JP2003011920A - Method and apparatus for opening plastic bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of opening a plastic bag with which the bag can be stably opened without breaking by pin holes when a pin is inserted into the two pin holes provided on an extension of one of rims of an opening to open held bags one by one. SOLUTION: The pin 4 with an upper end open is inserted into a pin hole 3 formed on an extension 2 of a lower rim of an opening O of a plastic bag 1 to keep plastic bags 1 stacked, and the extension 2 is pressed by a center holding member 5 between the pin holes 3. Air 7 with a temperature of 50 to 80 deg.C is blown from an air nozzle 6 in this state to have the opening O of the bag 1 partially opened. An opening member 9 is inserted into the opening to enlarge the opening or the bag. The pin 4 is drawn out of the pin hole 3 at this time. When the center holding member 5 is opened to discharge the opened bag, the lower bag is held by side holding members 11 on extensions 2 on both external sides of the pin holes 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag opening method and a bag opening device, and more particularly, one edge of an opening is extended and an upper end is opened in two pin holes provided in the extension. The present invention relates to a method and an opening device for opening the plastic bags held by inserting the pins.

[0002]

2. Description of the Related Art In an apparatus for packaging and packing articles in a plastic bag for packaging, it is necessary to open the bags held in a stacked manner one by one. In order to facilitate the operation of stacking the packaging bags and opening them one by one from the top, conventionally, as shown in FIG. 4, one edge of the opening 0 is extended to form an extension 2. Forming a plastic bag 1,
Two pin holes 3 are provided in the extension portion 2, and the pin 04 is inserted into the pin hole 3 as shown in FIG.
A method has been adopted in which the plastic bags 1 in this state are opened one by one from the top and the items are put therein.

When the pins 04 are inserted into the pin holes 3 as shown in FIG. 5 and the bags held therein are opened and used one by one, the plastic bag 1 must be removed from the pins 04. Conventionally, an article is put in the plastic bag 1 with the pin 04 inserted in the pin hole 3 and the plastic bag is torn off at the pin hole 3 portion by using the force at that time. Reference numeral 05 is a perforation provided so that the plastic bag 1 can be easily torn off at the pin hole 3.

Since the broken piece remains in the pin hole 3 portion in the plastic bag 1 thus torn off in the pin hole 3 portion, and the appearance of the packaged product is impaired, the present applicant has previously made the upper end as shown in FIG. The plastic bag 1 is held by inserting the hole of the plastic bag 1 into the opened pin 4, and when the bag is opened by blowing air obliquely from above into the opening 0 of the plastic bag 1, the plastic bag 1 is not broken. A method has been proposed in which the hole is pulled out from the pin 4 to open the bag (Japanese Patent Laid-Open No. 2000-255514).

However, in this opening method, the plastic bag 1 is attached to the center holding member 5 at one place inside the pin hole 3.
If the holding member 5 is opened when the opened bag is sent out, the laminated plastic bags 1 may be disturbed or the bags may be displaced to hinder the opening operation. It was

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, one edge of an opening portion is extended, and a pin having an open upper end is inserted into two pin holes provided in the extension portion of the edge so as to be laminated. (EN) Provided are a plastic bag opening method and a plastic bag opening device capable of smoothly opening a held plastic bag when air is blown obliquely from above and opening one by one from above. That is the issue.

[0007]

According to the present invention, in order to solve the above-mentioned problems, one edge of an opening is extended, and a pin whose upper end is opened in two pin holes provided in the extension of the one edge. In a method of opening a plastic bag in which the plastic bags held by stacking and holding the same are blown obliquely from above to open the plastic bags one by one from above, the extension is provided between the two pin holes. And the side holding members on both outsides of the pin holes, the side holding members are released when air is blown obliquely from above to open the bag, and the stacked bags are released when the opened bag is discharged. A method for opening a plastic bag is provided in which the remaining bag is pressed by the side holding member to release the center holding member.

In the bag opening method according to the present invention, since the extension of the edge of the opening is pressed by the center holding member between the two pin holes and air is blown obliquely from above toward the opening of the bag, the bags are stacked. It is partially opened while being held in position, with the bag's pin holes coming out of the pins.

When an opening member that expands in the up, down, right and left directions is inserted into the opening formed in this way to expand the opening, the extended lower edge of the bag extends in the middle of the pin hole. The pin is lifted up except for the part held by the center holding member, so that the pin hole that has not come out of the pin also comes out of the pin whose upper end is open.

As described above, the plastic bag is not torn at the pin hole and is disengaged from the pin and the opening is expanded so that the item to be packaged can be received. Unlike the conventional bag, the bag opened in this manner has no broken pieces around the pin hole portion, and a packaged product having an excellent appearance can be produced. After the bag is opened as described above, the bag laminated under the opened bag is held by pushing the extension portions of one edge on both outsides of the pin holes by the side holding members. Even if the center holding member is opened when the opened bag is discharged, the stacked bags are pressed by the side holding members and the stacked state is not disturbed.

In this way, at least one of the center holding member and the side holding member is always in contact with the upper surface of the stacked bags, and the upper surface of the stacked bags is pushed up from below. In response, the upper surface is always held at a constant height. According to the opening method of the present invention, it is possible to open the stacked plastic bags one by one in a stable state from the top.

In the bag opening method of the present invention described above, when the temperature of the air blown to open the bag is raised, the temperature of the opened bag is raised and its flexibility is increased, so that the item to be filled should be It can be smoothly inserted into the bag, and the bag will not be torn by the insert.

Further, in order to solve the above-mentioned problems, the present invention provides two pins having an open upper end to be inserted into a pin hole formed in an extension of one edge of the opening of the bag, and the inside of the pin. A center holding member that is disposed between both pins to press and release the lower edge portion of the bag, and a side holding member that is disposed on both outsides of the pin and that presses and releases the lower edge portion of the bag outside the both pins. There is provided a plastic bag opening device having a member and air blowing means for blowing air between the two pins from obliquely above.

According to this plastic bag opening device,
The above-described opening method of the present invention can be smoothly carried out.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for opening a plastic bag according to the present invention will be specifically described with reference to the embodiments shown in FIGS. 1 to 3, reference numeral 1 denotes a plastic bag for packaging, which is closed except for the opening 0. One edge of the opening 0, that is, the lower edge in the drawing is extended, and the extension 2 is formed with two pin holes 3 spaced from each other.

The plastic bags 1 formed in this way are laminated and held by inserting the pin holes 3 into the two pins 4 which are open at the top. The extended portions 2 of the laminated plastic bags 1 are pressed between the pin holes 3 by an appropriate center holding member 5. Further, the laminated plastic bag 1 has the edge 2 on the outside of the pin hole 3 and the side holding member 1
Hold down with 1.

The laminated plastic bags 1 are pushed up from below with a predetermined pressure by an air cylinder or the like,
The pushing force is applied to the center holding member 5 and the side holding member 1.
1, the upper surface of the laminated plastic bag 1 is always kept at the same level.

After the plastic bags are held in a laminated state as described above, the pressure by the side holding member 11 is released and air 7 is blown from the obliquely upper direction toward the opening 0 of the plastic bag. The opening 0 of the uppermost bag is opened as shown by the solid line 8 in FIG.

The air 7 blown from the air nozzle 6
Is hot air having a temperature of 50 to 80 ° C., which raises the temperature of the bag to be opened and enhances its flexibility, so when the bag is filled with an item, the bag is torn at a corner or the like of the item. Can be prevented. The specific temperature of the air is selected in consideration of the material and thickness of the bag used, the shape and hardness of the product to be filled, and the like. In this way, the opening member 9 is attached to the opening formed by the air 7 from the air nozzle 6.
Is inserted. The opening member 9 includes a lower bar 9-1 (two bars) and an upper bar 9-2 (two bars) that can expand and contract the mutual spacing.
It has 4 bars.

After the opening member 9 is inserted into the opening of the bag, the upper bar 9-2 is displaced upward, and the opening of the bag is expanded as shown by an imaginary line 10. By the partial opening operation of the bag by the air 7 or the expansion operation of the opening by the opening member 9, the pin hole 3 into which the pin 4 has been inserted is pulled out from the pin 4 whose upper end is open, and at this time, the extension portion 2 cannot be broken at the pin hole 3.

As described above, even if the pressing by the side holding member 11 is released, the upper surface of the laminated plastic bag 1 is subjected to the pushing-up force from below by the center holding member 5, and the upper surface of the plastic bag 1 is always the same. It is designed to be maintained at the height. After the top bag is pulled out from the pin 4, the bag stacked under the opened bag is held by the side holding member 11 as shown in FIG.

After the bag 1 is opened to the maximum extent by the opening member 9 in this manner, the articles to be packed are filled in the bag through the opening. It should be noted that the pressing force of the holding member 5 is weakened before filling the bag 1 with the product, during the filling operation, or after the filling operation so that the opened top bag 1 is released from the stacked state. May be.

When the bag filled with the goods is discharged, the center holding member 5 opens the edge 2 of the bag. Even if the center holding member 5 releases the bag holder, the extension 2 at the edge of the bag is pin 4
The side holding members 11 are pressed on both outer sides of the bag so that the stacked state of the bags is held in an orderly manner, and the pushing force from below against the stacked plastic bags 1 is received by the side holding members 11, and the upper surface of the plastic bag 1 Is held at a constant height. Further, as the opening member 9, a member that is inserted into the opening of the bag 1 and is configured to expand the opening in the up-down direction, the left-right direction, or the up-down and left-right directions is used in the shape and size of the bag to be opened. It may be appropriately selected and used accordingly.

The present invention has been specifically described above based on the illustrated embodiments, but the present invention is not limited to these embodiments, and its specific structure is within the scope of the present invention shown in the claims. Needless to say, various modifications may be added to the configuration.

For example, in the above-described embodiment, the opening member 9 has a structure in which the upper bar 9-2 is displaced straight upward to expand the opening of the bag. An opening member configured to expand the opening by displacing obliquely upward and obliquely downward by 45 ° may be used, and in short, a well-known opening expanding member of this type may be appropriately adopted.

Further, in the above embodiment, the air 7 blown from the air nozzle 6 is used as hot air having a temperature of 50 to 80 ° C. to raise the temperature of the bag to be opened to enhance its flexibility. When the outside air temperature is high, such as in summer, or when the bag is made of a flexible plastic material, it is not necessary to use hot air, and air at room temperature may be used.

[0027]

As described above, according to the present invention, one edge of the opening portion is extended, and the pin having the open upper end is inserted into the two pin holes provided in the extension portion of the one edge to be laminated. In the method of opening a plastic bag, in which the plastic bags held by the above are blown with air obliquely from above and opened one by one from above, the extended edges are pressed by the center holding member between the two pin holes. The side holding members are pressed on both outsides of the pin holes, the side holding members are released when air is blown obliquely from above to open the bag, and when the opened bag is discharged, the remaining laminated bags There is provided a method for opening a plastic bag in which the side holding member is pressed to release the center holding member.

According to this opening method, the extension portion, which is formed by extending one edge of the opening portion of the bag, is opened while pressing the center holding member between the two pin holes. It can be pulled out and opened at the pin hole without breaking the bag. Further, when a bag with the center holding member opened is discharged, the stacked bags are held by being held by the side holding members at their extension portions.

Therefore, at least one of the center holding member and the side holding member is always on the upper surface of the stacked bags so as to receive the force of pushing up the stacked bags from below. Is always held at a constant height. In this way, according to the bag opening method of the present invention, it is possible to stably produce a bag packaged product having no portion torn at the opening.

In the bag opening method of the present invention described above, the method of raising the temperature of the air blown to open the bag raises the temperature of the opened bag to increase its flexibility, The item to be filled can be smoothly inserted into the bag, and the bag is not broken by the inserted item.

Further, according to the present invention, the upper end to be inserted into the pin hole formed in the extension portion of one edge of the opening of the bag is opened.
A pin, and a center holding member that is arranged inside the pin and that presses or releases the lower edge of the bag between the pins,
Plastic having side holding members arranged on both outer sides of the pin for pressing or releasing the lower edge portion of the bag on the outer sides of both pins, and air blowing means for blowing air between the two pins obliquely from above. A bag opening device is provided.
According to this plastic bag opening device, the above-described opening method of the present invention can be smoothly carried out.

[Brief description of drawings]

FIG. 1 is a plan view showing laminated plastic bags to which an opening method according to the present invention is applied.

FIG. 2 is an explanatory view showing a state in which the opening method according to the present invention is applied to the plastic bag shown in FIG.

FIG. 3 is a side view taken along arrow A in FIG.

FIG. 4 is a sectional view of the bag shown in FIG.

FIG. 5 is a perspective view showing a conventional bag opening method.

FIG. 6 is a sectional view showing an improved conventional bag opening method.

[Explanation of symbols]

0 opening 1 plastic bag 2 extension 3 pin hole 4 pin 5 Center holding member 6 air nozzles 7 air 9 Opening member 9-1 Lower bar 9-2 Upper bar 10 bag openings 11 Side holding member

Claims (3)

[Claims] 1. A plastic bag, in which one edge of an opening is extended, and a pin having an open upper end is inserted into two pin holes provided in the extension and stacked and held, is aired obliquely from above. In a method of opening a plastic bag by spraying and opening one by one from above, the extension portion is pressed by a center holding member between the two pin holes, and is pressed by side holding members on both outer sides of the pin hole, and diagonally upward. When the bag is opened by blowing air from the side holding member, the side holding member is released, and when the opened bag is discharged, the remaining laminated bags are held by the side holding member to release the center holding member. A method of opening a plastic bag, which is characterized by: 2. The method for opening a plastic bag according to claim 1, wherein the air is hot air. 3. Two pins whose upper end is opened to be inserted into a pin hole formed in an extension of one edge of the opening of the bag,
A center holding member that is arranged inside the pin and presses or releases the extension of the bag between both pins, and a center holding member that is arranged on both outsides of the pin and presses or releases the extension of the bag on the outside of both pins. An opening device for a plastic bag, characterized in that it has a side holding member and an air blowing means for blowing air obliquely from above between the two pins.