JPH02109859A - Perforated bag made of synthetic resin film and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a bag good in permeability and not affected by rain or the like by a method wherein a bag made of two faces of a surface and a rear face formed by sealing and cutting a tubular thermoplastic synthetic resin film perpendicular to a lengthwise direction is provided with a plurality of holes on either of the two faces of the front or the rear. CONSTITUTION:A plate 14 of required size covered with soft and smooth cloth is put in at the time of start up of a bag manufacturing machine or by tearing a film 10. The plate 14 is made of a chamfered thin iron plate, a gypsum board or the like. The plate does not rise with the film but maintains its position at a lower position of a roll 12 by its own weight. On the other hand, one of the faces of the plate 14 is provided with a heater 16 having a required number of heating needles 15, wherein the heater operates toward the plate 14 when the need arises by normal electric means to press the film 10 together with the plate 14 with the heating needles 15 to form melt holes at required positions on the film. The film 10 provided with the holes reaches via rolls 17 and 18 a horizontal section 19 where it is heat-sealed by a heat-sealing section 11 and then cut via a feeding roll 19.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to packaging made of synthetic resin film provided with ventilation holes, which is used for packaging powder, granules, especially powder, granules, fertilizers, feeds, etc. This article relates to a bag and its manufacturing method.

[Conventional technology]

Packaging containers for powder, granular fertilizers, feed, etc. are generally made of synthetic resin film formed into a tube shape using the inflator method, which is cut using a continuous packaging bag manufacturing device, and one end is cut. Packaging bags formed by sealing are used, but since the surface of the bag is airtight, depending on the type of contents, the quality may deteriorate due to caking, stuffiness, fermentation, etc. To prevent this, bags with ventilation holes are used.

This vent is generally formed by two methods.

The - method is carried out using an ordinary packaging bag continuous manufacturing device, that is, a third
As shown in the figure, a film supply roll 51 and a film pull-out roll 52 each have a tube-shaped film rolled into a band.
This is done by setting a conical hole jig 56 between the sealing hot plate 53 and the film feeding roll 54 in an apparatus composed of a sealing hot plate S3, a film feeding roll 54, and a cutting blade 55. There is.

In this case, the holes are formed by vertically operating the jig 56 from above the horizontally flowing 41B. Therefore, the hole is naturally
Two film surfaces, top and bottom (front and back) when forming a bag
2, and because a cone-shaped jig is used, the holes formed are dip holes, and from the properties of the target resin film, it is possible to obtain holes with a controlled desired diameter. It is difficult.

Another method is to form punch holes, and after the packaging bag is formed by the manufacturing equipment,
The required number of sheets are piled up and holes are formed using a blank hole jig or a device equipped with a blank hole jig. In this case as well, the holes are formed on both the upper and lower (front and back) sides of the bag, as described above. Furthermore, in this case, due to the nature of the jig, it is difficult to provide holes with a diameter of 3 m/m or less.

[Problem that the invention seeks to solve]

Generally, fertilizers, feed, etc. stored in packaging bags are handled by the seller.
When they are delivered, they are usually left piled up in the gardens of farmers, who are the consumers, or on the roadside in fields. For this reason, when it rains, if the bag has ventilation holes on both the top and bottom (front and back), rainwater will enter the bag through the holes on the top, causing the contents to solidify, steam, and ferment. A problem arises in that the quality deteriorates. Therefore, businesses and consumers want to use perforated packaging bags with good air permeability to prevent the contents from condensation and stuffiness due to the airtightness of the bag.However, since the holes are on both sides of the bag, There are problems such as. In order to prevent this problem, a cone-shaped jig with many small holes is used.However, as mentioned above, the hole formed is a difference hole.
Also, since the material of the bag is a resin film, it is difficult to obtain a hole with a desired diameter under controlled conditions. In other words, since the hole formed by the conical jig is an immediately opened hole, the initial diameter is 11 mm.
/Even if it ranked No. 1, the pores became smaller and closer to being blocked over time, resulting in insufficient ventilation, and there was also the problem that the effects of rainwater could not be completely avoided. .

In addition, the method of forming the open holes has the problem that after the bags are made as described above, the desired number of bags are stacked and the open holes are formed using a punching jig, which increases the number of steps. The problems caused by holes being formed on both the top and bottom (front and back) of There was a problem that pores of 3 m/m or less could not be formed.

The present invention was devised in order to solve the problems of the prior art as described above, and despite having a desired diameter and required number of ventilation holes, it has good air permeability and is not affected by rainwater, etc. It is an object of the present invention to provide a packaging bag that does not receive any damage, and to provide a method for continuously producing this packaging bag.

[Means for solving problems]

The packaging bag of the present invention is a packaging bag formed by sealing and cutting a tubular thermoplastic synthetic resin film in a direction perpendicular to its longitudinal direction, and has two sides, one of the front and back sides. It consists of a structure in which a plurality of holes are provided on one side.

Raw materials for thermoplastic synthetic resin films include polyvinyl chloride, polyethylene, polystyrene, polypropylene,
One or a mixture of two or more synthetic resins such as nylon may be used.

The tubular synthetic resin film is preferably formed by an inflation method using the above raw materials, but may be formed by other methods.

The method for manufacturing perforated packaging bags of the present invention uses a conventional synthetic resin film packaging bag continuous manufacturing apparatus, that is, an apparatus mainly composed of a film supply roll wound with a tubular synthetic resin film and a cutting section. Two sets of rotating rolls, each consisting of a pair of rotating rolls, are provided at a distance in the vertical direction, and the tubular film is sandwiched between the film supply roll and the sealing part and is caused to pass through continuously. A plate covered with a flexible cloth is inserted into the film passing between the rotating rolls, and a hole provided on one side between the two sets of rolls is used to pass the film through the plate using the heating needle of the device. The process consists of pressing the film toward the body side to form melt holes on the film surface.

Hereinafter, the packaging bag of the present invention will be explained based on FIG. 1, and the manufacturing method thereof will be explained based on FIG. 2.

In Fig. 1, a packaging bag 1 is made by forming a sealing part 2 and cut parts 3, 4 in the longitudinal direction (in the direction of the arrow in the figure) by a manufacturing method according to the present invention, which will be described later. One side 6 of the bag is provided with three holes θ near and parallel to the sealing part 2, and three holes 7 near the cutting part 4 and parallel to it. As described above, the packaging bag of the present application is provided with ventilation holes only on one side thereof.

FIG. 2 is a diagram of main parts of a continuous packaging bag manufacturing apparatus for carrying out the manufacturing method according to the present application. The main parts of this device are the same as the conventional one. In FIG. 2, the film 10 is pulled out by the pull-out roll 9 from the film supply roll 8 on which the tubular film has been wound up. Two sets of rotating rolls 12 consisting of a pair of rotating rolls
13 are provided at a required distance. The film 10 rises vertically from the rotary roll 12 and passes through the rotary roll 13 in the direction of heat sealing. In this case, the film 10 contains the rotary roll 1
Between 2 and 13, a plate 14 of a required size covered with a soft and slippery cloth is inserted in advance at the start of the bag-making machine or by tearing the film lO. This plate 14 is made of a thin iron plate or a right front board, etc., and even if the film 10 passes upward, it will not rise with the film due to frictional resistance since it is covered with the cloth as described above. This does not occur and the roll 12 can maintain its position on top of the roll 12 due to its own weight. On the other hand, a heating device 16 having a required number of heating needles 15 is provided on one side of the plate 14, and this is operated by ordinary electrical means in the direction of the plate 14 when necessary to heat the film 10 on the plate. 14 and the heating needle 15, it is possible to form melt holes in desired areas of the film. Note that by adjusting the operating stroke of the heating needle 15, the diameter can be adjusted to 0.
Holes from 5 m/m to 3 m/m can be freely selected. The film 10 provided with holes is then rolled into a roll 1.
7 and 18, it reaches a horizontal part 19, where it is heat-sealed by a heat-sealing part 11, passes through a delivery roll 19, is cut by a cutting part 21, and is collected on a collection shelf 22 as a bag. In this way, packaging bags having ventilation holes only on one side as shown in FIG. 1 are continuously obtained. Although not shown, a plurality of support rolls equipped with springs are provided on both sides of the plate 14 to maintain the verticality of the plate. Furthermore, since the operation time is instantaneous when forming the melting hole with the heating needle 15, there is no fear that the cloth or film covering the plate body 14 will be damaged.

〔Example〕

Continuous manufacturing of packaging bags 2 as shown in FIG. 2 explained above
A bag-making operation was carried out using a tube-shaped vinyl chloride resin film obtained by the inflation method, having a thickness of 0.15 m/a+, a length of 500 m, and a width of 500 m/m wound onto a roll, as a raw material using a vacuum cleaner. By adjusting the heating needle, as shown in Figure 1, only one side of the bag can be heated. is formed by melting with a heating needle, and by continuing the operation, it has a width of 50 mm (1 m/m, length of 750 mm).
660 packaging bags of m/shoe size were manufactured.

The manufacturing capacity was comparable to the conventional method of providing ventilation holes on both sides of the bag using a concave needle. Also, the holes provided should be managed.
A beautiful piece with a diameter of 2■/11 was cut by 1υ at Ut. In addition, during the operation, the film in a close contact state is once expanded by the plate, and it has been found that this expansion makes an unexpectedly large contribution to preventing blocking after bag making.

[Experiment example]

Ten bags manufactured by the above method were filled with caking powder compound fertilizer, and the same number of holes with a diameter of 2 m/m were drilled into the bags using a cone-shaped long hole jig using the conventional method. Ten bags were prepared on both sides in the same position. Although the holes were made using a long-hole jig, the holes were not aligned, and some of them were blocked.

Ten bags each were placed in two rows of five stacks in the open air. In this case, the packaging bags of the present invention were stacked with the holes facing down.

Water was applied from the top for 30 minutes, equivalent to rainfall ffi 20 m/+/ 1 hour.

When observed after 48 hours, no caking was observed in the group of the present invention, but caking was observed in all of the samples with holes provided on both sides.

〔Effect of the invention〕

Since the packaging bag of the present invention is constructed as described above, when it is stored in the open, even in rainy weather, by placing the bag with the ventilation hole facing down, the influence of the rain can be eliminated to the maximum extent possible. Furthermore, since the method of the present invention can be incorporated into a continuous packaging bag manufacturing device, it greatly contributes to the rationalization of manufacturing packaging bags with ventilation holes provided only on one side. In addition, by making the ventilation holes melt holes, it is possible to obtain a controlled condition, that is, a constant quality, so by adjusting the diameter and number of the ventilation holes depending on the quality of the fertilizer, feed, etc. to be filled, good control of the contents can be achieved. It has become possible. Furthermore, the provision of a step of temporarily expanding the film during the manufacturing process is an unexpected advantage of this method, since it greatly contributes to preventing blocking of the subsequently manufactured bag.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a packaging bag of the present invention. FIG. 2 is a diagram of the main parts of a continuous manufacturing apparatus for packaging bags according to the method of the present invention. FIG. 3 is a diagram of the main parts of a conventional packaging bag continuous manufacturing device. Explanation of symbols 1...Packaging bag of the present invention, 8...Film supply roll 9...Drawer roll, 12.13...Rotating roll. 14... Plate covered with soft cloth, 15... Heating needle, 16... Heating device Figure 2 Figure 3 Representative Patent Attorney 1) Osamu Shiro

Claims (1)

[Claims] 1) Front and back surfaces 2 formed by sealing and cutting a tubular synthetic resin film in a direction perpendicular to its longitudinal direction.
1. A perforated packaging bag made of a synthetic resin film, characterized in that the packaging bag has a plurality of holes for ventilation on one of the front and back sides. 2) The packaging bag according to claim 1, wherein the plurality of holes for ventilation are fused holes. 3) A method for manufacturing packaging bags using a synthetic resin film packaging bag continuous manufacturing device configured with a tubular synthetic resin film supply roll and a sealing part and a cut part as main parts, in which the film supply roll and Two sets of rotating rolls, each consisting of a pair of rotating rolls, through which the tubular film is sandwiched and continuously passed through the sealing part, are provided at a distance in the vertical direction, and a distance between the two sets of rotating rolls is provided between the two sets of rotating rolls. A plate previously covered with a flexible cloth is inserted into the film passing through the film, and a heating needle of a perforating device provided on one side between two sets of rolls is used to push the film toward the plate side. A method for producing a perforated packaging bag made of a synthetic resin film, which comprises pressing the film to form melt holes on the film surface.