Photo Credit: Kodak Sonora Process Free Plates
Since the introduction of the CTP (Computer-to-plate) plate from AGFA in 1993, it only took 2 years for more than 50 CTP systems to be brought to the DRUPA exhibition held in 1995. Nowadays, if you walk into a litho offset shop, you will definitely find a CTP system somewhere, usually in a separate CTP room or sharing space within the prepress department.
Just like any equipment you find in a manufacturing site; the CTP system needs a dedicated, trained, operator to run and maintain it on a daily basis. For the conventional CTP plate, after the raw plate is lasered by the imagesetter, it needs to go through the plate processor for “developing”, which removes the coating from the non-printing area after the raw plate was exposed to the laser. This process involves a few variables to look for to ensure the quality of run-ready plates. Common issues with the plate processor are: banding due to a weak chemical developer, undesired marks on the plate due to a hard (old) processor brush, plate coating damage due to uneven brush pressures sets, chemical re-deposits due to poor processor chemical maintenance, etc. Troubleshooting the conventional CTP plate is beyond the scope of this article.
Let’s assume you have all the moving parts dialed in on your CTP system and the processed plate looks great. Here are a few questions to ask yourself:
- Have you done an estimate on all the consumables and labor you put in to run the plate processor monthly or annually?
- What if there was an option that you can totally eliminate the need for a plate processor filled with chemicals and also have the ability to mount the lasered plate directly on the printing press?
- What if you could eliminate the need to dump chemicals on a regular basis?
If your answers to the questions above leave you looking for other options, you might consider the process free (or processless) plate. There are a few plate vendors on the market that provide this solution to litho offset printers, such as Fujifilm, Kodak, Agfa, Ipagsa, Saphira, etc. We are going to pick two candidates to show you how the technology works and provide an ROI (Return on Investment) for switching from the conventional plate to the process free option.
Process Free Plate Technology Overview
The diagram above shows the various layers of the Fujifilm Superia Pro -T3 process free plate.
- Over coat layer: controls the diffusion of oxygen, ensuring optimum plate stability.
- Photosensitive layer: New Fine Particle Dispersion (FPD) technology improves the rate of fountain solution that penetrates the coating, speeding up the on-press start-up routine and improving on-press performance.
- Under coat layer: incorporates Rapid Stable Start-up (RSS) technology which helps to release the coating from the surface of the aluminum when the ink is applied.
- Aluminum base: new micro-graining process applied to the surface of the aluminum, guaranteeing the widest possible latitude in terms of ink-water balance on-press.
Above diagram shows how the Fujifilm process free plate works:
- Step 1 is the raw process free plate without exposure (out of box).
- Step 2 shows the exposure procedure of hardening the image area on the Process Free plate, highlighted in dark blue. Once exposed, the plate is ready to be mounted on printing press.
- Step 3 illustrates the effect of fountain solution being applied to the exposed Process Free plate and how it penetrates through the “soft” non-image area on the plate. Thanks to Fujifilm’s FPD & RSS technologies, the coating adhesion on the non-image area is further reduced from aluminum base.
- Step 4 depicts that after ink has been applied onto the Process Free plate, the plate coating layer is removed and now ready to print. Please note, the removed coating layer is deposited into the water/fountain solution pan and therefore you may need to increase the frequency of pan cleaning.
Kodak also has a fleet of Sonora Process Free plate products, here is the link to check them out: https://www.kodak.com/pe/es/print/Product/Product_Specs/?contentId=4294993922&TaxId=4294970847
The Benefits of Switching to the Process Free Plate
Labor Savings: The conventional plate processor needs a dedicated trained operator to operate and maintain it. Regular work includes roller removal, cleaning rollers, scrubbing trays, mixing chemicals, filling jugs, repairing hoses, maintaining processor gears, etc. With the Process Free plate, it alleviates the burden from prepress employees so they can focus their attention and time on other areas within prepress.
Cost Savings: Besides the chemical consumables, which is one of the major expenses when operating a plate processor, there are huge savings on in plant utilities as well. The process free plate eliminates the extra usage of water and electricity that are required by a plate processor. Of course, there is no more cost for repairing and replacing parts for the plate processor. Below is a link to an article that Kodak produced and it details typical savings by switching to their process free plate: https://www.kodak.com/uploadedFiles/Graphics/Products/Digital_Offset_Plates/Process_Free_Plates/Economic_Benefits_of_Process_Free_White_Paper_EN.pdf
Environmentally Friendly: The Process Free plate requires no additional chemicals to develop before being mounted on press. Therefore, there is much less water pollution and printers can gain back the real-estate typically used to house plate chemicals.
The Trade-offs When Switching to the Process Free Plate
Start-up Paper Waste: For the conventional CTP plate, the ink transfer starts almost immediately on press startup; for the process free plate, (since there is no pre-development before the plates are mounted on press), the actual “developing” happens on the press. This means the top coat layer will be deposited into the water pan and also onto the paper with ink. Many of the Process Free plate manufacturers have claimed that their technology is very mature and that there should not be any extra paper waste other than the normal make-ready sheets needed for normal press operation.
Not so Visible Plate Image: After the process free plate is imaged by its imagesetter, the over coat layer and photosensitive layer remain on the plate. Therefore, the user won’t see much difference between the imaged & non-imaged areas on the plate. This could be a problem for the operators if they set the ink keys manually before press startup. It will take them a while to get used to the “not-so-visible” plate behavior before setting the ink keys correctly. But if there is an ink presetting system in place between the prepress department and the press room, this issue goes away.
If you still want to measure the process free plate after it is processed/developed, the Techkon SpectroPlate All-Vision offset plate microscope can be used. To learn more, use the following link: https://www.techkonusa.com/products-2/spectroplate-digital-microscope/.
The SpectroPlate All-Vision has a number of unique features including:
- The device has custom profiles for over 100 plates from different manufacturers. The profile takes into consideration the sharpness/contrast of the dots of the plate, the background color of the plate, and the noise in the plate.
- It utilizes an IR light source allowing a better view of the low contrast dot, which is the norm for processless plates.
- It is widely used by most technicians of the three largest plate manufacturers; Agfa, Fuji and Kodak.
- The device is extremely reliable. It uses an LED light source and has no moving parts.
Plate Price and New Imagesetter: I won’t be very surprised to hear if the process free plate unit price is slightly higher than the conventional or even chemistry-free CTP plate. Also, it is likely that you will need to get a new CTP imagesetter for the transition to process free plates. But considering all the savings & benefits aforementioned, it seems to be a quite profitable investment with a high ROI.