JPH01133725A - Manufacture of corner-less bag body - Google Patents

Abstract

PURPOSE: To manufacture a complete bag without corner by repeating a series of steps of synchronously interlocking a main cutter with a corner cutter after cutting by side sealing, and again resetting the corner cutter to a notch cutout position. CONSTITUTION: A film 1 is intermittently transferred via a feed roller 5 and a take-up roller 6, and a corresponding site of a line 3 to be scheduled to be cut of a side seal 2 is temporarily stopped on a line Y-Y'. And, both edges of the seal 2 are cut in a round shape (or V shape) by descending of corner cutters 14 to form notches 4. The cutters 14 are returned to raised ends, and a moving base 10 is, for example, shifted to left by a distance corresponding to a predetermined interval S between the cutters 14 and a main cutter 17 together with a column 11. The cutter 17 and lower blade 19 corresponding thereto are disposed on the line Y-Y'. The seal 2 is cut by the descent of the cutter 17. When the cutter 17 is returned to the raised end, the base 10 is moved to left at a predetermined shift amount, and the cutters 14 are reset on the line Y-Y'.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a plastic film bag, particularly a cornerless bag.

<Prior art> The general manufacturing method for plastic film bags is 2.
The folded plastic film is intermittently transferred using a take-up roller, side seals of a required width are applied to the plastic film at predetermined intervals in a direction perpendicular to the transfer direction using a heat seal bar, etc., and the side seals are applied using a cutter. It is separated by cutting within the width. in this case,
Right-angled corners are formed at the four corners of the bag. These sharp corners have caused problems such as punctures on fingertips when bagging items, or damage due to punctures of other bags.

In order to solve this problem, Japanese Patent Publication No. 44263 (1973) discloses a method for manufacturing a bag with cut corners.

A notch is inserted, and when a tangent line is drawn at or near the center of the bottom of the notch, the slope of the tangent line is zero or substantially zero, and after inserting the notch, the side seal is formed by heat. This method involves fusing at the same time.

<Problems to be Solved by the Invention> The above-mentioned conventional method positions the welding and welding within a certain tolerance range in the width direction of the notch to avoid leaving uncut pieces on the side of the lip. A force notching cutter and a thermal force are placed at separate locations along the direction of film travel, and the notching and side seals are fused at separate locations. Therefore, in order to position the fusing and welding within a certain tolerance range in the width direction of the notch, it is necessary to set the transfer speed of the film and the timing of the activation of the thermal power. The above-mentioned timing setting work for adapting to different types of bag manufacturing poses a serious problem.

In addition, even if the above timing is set, when the film is transferred by the roller, the welding and welding position may fall outside of a certain tolerance range in the width direction of the notch due to slack or elongation of the film, so there will always be uncut parts left uncut. It is not possible to obtain a product with no corners, and furthermore, even if the melting and welding is done within a certain tolerance range, if the melting and welding point is at the very edge of the tolerance range, there will be some uncut parts. There is a problem with corner angles.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems of the conventional art, and is characterized by the fact that the two-folded plastic film, which is intermittently transferred by a take-up roller, is moved in the transfer direction. a step of forming side seals with a required width at predetermined intervals in a direction perpendicular to the side seal; a corner cutting step of notching both ends of the side seal into a shape or V-shaped notch with a corner cutter; and a step of cutting the side seal with the corner cutter after cutting the notch. It consists of a step of cutting and separating the side seal portion with a main cutter that moves in synchronization to a point where the ridge line of the notch matches, and after the completion of the side seal cutting step, the main cutter and a corner cutter move in synchronization to cut the corner cutter. The series of steps described above for returning the notch to the cutout position is repeated.

According to the above structure, the present invention uses a corner cutter to form a notch or a V-shaped notch at both ends of the side seal while the intermittent film is stopped, and then cuts the ridgeline of the notch by working integrally with the corner cutter. The main cutter shifts to the matching point to cut the side seal portion.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, ``■'' is a plastic film (hereinafter simply referred to as a film), on which side seals 2 of a required width B2 are applied at predetermined intervals B1 by a well-known side sealing device (not shown). 3 indicates a planned cutting line to be cut by a main cutter 17, which will be described later. 4 is a notch cut into a shape (hereinafter referred to as an R shape) by a corner cutter 14, which will be described later. This notch 4 is inserted into both end edges of the side seal 2. 5 is a feed roller for the film 1, and 6 is a take-up roller. The film 1 is transferred intermittently by the feed roller 5 and the take-up roller 6. Y-Y' is a corner cut portion where notches 4 are inserted in both end edges of the side seal 2, and also a cutting portion. That is, both
are at the same position on Y-Y'. Therefore, the intermittent transition of the film 1 is caused by the planned cutting line 3 of the side seal 2 portion.
moves intermittently so that it stops at the 'y'-Y' position.

7 is a corner cutting and cutting device. The configuration of this device will be explained below. First of all, the corner cutting and cutting device 7 is arranged between the feed roller 5 and the take-off roller 6. 8 is a fixed base installed on the floor. A pair of kite rods 9 are installed on the fixed base 8 with axes in the same direction as the transfer direction of the film 1, and a movable table 10 is guided by the kite rods 9 so as to be slidable in the axial direction. Further, a moving table cylinder 12 is fixedly installed on the front wall of the fixed base 1, and its piston rod 13 is connected to the moving table 10.
is combined with

A gate-shaped column 11 that can run through the film 1 to be transferred is integrally fixed on the moving table 10, and a corner cutter 14 and a main cutter 17 are attached to this column 11 at a constant interval in the transfer direction of the film 1. S are arranged in parallel and are movable up and down.

15 is a cylinder for lifting and lowering the corner cutter 14;
is a cylinder for raising and lowering the main cutter 17.

The main cutter 17 is a single piece having an oblique blade over its entire length in the left and right direction when viewed from the front in FIG. Also,
A pair of left and right corner cutters 14 are configured to cut both ends of the noid seal 2. The pair of left and right corner cutters 14 are not shown in the drawings so as to be compatible with bags of various widths, but they can be moved and adjusted to change the size of the left and right spacing. Furthermore, the corner cutter 14 is R
It is rectangular (or Y-shaped).

On the other hand, on the movable table 10 there is a lower blade 16 corresponding to the corner cutter 14 and a lower blade 1 corresponding to the main cutter 17.
9 has been installed. Incidentally, when the corner cutter 14 is movable and adjustable, the corresponding lower blade 16 is also movable and adjustable.

Therefore, in the present invention, in the above structure, the film 1 is moved intermittently by the feed roller 5 and the take-up roller 6, and a portion corresponding to the scheduled cutting line 3 of the side seal 2 is temporarily stopped on the line YY'.

First, move the corner cutter 14 downward as shown in FIG.
Go to cup 1 and insert notch 4.

When the corner cutter 14 is returned to the rising end, the moving table cylinder 12 moves the moving table 10 together with the column 11 to the first position.
Shift to the right in the diagram. This shift amount corresponds to a constant distance S between the corner cutter 14 and the main cutter 17. As a result, as shown in FIG. 2, the main cutter 17 and the corresponding lower blade 19 are
The main cutter 17 is located on the Y' line -1-, and the main cutter 17 is correctly located at the ridge line matching point of the notch 4. Therefore, when the main cutter 17 is moved downward to cut the Zydo seal 2,
Cut between the ridge line matching points of the notches 4 on both ends of the side seal 2, that is, the matching ridge lines at any i1 of the Y shape, and cut between the n points, and cut each corner part as shown in A in Fig. 2. At C, a bag with no uncut corners is cut off from the film 1.

After cutting with this main cutter 17 and returning the main cutter 17 to the rising end, the movable table 10 moves to the left in FIG.
4 is returned to the Y-Y' line.

Then, the cut bag body is sent out by the take-up roller 6, and the film 1 is transferred by the take-up roller 6 by the feed roller 5, and then cut from the corner cut 1 to the side to be cut. The seal 2 is stopped on the Y-Y' line and cycles similar to those described above are repeated and continuously performed.

Note that the plastic film also includes a multilayer film in which paper or aluminum foil is coated with a plastic film.

<Effects of the Invention> As can be seen from the above explanation, the notch portion of the bag manufactured by the present invention does not have any uncut pieces such as sharp corners due to miscutting, and a completely cornerless bag can be obtained. This eliminates the possibility of injury to fingertips or the possibility of the corners piercing other bags and causing the bags to break.

Further, according to the present invention, the corner cutter and the main cutter are shifted together at a predetermined interval, and the main cutter is precisely positioned at the matching point of the ridge line of the notch cut by the corner cutter, so there is no deviation in the slant cutting. If the original film is printed, the center portion between the prints can be cut accurately, making it possible to form a bag without shifting the print position. Furthermore, even with the conventional overlapping cutting method, the limit is to overlapping 3 to 4 sheets, but even in the case of a bag with a zipper, continuous perfect angular cutting of -1,0- is possible at the stage of the original film. This makes it possible to provide a bag that is extremely efficient and inexpensive to manufacture.

[Brief explanation of the drawing]

The drawings show an embodiment of the method of the present invention; FIG. 1 is a side view of the corner cut state, FIG. 2 is a side view of the main cutter 1, and FIG. 3 is a view in the direction of the arrow 1 in FIG. 1. 1...Film, 2...Side seal, 4...Notch, 5...Feed roller, 6...Take-up roller, 1
0...Moving table, 11...Column, 14...Corner cutter, 16...Lower blade, 17...Main cutter, 1
9...Lower blade. Patent applicant: Seisaku Nippon Sha Co., Ltd.

Claims (1)

[Claims] A step of side-sealing a folded plastic film of a required width at predetermined intervals in a direction perpendicular to the direction of transfer of a plastic film that is intermittently transferred by a take-up roller, and cutting both edges of the side seals with a corner cutter. (2) a corner cutting process of notching a notch in the form of a shape or a V-shape; and a process of cutting and separating the side seal portion with a main cutter that is moved to a matching point of the ridge line of the notch in synchronization with the corner cutter after cutting the notch. A method for manufacturing a cornerless bag body, characterized in that after the side seal cutting step is completed, a main cutter and a corner cutter are synchronously interlocked to return the corner cutter to the notch cutout position.The above series of steps is repeatedly performed.