JPH0313063B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a continuous multicolor printing machine, and more particularly, it relates to a continuous multicolor printing machine, and more particularly, to a mesh belt formed by electroplating as an endless belt for conveying a substrate to be printed. This invention relates to a continuous multi-color printing machine that is used.

(Prior Art) Generally, various printing apparatuses such as gravure printing and rotary offset printing are used as means for continuous multicolor printing on long substrates such as paper, various films, and metal foils.

However, in the screen printing method using stencils, there is no appropriate method for transporting the substrate to be printed to ensure registration accuracy, and in order to perform multicolor screen printing, it is necessary to transfer the substrate in sheets. Printing is carried out in the form of a sheet while changing the plate for each color, or printing is carried out continuously by intermittently pulling the base material a fixed length at the rear of the printing area.

Therefore, in the former method, productivity is naturally very low, and printing on long substrates is completely impossible. In addition, in the latter method, tension is applied to the base material, which causes the base material to expand and contract. Accurate printing is limited by the base material, and large-scale equipment is required to keep the tension of the base material constant. control is required.

On the other hand, a different example of such continuous multicolor screen printing is an automatic screen printing machine for textile products. In this case, an endless belt is used for transporting the substrate, to which the substrate is glued using a suitable adhesive, so that the substrate belt becomes completely integral and provides an intermittent drive for constant feed. Therefore, the feeding accuracy, that is, the registration accuracy is maintained high. However, when the base material is paper, film, etc., even if adhesion is possible, peeling is difficult or impossible, and therefore a conveying method using a belt cannot be adopted, which is an obstacle.

(Objective of the Invention) That is, the object of the present invention is to achieve precise printing accuracy by adopting the same conveying method as an automatic screen printing machine without adhering even to substrates that cannot be conveyed by adhesion with an endless belt. The object of the present invention is to provide a continuous multicolor screen printing machine having the following features.

Another object of the present invention is to provide a continuous multicolor screen printing machine that uses a mesh belt formed by electroplating as an endless belt for conveying a substrate to be printed.

(Structure of the Invention) According to the present invention, (A) a plurality of conveyance units each consisting of a pair of rollers and an endless belt stretched between the rollers; (B) intermittently driving the rollers constituting the conveyance unit. A drive mechanism for intermittently feeding an endless belt; the conveying units are aligned in the feeding direction of the substrate to be printed, and above the conveying units there is a printing unit equipped with a screen. In a continuous multi-color printing machine provided with a plurality of units, each of the conveying units has one roller connected to the same drive motor via a predetermined drive transmission mechanism, and is driven intermittently in synchronization with each other, and A mesh belt of 40 to 200 meshes formed by electroplating is used as the endless belt constituting the conveyance unit, and a suction table communicating with a suction device is provided below the conveyance area of the mesh belt for each conveyance unit. A continuous multicolor printing machine is provided, characterized in that the substrate to be printed is conveyed integrally with the mesh belt by suction force.

(Function) The present invention uses an endless metal mesh belt as a conveyance material instead of an endless belt for conveyance in an automatic screen printing machine, and the base material is transported through the metal mesh belt to a suction table fixedly provided on the underside of the metal mesh belt. It is characterized by being constantly sucked and conveyed by constant suction pressure from the machine, regardless of whether it is in progress or stopped, and its position is secured even when stopped. ) Feeding accuracy can be maintained regardless of the degree of expansion and contraction of the base material. Therefore, it is possible to print with high registration accuracy on any material.

(2) Since the mesh belt of the conveying material and the base material are completely integrated over the entire length of the printing area, the tension adjustment device for both the unwinding section and the winding section of the base material is simplified.

In the present invention, it is also important to use a metal mesh belt formed by electroplating.

That is, in the case of an ordinary mesh belt made of wire gauze, unevenness is formed on the belt surface, which makes it impossible to perform fine printing in screen printing, which is undesirable.

On the other hand, mesh belts formed by electroplating have significantly superior smoothness, and when used to transport substrates in screen printing, they have the advantage of being able to effectively perform even extremely fine printing. It is.

Further, according to the present invention, each of the transport units includes:
One of the rollers is connected to the same drive motor via a predetermined drive transmission mechanism, and is driven intermittently in synchronization with each other.

By using such a driving means, the electroplated mesh belt can be effectively used for conveying the substrate.

That is, the electroplated mesh belt as an endless belt for conveyance is known per se, for example, from Japanese Patent Publication No. 33-8274.

However, such electroplated mesh belts have a limited circumferential length due to manufacturing constraints, and are therefore unsuitable for applications such as continuous multicolor screen printing where the conveyance process is extremely long. Moreover, in continuous multicolor screen printing, extremely high dimensional accuracy is required for conveying the substrate to be printed. As a result, it is difficult to maintain high feed accuracy when the multicolor screen printing process is divided into multiple processes and the conveyance unit is also divided for each process, so electroplating method mesh belts are used for continuous multicolor printing. It was not used at all.

According to the present invention, by employing the above-described driving means, high feed accuracy can be obtained extremely easily.

As described above, in the conventional technology, electroplated mesh belts are recognized to be unsuitable when the conveyance process is long, and when used in screen printing, they are extremely useful from the viewpoint of smoothness, etc. Since it was not recognized at all, it was never used in the field of continuous multicolor printing.

(Preferred Embodiments of the Invention) The present invention will be described in detail below based on specific examples shown in the accompanying drawings.

The first part showing the continuous multicolor screen printing machine of the present invention
In the figure, a driving roller 2 is on the rear side in the direction of movement of the substrate 1 to be printed, and a driven roller 3 is on the front side.
are provided in parallel to each other, and an endless metal mesh belt 4 is cyclically stretched therethrough.

In the present invention, the first feature is that a plurality of such conveyance units are provided in the traveling direction of the base material 1.
This can be understood from the diagram.

The drive of the drive motor 5 is transmitted to the drive roller 2 in each conveyance unit via a reducer 17 such as a worm gear and a line shaft 18, and intermittent operation is performed for the same period. Intermittent feed is given accordingly. As the intermittent feeding method, any method disclosed in Japanese Patent Publication No. 55-24427 and the like can be used.

In the present invention, a suction table 8 is provided below the conveyance side of the mesh belt 4 of each conveyance unit, and the substrate 1 is conveyed to the printing area integrally with the mesh belt 4 by the suction force. The suction tables 8, 8, . . . are connected to a vacuum pump or an exhaust fan 10 through pipes 9, respectively.

That is, this suction table 8 and mesh belt 4
The second part to explain the positional relationship with and its structure.
Referring to the drawings and FIG. 3, the suction table 8 is fixed to a machine base (not shown) in a position close to and below the mesh belt 4 on the conveyance side.

In addition, a large number of small holes 8A are provided almost evenly over the entire surface of the upper surface of this suction table 8, and a suction pipe 9 is connected to the lower surface and the side surface and leads to a vacuum pipe or exhaust fan 10. Due to the operation, the hollow chamber 8B becomes vacuum or negative pressure.

That is, when the substrate 1 on the mesh belt 4 is transported, if the vacuum pump or exhaust fan 10 is operated, the hollow chamber 8B of the suction table 8 becomes vacuum or negative pressure, so that the substrate 1 is transferred onto the mesh belt 4. The paper is in close contact with the paper, and is smoothly conveyed to the printing area without any problems such as misalignment.

The mesh belt 4 has small mesh holes 4A formed therein, but it is advantageous to have a high mesh from the viewpoint of providing a suction effect to the entire surface of the substrate 1 to be conveyed and also from the viewpoint of smoothness of the printed surface.

In the present invention, it is important that the mesh belt 4 is manufactured by the same method as the rotary screen mesh by electroplating, which is currently in widespread use.

That is, the mesh belt formed by this electroplating method has excellent resistance to friction with the suction table 8, and is completely endless, which is advantageous over a normal mesh belt made of wire mesh. In addition, such electroplated mesh belts are ideal for multicolor screen printing because they have outstanding smoothness and enable particularly fine printing.

In the present invention, this electroplated mesh belt is particularly applicable to Japanese Patent Application Laid-open No. 13196/1983 and
Forming by the method disclosed in Japanese Patent No. 24293 is particularly suitable from the viewpoint of the aperture ratio.

Further, in the present invention, the electroplated mesh belt used has a mesh size of 40 to 200 from the viewpoint of smoothness and the like.

Returning to FIG. 1 again, in the present invention, the suction force is applied to the entire surface of the base material 1 by the operation of the vacuum pump or the exhaust fan 10, so that the base material 1 is attached to the mesh belt 4.
The belt 4 is conveyed to the printing area in close contact with the belt 4. At this time, by continuing to perform the suction operation even when the mesh belt 4 is stopped, the base material 1 is fixed in close contact with the mesh belt 4, so that smooth and accurate printing can be performed without misalignment, expansion or contraction, etc. administered.

On each conveying unit, a plurality of plate screen printing devices 11 are arranged at intervals according to the feeding repeat, and an intermediate drying device 12 is placed between them as necessary.
is provided, and printing and drying are performed for each color.

The base material 1 is attached to the mesh belt 4 by the suction action.
After the necessary number of colors have been printed, the sheet is separated from the mesh belt, passes through a final drying device (not shown), and is then moved to winding or other processes.

Although the embodiment shown in FIG. 1 has been described using a lithographic screen as an example, it is of course possible to apply the present invention to a rotary screen.

(Operation and Effect) In the continuous multicolor screen printing machine of the present invention, the base material to be printed is conveyed with high precision together with the mesh belt, and expansion/contraction and slight movement of the base material are prevented from before printing starts to after printing ends. Furthermore, the smoothness of the mesh belt allows for extremely fine printing.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example in which the present invention is applied to printing using a lithographic screen, and FIGS. 2 and 3 are diagrams showing the structure and arrangement of a mesh belt and a suction table in the present invention. Reference number 1 is the printing substrate, 2 is the drive roller, 3 is the driven roller, 4 is the metal mesh belt, 4A is the mesh small hole, 5 is the drive motor, 8 is the suction table, 8A is the small hole, 8B is the hollow chamber, 9 1 is a suction pipe, 10 is a vacuum pump or exhaust fan, 11 is a lithographic screen printing device, 12 is an intermediate drying device, 1
4 is a receiving plate, 16 is a receiving roller, 17 is a reducer, 18
is the line axis.

Claims (1)

[Scope of Claims] 1. (A) A plurality of conveyance units each consisting of a pair of rollers and an endless belt stretched between the rollers; (B) An endless conveyor belt that is constructed by intermittently driving the rollers constituting the conveyance units. A drive mechanism that feeds the belt intermittently, and the conveyance units are aligned in the feeding direction of the substrate to be printed, and a plurality of printing units each having a screen are provided above the conveyance units. In a continuous multi-color printing press, each of the conveyance units has one roller connected to the same drive motor via a predetermined drive transmission mechanism, and is driven intermittently in synchronization with each other, and the conveyance unit is A mesh belt with 40 to 200 meshes formed by electroplating is used as an endless belt for printing, and a suction table connected to a suction device is provided for each conveyance unit below the conveyance area of the mesh belt. 1. A continuous multicolor printing machine, characterized in that the substrate is conveyed integrally with the mesh belt by suction force.