The rubber rollers of printing press machine play an important role in the printing process, but in actual production, many printing companies will soon need to replace the original rubber rollers. Due to insufficient cleaning and maintenance of the rubber rollers by most manufacturers, the original rubber rollers are prematurely aged, causing printing failures and cost loss.
Ink roller
Ink roller refers to the rubber roller in all ink supply systems. The role of the ink roller is to quantify and uniformly transfer the printing ink to the printing plate, which can be divided into three types: ink, ink transfer, and printing plate.
The ink is used to extract a fixed amount of ink from the ink fountain and then transfer it to the transfer roller. The ink transfer roller receives these inks and distributes them evenly to form a uniform ink film. It is then passed to the platen roller, which is responsible for distributing the incoming ink on the printing plate. At this point, the task of the ink roller is completed.
In offset presses, rubber rollers and hard rollers are always spaced apart to form a soft-hard alternate arrangement. This arrangement is more conducive to ink transfer and uniform distribution. The function of the ink roller can further strengthen the axial distribution of the ink. When it is working, it also rotates in the axial direction and performs a series of axial translation. Therefore, it is called an ink roller.
The ink roller is used to transfer ink, so the rubber must be ink-friendly. Due to the long-term contact between the adhesive layer and the ink, it must have certain resistance to ink corrosion. At the same time, the speed of the offset press is very high, and the speed of the ink roller is also very high, which causes serious heat generation of the adhesive layer, thereby accelerating the aging of the rubber. Therefore, to make the rubber roller durable, the requirements on the rubber material are also very high.
Water roller
The water roller is a rubber roller in the water supply system, similar to the ink roller, and its function is to uniformly transport water to the printing plate. Water rollers also have water, water, and plate. At present, there are two types of water supply methods for water rollers. One is the continuous water supply method. The water supply amount is achieved by adjusting the speed of the bucket roller, which is suitable for high-speed printing. The other is intermittent. The platen roller is covered with a fleece cover, and the water roller swings back and forth to supply water.
The water roller is used to transfer water, so it must be hydrophilic and resistant to water corrosion, and its hardness is usually lower than that of the ink roller.Ink rollers and water rollers of offset printing presses traditionally use nitrile rubber, but they have their own emphasis on the formula of rubber compounds. Of course, other materials can also be used as long as they meet the requirements for use.
Causes of Rubber Roller Wear
1. Improper pressure adjustment of the ink roller will cause wear of the ink roller, especially if the pressure is heavy on one side and light on the other, it will easily cause damage to the rubber roller.
2. Forgetting to close the handles on both ends of the water bucket roller will cause the colloid of the metering roller to tear and damage. If one end is not closed or the other end is not in place, the metering roller and the plate-type water roller will be worn.
3. During the plate loading process, the PS plate is not installed properly, the bite of the PS plate and the tension screw at the end of the plate are not tightened. The PS plate will wear out the rubber roller due to the untensioned part and the protruding protrusions; The plate is too tight or the top plate is too powerful, which causes the plate to deform or rupture and damage the ink roller, especially because the plate water roller has low rubber hardness and its damage is also * obvious.
4. In the printing process, when printing a long order, the running conditions of the two ends and the middle are different, which will cause the two ends of the ink roller to wear.
5. Poorly printed film. The powder and sand particles falling off the film will cause the ink roller and copper roller to wear.
6. Use a sharp tool to draw a gauge line or make other marks on the printing plate, resulting in damage to the ink roller.
7. During the printing process, due to the poor local water quality and high hardness, and the printing plant did not install a proper water treatment device, the surface of the ink roller accumulated calcium compounds, which increased the rubber hardness and increased friction. This problem not only causes wear of the ink roller, but also causes serious print quality problems.
8. The ink roller is not regularly maintained and recycled.
9. The ink on the surface of the metering roller will not cause abrasion if it is not washed for a long time.
10. Special processes, such as printing gold and silver cardboard, stickers or films, require special inks and special additives, which will accelerate the cracking and aging of rubber rollers.
11. The roughness of ink particles, especially the roughness of UV ink, has a direct impact on the wear of rubber rollers.
12. The speed of wear of rubber rollers in different parts is different. Such as the ink transfer roller, because its action is stationary → high speed → stationary continuously reciprocating, its wear degree is faster than ordinary.
13. When the rubber roller is stationary for a long time when it is stopped for a long time, the rubber diameter of the rubber roller is uneven, and the rotation and deformation of the rubber roller are different, which exacerbates the wear of the rubber roller.
14. The temperature control of the working environment is not good. It exceeds the physical properties of the rubber roller and increases the wear of the rubber roller.
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Some machining centers have begun to appear that use resultant motion in less elaborate ways. That is, these machines use the resultant motion of different elements moving in different directions to achieve the motion along X, Y or Z, but they do so within machining center designs that are considerably more like standard machines.
The traditional cnc machining center has axis motors that push in one direction or the other along X, Y and Z. In the 1990s, all of us who attend machine tool trade shows learned that this wasn’t the only way to design the machine. A variety of builders brought out "hexapod" and/or "parallel kinematic" machines in which a daddy-longlegs arrangement of linear-motion members used CNC interpolation to achieve precisely the same X-Y-Z motion as a standard machine.
These novel machining centers make for attention-grabbing live demonstrations at trade shows. In fact, these eye-catching machines began to appear at trade shows not long after the use of attractive female models at these shows began to decline—almost as if some different means of capturing attendees’ attention had to be invented. However, real-life users of these machines remain uncommon to say the least. While a machine tool buyer may notice a trade show booth because of the complex motion of one these machines, that buyer is still more likely to spend money on a machine that has a more standard design.
But now, an important development may go unnoticed beneath the presence of these more elaborate machines. Some CNC machining centers have begun to appear that use the same fundamental idea—resultant motion—in a less elaborate way. That is, these machines use the resultant motion of different elements moving in different directions to achieve the motion along X, Y or Z, but they do so within machining center designs that are considerably more like standard machines.
Here are just two examples. One is the line of "relative motion" machining centers from Olympic Seiki (represented in the United States by Vigor Machinery Company). With these machines, it is not the tool motion or table motion alone that provides the machine’s traverse; it’s the tool and table together. In the X and Z axes, the ballscrew simultaneously moves both table and tool in opposite directions. The feed rate of the tool relative to the part is the sum of the traverse rates of both elements. Ditto for the acceleration. On smaller machines in this line, the resultant acceleration is 2G. In addition to speed, another benefit may be stability. With mated elements moving in symmetry, says the company, the design of this machine favors dynamic balance.
Another machine design taking advantage of resultant motion is the "Genius 500" horizontal machining center from Cross Hüller. On this machine, the X-axis motion—that is, the side-to-side motion—comes from elements that move up and down along the Y direction. The mechanism for this is an inverted V-shaped coupler that carries the spindle. This inverted V straddles between two sets of linear motors that run up and down. When the linear motors move together at the same speed, the result is pure Y-axis motion. But when the linear motors move differently, the difference causes the coupler to pivot, providing the motion in X.
As a result, there is no need for a motor to push along the X axis on this machine. Therein lies a benefit of the design. Whether the motion is X or Y, the force of the axis motors goes along the direction of gravity, where the machine is well-supported (by the floor). Thus the machine can move the tool rapidly throughout the X-Y plane, with none of the motion of the axis motors directly producing sideways forces.
In a wide range of applications of power supplies, as a professional power supply for LEDs, most of them require a certain waterproof function, and have high requirements for the level of waterproofing. Regardless of whether the requirements are waterproof, but also the ability to adapt to the ambient temperature and the operating conditions of equipment in severe weather have high requirements.
Waterproof power supply must have certain requirements for its insulation and working temperature. The working temperature of the led waterproof switching power supply is generally -40 -80 ° C (outer surface temperature of the case), the storage temperature is -40 -85 ° C, and the working humidity is 10-90% relative humidity.
LED waterproof switching power supply has great requirements for the working environment and has been widely used in daily life. So, what characteristics does it have?
1. High reliability: Especially the driving power sources like LED street lights are at high altitude, so it leads to inconvenience of maintenance, and the cost is even greater.
2. High efficiency: LED is an energy-saving product, and the efficiency of the driving power supply must be high. For the power supply, the structure placed in the led lamp is very important.
The luminous efficiency of LED will decrease with the increase of LED temperature, so the heat dissipation of LED is especially important. When the efficiency of the power supply is high, the power loss of the power supply becomes smaller, the heat generation in the LED lamp will also be reduced, and the temperature of the lamp will be reduced accordingly, which is beneficial to delaying the light decay of the LED.
3. High power: The power factor is the load requirement of the grid. Generally, there are no mandatory indicators for electrical appliances below 70 watts.
4. Driving mode: one constant voltage source provides multiple constant current sources, and each constant current source supplies power to each LED individually. Its advantage is that the combination is flexible, and the failure of all the LEDs will not affect the normal operation of other LEDs, which will be higher for cost.
The second type is direct constant current power supply, and the LEDs are operated in series or in parallel, but there is a obvious disadvantage that it is poor flexibility.
These two forms coexist for a period of time, and multiple constant current output power supply methods will be better in terms of cost and performance.
5. Surge protection function: LED's ability to resist surge is relatively poor, especially its ability to resist reverse voltage. For example, led lamps installed outdoors, due to the start-up of the grid load and the induction of lightning strikes, various surges can be invaded from the grid system, and some surges can cause damage to LEDs. Therefore, the LED drive power must have the ability to suppress the intrusion of the surge and protect the LED from damage.
6. Protection function: In addition to the normal protection function of the power supply, it is best to add negative feedback of LED temperature to the constant current output to prevent the LED temperature from becoming too high.
7. Protection: The type of the lamp is externally installed, the power supply structure should be waterproof and moisture-proof, and the shell should be resistant to sunlight.
8. The life of the drive power must be adapted to the life of the LED.
9. To meet the requirements of safety regulations and electromagnetic compatibility.
LED waterproof power supply supplies are mostly used to provide driving capabilities for various LED lamps, such as LED spotlights, LED street lights, LED underground lights, LED ceiling lights, and LED panel lights. The biggest feature of the led power supply is that it is waterproof and can be used outdoors. At the same time, it is not afraid of bad weather such as rain, fog and direct sunlight.
Cosplay is now a very popular event. Due to everyone's love for secondary animation, more and more people have joined the C circle. In order to perfectly restore their favorite anime characters, many people even spend a lot of money and time to make COS costumes and then learn the exclusive actions of anime characters. I have to say that this spirit is worthy of everyone's appreciation.
In fact, no matter what kind of anime character needs to do a lot of preparations when releasing COS, just taking the hairstyle of some anime character, it is likely that a hairstyle will take several hours or even ten hours. sort out. So, as time goes by, many people say that hair is the nemesis of anime cos wigs, so do you know how to distinguish them?
Goku's hair in Riman's "Dragon Ball" can also be regarded as one of the nemesis of COS, but don't look at Goku's hair style so free and easy, but its level is only the first level. Why do you say this way? In fact, it is not difficult for everyone to realize that this type of hairstyle for COS Goku is very simple. You only need to have longer hair and a bottle of hair spray to complete it. In anime. If you come across something like this without much technical content, you can directly define it as elementary without much thought.
Many people think that Ran Mouri's anime cos wigs is very simple, even easier than Goku's, but it is not. COS Goku is actually the simplest, because the hairstyle of Goku's anime character has basically no regularity, as long as the hair is roughly similar to the original character, no one will notice whether it is exactly the same.
However, although Ran Mouri's hair looks simpler and has only one corner, her requirements are much higher. Because the fans are paying attention to Ran Mouri COS, the first thing they pay attention to is hairstyle. Xiaolan is very famous for this feature. Therefore, compared to Goku, Ran Mouri has a certain amount of attention and attractive role in hair, and is uniformly defined as intermediate.
After reading the junior and intermediate wigs, do you really look forward to what the advanced COS nemesis looks like? In fact, Serestia Ludenburg in The Projectile Breakthrough: School of Hope and Desperate High School Students, and Giorno in Jojo's Bizarre Adventure. Chobana, Ekalem in One Piece, and Zhou Tengxiyin in Blessings to the Goddess are all advanced.
And their characters have a common feature, that is, curly hair, if it is just pure curly hair, it is nothing, but if you want to get them, it is quite difficult. So far, with the exception of Giorno. Qiao Ba has cos out of COS, the other three anime characters have almost never been out of COS.
The reason why you don’t go to COS is also very simple. Insufficient hair volume is the most important reason, so everyone says that hair is a nemesis of COS. It is still very valid.