Taping the performance characteristics and causesPrints appear parallel to the axial, two-tone streaks ink imprinting, known as the printed bars, commonly known as bars, stripes, halftoning, section head, this is a more common offset and printing problems that cannot be solved. If taping slightly, there would be no impact on the overall picture, but if it impairs the screen accuracy, effect, or the customer does not accept, you must find a way to exclude. Completely ruled out is not easy, if not impossible, to minimize the consequences can only be.
most often caused by a variety of factors, it is difficult to identify and rule out all at once. According to the phenomena and characteristics, taping can be divided into two kinds of situations.
1, ink dot irregular increases, elongated, heavy shadows, ink increased, forming a distinct dark streaks, known as color bars, usually in print lines, words, outlets and field of an image appear.
2, water bar in the taping occurs where image dot irregular reduction constitutes an obvious pale streaks, known as the water poles, also known as the white bars, and colorless white bar is due to ink thinning or dot narrowing caused by Western blot. Both bars are made of rubber, water rollers and plates, caused by a bad contact on the surface.
due to printing version drum, and pressure printing drum of Windows in and face conversion of process in the produced collision, and impact, cam, and Rod, institutions in inertia role Xia will vibration, and drum work outside round surface no longer do, speed uniform scroll, so in ink roll and printing version Zhijian, and printing version drum and rubber drum Zhijian, and rubber drum and pressure printing drum Zhijian, are will produced tiny of slip, and damage ink balance, for ink layer rupture and effect ink layer of thickness, led dot increases or narrowed, in parallel Yu drum axis direction appeared taping. High machine speed, taping the phenomenon is much more serious. Include the following three aspects.
1. Design roller position unreasonable, oscillating rollers reversing is not performed while the drum break into the roll, wall panels, rollers because of insufficient strength and rigidity and deformation.
2. precision gears, eccentric sleeve, roller Assembly accuracy is not high, the smoothness of the mechanical movement.
3. dynamic load dynamic loading effect on ink is the imbalance between rotating parts rotate, mechanism of reciprocating motion to vibrate and accelerating impact of cam mechanism. Factors with the taping of embossing, ink, wetted parts of rollers, bearings, rollers gears, main drive gear, gears, rollers and ink roller, rubber roller, water roller, gripper cam, rack, and chassis Assembly and adjustment of the machine. These parts error when printing directly to most forms, taping the extent of overall evaluation is also on the accuracy of an offset printing press.