Analysis of the positioning of the size of the printing plate
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
For a printing plate staff, the positioning of the pre-size of the printing plate is the first step in making the printing plate. It is the positioning of this size. It is not a fixed data, but an uncertainty data that changes whenever and wherever possible due to changes in conditions and objectives. It should be started from three aspects. The specific analysis is as follows:
First, we must master the characteristics of the offset printing machine, manufacturers and other characteristics
Each offset press in each printing unit has different characteristics depending on its model, manufacturer, etc., so they require different characteristics when working. Not to mention the difference in the positioning of the front gauge of each offset press. Let's take a few typical offset presses in this unit as an example to talk about the difference in positioning of their front gauges. For example, the offset offset press produced by Beijing People's Machinery Factory, like the J2108B type of monochrome offset press, uses the front gauge size of the plate to be 9cm, which is the distance from the core of the plate to the edge of the plate. Is 9cm; like the JS2102 type of monochrome double-sided offset press, the front gauge size of the upper and lower plates used is the same as 4.5cm, that is, the distance from the core to the edge of the plate is 4.5cm; The same as the double-sided offset monochrome offset printing machine, the upper and lower plates used for the positioning of the front gauge size are different, the front gauge size of the upper version is 7.5cm, and the front gauge size of the lower version is 6cm. Therefore, the positioning of the front gauge size of the printing plate used in the same monochrome double-sided offset printing machine may vary from manufacturer to manufacturer; the J2205 type two-color offset printing machine produced by Beijing People’s Machinery Factory shall also The size of the front plate of the plate used is different, and its front gauge size is 10cm, but its front gauge size is 10cm when printing the book edition, and when the book cover is printed, its The positioning of the front gauge is 9cm, which is another feature.
Second, to understand the work requirements and the use of the printed plate
Usually printing companies, their business has a certain standard, that is to say, within a certain range, there are very few cross-professional undertaking business. This creates an unwritten rule in the middle of the platemakers: in non-special circumstances, the orientation of the pre-size of the plates they make appears to be fixed. However, in the case of special circumstances, we must first look at the subpoena, samples and then find countermeasures. Let's take the printing plate on the cover of the book as an example to explain the positioning of the front gauge in the actual operation process. It is mainly divided into five steps: 1. After receiving the subpoena, we must first see the requirements written above (printing The requirements of the edition), and then clearly arranged the stamp pad. 2. Distinguish the day and the corner of the film supplied to the film, that is, the direction of the mouth. Measure the actual size of the core and whether there is a cut. 3. Whether the printed cover requires a leap, and special circumstances should be treated specially. 4. When looking at the marking of the film, it should be noted that the actual data of the front gauge size is the normal size plus the size of the mouthpiece minus the size of the machine bite (the size of the bite of the offset press is between 1.5 and 2 cm). ). 5. Finally, re-measure the size of the entire core and the contrast with the paper used. It can also be seen that if a qualified printing plate is to be made, the positioning of the pre-size of the printing plate is just right, and it is inseparable to see the targeted objects.
Third, the specific conditions of raw materials
Printing plates often make people only remember how to calculate the size of the front gauge, while ignoring the specific conditions of the raw materials, because sometimes the specific conditions of the raw materials, the positioning of the pre-size of the printing plate has a pivotal position. Such as: the size of raw materials. For example, the size of the YP-II type positive image PS plate used for the printing plate (92x76cm), the size of the cut paper used for printing (the size of the normal folio is 78.7×54.5cm, and the size of the large folio is 85×58.5cm; the size of the international version of the folio is 88.5×61.5cm. For example, the double-sided monochrome offset printing machine produced by Harbin Machinery Factory uses the size of the printing plate of 88x76cm, which is better than the normal YP-II type. The size of the plate made of the PS plate is 4 cm short, and the dimensions of the three-paper (52x54 cm) and the long three-open paper (36 x 78.7 cm) are not significantly confusing. If you don't understand the truth, you will often make mistakes. Know the size of the paper used. If the front gauge size of the printing plate is not allowed to be used during the plate making process, the size of the known core can be divided by 2 according to the known cut paper size to obtain the size of the bite. Then, combined with the data of the usual plate making, it can be calculated, so that the size of the front gauge required for the offset printing machine for this printing plate can be calculated. Because in the daily work, the offset of each offset press is generally between 1.5 and 2 cm. According to the comparison between the two, the data obtained can be obtained correctly.
In daily work, in general, the plate making is the size of the front gauge to determine the entire heart rate. However, in special cases, the printing plate cannot be placed in the middle or left or right in a certain direction. For example, there is a problem with the rubber roller on the offset printing machine or a certain part of the printing cylinder, which cannot ensure the printing quality. , but the rest are very good, in order to minimize the loss, and without affecting the quality of the printing, it is necessary to make the entire version of the plate to the left or right of the plate during the plate making, sometimes In order to take care of the offset printing machine, it is not necessary to transfer the paper ruler line, in order to facilitate printing. In addition, the cutting paper on the cutting machine can be calculated without unnecessary scraps, which causes unnecessary waste. The printing plate core will be left or left during production. Right to one side. For example, when printing three printed materials, its opening specification is 52x54cm. This kind of printed matter needs to transfer the paper-regulating ruler of the offset printing machine when printing. If the size of the paper is opened to the normal opening size, printing After cutting the unused parts, it will not cause paper waste, which can save a lot of trouble for the operators on the offset printing machine. Why not? These require the plate maker to look carefully at the subpoena before printing the plate or to know the paper they are going to print. Otherwise, if you print the plate according to the rules, it will definitely cause waste of the plate or paper.