How to improve the quality of carton printing?

As we all know, the key factors affecting product quality are equipment, raw materials, personnel, and the environment. The same applies to the carton packaging industry. Many companies are commendable in order to create high-quality brands, spare no expense, update equipment, carry out technological advancement, strictly control the entrance of raw paper to the factory, and sincerely recruit talents from all over the world to improve the working environment. However, they are good at research, good at creating, and good at doing. Interested people will also benefit greatly. Here only a brief description of the experience of improving carton quality from the point of view of ink printing.
First, to ensure the clarity of printing First, the printing plate should be made of wear-resistant, moderate elasticity, and high quality materials. The thickness of the same plate should be the same, the thickness of the resin plate should be no less than 4mm, and the rubber plate should be 6~7mm. . Regardless of whether it is using a dark film or a handmade knife, the layout must be neat, the pattern should be neat, the depth of the lines should be no less than 3mm, the arrangement of the text patterns should not be overcrowded, the arc should be sleek and uniform, and the straight lines should be straight and smooth. . When printing, the ink should be properly lightened, the ink layer of the ink coating roller should not be too thick, and the pressure of the roller is moderate, so that the printing ink is even and the surface of the ink box has no obvious dent. Do not increase the ink concentration, increase the pressure of the ink roller to improve the printing effect. This not only fails to achieve the ideal purpose, but causes the printing area to be smeared and the printing quality is worse. Especially the text is small, the pattern is complicated, the lines are delicate, and the printing requirements are High-precision layout, the disadvantage is more obvious; printing speed can not be less than 800 rev / min, too low ink in the box uneven, and there is a phenomenon of exposed bottom. Too fast ink is too thick, the layout is easy to blur, but also to prevent paper hair, paper scraps, etc. into the printing press stick to the printing plate, if there is a piece of paper glue sticking, to stop immediately, wipe with a rag and dip in alcohol.
Second, the printing color should be pure, the quality of bulk colorless water-based ink is related to the carton printing the key to pure, bright, so be careful when choosing. There is no significant difference between high-quality ink and color scale, delicate touch, sticky silk, concentration suitable for water or alcohol solvent dilution without precipitation, agglomeration phenomenon, stirring with a wooden stick without foam, mixed with other ink color, good affinity, no phase Solubility, pure ink, no abnormal reaction. On the contrary, it cannot be used.
It is best to print batches at one time when printing, otherwise, the same barrel of ink is used, and color differences also occur. The reason is that the original ink is diluted with water or an alcohol solvent and is not sealed. When it is exposed to the air for a long time, the chemical components in the ink react with the oxygen in the air, that is, the pigment is reduced, and the strong light can also decompose the ink.
Third, to prevent the application of whiteboard carton printing overprinting, ghost coating whiteboard paper in the manufacture of coating liquid for coating whiteboard containing glue, high-grade white paper surface also coated with a small amount of coating wax, so use whiteboard to do When the carton of cardboard is printed, slippage occurs at the instant when the plate comes into contact with the whiteboard. In addition, the pressure of the printing plate is too heavy, the water-based ink is not easy to infiltrate, and the printed carton ink is dried slowly. The printing job is continuous, and the printing products are stacked one on top of the other.
To solve this problem, the ink should be lightened with ethanol, do not use water, because it is not volatile, is not conducive to the drying of ink; printing pressure is properly reduced, the printing speed should not be too fast, not more than 600 rev / min is appropriate. Before the stacking of printing presses, an exhaust fan or hot air drying box ink is installed.
Fourth, to ensure the accuracy of overprint Overprint accuracy first depends on the precision of the device and the adjustment of the paper feeding section to push the paper board is parallel, in addition is the layout production, assembly, correction. The following is a discussion of overprint accuracy in terms of layout collage.
After the plate is ready, take a piece of 0.5mm thick transparent polypropylene plate, draw a vertical line at the center of its length, and then press the size of the carton to be printed, draw a line with a small stroke to draw the length, height and height of the line, and press the sample or sample box. Production notices stipulate imposition. After positioning the layout, use the pen to draw the line on the edge of the printing plate. After that, the same size plate base prepared in advance is overlaid on the base plate of the well-drawn line, and all edges are accurately traced (for example, three colors can be used to overprint a plate base). ), Finally, press the printing color, and the corresponding printing plate is firmly stuck in the painted position with neoprene. Then use the double-sided adhesive to attach the printing plate to the roller of the printing machine. The center line of the printing plate can be aligned with the centerline of the platen roller of the printing machine. As long as the position of the imposition is accurate and other objective conditions are satisfied, overprinting is accurate. 
Fifth, the impact of full-version printing on the strength of the carton We know that when the carton is printed, the corrugated cardboard is formed by the paper guide rollers and printing rollers of the printing machine, and the paperboard is pressed by the rollers during the transfer process. Changes in the physical properties of different procedures will inevitably affect the strength of the carton. Full-plate printing is particularly prominent. Compared with no-printing, the cardboard box of the same material has to be reduced in strength by about 30%. Therefore, it is necessary to pay great attention to the production process. The following measures can be taken to ease it:
First, properly adjust the gaps of the paper guide rollers of the printing press so that the paperboard passes smoothly without deformation (slightly smaller than the paperboard thickness of 0.1-0.15mm);
Second, the pressure of the printing plate can be adjusted to meet the requirement of clear printing.
Thirdly, the speed of the printing press should be properly increased (above 1000 rpm), so that the board can pass through the printer as soon as possible to reduce the time for the board to withstand the pressure.
Sixth, carton leakage version of timely printing in the actual production of the printing machine without a computer calibration device, due to the operator's careless word missing version of the phenomenon is difficult to avoid. After similar things happen, remedial measures should be taken promptly. If only the notch is cut, the slotted knife can be unloaded, and the missing layout can be subsidized to the corresponding position. Then the other steamed plates can be unwound and can be reprinted, but avoid the speed too fast. Ineffective or layout moves. If the printed carton has been nailed, in addition to dealing with the layout in accordance with the above method, but also adjust the gap between the guide roller to the shape of the carton after the smooth deformation is not appropriate, the printing roller pressure must be adjusted, and then transfer the paper Baffle, determine layout position, single delivery when printing.
Seven, thin cardboard printing notes so-called thin cardboard, that is, D, E fine corrugated cardboard, these thin cardboard after the printing of the application of flat pressure die-cutting machine stamping, due to small quantities or customers only once, plus a die-cutting knife The cost of the plate is high, so the printing slotted shape is used in production. In actual operation, because the paperboard is too thin, the printing speed must be slowed down, but the paper feeding device is not difficult to push paper, that is to push multiple paperboards at the same time into the printing press, resulting in a lot of waste. To solve this problem, you can use a single machine to slot, then print after binding and forming, but according to the two sides of the carton, different loading plates must be printed twice to complete a complete layout of the carton.
Eight, warpage cardboard to prevent the run version, slotted to take place on the warpage of the cardboard printing to take a single sheet, low-speed operation, while the appropriate increase in the amount of suction, depending on the layout, slotting in time and move the printing plate slotting phase Forward and reverse correction. Warp severely selected cardboard, every 3 to 5 positive and negative stacking with the weight of flattening reprint next time, or folded along the indentation line to the opposite direction of warping folded again.
In short, in actual production, under specific circumstances, we must also be flexible in dealing with objective conditions. The above is for reference only, because the author's level is certainly limited, and is willing to discuss with peers.