Pantone Cigar Paper Boxes Where CTP Plate Making Is Going

Pantone Cigar Paper Boxes Where CTP plate making is going

 

Ten years ago, when the era of computer direct plate making began with thermal technology, many professionals had the impression that we had reached the final stage of the development of offset printing plates. But this is not the case. Users decide what technology they choose in the future.

 

Until 15 years ago, every offset printing plant used film plate making and hand making. For 4-color printing, this process must be repeated four times. It is then exposed on a conventional offset plate with an ultraviolet lamp on a printer, and then must be developed.

By developing a large 8-page film exposure machine, it is possible to expose digital pages directly on 8-page film. You simply place a large sheet of film on a conventional plate and expose it on a printer.

 

Steps towards CTP

The use of digital offset plate exposure machine (CTP platemaking machine) can be directly exposed on the plate. So you can save on film processing, but you have to endure three hassles.

 

The first thing must be full-page digital proofing, which must be printed on a large-format digital proofing machine, otherwise errors can be found on the plate or press. The second thing you have to do is buy a plate exposure machine, which at first is much more expensive than a film exposure machine. The third thing must be converted to digital offset printing, which is highly sensitive, therefore difficult to handle, and twice as expensive as traditional printing. However, since the printing house has eliminated film processing, which greatly saves costs as well as time and eliminates the source of errors, the printing house has accepted this price increase.

 

Negative thermal plate

The sensitivity of the traditional plate is about 2000mj/cm2, and the energy requirement of Agfa's digital silver plate is 0.35mj/cm2, which is 6,000 times faster than the traditional plate. However, the fast sensitivity means that the plate is also easy to react in manufacturing, storage and processing, so it is difficult to deal with not only in the plate manufacturing plant and in transportation, but also in the storage, exposure and development of the printing plant.

 

This can not be changed when using thermal printing plates, and its spectral sensitivity is 830nm in the infrared band, so it can be processed in the bright chamber. When Kodak introduced this plate in 1996 in collaboration with Clio, it seemed that thermal technology was the most reliable CTP technology, since thermal cross-linked negative plates were initially used. This type of plate is preheated to 110 ° C by laser in the printed part. After the plate is imaged, it is heated in the furnace. At about 140 ° C, the polymer in the printed part is thermally cross-linked into a particularly resistant resin. After this so-called "preheating" process, the plate is developed, leaving only the part of the plate that produces the cross-linked coating; The coating of the unexposed part of the image is removed. Kodak guarantees a print run of 500,000, some users can exceed 800,000, and the baked version can reach a million prints.

 

Although this thermal negative plate has a high sensitivity of 150mj/cm2, its processing reliability is very strong, because there is neither a strong exposure nor an activated developer to affect the plate making results.

 

Positive thermal plate

All plate manufacturers want to use thermal plates to get a piece of the business, so they have developed positive plates with 830nm wavelength imaging. All non-printed parts of the positive plate must be dissolved with a laser beam to remove the coating in the developer. Therefore, high energy is required, the printing plate should be stored at the high temperature of the factory for a few days, and the air-conditioned truck is sent to the customer, and the printing plant should be kept at a constant temperature as far as possible.

The number of prints of this plate depends on the resistance of the coating, so the plate development time should not be too long. However, if the development time is too short, the plate will start to dirty after printing thousands of copies. This plate is therefore more sensitive to process changes than the photosensitive silver plate. This kind of thermal plate manufacturers advertise the strange claim that "no preheating is needed" because printing houses are reluctant to use power-hungry plate heating furnaces. However, the function of increasing energy is undertaken by the plate manufacturer, so keeping the sensitivity stable is particularly critical, so this point is not mentioned. The sensitivity of negative and positive thermal plates is 150-200mj/cm2, which is 10 to 15 times higher than the sensitivity of traditional printing plates. Today all such plates are quoted 180% to 200% higher than traditional plates.

 

Purple laser plate

Because the internal drum exposure machine is not possible to perform thermal exposure, Agfa put a silver salt version of its exposure with purple laser diode on the market for Drupa 2000. Subsequently, Fujifilm and Kodak also launched purple laser printing plates in the market. This plate can be processed under bright yellow safe light, and like the silver and polymer plates above, it is sensitive to process changes.

 

No processing plate

At Drupa 2004, Agfa introduced Azura(Green Star) hot melt printing plates, which no longer use chemical development, but only on continuous processing equipment to remove film, wash and glue. Therefore, the quality of thermal exposure is so stable that the safety of processing is as high as that of negative thermal version. But treatment-free plates are 10 percent more expensive than thermal plates, and printers accept that price because they save money on developer, monitoring, and blowdown costs. Since the 2006IPEX printing show, Kodak and Fujifilm have also offered process-free plates, which are thermally imaged and only removed when printed on the press.

 

A traditional printing plate

It seems that today's printers only have a choice between thermal, purple laser and process-free printing plates. But that impression was mistaken: in the late 1990s, Bess Printing developed an exposure machine called the UV-Setter for traditional offset printing. Now more than 800 of these machines have been sold worldwide, and sales figures are still rising rapidly. The reason is that this exposure machine has been very effective for several years, and the company has continuously worked hard to reduce the exposure time.

 

But the main reason is that printing houses only want to reduce the cost of printing plates when they board the CTP Express. At the same time, the printing plant maintains the greater processing tolerance of the insensitive offset printing plate as before.

 

If the printing house is already using CTP and paying higher plate costs, it can switch to buying UV-setters when investing in alternatives, so its plate costs can be almost halved in the future. If a printing plant uses 20,000 square meters of plates per year, calculated at 8 euros per square meter, the annual cost of printing plates is 160,000 euros, it can save 80,000 euros!

 

The plate is sensitive to violet light

Bessin uses UV lamps for exposure and uses a patented system that no one has been able to handle so far. Since the IPEX2006 printing exhibition, Bessin has had its first comrade - Luscher Company, in April 2006, the company launched a thermal version of the exposure machine with purple laser diode, which uses purple laser diode instead of thermal laser diode. Since January 2007, the first Xpose-UV-Conventional exposure machine has been used in Germany. The first batch of 20 exposure machines sold was delivered in April 2007.

 

The current price of this exposure machine is about 25% higher than the thermal exposure machine, because the current diode with 140mj/cm2 output power is very expensive. However, as the plate price was reduced by half, the higher price was reimbursed during the second working year and the lower price of subsequent plates was fully shown in the enterprise accounts.

 

Plate manufacturer's reaction

It has always been the case that when a new technology comes along, the same supplier can only provide one or at most two plates, and it will take two years or more until other plate manufacturers can also provide this plate. When the violet laser diode is used to expose on the traditional plate (PS plate), the situation is completely different, because all plate manufacturers see clearly the new market and provide similar plates for this digital UV exposure. There are about 20 plate mills offering more than 60 types of plates. It is not surprising that all plate mills are willing to work with two exposure machine manufacturers, Besprint and Luscher, in order to supply plate materials to their customers.

 

The reaction of the printing house

Whether the new demand for traditional offset printing will lead to a decline in the price of this printing plate, the answer is no. Because large plate manufacturers consistently claim that there is no money to be made from traditional offset printing. Anyone who has always considered taking the step of making plates on old conventional plates with a new digital plate exposure machine now has a second exposure machine supplier to choose from. There may soon be more suppliers.

 

So why did Agfa, Fujifilm and Kodak abandon the business? Because they produce plates, are they worried that these plates will not sell when they adopt new exposure machines?