How to use a small offset press to print color printing products - East Airlines offset printing press experience
The following links should be noted when printing in color.
1. rule
Because the accuracy of the rules is the premise of color printing, use 20-40 sheets of paper repeatedly to print three or four times before printing, and then check whether the front gauge and pull gauge are accurate. If the front gauge is not accurate, check the paper feed. Time, feed roller pressure, parallelism, timing of the feed roller and pull gauge, and gripper pressure. If the pull gauge is not accurate, check the timing, the distance between the paper gauge and the pull gauge, and the pull gauge pressure. The above adjustment can be adjusted according to the instruction manual until the adjustment is appropriate.
The printing speed is generally set to 4500 pieces/hour for printing four-color prints to better ensure the stability of the rules at medium and constant speeds.
2. pressure
The pressure mainly refers to the plate pressure and the pressure between the three rollers. The pressure during the adjustment should not be too great, nor too small, because the production of distortion, dot distortion, sticky paper, paper fuzzing, and damage to blankets, etc., occurs beyond the General Assembly. If the pressure is too small, it will result in insufficient ink, blurred graphics, unreal dots, insufficient ink transfer, etc. Usually, the width of the ink bars of the three reel rollers is 5mm, 4mm, and 3mm in order when adjustment is made. . The roller width of the plate cylinder and blanket cylinder is (new blanket) 3mm-4mm, the old blanket is about 5mm, and the pressure of the impression cylinder and blanket cylinder is about 5mm. It is particularly worth noting that the pressure of each part is adjusted properly. In the printing process must not be adjusted.
3. Maintain a good ink balance
Speaking of ink and water balance, whether in printing or four-color printing is more important, because the water is too large, it will cause the network to send false, causing the picture to be false; too small, it will cause the network to be fuzzy, the screen is not layered, and easy Winning version.
When adjusting, first adjust the amount of ink according to different layouts, and then try printing again. In the case of ensuring the adjustment of the ink color, slowly reduce the amount of water supply until the dirty version, the smaller the supply of water, the better.
Here, we must pay special attention to the fountain solution concentration and room temperature to be controlled well, in case of overnight or rain, semi-finished products can be sealed by a single color sealing film, do not let the paper damp deformation.
4. Color sequence
The so-called color sequence is to print a variety of colors, it is necessary to print in a certain order, the general order is yellow, product, blue, black, but if you print yellow first, the human eye has poor resolution of yellow, which is for observation pressure The size of the ink, the size of the ink, and the second edition of the register are not easy. Therefore, according to the ink and layout can also be different according to blue, white, yellow, black mining printing. In addition, advanced color printers can also arrange the color sequence according to the color, style, and subject matter of the screen. This does not necessarily follow the above approach. In short, the operator should choose the appropriate printing order according to the actual situation during the printing to ensure the beauty of the printed product.
Liyang Paper Products Co., ltd is a factory and trade company located in Dongguan, China. Specialized in producing gift paper packaging, such as gift box,paper box, paper bag, Jewelry box，watch box, belt box, shoe box, wine box,cosmetic box, flower box, round box,ect.
Custom made base on your design is welcome, feel free to contact Liyang printing with your full details.
│ www.liyangprinting.com
