Comparison of the cost of gravure printing and flexo printing

Talking from design

Mr. Davi Griffiths, Sales and Design Manager, has been working in packaging design for 13 years. He collaborated with some powerful designers to work on graphics and structural design. Whenever a customer comes to the door with a product that does not have a packaging design, they provide design services for the customer. Sometimes they also make suggestions for modification to some of the design proposals brought by customers, and maximize the advantages of printing and packaging. Once a customer brought a graphic design that looked like it was made using standard computer software, neither highlighting product features nor taking into account the technical characteristics of gravure. So Mr. Griffiths and his colleagues thoroughly modified the packaging program so that the product packaging effectively highlighted the product itself and its selling points.

The first-class cutting device can be used to create a packaging model inside the company to facilitate the specific evaluation of the structure design. Ms. Elain eLippe, who is also the head of the design business, checked the final documents very carefully so that the documents could be used for color separation and trapping operations (currently outsourced), and then personally complete the group work. An important part of her work is to introduce the various advantages of gravure and its inherent limitations to the outside designers, explaining to the customer what gravure is best suited for printing.

In recent years, we have often read in paper magazines specializing in the processing of paper products. We heard such statements in various seminars and international exhibitions: The advantages of flexo printing are constantly being exerted; the cost of flexo printing is certainly lower than that of gravure printing. - Low equipment costs, low labor costs, and faster commissioning. In a society that relies on rapid response and effective supply chain management, flexo printing is often said to be faster than gravure delivery, enabling customers to have the fastest market response. It should be acknowledged that flexo printing has achieved great development in the flexible packaging market. Great progress will continue to be made in the future, and flexo printing has indeed made great strides in technology. However, technological innovations are often promoted too early to cause such misunderstandings: The flexo technology is the latest and the lowest cost. But in fact, compared to gravure, flexo printing is often more costly and of poor quality.

Now we should question the so-called cost-effectiveness ratio of flexo printing. What is regrettable is that for flexo printing, even if the gravure printing technology remains in place, the industry generally believes that the quality of flexo printing is approaching gravure printing instead of gravure printing. Quality and stable quality are still the biggest differences between flexo printing and best packaging printing methods - gravure printing. Other differences between flexo and gravure include:

Flexo printing production costs are higher than gravure printing production costs;

Flexo printing equipment is more expensive than gravure printing equipment;

Flexo quality is not as good as gravure quality.

In this case, gravure is the preferred printing method. Great news appeared on the "image carrier" side. In the 21st century, the technology of laser engraving and imaging directly on plastic rollers without copper material will make a profound change in the gravure printing process, so that the cost of the gravure cylinder used by the gravure printer is lower than the cost of the flexographic printing plate. The first part of this paper will compare the color printing costs of gravure printing and flexo printing with the perspective of paper product processors using current technologies. The second part describes the sober understanding of the gravure printing industry from the challenges of flexo printing technology. Some of the important gravure printing latest technology trends. The introduction of these new technologies is aimed at promoting the development of gravure printing and meeting the consumer market's demand for faster delivery, faster multi-color printing, and infinitely variable print production. Before the author explains the various advantages of gravure printing, readers are reminded not to forget that Valmot Rotomec produces both gravure and flexo presses as well as its ancillary equipment. Therefore, we do not have any prejudice on gravure and flexo printing technology.

Comparison of color printing costs between gravure and flexo

Before considering the cost structure of any form of packaging, there are three important factors to consider in addition to the packaging material (neutral in cost): the hourly rate of the equipment, the pre-press processing cost of the work piece, and the flexographic plate or gravure The cost of the plate cylinder. The equipment hour charge includes energy consumption, site space assistance services (such as support services before commissioning, project maintenance) and many other factors such as management fees. All of these are basically at the same cost level for gravure and flexo printing, negligible.

Gravure equipment cost is lower than flexographic equipment cost

According to statistics, the equipment cost of the first-class 10-color gravure printing machine is lower than that of the first-class 10-color printing machine by 30%. Similarly, the price of standard flexo presses is more than 30% higher than Rotopak 3000-5 new gravure presses that were introduced in early 1999. The staffing situation of multicolor gravure and flexo presses is usually at the level of modern paper product processing companies. The machine requires two operators and the cost is basically the same. Therefore, it can be said that the cost of a high-quality color flexo press is higher than that of a high-quality gravure printer. Since the staffing of gravure and flexo presses is the same, the hourly rate for flexo presses is very high, but in the comparison here we assume that they are the same as gravure hour rates. The cost of pre-press processing involves many links such as color separation, screening, continuous printing, overprinting, trapping (which also involves offset compensation in flexo printing) and proofing. These costs are basically the same in soft gravure printing, about $220 per color. In many cases, the 8-color flexo job is equivalent to a 7-color gravure job because the gravure cylinder has excellent line and tone printing capabilities. However, the author still ignores the cost advantage of gravure here, assuming that the number of colors of the soft gravure print job is the same. This can be concluded as follows. Under the assumption that the hourly rate and the prepress cost of the gravure printing apparatus are the same, the difference between the cost of the flexographic printing plate and the cost of the gravure cylinder is decisive for the difference in the cost per color of the gravure printing. Before delving into the issue of the difference between the cost of flexographic plate and the cost of gravure cylinders, the author intends to first analyze the other factor that has a significant impact on the cost per color, namely the performance of the press. When we compare gravure printing with flexographic printing, we must bear in mind that the operating procedures of each set of equipment are different and may have an impact on all aspects, especially the cost. It is also impossible to obtain undisputed figures forever. However, it was agreed that even in the case of a fully automatic control device, the speed of the conversion of the work piece of the satellite type flexo press would not be comparable to the job conversion rate of the combined gravure printing machine configured to be in place. Rotary gravure is a relatively simple printing method. Each printing device is equipped with engraving rollers, ink tanks, doctor blades and embossing rollers. Due to the simple process, the job's copying accuracy is also higher than that of flexo printing, the job replacement time is short, and the printing speed is fast, which is an important advantage of the printing short live job.

At present, many live jobs have to be processed on-line, especially for the most common pressure seals. These on-line processing operations can be borne by the soft gravure printing machine, but the flexographic control speed is also reduced due to the higher control precision required for flexo printing. According to our business experience with European and American international companies, the eight-hour 8-color gravure job is at least equal to the 10-hour flexo job. This is mainly due to the long replacement time of the flexo print job and the lower hourly output. Assuming the device hour rate is 500 US dollars/hour, the extra 2 hours will increase the price of the US$125 per color for the 8 color job. cost. The total cost also includes the printing cost of 380 US dollars per color. The cost of photopolymer plates is $160 per color, but the reuse of plates is a big problem, apart from printing plate installation costs. The degree of re-use of flexographic printing plates depends on the confidence of the paper processor in the equipment and processing procedures used by those who provide the high-quality packaging, as well as the cost of using the old plates. The cleaning and dismantling of flexographic printing plates takes time and effort. Moreover, the flexo printing plate will also become hard and brittle during storage, so the service life is affected. Wire version can not be stored and reused, because the docking part will be damaged when disassembling, and the printing plate can be used, especially when printing short-lived products, but it is necessary to maintain the quality of the printing plate wear. It is very laborious to make subjective judgments on the possibility of re-use in the future. After considering the above factors and integrating the experience of the paper processor, it is easy to conclude that half of the printing plate can be reused, and the cost per color when the printing plate is reused is reduced from 160 US dollars to 80 US dollars. For an ultra-short reprint job, a thin-walled sleeve can be used so that it is not necessary to remove the plate from the roller because the printed pattern is placed on the thin-walled sleeve. The average cost of a thin-walled sleeve is $140. A sleeve is required for each color pattern. This program is only applicable to ultra-short version of the reprint more work, but its production preparation time increased by at least two weeks. Installing a plate is considered to be the most important part of flexo printing. The importance of choosing the right mounting tape is second only to the proper choice of media and ink.

Experienced plate readers can prepare a plate in 20 minutes and install a plate. A total of 8 hours and 40 minutes are required for the 8-color flexo job. The preparation time of the 8 printing devices of the gravure printing machine is 1 hour and 30 minutes. The author also ignores this advantage of not counting gravure. The cost of a flexo-printed adhesive tape is US$13 per color, which is not a small consumable expense. Fine mesh anilox rolls cost over $4,500 per roll. The time required to change the anilox roller is considered to be part of the job replacement time, while the cost of cleaning and replacement of rollers is equal to the cost of gravure printing supplies.

Gravure cylinder costs

In Europe, the average production cost for lines and tone drafts is US$630 per color, prepress processing costs are the same as for flexo printing, US$220 per color, and drum retreading costs US$410 per color. In the above comparison, the 8-color job shall prevail. Although gravure cylinders can print 5 million impressions (nearly 4 million square meters), short-run jobs often require handling and installation of the rollers, which determines that every 8 operations, the rollers must be refurbished to make every job per color. Monochrome costs $52. As mentioned earlier, the hourly rate for flexographic equipment is very high, but in our cost comparison, it is assumed that the hourly rate with gravure is basically the same. In the case that the prepress processing cost of the soft gravure is the same as the other one, the author believes that the costs associated with each job have been fully described up to this point. If these costs are now considered to be the cost of the job to be printed six times before the design change, then the difference in cost per color after the first printing will favor gravure. The cumulative cost per color for flexo after First India was $596, for gravure it was $682, ​​and the difference in cost per color was $84. Flexo had an advantage. In the second printing, the cost difference is 82 US dollars, and the gravure printing has an advantage. The benefit of gravure after the sixth printing is $746 per color, which is roughly equivalent to a $6,000 reduction in the cost of each batch of jobs. Based on practical experience, we can draw the conclusion that the more reprints the job has, the less each time the print runs, the better the economic benefits of gravure printing.

The use of ink

The unit cost of flexo inks is relatively high due to the high concentration. Gravure printing has traditionally used thicker ink layers and therefore can offset each other. However, special gravure printing inks introduced by international ink manufacturers for some paper product processors and gravure printers can greatly reduce ink usage. The preliminary results show that when the printing speed is faster, the ink cavity structure with a 25% reduction in ink volume can greatly reduce the amount of ink and solvent retention. A printer with a new design structure can achieve a full ink supply with only 7 liters of circulating ink, while a flexographic printer requires 15-20 liters of ink, which will make it short live. In the printing process, the cost is increased by controlling multiple ink reflows.

Gravure printing plate cylinders can use a variety of inks and coating materials. To meet special product requirements, solvent inks, water-based inks, and coating materials can be used in various formulations without regard to the gravure cylinder. The gravure color control is very precise and in place. Since the gravure has a unique way of printing ink, there will be no change in color after tens of thousands of years of printing. Customers should know that the color of their product packaging should always remain unchanged during the printing process, which will help consumers easily identify their products. Using gravure printing technology can guarantee this completely. As we all know, flexo printing technology currently has a market, but the kind of publicity flexo printing is faster than gravure printing speed, and the cost of flexo printing is lower than the cost of gravure printing is unfounded. Gravure printing is the fastest printing method as a superior printing method, and the printing quality is the most stable, which is very beneficial to the product.