Printing is a process of mass copying. It is a high-speed, continuous production. Its main purpose is to produce qualified and high-quality printed products. Due to the many processes, there are many factors that affect the quality of printing, and often there are thousands of scraps when quality problems occur. In actual production, a large number of scrapped finished products or semi-finished products also occur from time to time. [NextPage] [NextPage] Candy Production Line,Production Line,Food Production Line,Chocolate Production Line U-PAC CO.,LTD , https://www.upac-machinery.com
Example 1: A printing factory prints a product brochure of a special wire factory, using double-sided coated paper with a basis weight of 157g / m2, both sides are printed in color, and the text below one of the pictures indicates that the paper shell should be extended The wire used for electric detonators was printed as an out-of-date wire for electric detonators due to proofreading errors, which was contrary to the original intention and caused an economic loss of nearly 100,000 yuan.
Example 2: When printing in the printing workshop of a printing factory, the outer border line of a few lines of text on a black plate was mistakenly removed as a film collage trace. This was only found when some of the products printed in the previous stage entered the next process. The problem, I had to rework and reprint the missing border lines. Fortunately, reprinting does not affect the accuracy of graphics and text, but the waste of manpower, material resources, and product consumption due to the reprinting of the border line is not small, and it delays the printing of other products and affects normal production.
Example 3: A printing factory undertakes to print a series of product labels of a food company. Due to the large variety, different tastes are required to be distinguished by different ink colors, and the pictures are roughly the same, only the difference of xx taste. As a result, the printing plates were not carefully checked during printing, and the wrong plate installation caused the product to be scrapped, which not only caused economic losses, but also delayed the delivery period and affected the normal use of labels by food companies.
Example 4: A ticket printing factory prints a batch of bills and uses kraft paper to cover the cover. It cuts its head when cutting the finished product. Across the board, dozens of bills became waste. Because the bill has a code, the number cannot be used normally if it is inconsistent. In desperation, the scrapped part has to be reprinted, and the whole production process is confused due to the number problem.
There are many similar examples in actual production. Every link in the printing process is directly related to the final quality of the printed matter, so no errors are allowed. It can be seen that it is of great significance to control the printing quality throughout every process and sell it to every operator.
The following measures can be taken to avoid the occurrence of printing quality accidents: First, the self-inspection of each process in the copying process. The second is the mutual inspection between related processes in the copy process. Specifically, in addition to performing routine inspections, each operator is required to carefully check the quality of the previous process, eliminate various hidden dangers of accidents, find problems as early as possible, and minimize losses. The following is a discussion of issues that should be noted when performing quality inspections in daily work for a few key processes. The basic responsibility of proofreading and proofreading is to be responsible for the originals. Through proofreading, the content on the proofs meets the requirements of the originals and corrects all typographical errors. If there are any omissions and doubts in some parts of the originals, the proofreaders should submit comments and the corrections shall be approved by the printing and printing unit. , Can not modify the original on the proofs without authorization. In short, proofreading should be faithful to the original manuscript without any errors that may exist. The one-word value of gold is not an exaggeration for proofreaders. Proofreading is an important part of ensuring the accuracy of printed content.
Copy
Exposure is to transfer the image on the original plate to the printing plate correctly. The original version is a graphic product made in the previous process, and is the copy object of the printing process. Therefore, it is very important to check the original version before printing, and its inspection content mainly includes:
1Original name. Whether the content is consistent with the craft bill;
2Original specifications. Whether the quantity is consistent with the craft bill;
3 Whether the original version of the positive and negative positive and negative directions meet the requirements of the printing process;
4 Whether the quality of the original version and the quality of the collage meet the requirements for printing;
5 Whether the necessary rule lines and various marks (such as plate marks, color marks, etc.) are complete
Whether the 6 sets of color versions are accurate;
7 Is the layout clean and free of residual waste tape, dirt, etc .; is the Japanese layout flat and crease-free? Scratches, etc.
The inspection of plate quality after printing is an indispensable process. It can be said to be an important part of comprehensive quality control. Its purpose is to prevent unqualified plates from entering the printing process, causing unnecessary waste and rework.
The main content of quality inspection of printing plate:
1 Inspection of the appearance quality of the printing plate: it includes the flatness, cleanliness and evenness of the rubber plate.
2 Checking the format specifications of the printing plate: it includes the layout size, the position of the picture and text, and the size of the gripper. Check the folding relationship, etc., one by one, according to the printing process sheet. It is required that the size of the printing plate is accurate, the error is less than 0.5mm, the size error between the color plates is less than 0, 1mm, and there is no slanting phenomenon in the graphics.
3 Inspection of graphic content: check whether the graphic content is complete, whether there are damaged characters, blind characters, missing words, etc. against the original version; for the multi-color version, check whether the color version is complete, whether there is a lack of color or sunburn; necessary Is the rule line complete and complete?
4 Check the quality of the dots. Use a magnifying glass to observe whether the dots are full. Smooth and so on.
5 Check the depth of the picture and text: With the help of a magnifying glass and a control bar, check the brightness of the printing plate separately according to the original printing plate and the printing plate quality standards. in. The reproducibility of the dots in dark and different tone areas, too deep and too shallow plates can not be printed on the machine.
print
Newly obtained printing plates often affect the quality due to various factors in the production process of the printing plates (such as process operation, production environment, workers' quality, etc.). The printing plate should be checked before the machine, so that the responsibilities can be separated and the phenomenon of whispering between various departments can be avoided. In addition to the printing staff and full-time personnel for this work, each operator on the machine has the responsibility and obligation to review and accept the quality of the printing plate. Only qualified printing plates can be installed. The content of the inspection mainly includes color. Whether the color tone is dark, the dots are fictitious, whether the text is correct, whether the lines are incomplete, and whether the specifications, cleanliness and flatness of the printing plate meet the requirements.
In addition, in the process of printing production, the implementation of three diligence, diligently draw ink fountain. Seeing the water content of the layout frequently, looking at the proofs frequently, Sanqin are effective quality control measures in the printing process. Diligently draw ink. It is an important job to keep the consistency of the ink color of the printed matter. Looking at the proof sheet is to require the operator to frequently take out the printed sheet for inspection, mainly to check the accuracy of the printing position and the image quality. The shorter the inspection interval, the better, which can greatly reduce the scrap rate.
Only a few important links in the printing process are listed and analyzed above. Avoiding the occurrence of printing quality accidents must be carried out from many aspects and multiple channels. Each operator should have a high sense of responsibility for his work. Only all staff can work together to improve the quality of printed matter and reduce the occurrence of quality accidents. Enterprises create higher benefits.
A Case of Diagnosis of Dirty Prints
The four-color machine prints the cover of the book, and then the second and third seals are printed by the J2108 single-color machine. Sometimes this situation occurs: when the back of the printed product is a large solid color block or a large area of ​​shading, it sometimes appears on it. A strip-shaped floating soil nearly 2cm long, and the color of the floating soil is multi-colored such as blue and red. This situation is often misunderstood by some operators as a result of the four-color machine's dry printing and sticky back. In fact, when the unprinted paper on Feida is checked, there will be no dirt on the back of the paper. Looking closely at the dirt marks, it feels like the dirt marks are from the graphic blocks on the front, which are caused by pressure and dragging to the back, so I thought that the pressure of the brush wheel on the cardboard was too heavy. Lighten the pressure, and the dirt on the printed matter is gone. The dirty stains are time-varying, mainly because some of the prints are not dry, so it is easy to cause people to make wrong judgments.