JP2000317882A - Sheet material cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain scuffing over a long period of time and to restrain coloring or damage of a coat layer in photographic paper or the like by specifying the direction of a tool mark of at least one surface constituting the knife edge to the knife edge line in at least one of a movable blade and a fixed blade. SOLUTION: A fixed blade 1 having a knife edge 1a is fixed to a frame, and a movable blade 2 having a knife edge 2a is adapted to intersect the knife edge 1a to be brought into sliding contact with each other and move in the vertical direction. Both blades are formed by a blade material 1.5 mm thick and 5 mm wide, which is edged by grinding after heat treatment, the knife angle is α=45 deg. in the fixed blade and β=75 deg. in the movable blade, the surface roughness of the each knife edge constituting surface is 1.6S, and the opposite face angle of the coat surface side is 9 deg.. In this arrangement, when the directions of tool marks are all in the range of 45 deg. to 135 deg. to the knife edge line, scuffing height is reduced (e.g. 0.05 mm or less). The more the number of faces which satisfy the above conditions is increased, the less the scuffing height is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a sheet material coated with a coating agent such as a photosensitive agent on photographic paper and using both sides of the cutting line, or for cutting a relatively thick sheet material. It belongs to the technical field of a suitable sheet material cutting device.

[0002]

2. Description of the Related Art As a conventional sheet material cutting device, there is provided a device comprising a rotary blade and a fixed blade (for example, Japanese Utility Model Publication No. 45-16869).
Japanese Patent Publication No. 48-5909), or a movable blade that moves linearly in a direction perpendicular to the edge of a fixed blade (Japanese Patent Publication No. 58-37594). However, for cutting thick paper or the like, a sheet material cutting device that cuts by cutting two straight blades having stable cutting lines by cross pressure contact is preferable. These cutting devices cut the sheet material by shearing, and in many cases, the fixed blade and the movable blade slide by cross-pressing the respective cutting edges.

[0003] When a sheet to be cut having a large thickness is sheared, fluffing tends to occur at the cut edge. In recent years, very high quality has been required for the cut edge of the sheet material.In fields where the cut sheet material such as photographic printing paper is handled as a product in almost the same form, the amount of fluff on the cut edge or It was an important issue to suppress unevenness to an extremely small level. Further, in the case of a sheet material coated with a coating material such as photographic printing paper, coloring due to peeling, displacement or the like of the coating material is likely to occur on one side of the cutting line during cutting. The present inventor, in the shearing of the sheet material, the front and back of the sheet material to be cut,
By setting an angle (hereinafter, referred to as an opposing surface angle) formed by a surface (hereinafter, referred to as an opposing surface) formed by a blade edge of the blade facing the front and back surfaces within an appropriate range, the above-described fluffing and the separation of the photosensitive agent are prevented. Proposed a sheet cutting device that suppresses this (Japanese Patent Laid-Open No. 10-3)
No. 15183). In these cutting devices, one or both of a pair of blades has a cross-sectional dimension of 2.1 mm or less in thickness,
In many cases, a blade material having a width of about 8.5 mm or less is fixed to a base metal.

[0004]

According to a subsequent study by the present inventor, as described above, the facing surface angle formed between the front and back surfaces of the sheet material to be cut and the cutting edge forming surface of the blade facing the front and back surfaces, as described above. It was found that only by setting the value in a proper range, it was not possible to sufficiently suppress fluffing, and it was not possible to maintain this suppressed state for a long period of time. The present invention provides a cutting device that suppresses fluffing of a sheet material in which fluffing is likely to occur over a long period of time, and further suppresses coloring or damage of a coating layer of a sheet material coated with a coating material such as photographic paper. The task is to

[0005]

According to the study of the present inventors, the direction of a tool mark (grinding line) formed on a surface constituting a cutting edge (a cutting surface forming surface) is controlled to suppress fluffing and maintain its effect. It was found to have a significant effect on sex. In other words, when the tool mark is sheared by a blade whose angle is parallel or nearly parallel to the cutting edge, the fiber is not necessarily cut reliably from the middle position between the cutting edges, but it is shaped like a half-cut. It is easy to remain in a fluffy shape,
It was found that the fluffing became severe with the use. In the manufacturing process of the blades of these sheet cutting devices, a grinding machine used for grinding and finishing the cutting edge has a long N and S magnetic poles arranged in parallel as a table for holding the workpiece, for holding the workpiece by suction. In general, magnetic chucks are used, which are arranged alternately in the shape of a circle, and the magnetic poles are generally arranged such that their longitudinal directions are parallel to the rotation axis of the grinding wheel. On the other hand, FIG.
As shown in the figure, for example, when a large number of workpieces 5 having an elongated shape with a small rectangular cross section as a blade material or the like are magnetically held with their edges in contact with the magnetic pole chuck surface 7 so that the cross section is inclined. To do this, it is necessary to hold the workpiece by chucking the workpiece so that its longitudinal direction is perpendicular or nearly perpendicular to the longitudinal direction of the magnetic pole. For this reason, in the case of an elongated blade or blade material, the longitudinal direction is arranged at a right angle or close to the axis of rotation of the grinding wheel, and the tool mark formed by grinding on the surface constituting the blade edge is The angle was usually parallel or nearly parallel to the edge line.

[0006] In order to suppress the fluffing of the cut edge of the sheet material and to shear it, the cutting edge line is made to approach each fiber as close as possible. For this purpose, at least one of a pair of cutting blades, preferably both cutting blades, are opposed. It is desirable to make the surface angle as large as possible (although the cutting edge angle will be small), but if the tool mark formed on the cutting edge forming surface is parallel or nearly parallel to the cutting edge line, the cross section of the cutting edge is just 2. Since the waveform curve of the book is cut at random and the end points are joined together, the sharp edge shape as aimed at the microscope level is not obtained,
In addition, in such a shape, since the cutting edge is easily worn in the early stage of use and sharpness is reduced, in the case of a shearing blade, the fiber of the sheet material is not necessarily cut reliably from an intermediate position between the both cutting edges. It turns out that it remains in a fluffy shape like a half-cut piece.

Therefore, a sheet material cutting apparatus according to the present invention is a sheet material cutting apparatus using shearing with a movable blade and a fixed blade, wherein at least one of the blades has a tool mark on at least one surface constituting the blade edge. A sheet material cutting device characterized by being at an angle of 45 ° or more and 135 ° or less with respect to a line.

The effect of the present invention is that the thickness of the sheet to be cut is
Effective for 0.1mm or more, 0.2mm
The above is particularly effective. As shown in FIG.
For example, the force F applied by the cutting tool 2
Generates a tension in the in-plane direction of the sheet to be cut as a representative of d, and the fiber is torn by this tension, but the width of the portion where this tension acts at the center in the thickness direction far from the cutting edge line However, the fibers do not always break at the center of the tension acting portion, so that the fibers remain in a fluffy state. Then, the front and back S1 of the sheet to be cut and the front and back S
As the angle (opposed surface angle) γ formed by the cutting edge forming surface (opposing surface) 2c and the cutting edge 1 increases, the cutting edge is more likely to bite into the sheet to be cut, and the fluffing is suppressed.

According to the intention of the present invention, it is ideal that the direction of the tool mark is 90 ° with respect to the cutting edge line. There may be a slight inclination with respect to 90 °. In other words, a grinding machine used for grinding and finishing the cutting edge is configured such that elongated N and S magnetic poles for adsorbing the workpiece on a table for holding the workpiece are alternately arranged in parallel at regular intervals. In general, the magnetic poles are arranged so that each longitudinal direction is parallel to the axis of rotation of the grinding wheel, so that a number of elongated blades are arranged in parallel in the thickness direction. In order to make the direction of the tool mark exactly 90 ° to the edge of the cutting edge, a long blade must be placed in parallel with the long magnetic pole. In this case, the direction of the tool mark is 45 ° with respect to the cutting edge line.
It is only necessary to tilt the blade within a range of 135 ° from the angle.

The direction of the tool mark is set to 45 with respect to the edge line.
The reason why the angle is limited to from 135 ° to 135 ° is that if the direction of the tool mark is less than 45 ° or more than 135 ° with respect to the cutting edge line, the characteristics become close to those of a conventional sheet material cutting apparatus. The direction of the mark is preferably in the range of 60 ° to 120 ° with respect to the cutting edge line, and more preferably the direction of the tool mark is in the range of 75 ° to 105 ° with respect to the cutting edge line. Of course, if the blade has a sufficient cross-sectional dimension (width, etc.) to sufficiently span the gap between the magnetic poles,
It is preferable that the direction of the tool mark is set to be exactly 90 ° with respect to the cutting edge line while being placed parallel to the magnetic pole.

In the present invention, in order to sufficiently suppress the fluffing, at least one of the blades has a large facing surface angle γ of 20 ° or more in order to sharply bite into the sheet to be cut, or In particular, it is desirable that the direction of the tool mark with respect to the blade having the large facing surface angle be within the angle range of the present invention. Desirable facing angle is 30 °
The above is more preferably 40 ° or more. But,
When the sheet to be cut is a sheet to which a coating agent is applied, for example, such as photographic printing paper, the facing surface angle γ on the side where the coating agent is applied is desirably reduced, and more desirably, The coating surface is protected by increasing the facing surface angle of the blade. Specifically, it is desirable that the facing surface angle γ on the coated surface side be 0 ° or more and 10 ° or less, and that the sum of the included angles of the two blades be 105 ° or more and 125 ° or less.

The reason for limiting the facing surface angle γ on the coating surface side is as follows.
If the angle is less than 0 °, the part other than the cutting edge of the blade comes into contact with the coating surface of the sheet material before the cutting edge, and the sheet material may be bent or the coating surface may be damaged. This is because stresses are concentrated in a narrow area of the coating surface when biting into the surface, causing damage such as peeling or discoloration of the coating layer. Preferably it is 1 to 8 °, more preferably 2 to 6 °. In addition, the reason for limiting the sum of the blade angles of both blades is that if the sum of the blade angles of both blades is 105 ° or less, at least one of the blades is too sharp, and chipping or biting tends to occur,
If the angle is more than 125 °, at least one of the blades has an excessively large blade edge angle, so that the sharpness is deteriorated, that is, the cut edge tends to be fluffy.

[0013]

Next, the effects of the embodiment of the sheet material cutting apparatus according to the present invention will be specifically described with reference to test results in comparison with comparative examples. FIG. 1 is a perspective view showing a configuration of a cutting blade of a sheet material cutting device subjected to a test. In the drawing, a fixed blade 1 having a linear blade edge 1a is fixed to a frame (not shown). The movable blade 2 having the movable blade 2 moves up and down while crossing the blade edge 2 a of the fixed blade 1 with the blade edge 1 a of the fixed blade 1, and cuts the sheet material S between the both blades in cooperation with the fixed blade 1. . 2 and 3
FIG. 3 is a three-sided view of a fixed blade and a movable blade of the sheet material cutting device in FIG. 1, respectively, in which the angle of the blade constituent surface of each blade with respect to the blade line of the tool mark is indicated by θ. In addition, both the blades are blades 1.5 mm thick and 5 mm wide, each of which has a blade formed by grinding after heat treatment, inserted into a groove formed in the shank material and bonded and held. The angle of the blade edge is fixed blade α = 45
°, movable blade β = 75 °, and the surface roughness of each cutting edge constituting surface is 1.
6S, and the facing surface angle on the application surface side is constant at 9 degrees.

In the test, a sheet material S of 280 μm-thick photographic paper having an emulsion coated on its surface was inserted into the sheet material cutting apparatus having the above-mentioned configuration, and cut with the coated surface as the movable blade side. Table 1 shows the results of cutting conditions tested by changing the angles .theta.1b and .theta.2c and .theta.1c and .theta.2b of the tool marks on the opposed surfaces 1b and 2c and the inclined surfaces 1c and 2b of the fixed blade 1 and the movable blade 2. ("Ratio" in the table represents a comparative example).

[0015]

[Table 1]

From the test results in Table 1, the following was found.
That is, in Comparative Sample 1 in which the tool mark directions are all parallel to the cutting edge line, the cut surface of the sheet material S has a height of 0.2 mm.
In contrast to the occurrence of the above-mentioned fluff, Sample 16 of the present invention, in which the tool mark directions are all within the range of 45 ° to 135 ° with respect to the cutting edge line, has an extremely good fluff height of 0.05 mm or less. Cut surface was obtained. Further, as the number of surfaces in which the angle of the tool mark is in the range of 45 ° to 135 ° with respect to the cutting edge line as in Samples 2 to 15 of the present invention, the cut surface of the sheet material S increases. The height of the fluff generated on the cut surface became low, and the cut condition became good.

Samples 2, 3, and 4 and Samples 5, 9, and 13
As can be seen from the respective comparisons, it is better to set the tool mark in the range of 45 ° to 135 ° with respect to the cutting edge line on the fixed cutting edge side where the cutting edge angle is as small as 45 ° (the facing surface angle is as large as about 45 °). The edge angle is as large as 75 ° (the facing surface angle is 9
On the movable side, the fluffing can be suppressed smaller than when the tool mark is in the range of 45 ° to 135 ° with respect to the cutting edge line. In other words, it can be seen that the effect of the present invention is greater when applied to a blade having a small edge angle (a large facing surface angle). If this is compared to the combination of a knife and a cutting board, in the case of a combination of blades with different edge angles, the blade with the smaller edge angle cuts into the sheet material and cuts the fiber when cutting. Since the tool with a larger angle plays a role of a cutting board, the tool mark of the tool with a small edge angle is 45 ° to the edge line.
This is because the effect becomes more remarkable when the sharpness of the cutting edge is increased in the range of 135 ° to 135 °.

[0018]

As described above, according to the sheet material cutting apparatus of the present invention, the edge of the blade is sharpened by setting the tool mark of the blade within the range of 45 ° to 135 ° with respect to the edge line. At the time of cutting, the fibers of the sheet material are surely cut at predetermined positions, and a good cut surface with little fluff can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a cutting blade of a sheet material cutting device subjected to a test.

FIG. 2 is a three-side view of a fixed blade of the sheet material cutting device of FIG. 1;

FIG. 3 is a three-side view of a movable blade of the sheet material cutting device of FIG. 1;

FIG. 4 is a diagram illustrating occurrence of fluff during shearing.

FIG. 5 is a diagram for explaining a method of magnetically holding a small rectangular section material.

[Explanation of symbols]

Reference Signs List 1 Fixed blade, 1a cutting edge, 1b facing surface, 1c shaving surface, 2 movable blade, 2a cutting edge, 2b shaving surface, 2c facing surface, θ1b, θ1c, θ2b, θ2c Angle of tool mark to cutting edge line, S sheet material , D In-plane tension, F
Force, γ Face angle

Claims (4)

[Claims] In a sheet material cutting apparatus in which a movable blade and a fixed blade are sheared, at least one of the blades has a tool mark on at least one surface constituting a blade edge in a direction of 45 ° or more with respect to a blade edge line. ° or less. 2. The cutting edge of at least one of the blades has an angle of 20 ° or more between the front and back surfaces of the sheet to be cut and the blade forming surface facing the front and back surfaces, and at least one surface forming the cutting edge of the blades. Tool mark direction is 4
2. The sheet material cutting device according to claim 1, wherein the angle is 5 ° to 135 °. 3. A sheet cutting device for a sheet to be cut to which a coating agent has been applied, wherein a blade on the side of the sheet to which the coating agent has been applied opposes the surface to which the coating agent has been applied. The angle formed by the cutting edge forming surface is 0 ° or more and 10 ° or less, and the direction of the tool mark on at least one surface forming the cutting edge is 45 ° or more and 135 ° or less with respect to the cutting edge line. The sum of the cutting edge angles of the two blades is 105 ° or more and 125 ° or less.
Or the sheet material cutting device of 2. 4. The direction of the tool mark on at least one surface constituting the cutting edge is 45 ° or more and 135 ° with respect to the cutting edge line.
The following blades have a blade material fixed to a base metal, and the blade material has a cross-sectional dimension of 2.1 mm or less in thickness and 8.5 mm in width.
The sheet material cutting device according to any one of claims 1 to 3, which is at least one of the following.