Factors affecting the quality of cardboard printing

Cardboard bending refers to the cardboard in a large range of convex or concave. If you make a carton with bent cardboard, it will not be square, affect the appearance and have unstable compressive strength. Curved cardboard is not easy to stack, can not smoothly into the printing machine, seriously affect the printing effect and slotting die-cutting accuracy. The general requirement of cardboard bending can not exceed 15 ‰. For example, the bending height on the length of 1m cannot exceed 15㎜. Therefore, in the production process, the bent cardboard should be produced separately from the flat cardboard. The bent cardboard is folded and flattened by the press line or steam spray before production.

Paper absorption of ink, mainly depending on the tightness of the paper between the fibers (the size of the gap). When the paper fiber gap between the small, because the broom fiber is too little, so that the role of fiber capillaries are affected, resulting in paper on the ink absorption is reduced; if the paper fiber gap is too large, it will be too much absorption connection material and cause the ink pigments are absorbed together, so that the print appears through the phenomenon of printing. Paper can be used for printing smoothly and with high quality, depending on the suitability of paper for printing. Printing requirements for paper are: paper shades as far as possible to achieve the same texture of color purity; paper dust degree shall not exceed the allowable range, with a minimum of light transmission, and have to ensure the normal printing of mechanical strength; paper thickness, tightness, structural characteristics, etc. to maintain the same in the same printing batch; paper edge should be right angle and slope error can not exceed ± 3mm.

Paper in storage, printing and other processes, will be different because of the surrounding environment and various changes. Such as under the action of external forces, will instantaneously change their shape and size, and when the external force stops, the paper will return to its original shape and size, this deformation process is called sensitive elastic deformation; when the paper is subjected to external forces in a certain interval of time to change their shape and size, the external force to stop acting slowly back to the original shape and size, this deformation process is called hysteresis elastic deformation; when After the cancellation of the external force, the paper is still maintained in the external force caused by the shape and size of the deformation of the state, known as plastic deformation. Sensitive elastic deformation, hysteresis deformation is a reversible deformation, and plastic deformation is not reversible deformation. The amount of water content of the paper directly affects the quality of the print. Too much water content, the strength of the paper will be reduced, under the action of external forces, the paper fibers will be pulled out, so that plastic deformation is enhanced, so that the drying speed of the print is affected; such as too little water content, the paper will be brittle, easy to cause breakage, static electricity, etc.

The surface strength of the paper determines the paper in the printing of its surface wear resistance, resistance to powder, resistance to linting, etc. has a decisive impact. Printing in order to get a clearer dot, will use some higher viscosity ink, if the surface strength of the paper is not enough, it will be easy to fall off powder, hair phenomenon, and adhere to the surface of the plate; if the use of lower viscosity ink, in lithographic printing, will be due to ink and fountain solution emulsification, thus causing the printing plate blank place soiled.