Handling of scratched plates by hard objects
When printing large quantities of prints, every time 3000 prints or paper is loaded, the plates and blankets need to be cleaned. Sometimes there is a hard object on the cloth for cleaning the printing plate. If you do not pay attention, the printing plate will be marked with a line of dirty marks. Reprinting the plate is a waste of work, time, and waste; using a revision paste, the dirty marks are not coated with the photoresist, so they cannot be repaired.
Treatment method: Dip a clean cloth with a clean cloth, then a little dampening powder, and rub it lightly on the dirty marks. When starting the machine, first fill the plate with water and run it a few times, then lower the ink roller, and the dirty marks will disappear.
From this, don't underestimate the importance of rag cleaning. (Li Chun, Fuchun Color Printing Factory)
Print cylinder maintenance experience
(1) Before leaving work every day, the press operator should clean the shoulder iron (roller pillow) of the plate cylinder and rubber cylinder.
(2) When replacing the rubber cloth, clean the surface of the rubber roller with pure alcohol, gasoline or car washing water, then dry it with a cloth, and finally add RESOST 7-3 anti-rust oil on the surface of the plate cylinder and rubber roller with a cotton cloth or a brush. Add twice in succession, with an interval of 5 minutes to dry.
(3) The liner paper used for the printing plate cylinder and rubber cylinder can be soaked in engine oil and then dried before use, so that the use effect is better, or it can be cut to an appropriate size with an offset plate of appropriate thickness. (Lv Beizhan, Shanghai Donnelly Printing Co., Ltd.)
An example of troubleshooting for paper skew
One of our company's Roland 702 offset presses has often had skewed paper feed for some time. The initial slanting range is small, which can be solved by adjusting the tightness of the transfer belt and the amount of air suction. However, after a period of time, the paper skew failure reappeared, and the skew width was larger than last time. Adjusting the transfer belt to the tightest position and the maximum suction volume have not worked. Adjust the unilateral pressure roller, with the help of front suction and rear suction, it still has no effect. Due to business tension, the effect of diagonal sheets on printing is not large, so it has been dragging and not solving. After a period of time, the slanted sheet has a larger amplitude, and often stops due to poor paper feed caused by the slanted sheet, which seriously affects normal production and print quality.
Because adjusting the operable parts of Feida does not work, it is believed that the failure is caused by mechanical reasons. After resetting the above adjustments, the operator measured the transfer belt at the feeder part of the machine, and found that the two transfer belts turned back and forth at the same time, and the difference was 6mm, so it was suspected that the transfer belt was aging. The slower transfer belt was replaced, and the trial printing was restarted. The skewed paper sheet was not ruled out, and the difference between the two transfer belts in one revolution was 5mm, so the problem was not the transfer belt.
For this thorny problem, the operator had to follow the vines and check all the mechanical parts related to the paper belt. It was found that the tension adjustment lever of the paper belt under the paperboard was normal, but it failed to adjust such a large range; the bearings on both sides of the front gauge were basically similar; looking up again, it was found that the operating side shaft at the top of the paper belt was a rubber bush And the diameter can be adjusted through the universal shaft. After adjustment, start trial printing and troubleshoot.
Through this failure, we have learned a lesson. When introducing new products and equipment, operators should be given certain training so that they can fully understand, become familiar with, and master the mechanical structure adjustment methods of the entire machine and some common parts. Function to prevent unnecessary trouble caused by improper adjustment of the machine. (Wang Jianming, Wang Guomin, Zhejiang Ideal Packaging Group Company)
An example of image processing without printing
A Swiss-made four-color offset printing machine from our factory showed that the third-color printing was not realized during the production process. Immediately checked the gasket and the blanket, and there was no problem. After a detailed inspection, it was found that the piezoelectric magnet pull rod nut Loose, so that the closing pressure eccentric sleeve does not rotate in place. Similar phenomena occurred many times afterwards. After tightening the connecting nut, the fault was eliminated. (Li Zhenhua, Haoyi Color Printing Factory) [next]
Solutions to the inaccuracy of several overprints in bill printing
Our factory is the main printing unit for tax invoice printing in Hebei Province. Most of the printed products are 3 to 6 pairs, and the quality requirements are high. Several sets of overprints must be accurate. In the past, the sample was printed on the machine that was printed first, and the other machine was printed like this, but the phenomenon of inaccuracy of several sets of overprints often occurred, which caused a large number of products to be over-stitched. In my work, I have summarized the method of unifying the side and front regulations to solve the problem of inaccuracy of several overprints in bill printing, so that over-stitch binding no longer occurs, and the quality and output are greatly improved.
Specific methods: â‘ Unified side rule: design a 3mm line on the printing plate. As shown in the figure, the line thickness on the edge of the paper is 0.5mm. During printing, make the steel well aligned with the edge of the paper. â‘¡ Unified pre-regulation: When printing the same product, make the pre-regulation consistent, and the operators shall strictly follow the same size. (Li Dajun, Ticket Service Center, Hebei Taxation Bureau)
An example of troubleshooting for inaccurate overprint of self-adhesive trademark printing
Our factory is a four-color self-adhesive label printing machine. After several months of use, the overprinting failure occurs, and the irregular stroke jumps up and down by 0.5 ~ 0.2mm.
Consider first whether the film is elastic or not. Rewinding the self-adhesive film still cannot solve the problem.
Then consider whether there is a gap in the transmission part of the machine. After disassembling the transmission gear box that drives the stroke adjustment, it is found that the design of the snap spring of the bicycle flywheel is used. Because the gear box needs to be filled with oil twice a day, there are more places on the gear and less places on the gear, causing the trip to jump. The analysis found that it was caused by the use of inferior motor oil. The use of labelled, fluid oil has a good solution, the problem is completely solved, and there is no overprinting phenomenon. (Li Jin, Fuchun Color Printing Factory)
Routine troubleshooting of paper cutter
The photoelectric protection function of a full-open paper cutter made in Tianjin fails, and the machine can still work after emergency treatment, but because there is no protection detection, the operator is very worried about personal safety, resulting in low work efficiency.
After removing the circuit board and conducting visual inspection, it was found that the substrate around the power bridge pile was discolored, it was concluded that the bridge pile was burnt out, and the bridge pile was powered on and tested, and there was still no response. Measured with a multimeter, the newly replaced bridge pile has also been burned out, thus judging that there is a short circuit part. Inspecting the components one by one from the bridge stack, it was found that a three-terminal voltage regulator block (7805) was broken down, the component was purchased to be replaced, and the power indicator on the circuit board turned on after powering up. The operator installs the circuit board on the machine, and operates according to the normal procedure to check whether the photoelectric protection function is working, covering the optical eye with his hand, and the falling knife stops immediately. After several attempts, it is normal. The fault is eliminated. (Xinhua Xinhua Printing Factory Wang Minghui)
An example of troubleshooting for printed matter ghosting
The company purchased a new PZ-41020B folio four-color offset printing machine. After the machine is installed in place, ghosting occurs during the trial printing phase. After repeated debugging, it has been difficult to solve effectively.
Trouble phenomenon: After analyzing the printed products, it is found that the ghost phenomenon is mainly manifested in black characters, and it is intermittent. Sometimes the local text is a little bit, but it is not obvious; sometimes it is on the entire layout, and it is obvious and irregular.
Troubleshooting: Check that there is no problem with the paper and the liner, and the cutting and installation of the blanket are also very standardized. Therefore, the factory technicians speculated that the spring of the roller gripper may be fatigued and the elastic force decreased, resulting in inconsistent movements during the tooth opening process. Remove all the gripping springs on the rollers and replace them with imported springs with excellent performance. As a result, the fault still exists. Then open all the guards of the unit, and check them group by group according to the printing color sequence of K → C → M → Y. As a result, it was found that the impression sleeve of the impression cylinder of the K color group was slightly loose, and the cooperation gap increased. After assembly and positioning, the fault can be eliminated.
Failure analysis: The machine's assembly accuracy is not enough, it will produce jitter during operation, resulting in inconsistent front and rear marks on the remaining black ink on the rubber roller of the K group, resulting in ghosting failure. (Wang Fei, Shandong Linyi Daily Printing Company)
Two tips
Tip one: install an exhaust pipe
Our factory purchased a Komori offset press using pneumatic transmission in 1997. Bleed air from the air compressor every day after work The working environment and the appearance of the ground.
Inspired by the decompression exhaust pipe of the household electric water heater, the author connects a plastic pipe with a diameter of 10mm from the air compressor exhaust port, one end is connected to the air compressor exhaust pipe, and the other end is inserted into the drain port (available water tank drain port) ), Which not only facilitates the discharge of wastewater, but also reduces the pollution of wastewater to the ground. This method is also applicable to other offset printing machines.
Tip two: small offset printing machine conversion tape
The factory borrowed a small offset printing machine AR-010 made in Japan from China Banknote Card Factory in 2002. Due to the long service life of the machine when borrowed, the feed belt was smooth and tacky, and each printing deviated from the positioning wheel. One of the four feed belts was broken and could not be used. Multiple contacts with the manufacturer had no results. Because the problem of the paper conveying belt may cause the production to stop, the author found the waste roller lining cloth used in the offset press, butted the interface with the sewing machine, and made the interface align with the paper feeding direction. After being installed, the paper positioning effect is very good, which solves a major problem in the work. (Song Zhigang, Beijing Banknote Printing Factory)
- No Slightest Damage to Your Feet: Our foot files are mild to your skin and remove dead skin from your feet safely and painlessly. Whether you're using the foot grit files or the metal foot rasp, the handles make the whole process easy to do.Function Well Both in Wet and Dry:Gives equally good results on both dry and wet foot surfaces that allows the user to work according to their own preference and satisfaction.Save Time:Are you still spending much money at pedicure salon or taking time on the way to salon,our Foot File is the best choice for you to get professional foot care pedicure at home.
Foot File
Metal Foot File,Wooden Foot File,Foot File,Stainless Steel Foot File
Yangjiang Yangdong Kartier Beauty Tools Product Factory , https://www.kartierbeauty.com