The reduction of printing plate durability is a relatively common problem in printing production, which will cause a series of problems such as increased raw material consumption, increased production costs, and longer production cycles. Therefore, improving the printing plate durability is one of the main means for printing companies to improve economic efficiency. There are many reasons for the reduction of printing plate durability. When printing plate resistance decreases in printing production, printing companies should plan and step by step to check, strengthen the communication between the pre-press, printing and material supply departments, and jointly solve.
Printing process
Since in printing production, the printing staff usually finds that the printing plate durability has declined first, then the printing staff should base themselves and gradually investigate the reasons for the decline of the printing plate durability from the beginning of the printing process.
1. Improper concentration of fountain solution
Improper use of fountain solution may result in a decrease in the printing durability of the printing plate, which is mainly caused by the inappropriate concentration of fountain solution. Generally, printing personnel are used to monitoring the concentration of fountain solution by measuring the pH value of fountain solution, thinking that as long as the acidity of fountain solution is not strong, it will not corrode the printing plate. However, the buffer content of some fountain solutions on the market is relatively high, so that even if the concentration of the fountain solution is too high, the change of its pH value will not be too obvious, which will easily cause misjudgment of the printing staff. When the concentration of fountain solution is too high, it will cause excessive emulsification of the ink, affect the normal transmission of the ink, disrupt the balance of water and ink, and cause the printing plate to endure. When the concentration of fountain solution is too low, in order to avoid the printing plate from getting dirty, the printing staff will increase the amount of water, which will easily cause excessive moisture on the plate surface, the paper will be wetted, and the phenomenon of powder and lint will occur , Blankets and ink rollers accumulate, accelerating plate wear. Therefore, when the printing durability of the printing plate decreases, it is necessary to accurately check the concentration of the fountain solution. The more common and reliable method now is to determine whether the concentration of the fountain solution is appropriate by detecting the conductivity of the fountain solution in the water tank. It should be noted that in some places, the water quality is poor, and the content of impurities and calcium and magnesium ions is large (commonly known as "hard water"). This requires the addition of water filtration devices and softened water devices. The water is first treated and then connected to the water tank.
2. There is a speed difference between the plate cylinder and the rubber cylinder
Ideally, in the printing process, the linear speed of the surface of the plate cylinder and the blanket cylinder should be equal, but in fact the blanket will elastically deform under the action of printing pressure, resulting in a speed difference between the blanket and the plate. The surface of the printing plate is abraded, destroying the original surface structure and adsorption performance of the printing plate, thereby reducing the printing plate's resistance to printing. In theory, the speed difference between the blanket and the printing plate cannot be completely eliminated, so the speed difference can only be minimized by selecting a highly elastic blanket and adjusting the liner thickness. In addition, due to the speed difference between the plate cylinder and the rubber cylinder, the pressure between them will become greater and greater, and the wear on the printing plate will become more and more serious, so the pressure between them must be adjusted to an appropriate size.
3. There is a speed difference between the printing plate and the water roller and ink roller
There is also a speed difference between the printing plate and the water roller and the ink roller, which will cause wear on the printing plate. According to the method of the above example, first check the elasticity of the rubber on the surface of the water roller and the ink roller, and then adjust the appropriate pressure to reduce the wear of the water roller and the ink roller on the printing plate.
CTP plate making process
If, after checking the printing press, the printing staff still cannot find the cause of the reduction in the printing endurance of the printing plate, the next step is to check whether there is a problem with the printing plate itself. Most printing companies have already used CTP platemaking. CTP platemaking saves production time, improves platemaking quality and production efficiency, and also puts forward higher requirements for platemaking personnel than traditional platemaking. In the CTP plate-making process, the following aspects will affect the printing plate durability.
1. Laser energy is too low
During the plate-making process, if the laser energy of the CTP is lower than the laser energy required for the polymerization reaction of the plate material, the photochemical reaction of the photosensitive layer of the plate material will be insufficient, resulting in a decrease in the printing plate durability. Different brands and models of plate materials require different laser energy, and plate-making personnel need to pay attention to adjustment. In addition, after CTP is used for a long time, especially when there is a lot of dust in the CTP plate making room, the optical path will be damaged, so that the laser energy cannot reach the set value, so the plate making personnel should regularly check and clean the optical path to ensure proper Laser energy.
2. Preheating temperature is too low
During the pre-heating process, some platemakers worry that too high pre-heating temperature will cause paste plates, and it is customary to adjust the pre-heating temperature to be lower; when the CTP temperature control probe fails, the pre-heating temperature will not reach Set value. These will cause the preheating temperature to be low, so that the photosensitive layer of the printing plate that has undergone the photochemical reaction cannot be fixed on the aluminum plate base, causing the printing plate to have a reduced durability.
3. The developer concentration is too high and the development time is too long
During the development process, the developer concentration is too high and the development time is too long will cause the printing plate photosensitive layer to be excessively "corroded", so that the printing plate durability is reduced. Therefore, the plate-making personnel should strictly control the developer concentration and development time.
4. Insufficient flush volume
In the process of rinsing, if the amount of flushing water is insufficient, the developer on the printing plate cannot be rinsed out completely, causing the developer to remain on the printing plate, corroding the photosensitive layer, and causing a drop in printing durability. Plate-making personnel need to carefully check the water outlet of the plate-making machine to avoid the water outlet being blocked.
Printing supplies
Printing consumables may also cause the printing plate's durability to decline. If there is a quality problem in the plate material itself, you can find the problem by comparing with different printing machines or CTP publishing. If there is a problem with the ink, it is more troublesome, because the printing company lacks the ink detection method, even if the ink is tested by a special agency, the ink factor cannot be completely ruled out, because the ink used by each printing company has a slight formula Different standards cannot be unified. Generally, after excluding other factors that may affect the durability of the printing plate, you can ask the technical personnel of the ink manufacturer to follow the production, adjust the ink formula according to the actual production situation to solve the problem of the reduction of the printing plate durability.
There are four types of wayfinding signs: identification, directional, informational, and regulatory. As standalone signs, they serve a specific role; as part of the greater wayfinding system, they inform each other.
Here`s what facility managers need to know about deploying each of the primary wayfinding types of signage.
1. Identification
Identification is the most common type of wayfinding signage. They tell a person when they have arrived at their destination. They also serve as general wayfinding landmarks.
Need to get your bearings? Identification signage is there for you. If you`re looking for Sales and you keep seeing signs for Human Resources, you know you`re in the wrong place.
Make identification signs uncluttered and straight to the point. What does the sign signify? Someone should understand it in seconds.
General examples
- Door plaques (Assistant to the Regional Manager)
- Departmental markers (Accounting and Finance; Sales)
- Landmark signage (donor plaque; historical marker)
2. Directional
Directional signage helps people get to where they`re going. It`s an invisible hand guiding them from wherever they are to their destination, one step at a time. They`re best used at junctions and areas without a clear traffic flow.
Anyone unfamiliar with their surroundings benefits from diverse directional signage. It can be as simple as a plaque at each junction sending people left or right. Or, it may be as comprehensive as colored lines on the floor leading people directly to their destination.
Continuity is key for directional signage. If a person becomes lost anywhere between two points using directional signage, it`s immediately invalidated. Picking up the trail again means backtracking or getting lucky.
General examples
- Junction signage (left to cafeteria; right to an exit)
- Colored lines on the floor (blue for marketing; red for sales)
- Directory signage (CEO, 8th floor; HR)
3. Informational
Whereas identification signage marks a particular area, informational signage pertains to the overall facilities. These signs give people broad information they need while navigating.
Informational signage is best placed in an area with broad exposure. Lobbies, waiting rooms, building entrances, and atriums are popular examples. Signage should answer questions before they`re asked. Where are your bathrooms? How late are you open? Do you have an elevator?
Informational signs should be universally understandable at a glance-signs and symbols anyone can understand.
General examples
- Amenities and accommodations (free Wi-Fi; elevators)
- Facilities signage (bathrooms; exits; cafeteria)
- Business information (hours of operation; address numbers)
4. Regulatory
Regulatory signage is a proactive form of wayfinding. It`s focused on safety and liability concerns and sets boundaries-what is and isn`t acceptable in your facilities. It`s used to establish and reinforce rules, safety standards, and privacy expectations.
Regulatory signage is generally big and bold. No frills-only a clear, concise, prominent message. Someone probably won`t open a closet if there`s a [Caution! High Voltage!" sign on the door. Similarly, displaying a [No Pets Allowed" sign means Fido isn`t welcome.
Use regulatory signage wherever it applies and leave no room for ambiguity. A handicap sign sets a clear precedent, just like an [Employees Only" sign on a locked door.
General examples
- Rules and regulations (no smoking; no firearms)
- Compliance standards (ADA accessibility; high voltage sign)
- Access control (no entry beyond this point; employees only)
Combining wayfinding signage
Every type of wayfinding signage can and should be used with every other. Regulatory signs should keep people out of restricted areas as they follow directional signage to their destination. Identification signage should tell someone where they are, so they can follow directional signage to where they want to be. Informational signage-coupled with regulatory signage-needs to set behavior expectations in your facilities.
Additionally, all signage should be simple. Regardless of its purpose, someone should be able to look at a sign and known in seconds what it says, as well as what it means in relation to wayfinding.
Whatever the information, make sure you have the right mode of delivery. The simpler your signage and the more cohesive it is across all four types, the more effective it will be for anyone using it.
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