29 printing common sense

       1. What is the meaning of quality?What is the meaning of the print quality?
Also called quality quality, reflect the products or services, characteristics and features of the ability to satisfy stated or implied needs.
Print quality is refers to the print quality of printing technology in the process of copying, including absolute quality and average quality.
       2. Color print quality requirements which a few main areas?
Overprint accurate, uniform ink bright bright and full, rich layers, branch, field flat, clear text, no stroke is short of break, no apparent streaks, non greasy's's paper, no hair, no ink phenomenon such as skin and loyal reduction in the authenticity of the manuscript.
       3. What is the difference between offset printing and other printing?
      (1) using the basic principle of oil and water will not mix to complete printing:
      (2) is in the same plate blank parts and basic on the surface, and selective adsorption of water and ink;
      (3) through the intermediate (rubber cloth roller) to mark:
       (4) is presented by dot size order.
        4. Offset printing process principle is what?
Offset printing is to use the basic principle of oil and water don't mix at the printing effect.Press water first, make the layout of the blank part of the adsorption of water, and the image part is repel water.Inking, blank part rejection and the image part is adsorption ink printing ink.

       5. What is the ph value in wetting liquid?
Ph is said wetting liquid contained in the content of acid, alkali value (concentration), with the hydrogen ion concentration of negative to the numerical solution of acid and alkaline.Ph = 7, neutral solution ph > 7 alkaline solution, ph < 7 acidic solution.
      6. Production of wetting liquid ph value should be controlled in the range?
Ph in the ps version of wetting liquid, general control in 5 ~ 6 is advisable.
      7. The wetting liquid, improper control of ph value, have any impact on the quality of the product?
Strong acidic: easy cause plate flower version, the smaller branches, reduce the plate printing endurance, ink emulsification, easily causing imprinted on the back is not easy to dry, product quality problems such as dirty.
Weak acidic: plate network easy to paste, and easily, and easy to dirty, paste version and dirty.
What is the distinguishing feature of 8. Alcohol wetting?
     1) good wettability, the board has good spreading properties;
      (2) because alcohol is volatile, layout of water transferred to the rubber cloth, water has a certain degree of volatility, so the water absorbing capacity of paper will reduce;
      (3) alcohol in volatile, can take away a lot of heat, make the space temperature is reduced, guarantee the flow of the ink performance.
     9. What is the role of wetting liquid in production?
   1) can't afford to make the blank part is dirty and greasy (not fat);
   (2) by hydrophilic colloid and organic acids can keep blank part good hydrophilic;
   (3) by surface active substance and surfactant, the blank layout part only need less water, can make blank parts are protected, is conducive to ink balance;
   (4) through the buffer solution (with ion effect) wetting liquid ph stability.

    10. Printing, the layout of water size and product quality have what effect?
Printing operations in the layout of moisture control diao;When, cause moisture slants big, prone to product the inky light, ink without luster, color, bright colors and version easy flower version, printing ink emulsification, at the same time can cause paper expansion deformation, cause quality problems such as misregister;And moisture slants small, easy to make the layout on dirty or greasy and outlets and even and paste and other quality problems.
     11. In the daily production requirements of the ink balance is what meaning?
Ink balance is refers to under certain conditions, adjust the supply of wetting liquid, make the ink emulsification quantity control in the smallest range, with the least amount of water and the amount of ink, the ink plate image should be.
   12. How to achieve ink balance at work?
    (1) plate should have good hydrophilic and oily, has good stable foundation and adsorption.
    (2) should have good even thickness of sand holes mesh, with good water storage function of the plate, and to have stronger resistance to mechanical abrasion performance.
    (3) workshop has the good production environment, the workshop temperature, relative humidity pushed.
    (4) uniform machine is normal, not fast and slow.
   (5) should have good paper and ink.
   6 plate picture and text part of the ink layer thickness is 2 ~ 3 um, blank portion of the water film thickness of 0.5?1 um.Ink contains the amount of wetting liquid was 15% ~ 26%, the biggest is not more than 30%.
     13. What is the gauge wire?
For plate making, printing, cutting, binding line prepared various shapes needed is called the gauge line, also called specifications.
     14. What are commonly used gauge line?
Generally a school edition specifications with the Angle of the line, drag a line, overprint with reticle, binding with the tangent, cutting knife line and net tangent, etc.
    15. What are the main factors that cause misregister?
Cause misregister, generally there are mainly four factors:
    (1) process improper operation caused misregister (generally refers to the transfer of the machine when debugging time and location wrong);
    (2) mechanical equipment wear and tear caused by misregister (generally worn parts such as bearings, gears, shaft sleeve, and other related parts, etc.) :
    (3) material reasons (with paper texture and wire lock and so on);
    ( 4) puzzles (no (printing film in front of the small patches is not straight).
    (5) plate deformation plate version because of the pull force is too large, when the plate deformation caused by);
    6 other aspects such as weather mutations cause production environment temperature and humidity change cause paper serious deformation, lead to misregister

   16. Four-color machine misregister and single, double color printing misregister have why to distinguish?
Single, double color after misregister is a color with the color with circumferential and axial overprint is not straight;And four-color machine misregister meaning is refers to the four color printing overprint accurate, but before and after the position of the printed sheet gauge line is not in the same position, press do not have a unified specification (circumferential and axial), which is told by bite or white edge at the side gauge size have differences, is generally not easy to find.
    17. In terms of j2108 or model j2205 offset press, the paper from the paper feed shelf to former gauge to complete printing to paper platform comprises several transition?
    (1) the paper before the arrival of gauge transition;
   (2) gauge and side gauge before handover;
   (3) lateral gauge with paper teeth transition;
   (4) paper teeth and embossing grind transition;
   (5) imprinted grind and pick up paper teeth to handover.
   18. There are several kinds of common rules before a form?
On a swing top rules and regulations before swinging her two forms.
    19. The common forms of paper feeding device has several?
On a swing under the paper feeding device and swinging paper feeding device in two forms.

Swing on the top regulation characteristic is what?
Pendulum on the gauge block version before only in the former paper slightly left after losing the cardboard to enter full zhang positioning location, and the positioning of the paper work, its positioning time depends on the roller diameter and the dimension of a paper size.
     21. The swing top regulation characteristic is what?
Rules without etc before the paper to drag a little margin left lose cardboard location position, can work on the paper.So in the same conditions, using the pendulum under the provisions of a time long before, positioning stability is good.
    22. What are the typical features of swinging paper feeding device on?
    1) trajectory like a drop of water closed curve, eccentric device is used to complete;
   (2) the paper returned device can avoid the roller surface.
23. What are the typical features of swing downward paper feeding device?
    1) centering swing, trajectory is circular arc form:
Sway

(2) than on paper more than a paper roller, adopts eccentric structure, avoid paper with roller device returns a collision.
24. The paper tooth movement characteristics in daily work is what?
    (1) paper tooth row in the former gauge sheet when at rest or relative stationary state;
    (2) the paper feeding speed is smooth acceleration (range from zero one roller surface linear velocity);
    (3) paper tooth row paper handover with roller at the same point of tangency, and then the two opposite direction, but the surface velocity equal, which is relatively static state transition.
25. What is the movement characteristics of high-speed slitter body?
Two (1) using an eccentric CAM structure, reduce paper axis force, good stability;
    (2) adopts pneumatic type structure, the use of internal pressure and the change of song control suction nozzle and the whereabouts of ascension, make suction action right;
    (3) guide groove structure is used to complete the movement of the paper-feeding suction nozzle, can control paper skew;
    (4) the use of rotary valve, valve core and valve seat matching with high accuracy, at the same time, adopting the lap joint structure is advantageous for the valve spindle with paper axis and dismantling.
26. The embossed paper grind and grind at the turn of the synchronization request is what?
    (1) to complete the grind transition time to ensure that:
(2) grind the handover mouth no broken paper edge;
    At the turn of the pet-name ruby grind effect to ensure overprint accurate enough.
27. What is a printing pressure?
Put the plate on the graphic part transfer ink to printing substrates by positive pressure said printing pressure.
What kinds of representation. 28 printing pressure have?
     (1) surface pressure;(2) the line pressure;(3) the compression quantity;(4) the contact zone width said.
29. What is the ideal pressure?
Using the minimum force and the dot size required to achieve consistent with the original pressure for a noble ideal.