the biggest threat facing its member companies and will also affect the quality of recycled paper. However, the manufacturer of the new digital press and HP's Indigo division, Ingedev, claimed that there are potential problems with their equipment. However, they have repeatedly stated that they have not found any problems so far and that there will be no problems in the future. Companies such as Hewlett-Packard, Pucci, Kodak, and Océ set up a Digital Printing and Deinking Alliance (DPDA) last year. The main purpose is to help people better understand deinking issues and to develop practically with partners in the supply chain. Effective management system. Ingede's spokesperson, Fisher, welcomed the establishment of the DPDA. He said: “This is the first step for ink jet equipment manufacturers to deal with deinking. Their products must be recyclable.” Hill explained that the association hopes that people will take the initiative to solve the deink problem of digital printing and avoid the mistakes that their member companies introduced when they introduced flexo equipment more than 20 years ago. He said: "We have seen the seriousness of this problem and we hope to find the ideal solution before ink jet equipment manufacturers bring products to market." Ingede hopes that any new printing technology will not be able to The deinking process is performed under the premise of changing the current recycling system.

According to Fisher, in Germany, any new product that breaks the existing recycling system must be labeled. Both Germany and the European Union have adopted legislation that strictly stipulates that all new products must be recyclable. Although Ingede's response was somewhat strong, ink jet equipment suppliers have indeed increased their focus on this issue. They said that no matter what the current deinking performance of digital prints, they will certainly try their best to improve the recycling rate of paper. There is no doubt about this. Don Burns, media business development manager at Kodak's Graphic and Video Group, said: "We can still be compatible with existing systems, but with the expansion of the market share of inkjet printing, this may become a very prominent issue. "Digital prints currently account for less than 5% of all paper entering the deinking process, and inkjet printing accounts for a negligible proportion of them, most of which are dry toner devices." The biggest difference between the different options ink jet equipment suppliers and Ingede is the number of digital prints that cannot be recycled. The former think that as long as the proportion of inkjet printing in the total printing volume does not exceed 10%, deinking will not become a problem, while the latter believes that even if digital printing accounts for only 5% of the total printing volume, It also brings people annoyance.

Kodak's Burns believes that ink-jet printing production will grow at least 100 times before deinking becomes a problem. Hewlett-Packard's ink jet research and development and environmental strategy expert Nils Miller said: "Although we are showing a small proportion in the printing market, but also need to study the deinking technology." Deinking is part of the paper recycling process, it for paper The re-use has a vital role. This technology is mainly used by paper mills for the production of recycled paper, and is most suitable for use with mainstream printing processes: lithographic offset printing and gravure printing. Waste paper deinking is a combination of chemical and physical processes. It mainly uses high-efficiency deinking agent to separate the oil-base ink, impurities and pulp through the deinking device to obtain the regenerated pulp. Companies such as Hewlett-Packard, Pucci, Kodak, Océ and NetScreen have all adopted water-based inks for their next-generation commercial inkjet printers, which obviously cannot copy the deinking process used for oil-based inks. Dye-type inks also have similar problems because dyes cannot be removed. Fisher likened the problem to washed off red socks. This problem is particularly serious for European deinking companies that have already invested in closed-circuit water systems, while companies located in other regions can use water washing processes.

Digital inkjet equipment suppliers stated that they can perform deinking of dye inks, and for pigmented inkjet inks, they can also find a reasonable solution.

Hewlett-Packard's Inkjet WebPress press uses an adhesive that can help the device produce ink particles that can be moved by flotation. Ingede is very satisfied with these results, and there are more than one equipment supplier once told Fisher that he intends to use other methods to achieve inkjet print compatibility with the existing deinking process. Printing with UV-cured inks is another common inkjet printing method, and the Agfa Dotrix press is the representative model. Unfortunately, UV-curable ink coatings cannot be deinked, either digitally or traditionally, because they can easily become large and difficult to remove. Speaking of other digital printing processes, dry toner printers from Canon, Kodak, Konica Minolta, Xerox, and Xeikon can also be combined with existing deinking technologies, and they are also compatible with paper fibers. The binding force is relatively weak, so it is also easier to recycle. The last thing we want to say is liquid toner. At present, only Hewlett-Packard's Indigo press uses ElectroInk ink. Test Ingede recommended inkjet device supplier's own Method 11 laboratory expansion test to test the deinking of inkjet prints, but many equipment manufacturers are skeptical of the effectiveness of this method, because they believe that this does not reflect the actual deinking process Happening. Hewlett-Packard Miller said: "Deinking is a very complicated process. It is difficult for us to describe its characteristics mainly because it has too many variables." Although inkjet printing may cause problems with paper recycling, We still believe that digital printing will be even better tomorrow.