Talking about the design points of paper gravure printing
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
First, gravure prepress design
1. Conceptual design
The packaging products designed by a good designer should be beautiful and elegant, the pattern should be able to play a good role in the promotion of goods, promotion, the text should be simple and clear, and the ink must be coordinated, so that people feel at first glance Read it as if it were immersive.
Since the designed packaging products are ultimately copied by the printing machine, the design of the printing method, the printing color sequence, and the accuracy of the equipment should be considered in advance by the designer.
2. Problems that must be understood during design
When designing paper gravure prints, it is necessary to understand the performance of the gravure press, the type of paper, the printability, the overprinting accuracy, the printing color sequence, and the reproducibility of the screen printing (the gravure printing machine has limited reproduction effect on the network version). In particular, transition dots are easily lost in high-speed printing, and the paste is more serious) and the characteristics of gravure. After the chest is well established, the designed product can be adapted to gravure printing in order to be perfectly reproduced.
Second, gravure prepress process arrangement
1. Process review
For the craftsman, the process review is extremely important. Regardless of the newly developed design products or the pirated products, they should be carefully reviewed. Because it helps to open up ideas, prepare for post-printing, and guide the route for production. The craftsman must also understand the performance of the gravure printing equipment, master the urgency and inconvenience in the printing process, and even the operation technology, think of the customer's thoughts, the urgency of the customer, and systematically carry out the pre-press printing process arrangement.
2. Color sequence arrangement
The gravure ink layer is thicker. If the color sequence is improperly arranged, the ink after printing will completely cover the previous printing ink color. Therefore, in the gravure printing, the arrangement of the color sequence is particularly important. The arrangement of the color sequence should be performed according to the type of product, the printing effect to be obtained, the depth of the ink, the degree of hiding, and the type of ink used (pigment type, dye type, special ink).
The principle of determining the first color:
2.1 If the substrate is aluminum foil and the customer has high color saturation requirements, white should be used as the first color.
2.2 If the substrate is ordinary white cardboard, the ground color should be ranked first in the absence of special requirements.
2.3 If the background color is overprinted by dark ink and clear ink, the dark ink should be placed in the first color (if the substrate is imitation metal paper).
2.4 If the text or pattern is light and has a trapping relationship with the background color, the light color should be the first color, the back color should be printed, and the text or pattern on the light color plate should be larger than the required size. Mm, in the dark version, the text or pattern is hollowed out according to the required size to facilitate printing registration.
3. Typesetting
According to the printing format of the equipment, the printing plate based processing drawings, and referring to the sample size, a reasonable typesetting (imposition) is carried out. Generally take a tight spelling method, if there is deep processing hot stamping, embossed lines, you can add 5 ~ 6mm knife in the middle. Because the bronzing or embossed lines are long, the quality of the long-line hot stamping, embossed and padded copper is not high. If the pressure of the hot stamping machine is uneven, the operator's pad (regulating pressure) is relatively time-consuming. It is longer.
Typesetting example: The product is a flip-top cigarette pack, which is printed on the BOBST-820 gravure printing machine. The tobacco factory adopts FK-type packaging machine. The single-size size is 249mm×98mm, and its imposition map is shown in Figure 1.
4. Plate making requirements
According to the sample, layout, customer requirements, basic processing drawings, the specific process parameters for making the gravure plate are as follows:
(1) The plate cylinder has a wall thickness of 12 to 15 mm.
(2) The thickness of the copper plating layer is 1.2 to 1.5 mm.
(3) The hardness of the copper plating layer reaches HV190.
(4) The hardness of the chromium layer reaches HV950.
(5) The surface finish of the chrome layer reaches 8 to 10 levels.
(6) The dynamic balance of the plate should not exceed 0.3 mm.
(7) The plate is incremented by 0.02 mm according to the printing color sequence.
5. Ink development
From the large ink factory to the small ink company in China, the gravure printing inks produced by the company have basically met the requirements of printability. However, for printing companies, it is not enough to meet the printing suitability requirements. It needs to be tested several times to meet the actual use requirements. First of all, before the production, the ink should be hue, saturation, printability, post-press processing suitability, friction resistance, high temperature resistance, leveling, adhesion and folding, light fastness, water resistance, bronzing suitability Wait for the emphasis test. Neglecting any point may bring difficulties to production, fail to achieve the desired input-output ratio, and may bring difficulties to subsequent packaging, causing packaging users to have a sense of distrust of the printing enterprise and even lose the market.
6. Formulation of gravure process sheet
The gravure production process sheet plays a decisive role in production. Each process item must be carefully and clearly listed (see Table 1). Only in this way can the production workshop implement the planned production step by step according to the quality standards required by the product and turn the quality off.
There are many studies in the gravure prepress design and process arrangement that need to be studied carefully. There are many problems worth exploring. It needs to be flexibly changed according to different products and different requirements.