JPH02256496A - Cutting method and cutting device for plastic film and plastic film - Google Patents

Abstract

PURPOSE:To reduce the rub between a film face and a round edge and prevent the deformation in the film thickness direction by inserting the tip of a round edge cutter into the edge receiving groove of the plastic film winding portion of a conveying roller, rotating the round edge cutter at the rotating speed in response to the conveying speed of the film, and cutting the film. CONSTITUTION:A film 1 is conveyed by a conveying roller 2 with an edge receiving groove. When the tip of the round edge cutter 30 with the cutting edge in the peripheral direction is engaged with the center of the edge receiving groove 2a of the conveying roller 2 during conveyance, and the plastic film 1 is continuously cut along the conveying direction while the round edge cutter 30 is rotated at the rotating speed in response to the conveying speed of the film 1. The film 1 is cut by the round edge cutter 30, thereby the deformation in the film thickness direction can be prevented.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a cutting method for continuously cutting a plastic film in the transport direction during winding and transport, a cutting device for carrying out the cutting method, and a cutting method. The present invention relates to a plastic film having a characteristic surface shape.

[Conventional technology]

For example, when cutting a 1 meter wide plastic film (hereinafter simply referred to as film) into 50 cm wide pieces,
A roller around which a 1 meter wide film is wound is prepared, and two take-up rollers capable of winding a 50 cm wide film are also prepared. Then, while continuously conveying the 1 meter wide film, the film is cut at the center in the width direction by a cutting device provided in the middle of the conveyance system. After this cutting, each 50 cm wide film is
Each is wound up by the two winding rollers.

Conventional examples of cutting devices provided in the conveyance system are shown in FIGS. 6 to 9.

First, the first conventional example shown in FIG. 6 is a cutting device using a razor blade. A conveyance roller 2 that grips and conveys the film 1 is provided in the middle of the conveyance system. ■ in Figure 6
As shown in FIG. 7, which is a cross section taken along the line -■, a plurality of receiving blade grooves 2a are formed on the entire outer peripheral surface of the conveying roller 2. Then, at the portion where the film l is wrapped around the transport roller 2, the tip of the razor blade 3 is inserted into the receiving blade groove 2a of the transport roller 2, and the film l is continuously cut while being transported.

Further, the second conventional example shown in FIGS. 8 and 9 is a cutting device using a shear blade. In this device, the film 1 is gripped and conveyed by a lower blade roller 4 on which a lower blade 4a is formed. Then, the upper blade 5 is inserted into the groove 4b while contacting the side surface of the lower blade 4a, and cuts the film l by shearing.

In addition, there is also a method in which the film is transported by a transport roller that has no grooves at all, and a cutter is pressed against the surface of the transport roller to cut the film wrapped around the transport roller.

[Problem to be solved by the invention]

In the first conventional device, the razor blade 3 is fixed. Therefore, a speed difference occurs between the razor blade 3 and the film l being conveyed, and this speed difference increases cutting resistance and friction. Therefore, the deformation in the thickness direction that occurs on the cut surface of the film L is large, and when the film is wound up by the take-up reroller, both end surfaces of the roller bulge out compared to other parts, which is a so-called heel height phenomenon. Due to friction with the film 1, the life of the razor blade 3 is short.

Further, in the second conventional example, the edge height is improved compared to the first conventional example. However, the upper blade 5 and lower blade 4
Since the shape of the cut surface changes significantly depending on the state of contact with the upper and lower blades, strict accuracy is required in terms of contact pressure, biting amount, rotational runout, etc. of the upper and lower blades. Therefore, the second conventional example is a highly accurate equipment compared to one using a razor blade, and is difficult to handle and expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plastic film cutting method and cutting device that can eliminate the hem height of a wound layer such as a take-up roller, have excellent maintainability, and further reduce costs.

Furthermore, another object of the present invention is to provide a plastic film that has less deformation in the thickness direction of the cut surface and can suppress the so-called edge height phenomenon.

[Means to solve the problem]

Claim (1) Shima: The plastic film cutting method according to the present invention is a method in which the film is continuously cut in the transport direction while the film is being transported. In this method, the film is transported by a conveyor roller with grooves on the entire outer circumferential surface, and a rotatable round blade is installed in the groove in the film-wrapping part of the conveyor roller with grooves. The plastic film cutting device according to claim (2), wherein the cutting edge of the cutter is inserted and the round blade cutter is rotated at a rotational speed corresponding to the transport speed of the film to cut the film. This is a device that continuously cuts the film in the transport direction. This device includes a conveyor roller with a receiving blade groove and a round blade cutter.

The conveying roller with receiving blade grooves has receiving grooves formed over the entire circumference of the outer peripheral surface. Further, the round blade cutter is provided opposite to the film winding portion of the conveyance roller with receiving blade groove, and is rotatably supported. Further, the cutting edge thereof is inserted into the receiving blade groove of the conveying roller with receiving blade groove.

The plastic film according to claim (3) has cutting marks formed by the locus of the cutter on the cut surface.

The cutting trace is in a range where the straight line connecting the cutting start point and the cutting end point is 5° or more and 90° with respect to the plane direction of the film.

The plastic film according to claim (4) is the plastic film according to claim (3), which has a cut surface having a cut mark, and 4) a tear protruding in the extending direction of the film. It has a section.

[Effect]

In the plastic film cutting device and the method of cutting by this device of the present invention, the film is wound around a conveyance roller with a receiving blade groove, and is continuously conveyed in a fixed direction by a conveyance system including this roller. On the other hand, the cutting edge of a round blade cutter having a cutting edge in the circumferential direction is bitten in the central portion of the receiving blade groove of the conveyance roller. During the process in which the film is transported by the transport row, the film is continuously cut in the transport direction by the engagement between the round blade cutter and the receiving blade groove.

In such a cutting method and apparatus, compared to a cutting method using a shear blade, there is no need to strictly control the accuracy of the cutter installation, easy mounting, and inexpensive equipment. Further, the round blade cutter is rotatable and rotates at approximately the same rotational speed (peripheral speed) as the film conveyance speed.

Therefore, the cutting resistance and friction between the film and the cutter are reduced compared to the conventional cutting method using a razor blade or pressing, and the deformation of the cut surface in the thickness direction is reduced.
Edge height is prevented.

In particular, in the cutting method and device, the cutting blade of the round blade cutter continuously acts on the film cutting, and the cut surface of the film shows characteristic cutting marks created by the running of the film and the rotation of the round blade. There is a close relationship between the cut marks and the deformation of the cut surface of the film in the thickness direction.

That is, if the circumferential speed of the round blade cutter is slower than the transport speed of the film, the angle of the cutting trace with respect to the plane of the film becomes smaller. If the angle is 5°, the cutter and the film surface will rub a lot, and the cut surface of the film will be greatly deformed.

On the other hand, if the film speed and the circumferential speed of the round blade cutter are very close, the cutting marks will be nearly perpendicular to the plane of the film. In this case, there will be less friction between the cutter and the film surface.
The wound film forms a wound layered body with a small edge height. Furthermore, if the cut surface of the film has a tear portion that protrudes in the direction of film extension, the protrusion in the film thickness direction at the cut surface will be smaller, forming a rolled layered body with a smaller edge height. do.

〔Example〕

First, the general structure of the entire film transport system will be explained with reference to FIG. A film 1 having a width of, for example, 1 meter is wound around the supply roller IO.

A plurality of conveyance rollers 2, 11, 12 are arranged in the conveyance system, and the film 1 is wound around each roller and conveyed. As will be described in detail later, a cutting device for cutting the 1 meter wide film 1 into, for example, 50 cm width is provided at the conveyance roller 2 portion. A take-up reroller 13 for winding up one of the cut films la is arranged downstream of the transport roller 2 in the transport direction. Further, on the downstream side of the conveyance roller 12, a winding roller 14 for winding up the other cut film tb is arranged.

FIGS. 1 and 2 show details of the cutting device disposed in the portion of the conveyance roller 2. In these figures, the conveyance roller 2 has a plurality of receiving blade grooves 2a all around its outer circumferential surface. It is a conveyor roller with receiving blade grooves. The receiving blade groove 2a has a width of 1 to 2 mm and a depth of 2 to 31 mm.
The number is 111.

A round blade cutter 30 is provided opposite the film-wrapping portion of the conveyor roller 2 with receiving blade grooves. Round blade cutter 30
is fixed to the rotating shaft 15 by a presser foot 5.

The rotating shaft 15 is rotatably supported by the housing 8 by a bearing 7 and a bearing retainer 9. Note that the housing 8 is a support frame 16 provided in the conveyance system.
2, and its position in the horizontal and vertical directions in FIG. 2 can be adjusted. Then, the round blade cutter 3
The cutting edge of No. 0 is inserted approximately at the center of the receiving blade groove 2a so as not to contact both side surfaces and the bottom surface of the receiving blade groove 2a.

Next, the cutting method will be explained while explaining the operation of the device.

The film l conveyed from the supply roller 10 is continuously cut in the conveying direction by a cutting device while being conveyed by each conveying roller 11, 2, and is then cut by a winding roller 13.
It is wound up at 14. At this time, the round blade cutter 30 provided in the cutting device rotates at approximately the same speed as the conveyance speed of the film 1 due to cutting resistance with the film 1. Therefore, friction between the film 1 and the round blade cutter 30 is reduced, and deformation of the cut surface of the film in the thickness direction is prevented.

The cut marks formed on the cut surface of the film during the above-mentioned cutting will be explained in detail with reference to FIG. 4. In this FIG. 4, the film l is conveyed from the left side of the figure to the right side,
The round blade cutter 30 is rotated counterclockwise.

The point where a part of the cutting blade of the round blade cutter 30 contacts the film l and starts cutting is 80 degrees, and the cutting blade leaves the film l at 4 degrees.
If the point B is the cut point of the film 1, the mark of the cutting edge left on the cut surface of the film 1 will be a line connecting A and B. In addition, point A is
This is the point at which the A0 point of the film 1 has advanced within the time required for cutting.

As is clear from FIG. 4, when the rotational speed of the round blade cutter 30 is slow compared to the film speed, the angle θ of the cut marks with respect to the film plane becomes small, like AzB. If the angle θ is less than 5°, the friction between the round blade cutter 30 and the film surface will be large (and the deformation of the film cut surface will be large). On the other hand, if the film speed and the rotation speed of the round blade cutter 30 are close to each other, the cutting marks will be Ax
As shown in B, it becomes close to perpendicular to the film plane. When the angle θ is 5° or more and less than 90°, the friction between the round blade cutter 30 and the film surface is small, so the deformation of the cut surface of the film in the thickness direction is small, and the wound film 11 is good with a small edge height. Forms a rolled layered body.

Further, the cross-sectional shapes of the films la and 1b obtained in this example are as shown in FIG. , then a cut portion 50b cut by the cutter 30, and finally a torn portion 50c torn by stress concentration in the film extending direction. As is clear from FIG. 5, the plastically deformed portions 50a are abundant in the film thickness direction, and the tear portions 50c protrude in the film extending direction. Therefore, no protrusion in the film thickness direction is formed on the cut surface 50, and a wound layered body with a smaller edge height can be obtained.

In addition, according to this embodiment, since the friction between the two is reduced, the amount of scraped powder on the film caused by friction is reduced, and furthermore, the life of the cutter edge can be extended.

MJILl Using the apparatus and method of the above embodiment, a polyester biaxially stretched film with a thickness of 10 μm was rolled up to a length of 5000 m under the conditions of a conveying speed of 200 ra/min, a winding tension of 10 kg/m, and a surface pressure of 30 kg/m, and the surface layer was The hardness was determined using a hardness tester type C manufactured by Kobunshi Keiki Co., Ltd., and the average of the five locations in the axial direction of the wound layer was 95°.

The edge height at both ends of the wound layer body at this time was 10 μm or less.

ILJ2 - Example" - When cut with a razor blade and rolled up under the same conditions as in Experimental Example I above, the hem height at both ends of the rolled layer was 70 μm =
It was 1007z+w.

Use a round blade cutter with a real M kanyu, l! “ilIm Polyester 2
When cutting an axially stretched film by the method of the above embodiment, a bearing 7 that rotatably supports the round blade cutter and has a heavy rotational resistance is used, and a length of 4000n+ is wound at a speed of 200 I/min. When rolled up with a hardness of 92°, the hem height at both ends of the rolled layer was 50 μm.

Under similar conditions, when the rotation of the round blade cutter was made lighter and the rotation speed and the film conveyance speed were approximately synchronized, the hem height of the wound layer was reduced to 108 m or less.

When we observed the cutting marks of the round blade cutter on the cut surface of the film, we found that the angle of the cutting marks with respect to the fill l and plane direction was approximately 3° for the former R and approximately 35° for the latter, and the rotational speed of the round blade cutter It has been found that when the speed is closer to the film transport speed, there is less friction between the film and the round blade cutter, and the height of the hem at both ends of the wound layer is reduced.

As described above, in the cutting device and method of this embodiment, the film to be cut and the rotary cutting blade of the round blade cutter are brought into contact with each other at approximately the same speed, thereby making it possible to cut the film with less friction. Therefore, films with low strength and easy to tear (
For example, it is possible to cut from thin films (for example, 11lI11 or less) to thick films of about 100 μm with high cutting resistance. Further, the material of the filter can be polyester, polyolefin, polyethylene, vinyl chloride, etc., and can be used for high-speed cutting and long length products.

In the above embodiment, the round blade cutter is rotatable and is not particularly driven, but it may be actively driven in synchronization with the film transport speed.

〔Effect of the invention〕

According to the present invention, there is no need to strictly control the mounting accuracy of the cutter, and an apparatus that is easy to handle and inexpensive can be realized. Further, it is possible to reduce the friction between the film surface and the round blade and prevent deformation in the film thickness direction.

Furthermore, since this plastic film has little deformation in the thickness direction, it is possible to form a wound layered body in which the edge height phenomenon is suppressed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of a cutting device according to an embodiment of the present invention, FIG. 2 is a cross-sectional configuration diagram showing its details, and FIG. 3 is a diagram showing the entire film conveyance system in which the cutting device is arranged. 4 is a diagram showing the action of the film 1 during cutting, FIG. 5 is a vertical cross-sectional partial view of the obtained film, FIG. 6 is a diagram showing the first conventional example of the cutting device, and FIG. is a sectional view taken along the line ■-■ in FIG. 6, FIG. 8 is a diagram showing a second conventional example of the cutting device, and FIG.
The figure is a sectional view taken along line IX-IX. DESCRIPTION OF SYMBOLS 1... Plastic film, 2... Conveyance roller with receiving blade groove, 2a... Receiving blade groove, 6... Rotating shaft, 7...
Bearing, 11.12... Conveyance roller, 30...
Round blade cutter, 50...cutting surface, 50b...cutting trace part, 50c...tearing part. Figure 1 Figure 2

Claims (4)

[Claims] (1) Plastic film transported in a certain direction,
A cutting method for continuously cutting in the conveying direction, which involves conveying a plastic film with a conveying roller with a receiving groove formed on the entire outer circumferential surface, and in the conveying process, Insert the cutting edge of a rotatable round blade cutter into the receiving blade groove of the plastic film wrapping portion of the conveying roller with receiving blade groove, and rotate the round blade cutter at a rotational speed corresponding to the conveying speed of the plastic film. A method for cutting a plastic film, comprising: cutting the plastic film. (2) Plastic film transported in a certain direction,
A cutting device for continuous cutting in the conveying direction, which includes a conveyor roller with a groove for conveying a plastic film, in which a groove is formed along the entire outer circumference of the outer circumferential surface, and a conveyor roller with a groove for the groove for conveying the plastic film. A plastic film cutting device comprising: a round blade cutter that is provided opposite to the plastic film wrapping portion, is rotatably supported, and whose cutting edge is inserted into the receiving blade groove of the receiving blade grooved conveyance roller; . (3) A plastic film having a cutting mark formed by the locus of a cutter on the cut surface, wherein the cutting mark has a straight line connecting the cutting start point and the cutting end point with respect to the plane direction of the plastic film. A plastic film with an angle of 5° or more and less than 90°. (4) The cut surface includes a cut trace portion having the cut trace;
The plastic film according to claim 3, further comprising a tear portion projecting in the film extending direction.