The ghost image trouble of the offset printing is that someone can make trouble
1,The ink is large very much in viscosity
When ink consistency is great, the viscidity is stronger, the printed sheet produces the micro- one in the course of impressing slipperily and moves the phenomenon, very apt to cause the emergence of the ghost image trouble, when it is insufficient to especially hold the paper tooth in the mouth and grip strength, the longitudinal ghost image is more obvious. As to this, so long as close through the black craft of adjusting being easy, dilute and deal with the ink appropriately, adding some auxiliary makes the ink reduce the viscosity, can dispel the ghost image of the blot well.
2,Printing plate tighten or " The bottom cushion " Actual situation
While putting edition, because of lacking scientific operation knowledge, has not tightened the printing plate and fastened the screw evenly sequentially, so that the printing plate has elasticity that differs to tie the surface of the cylinder tight to charter, the part has micro- getting up and bending, and printing plate the intersection of the back and bedding and padding softness or part adopt many cushion or pad, make hollow borderline their little too, it is apt to cause the emergence of some ghost image situation. As to this, should through put not being easy editions of operating technology imprison and overlay, when the printing plate charters and ties tight and makes tightening, should tighten twisting the entering amount of each screw evenly sequentially gradually, must guard against, tighten right away quickly a certain screw first. Make the printing plate unable to secure against the surface of the cylinder evenly in an all-round way. On the other hand, printing plate the back add bedding and padding that cushion use, texture should hard to try hard, prevent some large cushions from or dig empty a bit, in order to get the result of dispelling the ghost image trouble.
3,The printing pressure is too big
Impress pressure among the cylinder when being partial and large as the intersection of rubber and cylinder, rubber cloth crowd, stretch the displacement quantity out of shape generals and ministers of state certainly will increase, then impress in the course the ink marks can't restore to the original state in time in the twinkling of an eye after shifting, micro- location difference has emerged while so accepting the blot from the printing plate cylinder again, have formed the ghost image. As to this, so long as lighten the cylinder pressure appropriately, reduce deforming the coefficient telescopically of cloth of rubber, this trouble can be dispelled.
4,The cloth of rubber is empty to loose or the drum arises
Receive the strength irregularity when it is tightened that the rubber cotton bag is tied tight, so that some position has not stuck to the surface of the cylinder closely, appear hollowly or the bad situation of the drum arises, and some multi-layer cushion of the back of rubber cloth is stuck or when foreign matter is adhered to, some layout blot ghost image that it is apt to make. As to this, should unclamp the cloth of rubber to check, clear up the bad phenomenon, tighten the cloth of rubber again, in order to dispel the ghost image trouble of the blot.
5,The printing plate or rubber cloth holds and inserts improperly
As the printing plate or rubber cloth has not held clamping, it is apt to cause the ghost image trouble to take place to impress and present the trace in the course loose and take off. As to this, so long as check and take the corresponding measure conscientiously, can dispel the ghost image trouble of the blot. 6,The cylinder presses work jointly abnormally
, cause the position of blot not to cause the ghost image. As to this, so long as correct, adjust well from press organization jointly again, go on and repair abrading the position, enable cylinder before pressing and working accurately, coordinated and unifying jointly, this kind of trouble can be dispelled.
7,Grip the paper tooth and hold the paper pressure in the mouth insufficiently
It is insufficient to hold strength in the mouth to printed sheet when it is abraded, out of shape that the cylinder grits one's teeth to uses, hold the paper in the mouth to impress, make printed sheet it presses India and China to be slippery to shift out trace on not gritting one's teeth, slip person who move to be the same each time, so print the next, and ink marks printed to turn have accurate overlap again because of held up in fuzzy blot at the intersection of rubber and cloth, produced and held a ghost image of position. As to this, should check the cylinder and grit one's teeth, if because deformation causes and holds strength in the mouth unevenly, insufficiently, should adjust again. If hold in the mouth the paper tooth the line is abraded and held in the mouth by the not tight paper, should pull down and change the new fittings, so as to ensure, bite the intersection of paper and tooth, hold in the mouth, slip, move by the urgent paper, hold mouthfuls of the intersection of position and the intersection of ghost image and trouble can be dispelled.
8,The gear of the cylinder or bearing is abraded and become flexible
Act as the printing machine and undergo long term administration, maintain and overhaul the work and owe serious implementation, will lead to the fact the gear of the cylinder or bearing will be abraded seriously, will unavoidably shake in the course of impressing, the ghost image of the blot follows. As to this, after should repair abrading the part ing, this trouble can be dispelled.
9,It is uncomfortable to wrap up and line the cylinder with
As the printing plate cylinder and bag of the rubber cylinder are lined with the diameter with a wide gap and too big, because the linear velocity is inconsistent at the time of each impression, it is bad and gritting, make the surface of cloth of rubber crowded to produce the speed and move and deform like this, and apt the material of liner is moved to be crinkled in making, the ghost image trouble of the blot follows. As to this, should measure the centre-to-centre spacing of the cylinder again, standardize the requirement and control the good bag to line with the thickness according to the apparatus, keep the unanimity of the linear velocity of the cylinder, avoid the production of the ghost image trouble of the blot.