JP2002113796A - Zipper for plastic bag and method for manufacturing plastic bag using zipper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zipper for a plastic bag which keeps the plastic bag at a high-quality level by bonding the zipper to the plastic bag with a sufficient adhesive force and preventing the plastic bag from becoming creased due to thermal shrinkage as well as a method for manufacturing the plastic bag using the zipper. SOLUTION: The zipper 1, 1' for the plastic bag which is fitted to one side and the other side of the inside of an opening part of the plastic bag 14 and enables sealing and unsealing the opening part. Inside the zipper 1, 1', an adhesive 4a is provided an microcapsules 4 which break when the pressure of specified magnitude is applied are applied to the back of the zipper 1, 1'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic bag chuck attached to an opening of a plastic bag for sealing and opening the opening, and a method of manufacturing a plastic bag using the chuck.

[0002]

2. Description of the Related Art Generally, a plastic bag to which a chuck is attached so that an opening can be sealed and opened freely is made of PE.
It has been manufactured by heating and melting solid chips such as (polyethylene) and nylon, and heat-sealing and cutting a thin cylindrical film formed by inflation molding.

[0003] The inflation molding is a plastic molding method in which molten plastic is extruded from an annular hole provided in a die, and is wound while sending air into a formed cylindrical film. In general, a shape is formed such that a chuck is formed integrally with a plastic bag.

In the case where the chuck and the plastic bag are integrally formed, the thickness of the chuck portion is several times to several tens of times that of the film forming the plastic bag, and thus, the cooling is required during storage. There is a problem that countless wrinkles are generated around the chuck due to the difference in the amount of shrinkage. Also, at the time of winding after being extruded from the die, the trace of the chuck was transferred to the plastic bag, and there was a problem that wrinkles were attached, so conventionally, the plastic bag was formed by the above-mentioned inflation molding. In this case, a separately formed chuck which is heat-sealed has been provided.

[0005] That is, a plastic bag having only one end opened is formed by heat-sealing and cutting a thin cylindrical film without a chuck by inflation molding. If the formed chuck is applied and the chuck is heat-sealed, transfer of traces of the chuck can be prevented at the time of winding after inflation molding.

[0006]

However, even in the above-mentioned prior art in which the chuck is separately formed, heat is applied when the chuck is heat-sealed to the plastic bag. There is a problem in that a difference occurs in the amount of shrinkage, wrinkles move around the chuck, and the quality is reduced. In addition, it is conceivable to attach the chuck to the plastic bag with a general-purpose adhesive, but when a user opens the bag, excessive force is applied to the chuck, and a sufficient adhesive force is maintained so that the chuck is not peeled off by the force. It is extremely difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made by bonding a chuck to a plastic bag with a sufficient adhesive force and preventing wrinkles from being generated in the plastic bag due to heat shrinkage. It is an object of the present invention to provide a plastic bag chuck capable of maintaining a high quality bag and a method of manufacturing a plastic bag using the chuck.

[0008]

According to the first aspect of the present invention,
A plastic bag chuck attached to one side and the other side inside an opening of a plastic bag and capable of sealing and opening the opening, which has an adhesive inside and has a predetermined size. Microcapsules that burst by pressure are applied to the back surface.

According to this configuration, when the chuck is applied to the inside of the opening of the plastic bag and then a predetermined amount of pressure is applied to the chuck, the microcapsules provided on the back surface of the plastic bag are ruptured, and the plastic capsule is ruptured. The bag and the chuck are bonded.

[0010] The invention according to claim 2 is characterized in that the adhesive inside the microcapsules adheres the back surface of the chuck to the plastic bag at room temperature or 70 ° C or lower.

The invention according to claim 3 is characterized in that the kind of the adhesive in the microcapsule is selected based on the materials of the plastic bag and the chuck.

The invention according to claim 4 is characterized in that the microcapsules and the second adhesive are applied to the back surface of the chuck, and a release paper is attached thereon.

According to a fifth aspect of the present invention, there is provided a bag making process for manufacturing the plastic bag, and a chuck for attaching the chuck to one side and the other side inside the opening of the plastic bag manufactured by the bag making process. It is characterized by including an attaching step and a pressurizing step of applying pressure to the chuck attached in the chuck attaching step to burst the microcapsules applied on the back surface thereof.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. The plastic bag chuck according to the present embodiment is attached to one side and the other side inside the opening of the plastic bag, and the opening is sealed and opened freely, as shown in FIG. , A female part 2 and a male part 2 'on the surfaces 1a and 1'a.
And the microcapsules 4 are applied to the back surfaces 1b and 1'b.

The female part 2 and the male part 2 'are shaped so that the male part 2' can be fitted to the female part 2, and each is formed by projecting from the surface 1a or 1'a of the plastic bag chuck 1. It is. And when each is attached to one side and the other side inside the opening of the plastic bag,
It is configured such that the plastic bag can be sealed by fitting, and opened by releasing the fitting.

The plastic bag chucks 1 and 1 '
Is preferably made of an olefin resin such as polyethylene, polypropylene or eva or vinyl chloride from the viewpoint of ease of molding, but may be other plastics. Further, a slip agent, an antioxidant, an antiblocking agent, a color and the like may be appropriately blended.

The microcapsule 4 is a granular material applied to the back surfaces 1b and 1'b of the plastic bag chucks 1 and 1 'together with the second adhesive 5, and one microparticle is observed microscopically. As shown in FIG. 2, an adhesive 4a is included inside a skin 4b made of a soft hollow resin. In FIG. 1, for convenience of explanation, a state is shown in which a part of the skin 4b is cut out and the adhesive 4a flows out, but the adhesive 4b is applied to the plastic bag chucks 1 and 1 '. Is included.

The skin 4b is ruptured by applying a predetermined amount of pressure, and is applied to the plastic bag chucks 1 and 1 'by a second adhesive 5 described later. The pressure required for the rupture is preferably set in consideration of various pressures applied in the manufacturing process, and can be arbitrarily set by selecting the material of the skin 4b and the size of the grains. The size of the grains is preferably 0.5 mm or less in outer diameter.
The skin 4b is preferably made of a soft resin because it remains between the plastic bag and the plastic bag chuck after the rupture. However, when the skin is extremely small, various materials can be used.

The adhesive 4a exhibits an adhesive force at room temperature or 70 ° C. or lower, and its type is arbitrarily selected based on the material of the plastic bag and the plastic bag chuck to be bonded. That is, since the type of the adhesive to be enclosed in the outer skin 4b is selected according to the adhesive characteristics of the plastic to be bonded, strong bonding is always possible regardless of the material of the plastic bag and the plastic bag chuck. It can be.

The second adhesive 5 applies the microcapsules 4 to the back surfaces 1b and 1 'of the plastic bag chucks 1 and 1'.
b, and may be of the same type as the adhesive 4a or of another type. From the viewpoint of simplification of the manufacturing process, a second adhesive 5 containing a plurality of microcapsules 4 is prepared in advance, and this is attached to the back surfaces 1b and 1 'of the plastic bag chucks 1 and 1'.
It is preferable that the microcapsules 4 are applied to the microcapsules 4 after the application of the second adhesive 5.

Further, a release paper 3 is attached on top of the microcapsules 4 being applied. With such release paper 3,
The second adhesive 5 can be prevented from drying, and the second adhesive 5 can be prevented from drying.
The adhesive 5 can also contribute to the adhesion between the plastic bag and the plastic bag chuck 1 or 1 '. In view of the fact that the plastic bag chucks 1 and 1 ′ coated with the microcapsules 4 are taken up and stored for a predetermined period, the release paper 3 is technically indispensable. The release paper 3 does not have to be attached as long as the release paper 3 can be adhered to the device.

Next, a method of manufacturing the plastic bag chuck 1 will be described with reference to FIG. Since the plastic bag chuck 1 'having the male portion 2' is the same as the plastic bag chuck 1, the description is omitted here.

First, molten plastic is supplied from an extruder 6 to a die 7 in which a die slit 8 having a shape corresponding to the cross-sectional shape of the plastic bag chuck 1 is formed, and a chuck sheet 9 is extruded and formed. Then, while applying tension to the formed chuck sheet 9 by the rollers R1 and R2, the front and back sides are reversed between the rollers R2 and R3.

After that, the second adhesive 5 mixed with the microcapsules 4 is applied to the back surface of the chuck sheet 9 by the application device 10, and the release paper 3 is attached thereto from above, and the plastic bag chuck according to the present embodiment is attached. Complete 1
The plastic bag chuck 1 thus manufactured is
After being wound up by a winder (not shown) and stored, the pressure at the time of winding up must be lower than the pressure at which the microcapsules 4 burst.

On the other hand, the plastic bag to which the plastic bag chucks 1 and 1 'are bonded is made of, for example, an olefin resin and is manufactured by inflation molding. That is, as shown in FIG. 4, the molten plastic is supplied to the mold 12 by the extruder 11 and is extruded from the annular die slit 13 formed in the mold 12 and wound up at a predetermined tension T to obtain a desired thickness. Is manufactured (bag making step). Incidentally, the material of the plastic bag may be a non-olefin resin, and like the plastic bag chucks 1 and 1 ', a slip agent,
An antioxidant, an anti-blocking agent, a color and the like may be appropriately blended.

Next, a method of manufacturing a plastic bag using the plastic bag chucks 1 and 1 'in this embodiment will be described with reference to FIG. First, while transporting the cylindrical plastic bag 14 obtained in the bag making process in a folded state as shown in FIG.
, And the cut opening is used as the opening of the plastic bag 14 after production.

At the same time, the plastic bag chucks 1 and 1 'manufactured as described above are attached to the female portion 2 and the male portion 2'.
Are guided and transported inside the cylindrical plastic bag 14 in a state where they are fitted (see FIG. 6). At this time, the release paper 3 attached to the plastic bag chucks 1 and 1 ′ is peeled off and guided to the transport line of the plastic bag 14, and one side 14 a inside the opening of the plastic bag 14 is connected to The plastic bag chucks 1 and 1 'are positioned with respect to the other side 14b (chuck mounting step).

Thereafter, the plastic bag chucks 1 and 1 'attached to the plastic bag 14 are pressurized by the pressurizing device 16 (pressurizing step). Such pressurizing device 1
Numeral 6 is set so as to obtain a pressure equal to or greater than the size at which the microcapsules 4 burst. As shown in FIG. I have it.

By such pressurization, the microcapsules 4 applied to the back surfaces 1b and 1'b of the plastic bag chucks 1 and 1 'are ruptured, and the adhesive 4a contained therein is ruptured.
Flows out, and the plastic bag chucks 1 and 1 ′
Are firmly bonded inside the opening of the plastic bag 14.

The plastic bag 14 which has been subjected to the pressurizing step is further conveyed by the feed roller R4, cut and sealed by the cut seal bar 17, and the plastic bag chuck 1 is inserted into the opening as shown in FIG. And 1 '. The plastic bag 14 is sealed when the plastic bag chucks 1 and 1 'are fitted, and is opened when the fitting is released.

According to the plastic bag chuck of the present embodiment, since the microcapsules 4 containing the adhesive 4a are applied to the back surface thereof, the adhesive 4a comes into contact with the outside air until the pressing step is performed. And the pot life can be maintained for a long time.

After the microcapsules 4 are fixed to the plastic bag chucks 1 and 1 ′ by the second adhesive 5, the release paper 3 is attached to the microcapsules 4. The bag chucks 1 and 1 'can be wound up. Thereby, the working efficiency in the process of manufacturing the plastic bag chucks 1 and 1 'can be improved.

Further, since the plastic bag chucks 1 and 1 'and the plastic bag 14 are adhered to each other by pressurization, it is possible to perform a cold seal and to prevent wrinkles due to a difference in heat shrinkage therebetween. it can. The adhesive included in the microcapsules 4 may be a general-purpose instant adhesive or a hot melt adhesive that exhibits an adhesive force at 70 ° C. or lower.

Further, in the conventional adhesive bonding by heat fusion, the adhesive force cannot be maintained unless the plastic bag and the plastic bag chuck are made of the same material. Since the bonding is performed with the adhesive 4a, the adhesive force can be always maintained even if the materials are not the same.

Although the present embodiment has been described above, the present invention is not limited to this. For example, the shape of the microcapsule can be other than a spherical shape, and the microcapsule can be made of a material other than a soft resin. It can also be a skin consisting of: Further, the plastic bag to be applied may be a multi-layered one or a plastic bag having a surface colored or patterned.

[0036]

According to the first and fifth aspects of the present invention,
Since the adhesive before the bonding process is contained in the microcapsule, it can be kept in a state where the adhesive force is always maintained without touching the outside air. Since the chuck can be adhered to the plastic bag by pressurizing, the wrinkle due to heat shrinkage can be prevented without heating. Therefore, the quality of the plastic bag can be maintained.

According to the second aspect of the present invention, the plastic bag and the chuck can be bonded to each other to such an extent that there is no difference in heat shrinkage, and wrinkles can be prevented.

According to the third aspect of the present invention, the type of the adhesive contained in the microcapsule is selected according to each material of the plastic bag and the chuck, so that a suitable adhesive is always applied to the plastic bag to be manufactured. Plastic bags can be kept of higher quality.

According to the fourth aspect of the present invention, the microcapsules and the second adhesive are applied to the back surface of the chuck, and the release paper is attached thereon, so that the plastic bag can be used without waiting for the second adhesive to dry. The chuck can be wound up, and the working efficiency in the process of manufacturing the plastic bag chuck can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a plastic bag chuck according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a state in which a part of a microcapsule applied to a plastic bag chuck according to an embodiment of the present invention is partially cut away.

FIG. 3 is a schematic view showing a manufacturing process of the plastic bag chuck according to the embodiment of the present invention.

FIG. 4 is a schematic view showing a manufacturing process of a plastic bag to which the plastic bag chuck according to the embodiment of the present invention is applied.

FIG. 5 is a schematic view showing a step of bonding the plastic bag chuck of the embodiment according to the present invention to the plastic bag.

FIG. 6 is a schematic view showing a state in a manufacturing process in which the plastic bag chuck according to the embodiment of the present invention is attached to the plastic bag.

FIG. 7 is a perspective view showing a state in which the plastic chuck according to the embodiment of the present invention is attached to a plastic bag.

[Explanation of symbols]

 1, 1 '... plastic bag chuck 1a, 1'a ... front surface 1b, 1'b ... back surface 2 ... female part 2' ... male part 3 ... release paper 4 ... microcapsule 4a ... adhesive 4b ... skin 5 ... first 1 Adhesive 6, 11 Extruder 7, 12 Mold 8, 13 Die slit 9 Chuck sheet 10 Coating device 14 Plastic bag 14a One side inside opening 14b ... The other side inside opening 15 … Opening cutter 16… Pressurizing device 17… Cut seal bar

Claims (5)

[Claims] 1. A plastic bag chuck attached to one side and the other side inside an opening of a plastic bag and capable of sealing and unsealing the opening. A microcapsule, which is ruptured by pressurization of a size, is applied to a back surface thereof, and is a chuck for a plastic bag. 2. The adhesive inside the microcapsule,
2. The plastic bag chuck according to claim 1, wherein the back surface of the chuck is bonded to the plastic bag at room temperature or at 70 [deg.] C. or lower. 3. The plastic bag chuck according to claim 1, wherein a type of the adhesive in the microcapsule is selected based on materials of the plastic bag and the chuck. 4. The chuck according to claim 1, wherein the microcapsules and the second adhesive are applied to the back surface of the chuck, and a release paper is attached thereon. Chuck for plastic bag. 5. A bag-making process for producing said plastic bag, a chuck-attaching process for attaching said chuck to one side and the other side inside an opening of said plastic bag produced by said bag-making process. 5. A pressurizing step of applying pressure to the chuck attached in the attaching step to burst the microcapsules applied to the back surface thereof. A method for producing a plastic bag using the plastic bag chuck according to 1 above.