JPS6351173A - Printing method for corrugated fiberboard sheet - Google Patents

Abstract

PURPOSE:To improve the visibility and accuracy of printing, by a method wherein the corrugation line direction of corrugated core paper of a corrugated fiberboard sheet is made parallel to the axial direction of a plate cylinder and at the same time, the line surface on the printing side is turned to protrudingly curved surface by bending a corrugated fiberboard sheet and given tension to achieve printing. CONSTITUTION:The corrugation line direction of the corrugated core paper (a2) of a corrugated fibreboard sheet (a) is conformed to the axial direction of a plate cylinder 13. At the same time, tension T is given to the line surface (a) on the printing side by making the liner surface a1 on the printing side (a) protruding surface by bending said corrugated fibreboard sheet and paper is passed between a plate cylinder 13 and a plate cylinder 14 to achieve printing. As a means of passing the corrugated fiberboard sheet (a), the group 17 of plural guide rollers arranged on the upper and lower sides can be utilized as, for instance, the guide passage of a depressed curved surface is formed on the front and rear sides of the plate cylinders 13 and 14. Further, slide members may be adopted instead of the rollers, or otherwise by jointly using them. Thus, the fed corrugated fiberboard sheet (a) is printed by receiving a printing pressure from a printing plate 15 and the liner surface (a1) of a protrudingly curved surface state is given tension T. It is changed from a released state to a strained state and flattened.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for printing corrugated cardboard sheets, which involves printing on the liner surface of the corrugated cardboard sheets.

(Prior Art) Letterpress printing presses are often used for general commercial printing on corrugated cardboard sheets, and flexible printing presses that use rubber or elastomer printing plates and quick-drying liquid inks are particularly popular. .

As shown in FIG.
) and an impression cylinder (4). A letterpress printing plate (3) made of a highly flexible material is mounted on the plate cylinder (3).
5) is installed, and the unlock roll (2) in contact with it is attached.
An ink film is supplied from 1. Plate cylinder (3) and impression cylinder (41)
A corrugated cardboard sheet (al), which is a printing material to be passed between them, is supported by the circumferential surface of the impression cylinder (4) while being passed through the liner (a) on the other side.
1) The surface is in contact with the printing plate (5), and printing is performed while receiving a printing pressure of usually 3p, s, i or less.

In recent years, there has been a movement in the corrugated board industry to make exterior corrugated cardboard more beautiful by applying beautiful printing, and there are also requirements for flatness printing such as barcodes and fine print, which require precise printing. Because of these fundamental structural problems, cosmetic printing and village printing have their own limits. In other words, if the printing material is high-quality paper or a flat object, it is possible to print beautifully and with daytime precision without any problems using current printing machines and printing technology, but if the printing material is a high-quality paper or a flat object, it is possible to print beautifully and with daytime precision without any problem, but if the printing material is a high-quality paper or a flat object, it is possible to print beautifully and with daytime accuracy without any problems, but if the printing material is a high-quality paper or a flat object, it is possible to print beautifully and day-precisionly. In composite paper with eight corrugated papers interposed between two liners (al),
As shown in Figure 3, the liner (a
In l), the rigidity in the thickness direction between the corrugated tops of the core paper is low, so when the printing press's printing pressure is applied, the liner surface of the corrugated sheet, which already collapses inward during the manufacturing process of the corrugated sheet, becomes corrugated. 8 The wavy surface has the same pitch as the wavy pitch of the paper and lacks flatness, resulting in uneven contact with the printing plate during printing, resulting in uneven shading in the print.
At present, there is a serious defect in print quality that the print quality is unclear, and it is difficult to obtain decorative prints or precision prints.

(Problem to be solved by the invention) In the conventional printing of the corrugated paperboard sheet.

Due to the lack of flatness and the difference in rigidity of the surface of the corrugated paperboard sheet (liner) that is the printing material, the printing pressure applied to the printing paper is not applied evenly to the liner surface, resulting in sharp and high precision. There are problems such as poor print quality.

(Means for solving the problem) The present invention is a corrugated sheet printing method developed to solve the above-mentioned problems. However,
The corrugation direction of the corrugated 8 paper of the corrugated cardboard sheet is made parallel to the axial direction of the plate cylinder, and the corrugated cardboard sheet is curved to make the liner surface on the printing side a convex curved surface to apply tension to the plate. By passing the paper between the blades and the impression cylinder for printing, the flatness of the liner surface on the print side of the corrugated board sheet is improved, and the difference in stiffness is reduced, improving the clarity and precision of printing. It solves problems such as.

(Function) The corrugation direction of the corrugated 8 paper of the corrugated board sheet is made parallel to the axial direction of the plate force, and the corrugated corrugated sheet is curved to make the liner surface on the printing side a convex curved surface to apply tension. Since printing is performed by passing paper between the plate cylinder and the impression cylinder, the tension applied to the liner surface on the printing side flattens the liner surface, improves the rigidity of the liner, and improves the rigidity of the plate cylinder. The printing pressure applied from the printing plate is equalized on the liner surface, resulting in clear, high-precision printing.

(Example) An example of the present invention is shown in FIGS. 1 and 2, and (
11) is fountain roll, 0? J is an unlock roll, 03 is a plate cylinder, αa is an impression cylinder, al19 is a printing plate attached to the outer periphery of the plate cylinder a3, (al is a corrugated cardboard sheet) ta + plate cylinder U and impression cylinder 04 ) and print on the liner surface (1, ).

As shown in FIGS. 1 and 2, the corrugated board sheet (a) has the corrugated direction of the corrugated 8 paper (a2) aligned with the axial direction of the plate cylinder (131 (and impression cylinder αa)), and the corrugated board The sheet is bent to make the liner surface (al) on the printing side a convex curved surface and tension T is applied to the plate cylinder Q31 and impression cylinder (14).
Print by passing paper between the two.

The paper passing means for the corrugated cardboard sheet (al) may be arranged on the upper and lower sides of the plate cylinder 0th floor, impression cylinder 04, as shown in FIG. It is possible to use the aη group of a plurality of guide rolls provided, and instead of the rolls, a sliding member can be used in conjunction with the rolls, and furthermore, it is possible to apply a pending force to the corrugated board sheet (a) by wind pressure. It is also possible to configure

The corrugated paperboard sheet faJ fed as described above is transferred to the printing plate (151
The liner surface (a
l) is applied with tension T as shown in Fig. 2, changes from a relaxed state to a tense state, and is flattened.
The resistance to the force acting perpendicularly to the paper surface is increased, and at the same time, the tension T improves the rigidity of the υ corrugated board. Uzuki 1 can withstand a large amount of printing pressure, and the printing pressure is evenly and appropriately applied to the entire printing area, so it can satisfy the various conditions required for corrugated board printing.
:] Quality is achieved.

The degree of curvature given to the corrugated cardboard sheet ta+ is difficult to specify depending on the degree of printing pressure of the printing machine, the quality of the paper board, the width of the corrugated paper, etc., so the curvature of the corrugated cardboard sheet can be determined by changing and adjusting the vertical device of the guide roll αD, etc. By changing and adjusting the curvature, the purpose can be sufficiently achieved by adding an extremely small amount of curvature, and it is preferable to keep it to the minimum necessary.The amount of deformation of the printed pattern is also extremely small and can be ignored.9 In particular, precision For designs that have specific characteristics, the printing plate can be made in advance (by making adjustments in consideration of the shrinkage allowance) to achieve a sufficient 2NK
is obtained.

The printing machines used in the method of the present invention include a letterpress printing machine,
In particular, a flexo printing machine as shown in the drawing is suitable, but any type of rotary printing machine may be used as long as it is equipped with a plate cylinder and an impression cylinder arranged opposite each other.

(Effects of the Invention) The present invention is as described above, and the corrugation direction of the eight corrugated sheets of corrugated paperboard is made parallel to the axial direction of the plate cylinder, and the corrugated sheet is curved so that the printing side The liner surface is made into a convex curved surface to apply tension and the paper is passed between the plate cylinder and the impression cylinder for printing, so the tension applied to the liner surface on the printing side flattens the same surface and increases the rigidity of the litchi. The printing pressure applied from the printing plate on the plate cylinder is equalized on the liner surface, resulting in clear and highly accurate printing.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that the design may be modified in a concave manner in a concave manner without departing from the spirit of the present invention. It is.

[Brief explanation of drawings]

Fig. 1 is an overall side view mechanical diagram showing one embodiment of the present invention;
The figure is a side view showing the state of the corrugated pole sheet during printing.
The figure is a side view of the mechanism of a conventional example. a: Cardboard sheet) al: Liner surface tL2: Corrugated core paper 13: Plate cylinder 14: Impression cylinder
172 Guide Roll Sub-Attorney Patent Attorney Shige Okamoto 2 persons Figure 3

Claims (1)

[Claims] When passing a corrugated sheet between a plate cylinder and an impression cylinder to print on the liner surface, the corrugated direction of the corrugated core paper of the corrugated sheet is made parallel to the axial direction of the plate cylinder, and the corrugated sheet is A method for printing a corrugated board sheet, characterized in that the liner surface on the print side is curved to have a convex curved surface to apply tension, and the paper is passed between the plate cylinder and the impression cylinder for printing.