JPS63116893A - Screen plate for printing - Google Patents

Abstract

PURPOSE:To make a printing pressure constant between a squeegee and a body to be printed over a full screen plate to form a uniformly and stably printed film, by a method wherein a photosensitive resin layer is formed on a screen mesh, and mesh element wires are so formed and arranged as to be reduced in diameter from the center portion in a plate frame into the peripheral direction. CONSTITUTION:Element wires 13 of a screen mesh 12 are so formed and arranged as to be maximum at the center portion of a plate and gradually smaller in diameter in the peripheral directions of the plate. In this manner, when a squeegee 18 is slid on the plate fane while being pushed into a body to be printed 19 by a fixed amount, the wires 13 in the peripheral portion of the plate become easy to stretch and, therefore, the squeegee 18 can be applied with the same reaction force due to the push of the squeegee at the center portion and the peripheral portions of the plate, and the printing pressure acting between the squeegee 18 and the body to be printed 19 can be made constant over the full plate. Although the diameters of the element wires 13 of the screen mesh 12 are varied in the plate face, the plate 16 is made constant in thickness by adjusting the thickness of a photosensitive resin layer 15. Therefore, there is no possibility that the printed film varies in film thickness on the plate face.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a screen plate used in screen printing for printing thermoplastic inks, pastes, adhesives, etc.

BACKGROUND OF THE INVENTION Conventionally, as shown in FIGS. 4 and 5, this type of printing screen plate has been made of fibers such as silk, nylon, Tetron, etc., or stainless steel, etc., which have a constant cross-sectional shape in the longitudinal direction. A screen mesh 2 made by plain weaving wire strands 1 is adhered to a printing frame 3 made of aluminum or the like while applying tension.

Then, a diazo photosensitive resin layer 4 is provided on the upper surface of the screen mesh 2, and this photosensitive resin layer 4 is partially etched to remove the unobstructed holes 6 of the screen mesh 2 (images). Line part) is formed.

Since a printing screen plate with such a configuration is used, as shown in Fig. 6, ink 7 is applied onto the screen plate 6, and the material is rubber-based or resin-based with a Shore hardness of 60' to 80°. Yes 45° to 60° to the printing medium 8
If the squeegee 9, which is attached at an angle of
The particles pass through the print area) and are transferred onto the surface of the printing medium 8, where printing is performed. However, when sliding the squeegee 9 against the printing material 8 while pushing it in a certain direction, the screen mesh 2 is created by weaving the strands 1 which have a constant cross-sectional shape in the length direction.
fr, whether the squeegee 9 is located at the center of the plate 6 (Fig. 6 ■)) or at the periphery (Fig. 6 (=) and (C)), The reaction force that the system squeegee 9 receives differs depending on the deflection of the plate 6. In other words, the reaction force is the smallest at the center of the plate 6, and increases as the position of the squeegee 9 moves closer to the periphery of the plate frame 3. As the reaction force increases, the tip of the squeegee 9 bends, as shown in FIGS. 6(a) and 6(C), and the plate 6 no longer comes into contact with the printing medium 8. In this way, even if the squeegee 9 is pushed a certain amount into the printing material 8, the contact pressure between the two, that is, the printing pressure, decreases as the position of the squeegee 9 moves from the center of the plate 6 to the periphery. do. If the printing pressure changes, the thickness of the film printed on the printing medium 8 will naturally become uneven, and stable printing will not be possible.

Problems to be Solved by the Invention The effective printing area of a conventional clean printing plate was a central portion of about % of the printing frame size, both vertically and horizontally, where there was little change in printing pressure. In other words, in the past, only about % of the total plate area was effectively utilized.

The present invention solves all of the above-mentioned conventional problems, and by making the printing pressure acting between the squeegee and the printing material constant over the entire surface of the screen plate, the entire surface of the screen plate is used as an effective printing area, To provide a printing screen plate capable of forming a uniform and stable printing film over the entire surface of the plate.

Means for Solving the Problems The present invention provides a screen mesh woven from wires whose cross-sectional shape changes in the length direction, a photosensitive resin layer formed on the screen mesh, and a screen mesh woven from wires whose cross-sectional shape changes in the length direction. It consists of a plate frame that fixes the plate frame, and the area of the cross-sectional shape of the screen mesh wire is reduced from the central part to the peripheral part within the plate frame.

Function: When the squeegee is slid within the plate frame while keeping the amount of pressure of the squeegee on the printing material constant, the area of the cross-sectional shape of the screen mesh element decreases from the center of the film toward the periphery. As a result, the reaction force due to the deflection of the plate can be kept constant even if the position of the squeegee moves from the center of the plate to the periphery.

Therefore, the pressure with which the squeegee presses the plate against the printing medium can be made constant over the area of the metal plate inside the plate frame. As a result, it becomes possible to make the entire surface of the screen plate an effective image area and to form a uniform and stable printing film over the entire surface of the plate.

The embodiment shoe 12 is woven from strands 13 having a circular cross-sectional shape. The diameter of the wire 13 is large at the center of the film, and gradually decreases toward the periphery of the plate. This screen mesh 12 is fixed to the printing frame 14 without applying tension,
Further, a photosensitive resin layer 15 is provided on the upper surface of the screen mesh 12, and this photosensitive resin layer 15 is thinned at the center of the film.
The thickness is gradually increased toward the periphery of the plate. therefore,
The thickness of the plate 16, expressed as the sum of the thicknesses of the screen mesh 12 and the photosensitive resin layer 16, is the thickness of the entire plate surface 7? It is constant. The photosensitive resin layer 16 is partially etched to create unobstructed holes 17 (image areas) of the screen mesh 12, thereby forming a predetermined printing pattern.

Next, the operation of the configuration of this embodiment will be explained. Since the diameter of the strands 13 in the center of the membrane is large and the diameter of the strands 13 in the periphery of the plate is small, as shown in FIG. When you slide the top, the material around the plate! 13 becomes easy to stretch, and the central part of the film (Fig. 3 (b)) and the peripheral part of the plate (Fig. 3 (b))
The reaction force that the system squeegee 18 receives due to the pushing of the squeegee 18 in =) and (C)) can be made the same, and the printing pressure acting between the squeegee 18 and the printing medium 19 is kept constant over the entire surface of the plate. be able to.

Note that even if the diameter of the wires 13 of the screen mesh 12 is changed within the printing plate, the thickness of the printing plate 16 is kept constant by adjusting the thickness of the photosensitive resin layer 16, so that the printed film The film thickness does not change within the plate surface.

As a result, not only the central portion of the screen plate 16 but also the entire surface of the plate can be effectively used as a printing area, and a uniform and stable printing film can be formed over the entire surface of the plate.

Further, in the above embodiment, by changing the wire diameter of the screen mesh 12, the cross-sectional shape can be changed. However, the cross-sectional shape of the wire is made square at the center of the plate, the corners of the square are rounded toward the periphery of the plate, and the cross-sectional shape of the wire is made circular at the side between the plates. Even if it is changed, the same effect as above can be obtained.

Effects of the Invention As described above, the printing screen plate of the present invention comprises a screen mesh woven from wires whose cross-sectional shape changes in the longitudinal direction, and a photosensitive resin layer formed on the screen mesh. The screen mesh is composed of a plate frame that fixes the screen mesh, and the area of the cross-sectional shape of the screen mesh wire is decreased from the center of the plate frame to the peripheral part, so the squeegee can be applied over the entire surface of the screen plate. It is possible to keep the printing pressure acting between the screen plate and the printing material constant, and it is possible to form a uniform and stable printing film over the entire surface of the screen plate with the entire surface of the screen plate as an effective image area.

Therefore, the present invention is extremely useful in practice.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a printing screen plate according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of Fig. 1, and Fig. 3 is a plan view of a printing screen plate shown in Fig. 1. Printing status diagram, 4th
The figure is a plan view of a conventional printing screen plate.
The cross-sectional view in the figure and FIG. 6 are diagrams showing the printing state when the printing screen plate shown in FIG. 4 is used. 12...Screen mesh, 13...
・Element wire, 14... plate frame, 16... photosensitive resin layer, 17... hole, 18... squeegee, 19...・Printing material, 2゜...Ink, 21...Squeegee holder, 22...
···table. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 16 - Screen plate 18 - Squeegee 19 - Typesetting body 22 - Table (α) (b) Figure 4 Figure 5 Figure 6 - Screen plate 7 - Ink 8 - Ridge printing body, o ( ) (b)

Claims (2)

[Claims] (1) A printing screen plate consisting of a screen mesh woven from wires whose cross-sectional shape changes in the length direction, a photosensitive resin layer formed on the screen mesh, and a plate frame for fixing the screen mesh. . (2) The printing screen plate according to claim 1, wherein the area of the cross-sectional shape of the screen mesh element wires is reduced from the central part of the plate frame toward the periphery.