One of the training seminars for flexible packaging technicians: plate-making knowledge training

Reading: Yu Dingzhao: Since entering the flexible packaging industry, he has been working at YinTeng. So far it has been 12 years. Now, YinTeng is responsible for purchasing, and has rich production experience and management experience. The manuscripts presented in this lecture are all compiled from the experience of the elites in the industry. They are willing to share with their peers and hope to help the soft pack friends in need.

The printing industry is a processing industry engaged in reproduction. Printing is a process technology that uses printing plates or other methods to transfer graphic information on an original to a printing material. Both printing and plate making are copies of originals. How to produce a good product that satisfies customers is a common concern and common concern. To produce a good product, people, machines, objects, rings, and laws are intertwined and indispensable.

one. Plate making process:

two. Plate making process:

three. Manuscript knowledge:
1, text:
The text should not be too small. It cannot be smaller than various fonts under the 4th character.
Use small lines and other lines as much as possible (same horizontal and vertical weights). Small texts should avoid using italics. Small texts should not be used as riding colors (ie, they should be clipped between reds). Small texts should not be stacked.
Red text can't be pressed on blue or green or blue text can't press on red.
There are text lines on the background or on the diagram. Small color blocks should be imprinted to avoid overprinting.
Try to avoid small texts and thin lines on the ground. This is because gravure plates can hardly take into account the depth of the field and the clarity of the text and lines.
The anti-white characters on the ground, try to use equal lines, try not to overlap.
Avoid black lettering Pressing on a dark electrical graph or on a light-colored electrical graph.
Avoid anti-white characters on the four-color electricity graph.
There should be no anti-white on the yellow or yellow on the white.
2, barcode
EAN-13 standard bar code magnification varies from 8 to 200% (can only be changed by an integer multiple of 5%), and vertical one-third can be cut off. The color of the bar code should be strongly contrasted with the background color. According to the standard, some colors should be avoided (reddish bar code cannot be done). Pay attention to the white border. The orientation of the bar code is consistent with the printing direction during plate making.
3, spot color gold, silver, etc. and a very bright royal blue, very pure purple, orange, blue, green and other colors, the general three primary colors stacked color can not achieve the desired effect, it is recommended to use a spot color. Text, lines, or logos, especially if the trademark requires a specific color, and multi-color overprinting can easily result in overprinting during printing, use spot colors as much as possible. Try to avoid large-area shallow nets below 20% and avoid uneven printing. There must be a spot color when there must be such a color, and it cannot be a very light three- or four-color overlay net.
4. Other color samples (such as offset printing and inkjet printing) other than the concave pattern can not be completely reduced due to the difference in ink, material, etc., and should have reasonable expectations.
5. The maximum number of colors should be less than the number of colors (including the white version).
6, color sequence general spot color should not be placed on the blue, goods, yellow. Usually placed before the transparent yellow, that is, black and white.
7. Light spots are generally placed on darker colors such as black, blue, and blue.
8, the transition can not do the opposite of the two-color transition superimposed (printed out is not black, is whitish).
Fourth, common sense of layout diagram:
1, the role of layout diagram: clearly marked the layout of the finished product on the roller and related dimensions.
2, Silver Teng's layout diagram provides:
Plug: outside diameter 98mm, inside diameter 84mm, taper 10 degrees, keyway 14×4.5, light blue thickness 15mm, print length 640\840\1050mm, circumference 400-720mm, mark line width 1mm×5mm, spacing 20mm, mark line spacing The edge of printing is 1mm, the last mark is 80mm from the printing direction, the detection line is 3mm from the edge, and the width of the inspection line is 2mm.
3, different bag typesetting need to pay attention to the place:
Trilateral seal typesetting a. Typography can be divided into: ↑ ↑ ↑ 正 正 正 back ←
Positive ←→Back 正正↓↓1↑↓正2↓背2↑背1
正 1 ↓正 2 ↑↑背 2 ↓背 1
Positive → Positive ← Back → Back ←
b. When two types of typesetting should pay attention to use (A positive B positive B back A back) or (A positive B back B positive B back) typesetting, that is, after folding from the middle, should correspond to the two varieties, in order to facilitate the bag, can not The two varieties do not correspond after being converted from the middle.
C. There are many food packaging bags that are single-sided aluminum (yin and yang bags), single or double version of the row, the middle to leave 5 ~ 8mm aluminum edge, the aluminum coating side must be in the middle.
2 Back-seal bags or pillow-shaped bags: Pay attention to the typographic orientation.
V. Some basic concepts of electric gravure
1. Dot gravure is a kind of plate roller that is partially concave on the layout and the blank part remains unchanged. The gravure concave pattern part is composed of halftone dots. The halftone dot is the basis of gravure, and it is one of the keys to quality evaluation of the gravure roll.
Two concepts about outlets:
Continuity Hue: Patterns in which the density transitions continuously between black and white polarities, natural color changes, and photographs are continuous tones.
Halftoning: Only black-and-white patterns are black and white, and there is no continuous pattern of density. Halftone belongs to the plate-making special terminology. Dots on the layout are halftone dots. Platemaking is the use of different sizes of dots to represent the shades of the screen, etc., and is converted into simulated tones by discrete digital dots. When printing, outlets are inked, transferred and transferred many times, and finally restored to the continuous tone of the original. The continuous tone can be made into a half-tone screen before the plate is made. The dot can be automatically converted by the computer before the electric carving. The general network consists of two parts, the network point (filling ink) and the mesh wall (supporting scraper). Network and network cables are generally used to quantitatively describe outlets.
Neting is using the area of ​​the dot to show its changing rules. In general, the whole point is set at 100% on the spot, and it is reduced to 90%, 80%, 20%, and 10%. To increase the level, half of the level difference is added (5%, 15%, ...85). %, 95%), and add one level (0.5% and 99.5%) to both ends of the halftone scale. This gives a total of 22 levels and is used to describe the percentage of the dot area.
The number of rows of outlets within the unit length of the network cable.
Corners are arranged at a certain angle, namely the net corner.
Production of gravure (including A-sheet and B-roll)
∣ → Lines (drawings) → ∣
A: Manuscript → ∣ ∣ → Workstation → Digital Information ∣ → Hierarchical (electric) → ∣ ↓∣
Electronic information ↘ 雕 镀 镀 chrome
B: Core → Machining → Nickel Plating → Copper Plating → Grinding ————— ↗
Plating (1) Nickel Plating: In order to increase the binding force between iron and copper, only a few minutes can be used for plating.
(2) Copper plating: Since the dots are directly formed on the copper surface, the copper plating quality directly affects the overprint accuracy of the printing, the uniformity of the ink scraping, and the scratch resistance. This requires the copper layer to be uniformly plated and has a certain degree of Hardness, Vickers hardness is generally 220 °.
(3) Chrome Plating: The process of chrome plating is essentially a metal crystallization process. First, the finished copper roller is placed in a plating bath and immersed in one third of the plating bath as a cathode. The electroplating solution is prepared by dissolving chromic anhydride and sulfuric acid in water, ionizing the salt solution during electroplating, separating the chromium ions, and performing a reduction reaction on the copper surface of the cathode, and then crystallizing the chromium atoms on the copper surface into metal chromium. The crystal forms a chromium layer.
Chromium plating is to prevent dot damage and enhance the hardness of the layout, increasing the resistance to printing force. The chromium layer will also affect the uniformity of the squeegee, so the surface of the chrome layer is required to be smooth, uniform, have a good hardness, and have a long printing time. The general chromium face shelf life is one year, and the imprint resistance is 50 to 600,000 turns and 350,000 meters.
7. Electric Carving Electric Carving is the use of diamond electric carving needles to carve outlets on the surface of the car's copper surface. That is: through the vibration of electric carving needles and the circumferential rotation of the printing roller, copper grains are dug out on the copper surface to form a Pyramid shaped cells are inverted, while electric carving needles are moved horizontally to distribute the dots on the layout.
Sixth, the relationship between platemaking and printing
1 printing methods and color sequence (1) table printing - the pattern on the roller is a negative image, the color from shallow to deep arrangement, the white version is at the front, play the role of the padding to increase the reflection density.
(2) India - The pattern on the roller is a positive image, the color is from dark to light, the white plate is at the end, and the substrate increases the effect of reflection density.
(2) Fixing the color sequence principle (1) Colors have the relationship of overprinting as far as possible.
(2) When the flexible film is printed in NY or PE, the overprinting relationship is as close as possible and the color sequence is at the front.
(3) spot color: the color of the text or small color, color order front. Large area spot color: 1 dark color sequence front. 2 light color sequence behind.
3 How to determine whether to use spot color:
(1) Some special bright colors use spot colors such as orange, ultramarine, gold, silver, etc.;
(2) If the fine text is overprinted with 2 or more colors, use spot colors, otherwise the overprint deviation will affect the effect.
(3) In the case of a large-area color patch, it is recommended to use a spot color. Otherwise, the color of the patch will be affected when adjusting the pattern effect, resulting in color cast.
The 4th version of the roller is the imposition of the unit pattern in both the horizontal and the circumferential directions. Therefore, the following principles should be applied to the selection of the layout width and the perimeter:
(1) If the conventional material is as far as possible in accordance with the widest material row, strive for the highest material utilization;
(2) If the special material is as far as possible according to the standard width of the stock, avoid the backlog of repurchased and unused materials;
(3) Within the allowable perimeter of the printing press, as far as possible to the large circumference of the row, this is conducive to speed up, improve efficiency, but also conducive to improving the shallow network transfer (this point is worth in-depth discussion). But it is emphasized that do not rely on the maximum value, because if the perimeter is too large, the plate roller is basically full of ink, but it will easily cause ink blistering, affecting the printing effect.
The best match between the 5th version of the roller and the ink is to print the best product. How can we improve the platemaking process by taking into account possible defects in the printing process? Here are some simple common examples:
(1) For the color of the anti-white silk, such as special coffee, special green, special blue, etc., it is considered to deepen the carving in the plate making process, of course, it can not be too deep, it is best about 45um, and strengthen the chrome surface polishing.
(2) For the first point, if there are spot color texts outside the spot color block, then it is not enough to consider deep carving. Because deeper carving can easily cause text edge glitches, it is necessary to separate the spot color version from the two. Sub-engraving, text on the use of shallow mesh type craft carving.
(3) There may be contradictions for such spot colors with anti-white text, because deeper carving will avoid text blemishes after drawing. If you do this, you can only look at the customer's requirements, and avoid the weight of light to achieve the best results. .
(4) For areas such as blue and special blue that tend to appear coarse around 80% of the net, when confirming before the platemaking, customers should be advised to increase to 90% or reduce to 70%.
(5) The inks of different types of different manufacturers are basically different in hue, and some differences are still relatively large, such as alcohol solubility and benzene solubility are obviously different, so you should consider using different engraving curves, so as to achieve the most Good reduction effect.
Seventh, business related layout diagram:
Receipt standardization requirements:
All contents must be marked in a comprehensive manner. If there are special signs, photoelectric eye cross lines and other details require the customer must mark, the manuscript is based on the actual number drawn;
If it is a tube material, the front and back contents of the side seal must be marked separately, not only one;
All widened engravers can be marked with inner widened widths, except for the glossy version and the original version.
How to arrange multiple varieties must be illustrated in detail;
In the new order, the column of the relevant roller must be clearly marked and cannot be written (especially the plug).
If there is no such content in the technical requirements column, it must be drawn;
For the chief editor, if the margin is less than 35mm, a written application is required for registration;
Regarding the effect of electricity distribution: The effect of electricity distribution can not be written better than the sample of glue. It should be marked as follows:
According to the best disk tuning, there are color draft (skin or print);
Chasing glue sample (print or color draft);
There are special requirements such as: "Grade level is better than good, good clarity, etc.", fruit map can be written "attractive and delicious."
For special requirements:
1a. Whether the customer has been printed and there are no new requirements this time. b. Changes must be marked with specific changes.
2 For large-area entities, there are anti-white characters, so be sure to ask who will protect the customer.
3 There are depth requirements, depends on whether the factory process is achieved. (or specify the deepening network)
4 Some colloidal or print samples have a large difference in chromatogram from that of the plate making factory (such as sapphire blue). When answering the manuscript, first ask the customer whether or not to look at the color setting or proximity of the sample.
5 If the substrate is never seen before, be sure to first ask the customer what substrate is equivalent to the substrate or bring the substrate back to the company's technical department.
6 pillow bag must provide pillow size, or change the bag type to unit price.
7 If the original roller is modified, if it is pulled back at the same time as the deplate, the rework will be indicated on the power of attorney for distribution and release.
8 Do not mark white or not under non-black 100 spot.
9 full version white special label.
10 For the company's internal inspection area, be sure to ask whether the customer is painted or coated or revised.
A. (In India) 70 line spot color spot out the most serious: 75 net into.
B. (table printing) 60 line spot color to find out the most serious area: 65 net into.
The above range can't be done within 5 nets.
11. The gray color of the three-color display is easy to color. When the user drafts, he or she must ask whether the customer can change to a single-sided net.
12. Color can not be written by the disk, can be written according to the color of the manuscript to check color or by glue or sample.
13. Due to inaccurate editions, if the originals have white borders, they should be bold (more than 0.5mm) when they are thin.
14. The client put forward "a little bolder words" to clarify two points: A. Whether it is a bit bolder or not means that the lines are clear, B. If it is not only clear, how much is required to be bold?
15.10% or less of the color to give customers do not do, whether the proposal can be achieved through the transfer of ink.
16. Changes can not be written in accordance with the disk, can be written specifically to change what. The plate has changed.
17. Even if the black draft can not be used as a standard color basis, the color basis can only see glue samples, color drafts or printed samples.
18. If the customer's white version is rather special, such as transparent, white, etc., and the original is not intuitive, we must allow customers to specifically mark, can not be written in accordance with the disk.
19. Look like what kind of standard, what size.
20. The light spot is in contact with the color patch in the circumferential direction. When the upper (or lower) surface is transparent, the light spot should be 2 mm away from the color patch so that no cropping or light spot can be cut due to sizing.
twenty one. A. If it is 13 barcodes, you must not write the last digit. When the last digit has no digit, add “X” to it. B. If you do 12-digit barcodes, write 12 digits.
Relevant written basis:
When the customer bases the shield, it must be faxed by the customer to prove what the basis is. If the customer has more than one copy of the transcript, it is necessary to clearly define what the genre should do. If the customer's original manuscript is obviously wrong (such as the word is wrong), if the business thinks that there is no need to modify it, the business must be signed, and if it is changed, the customer can prove it in writing! Different manufacturers borrow files must be issued by the relevant manufacturers commissioned certificate, otherwise it will not be drafted. Where there is incomplete information on less maps, less color drafts, etc., the version factory will not make orders. If the roller is required to be 25mm from the edge, it must be written in advance and signed by the manager of the plate factory to make the plate. The revision must be printed or the original roller can be registered. The original power of attorney must be signed by the customer to make the plate.
Others: The original proofing, the power of attorney must have the substrate, color sequence, the surface and India printed three content. Revision or remake. If there is a copy, check the injury.
Business drafting requires special considerations:
Very shallow net (near neutral gray) but requires four-color overlay. Such as milk, snow scene must pay attention.
The two-color transition of the opposite color is superimposed. At this time, it is not blackened or white.
In order to separate the color from the printed sample but need to strictly follow the sample, the color separation with the printed sample will be effected according to the sample; the sample is the secondary manuscript (all the originals are the secondary manuscripts). There are many outlets in the sample, and they are used as the basis for platemaking. In the scanning process, the electricity distribution personnel must first remove the outlets on the grid. This will affect the subtle level of the picture. There will always be differences after the separation, and in most cases it will be worse than the printing sample. It is advisable to look at the samples. In addition, the printed samples should be used for color separation. In the case of printed samples, certain printed samples must be brought in, and no running version is required. It is flat and brightly colored.
Strictly follow RGB ink-jet proofing. Because the hue of the ink is different, the glue sample can not catch up with some hue, such as a very bright purple, or there is a very bright royal blue on the sample. These gravure inks will appear dark when printed. Not bright.
On the printed sample is a spot color of pure purple, blue customers do not do spot colors, use color separation to hit.
The black characters are pressed on the dark electrical graphs, or the light graphs have anti-white characters.
There are anti-white characters on the four-color electricity graph.
There are disk files, there are transcripts, but disc files and transcripts are too different.
For black lines, color blocks, and shadows, the color of the three-color collision is best changed to single ash.
There are glue samples, film, usually customers will have electronic documents, it is recommended to copy, if there is a film separation, the effect of the film according to these conditions, the electricity will often ask two questions: 1 when the film size exceeds 43cm * 30cm , Electron scanning to cut off film 2 because the film itself is black and white, it is recommended that customers look like.
When using photographs, negatives, glue samples, seals, and film separations, the magnification should not exceed 150%, because the image quality will become thicker and the effect will be worse.
The manuscript used for color separation should pay attention to the thickness, generally not more than 2mm.
With disk power, the quality of the disk is poor, and there are two cases: 1 The resolution is not up to the requirement; 2 The resolution meets the requirement, but the graph itself is too bad, and the graph is coarse and the level of detail is very vague.
The use of several spot colors for more complex electrical subgraphs, because the spot color printing in the proofing, variability is very large, difficult to print, can use color separation as far as possible to do electricity sub-graphs.
In drafting, some lines should pay special attention. Scratch proofing does not have more advantages. The burr lines are more serious, and the glue sample body uses water-soluble ink, which is not conducive to preservation. Therefore, it is not appropriate to use glue samples as the basis for plate making.
Eight, conclusion
This article describes some common sense and production experience of gravure platemaking. Friends who are interested in the flexible packaging industry can begin to understand the entire flexible packaging production process from the gravure printing plate. Thus knowing what to know and knowing why, when there are problems in production, it is possible to have a very clear idea of ​​where to solve the problem.