JP2020055191A - Squeegee for screen printer - Google Patents

Abstract

To provide a squeegee for screen printer which can reduce the lateral leakage of ink from both ends in the width direction of the squeegee.SOLUTION: A notch 2 is provided over the entire width of a squeegee body 1 on a portion on a front surface lower end side of the band plate-like squeegee body 1. The upper end edge of the notch 2 has the shape that has the larger distance from the lower end of the squeegee toward the center from both ends in the width direction of the squeegee body 1 and has the maximum distance at the central position of the squeegee. At this time, the upper end edge of the notch 2 may be the mountain shape including the straight lines toward the center from both ends in the width direction of the squeegee body or the arc shape heading toward the center from both ends in the width direction of the squeegee body. The squeegee body 1 may be a structure in which a first squeegee member 1a on the front surface side of the squeegee is arranged on the surface of a second squeegee member 1b on the rear surface side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a squeegee for a screen printing machine.

  Since high-speed and high-precision printing can be performed, screen printing machines have been widely used so far. The screen printing machine is configured such that a squeegee is arranged on an upper side of a screen plate provided with pattern holes, and an object to be printed is arranged on a lower side, and a paste supplied on the screen plate at the time of printing. Ink is spread thinly with a scraper, the squeegee is pressed and the squeegee is moved in a state where the printing target and the screen plate are overlapped, and the ink is oozed out of the pattern holes toward the printing target to print. Attach to the surface of the object.

At this time, the squeegee moves on the screen plate, causing a problem that the paste-like ink leaks laterally from both ends in the width direction of the squeegee. Such a lateral leak of the ink causes drying and deterioration of the ink. And increase the amount of ink that is discarded.
In addition, there is a problem that the production cost and the environment are deteriorated due to the discarding of the ink. Therefore, a technology capable of reducing the amount of the discarded ink is required.

Therefore, as a technique for solving such a problem, for example, Patent Literature 1 listed below proposes a squeegee head in which scraping members are provided at both ends in the width direction of the squeegee. The take-out members extend forward of the squeegee and are inclined in such a manner that the distance between them increases as going forward. The scraping member functions to scrape the creamy solder protruding in the lateral direction of the squeegee and return it to the squeegee side.
However, such a squeegee head has a complicated structure and requires a device for attaching the scraping member.

JP 2007-15307 A

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a squeegee for a screen printing machine that solves the above-described problems and can reduce the lateral leakage of ink from both ends in the width direction of the squeegee with a simple structure. .

  The squeegee for a screen printing machine according to the present invention, which can solve the above-described problem, has a notch provided over the entire width of the squeegee main body at a lower end portion on the front surface of the strip-shaped squeegee main body. The upper end edge of the portion is shaped so that the distance from the lower end of the squeegee increases toward the center from both ends in the width direction of the squeegee body and becomes maximum at the squeegee center position.

  According to the present invention, in the squeegee for a screen printing machine having the above-described features, an upper end edge of the notch has a mountain shape including straight lines extending from both ends in the width direction of the squeegee body to the center of the squeegee. It is assumed that.

  Further, the present invention provides a squeegee for a screen printing machine having the above characteristics, wherein an upper end edge of the notch has an arc shape extending from both ends in the width direction of the squeegee body to the center of the squeegee. is there.

  Further, the present invention provides a squeegee for a screen printing machine having the above characteristics, wherein a vertical cross-sectional shape of an upper end side of a notch provided over the entire width of the squeegee main body has an angle of substantially 90 °. It is characterized by having a reverse L-shape.

  According to the present invention, in a squeegee for a screen printing machine having the above characteristics, a vertical cross-sectional shape at an upper end side of a notch provided over the entire width of the squeegee body is a shape including an R shape. It is characterized by the following.

  Further, the present invention provides a squeegee for a screen printing machine having the above-mentioned features, wherein the squeegee main body is formed of two members, and a front end side of the squeegee main body has a lower end side shape corresponding to the shape of the notch. A plate-shaped first squeegee member is provided, and a strip-shaped second squeegee member having no notch is provided on a rear surface side of the squeegee main body. .

  The squeegee for a screen printing machine of the present invention has a structure in which the ink does not easily spread horizontally during screen printing, and the amount of discarded ink can be reduced.

It is a figure showing appearance in a preferred example of a squeegee for screen printers of the present invention. FIG. 2 is a perspective view illustrating an appearance of the squeegee for a screen printing machine of the present invention illustrated in FIG. 1. FIG. 2 is a diagram illustrating an appearance of an example of a squeegee for a screen printing machine of the present invention in which an upper end of a cutout portion is different from that in FIG. 1. FIG. 3 is a diagram illustrating an appearance of an example of a squeegee for a screen printing machine according to the present invention in which an upper end of a cutout portion and a vertical sectional shape are different from each other. 5 is a photograph showing the amount of ink remaining on the screen plate after printing 100 shots and the state of lateral leakage when three types of squeegees having different structures are used in Examples.

The squeegee for a screen printer according to the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the squeegee for a screen printing machine according to the present invention has a notch 2 over the entire width of the squeegee main body 1 at the lower end portion on the front surface of the squeegee main body 1 in the form of a strip. The upper end edge of the notch 2 has such a shape that the distance from the lower end of the squeegee increases toward the center from both ends A in the width direction of the squeegee main body 1 and becomes maximum at the center position of the squeegee. . At this time, the front surface of the squeegee main body refers to a surface located in front of the moving direction of the squeegee (a surface in contact with ink).

In the case of the squeegee for a screen printing machine illustrated in FIG. 1 and FIG. However, the shape of the upper edge of the notch 2 is not limited to this.
In the present invention, the height and the depth of the notch 2 can be appropriately selected according to the viscosity of the ink used for screen printing and the like. For example, a squeegee having a width of 200 mm, a height of 50 mm, and a thickness of 9 mm can be used. In this case, the notch 2 generally has a distance of 11 mm from the lower end of the squeegee at both ends of the squeegee, a distance of 21 mm from the lower end of the squeegee at the center of the squeegee, and a depth of about 3 mm.

In the present invention, the notch 2 as shown in FIG. 1 is provided at the lower end portion on the front surface of the squeegee main body 1, so that the position closer to the center of the squeegee is closer than the end side of the squeegee. A large amount of ink can be stored (accommodated) in the notch 2, and when the squeegee moves, the ink at the end of the squeegee collects in the center of the squeegee due to the shape of the notch 2. In addition, the ink can be prevented from spreading in the horizontal direction, and the amount of the ink protruding from both ends in the width direction of the squeegee can be reduced.
In the case of the squeegee for a screen printing machine illustrated in FIGS. 1 and 2, the vertical cross-sectional shape on the upper end side of the notch 2 provided over the entire width of the squeegee main body 1 has an angle of 90 °. This angle is preferable, but it may be an acute angle smaller than 90 ° or an obtuse angle larger than 90 °.

In the present invention, the squeegee main body 1 may be formed of two members, and a first squeegee having a lower end side shape corresponding to the shape of the notch portion 2 on the front side of the squeegee as shown in FIGS. The squeegee member 1a may be arranged, and a second squeegee member 1b in the form of a strip having no notch may be arranged on the rear side of the squeegee. At this time, it is preferable that the first squeegee member 1a has a structure in which the first squeegee member 1a is stuck on the second squeegee member 1b, but the present invention is not limited thereto. May be positioned and superimposed without being bonded. Of course, in the present invention, the squeegee body 1 in which the notch 2 is formed by cutting the lower end side of one strip-shaped squeegee may be used, and the squeegee manufactured by casting using a molding die. The main body 1 may be used.
When the first squeegee member 1a and the second squeegee member 1b are attached to each other to form the squeegee main body 1 as shown in FIGS. It is preferable because a squeegee having a desired hardness (strength) can be obtained.

  FIG. 3 shows a squeegee for a screen printing machine of the present invention comprising a squeegee main body 1 in which a cutout portion 2 is formed by cutting a lower end portion on the front side of a single strip-shaped squeegee. In the case of this squeegee, the upper end edge of the notch 2 has an arc shape extending from both ends in the width direction of the squeegee body 1 toward the center of the squeegee. The squeegee has an inverted L-shape having a 90 ° angle.

FIG. 4 shows, as still another embodiment, a squeegee for a screen printing machine of the present invention comprising a squeegee main body 1 in which a notch 2 is formed by cutting a lower end portion on the front surface of one strip-shaped squeegee. In the case of this squeegee, the upper end edge of the notch 2 has a chevron shape composed of two straight lines extending from both ends in the width direction of the squeegee body 1 to the center of the squeegee, similarly to the squeegee of FIG. However, the vertical cross-sectional shape on the upper end side of the cutout portion 2 is substantially an R shape including a 1/4 arc as shown in the cross-sectional view taken along the line XX in the right drawing.
In the case of a squeegee having a longitudinal sectional shape including an R shape (curved surface) as shown in FIG. 4, an arc shape smaller than よ り 小 さ い or an arc shape larger than ４ may be used. The size can also be arbitrarily selected, and is not limited to the vertical cross-sectional shape on the upper end side of the notch 2 illustrated in the drawings.

The length in the width direction of the squeegee for a screen printing machine (squeegee main body 1) of the present invention can be selected according to the size of the printing machine and the plate making, and the thickness of the squeegee is usually 3 mm to 15 mm. The depth of the notch 2 (notch depth from the front of the squeegee) is generally about 1 mm to 14 mm, and the height of the squeegee is usually 30 mm to 50 mm, but may be more.
In the present invention, a thin plate made of stainless steel, glass epoxy, or the like may be disposed close to the rear surface of the squeegee body 1 for the purpose of reinforcing the squeegee against deformation.

  The material of the squeegee for a screen printing machine (squeegee body 1) of the present invention is preferably an elastic material such as urethane rubber or chloroprene rubber. In the case of a printing squeegee for a metal mask, a metal such as stainless steel or a glass epoxy or the like is used. Hard plastic may be used. In the present invention, carbon fiber or the like may be composited, or urethane rubber and a different material such as metal may be combined.

In the present invention, the surface (front surface) of the squeegee main body 1 may be subjected to a process of imparting releasability, and by such a process, the ink moves upward from the contact point between the squeegee and the screen plate along the front surface of the squeegee. After flowing toward, the effect of a flow (so-called ink rolling) that folds back due to its own weight and falls forward can be increased. At this time, the surface of the squeegee may be coated or impregnated with a fluorine resin, a silicon resin, or the like. When the material of the squeegee is metal, plating may be performed.
Further, in the present invention, irregularities may be provided on the surface of the notch 2 (the surface that comes into contact with the ink). In this case, the solvent component in the ink remains in the irregularities, and the fluidity of the ink is increased. It is possible.

[Comparison experiment between screen printing press squeegee of the present invention and conventional product]
As a product of the present invention, a squeegee was produced by bonding two squeegee members 1a and 1b (both made of urethane rubber) shown in FIG. 1 with an adhesive. The outer dimensions of this squeegee are 200 mm in width, 50 mm in height, and 9 mm in thickness, and the notch provided in the front of the squeegee has a distance of 11 mm from the lower end of the squeegee at both ends of the squeegee, and a distance from the lower end of the squeegee at the center of the squeegee. At a distance of 21 mm and a depth of 3 mm, the upper edge of the notch was formed into a mountain shape (square shape) consisting of straight lines extending from both ends in the width direction of the squeegee body toward the center of the squeegee.
Further, as another product of the present invention, one band-shaped urethane rubber plate was cut to produce a squeegee having a structure shown in FIG. The outer dimensions of the squeegee are 200 mm in width, 50 mm in height, and 9 mm in thickness. In front of the squeegee, a distance of 11 mm from the lower end of the squeegee at both ends of the squeegee, a distance of 21 mm from the lower end of the squeegee at a central position of the squeegee, and a depth of 3 mm Thus, the upper edge of the cutout portion is formed in an arc shape extending from both ends in the width direction of the squeegee body toward the center of the squeegee.
As a comparative product, a squeegee made of urethane rubber having a width of 200 mm, a height of 50 mm, and a thickness of 9 mm (no cutout) was prepared.

Using a commercially available screen printing machine and screen printing plate, place 25 g of screen printing ink on the printing plate, and compare the amount of ink remaining on the screen printing plate after 100 shot printing due to the difference in squeegee with the state of lateral leakage of the ink. did.
FIG. 5 is a photograph showing the amount of ink remaining on the screen plate after 100 shot printing and the state of lateral leakage when the above three types of squeegees having different structures are used.

From the photograph of FIG. 5, in the case of the comparative product having no notch (no processing), after printing 100 shots, a large amount of ink flows out to the portions corresponding to both ends of the squeegee (portions surrounded by solid circles). Although the ink at the stroke end portion (the portion surrounded by the dotted circle) is small, in the case of the present invention product (a squeegee having an arc-shaped notch portion and a squeegee having an angular notch portion), It was confirmed that there was little lateral leakage of ink from the lateral end, and there was much ink at the stroke end. For this reason, in the case of the product of the present invention, it was possible to perform further printing without replenishing the ink.
Further, the ink flowing out from the lateral direction of the squeegee was collected and the weight was measured. As shown in FIG. 5, as shown in FIG. It was also confirmed that the squeegee had the least amount of lateral leakage of the ink and was about one-half that of the comparative product having no notch.
In the above comparative test, an inverted L-shaped squeegee having a 90 ° angle in the vertical cross section at the upper end side of the notch was used. It has been confirmed that the same effect as described above can be obtained also when a squeegee having a shape including (Squeegee in FIG. 4) is used.

  By using the squeegee for a screen printing machine of the present invention, lateral leakage of ink during screen printing can be effectively suppressed, and the amount of discarded ink can be reduced.

DESCRIPTION OF SYMBOLS 1 Squeegee main body 1a 1st squeegee member 1b 2nd squeegee member 2 Notch

Claims (6)

  A notch is provided over the entire width of the squeegee main body at the lower end portion on the front surface of the strip-shaped squeegee main body, and the upper edge of the notch extends from both ends in the width direction of the squeegee main body toward the center. A squeegee for a screen printing machine, wherein the distance from the lower end of the squeegee increases and the shape of the squeegee becomes maximum at the center position of the squeegee.   The squeegee for a screen printing machine according to claim 1, wherein an upper edge of the notch has a mountain shape including straight lines extending from both ends in the width direction of the squeegee body toward the center of the squeegee.   The squeegee for a screen printing machine according to claim 1, wherein an upper end edge of the notch has an arc shape extending from both ends in the width direction of the squeegee body toward the center of the squeegee.   The vertical cross-sectional shape at the upper end side of the notch provided over the entire width of the squeegee main body is substantially an inverted L-shape having an angle of 90 °. A squeegee for a screen printing machine according to any one of the preceding claims.   The screen printing according to any one of claims 1 to 3, wherein a vertical cross-sectional shape at an upper end side of the notch provided over the entire width of the squeegee main body is a shape including an R shape. Machine squeegee.   The squeegee main body is composed of two members, and a plate-shaped first squeegee member having a lower end side shape corresponding to the shape of the notch portion is disposed on a front side of the squeegee main body, and on a rear side of the squeegee main body, The squeegee for a screen printing machine according to any one of claims 1 to 5, wherein the squeegee has a structure in which a strip-shaped second squeegee member having no notch is arranged.