JP2002053166A - Tape for automatic taping machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape for an automatic taping machine which has the excellent traveling property and easy cuttability. SOLUTION: In this tape for the automatic taping machine, two sheets of biaxially oriented propylene films having a heat seal layer are arranged so that each heat seal layer forms the outside, and a space between the films is adhered by an extrusion polypropylene resin layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape for an automatic banding machine used for individually packing goods using an automatic banding machine or for simply packing printed matter.

[0002]

2. Description of the Related Art An automatic strapping machine accommodates a wound strong string inside the machine, and a string unwound by a power input consisting of a simple operation such as depressing a pedal is used to surround a packaged object on a table. It is a very convenient machine that can be fastened tightly and can be strapped instantaneously, making packing work more efficient.

[0003] In this machine, it is necessary to pass the unwound string through the arch guide of the strapping machine and surround the object to be packed with the strap. Therefore, the strap that can be used in the automatic strapping machine has high rigidity.
It is required to have a so-called "stiffness" and to be wide and flat. Therefore, flexible cords which are usually available on the market cannot be used for automatic strapping machines. The straps used in the strapping machine are mainly made of polypropylene for packing heavy objects.
It is a strip having a width of about cm and having sufficient rigidity.

[0004] A strapping machine is used for simpler packaging, and rigidity and flatness are still required in this case, but with regard to strength, a string suitable for the object to be packaged is sufficient. is there.

Therefore, a paper string is also used. In this case, a paper having a high elastic modulus is used as the paper itself to increase the rigidity, and a heat-fusible plastic is applied to both sides of the paper so that both ends of the string can be heat-sealed. A strip film coated with a conductive material is used. However, in places where the items to be packed themselves have moisture, such as a lunch box, and therefore the packing work place is also full of moisture, the paper string may become wet even if the plastic material is coated on both sides. And it was not possible to pack it. Therefore, a plastic film is used as a film resistant to moisture. For example, JP-A-7-4
No. 1036 discloses a tape for an automatic banding machine comprising a composite film in which at least one layer is biaxially stretched. As a specific film configuration of the composite film, a composite film in which heat-sealable biaxially oriented polypropylene is combined on both sides of a biaxially oriented polyester is shown.

[0006]

In an automatic banding machine, a packing operation is performed by feeding a tape from a wound tape and passing the tape through a narrow gap of an arch-shaped guide rail at a high speed so as to form a space around an object to be packed. Once, then rewinding the extra tape separated from the guide rails to tighten the tape around the object to be packed, and heat sealing both ends of the tape.

[0007] It is necessary to stably pass this tape through the narrow gap of the arch-shaped guide rail at a high speed.
For this purpose, the tape that has been fed out is compressed in the guide rail by the reaction force of the frictional force of the guide rail and the pulling force, so that the tape does not buckle and bend, and the good sliding property between the guide rail and the tape Is required.

[0008] The rigidity of the tape can be increased by increasing the thickness of the tape or by using a material having a high elastic modulus. Specifically, the rigidity of the tape is determined in consideration of the manufacturing cost, physical properties required for the tape, and the like. Is done.

The slipperiness between the guide rail and the tape depends on the shape, material, surface condition and surface characteristics of the tape. Additives such as anti-blocking agents and slip agents are added to the monolayer film itself to improve slipperiness, but when combined with other films to form a composite film, slipperiness decreases. was there. Therefore, starch fine particles coated with a silicone resin on the film surface, so-called dusting agents, are adhered to reduce the contact area with a contact object, thereby reducing frictional resistance and improving slipperiness. However, there is a problem that the dusting agent accumulates on a guide rail of a strapping machine and adheres to a packaged object, or scatters in the air to pollute the environment.

However, it has been found that even when the rigidity and the slipperiness of the tape are improved to a considerable level, the tape cannot pass through the guide rail smoothly depending on the material of the guide rail.

The present inventors have conducted intensive studies on the cause and found that the smooth running of the tape is largely affected by the static electricity generated by the friction between the guide rail and the tape in addition to the rigidity and slipperiness of the tape. I found it. That is,
In order to reduce the frictional resistance with the tape and improve the corrosion resistance, the material of the guide rail of the strapping machine, for example, made of synthetic resin or metal coated with synthetic resin, becomes electrically insulating due to the surface. It has been found that the conductivity is deteriorated, and the influence of electrostatic charging due to friction becomes more remarkable, and the running property of the tape is deteriorated.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the biaxially stretched polypropylene resin films having a heat seal layer are disposed outside each other. As described above, the inventors have found that a laminated composite film obtained by bonding with an extruded polypropylene resin is useful, and have reached the present invention.

That is, the present invention provides (1) two sheets of a biaxially stretched propylene resin film having a heat seal layer,
An automatic banding machine tape characterized by being arranged such that the heat seal layer surface is on the outside, and the films are bonded by an extruded polypropylene resin layer.
(2) On the inside of the edge line of the tape, fine scratches penetrating the biaxially stretched propylene resin film layer are provided densely along at least one edge line. (1) The tape for an automatic banding machine according to (1).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The tape of the present invention is formed by bonding a heat-sealable biaxially stretched polypropylene resin film to each other with a polypropylene resin extruded from a T-die of an extruder so that the heat-sealing layers are respectively disposed outside. It is composed of a so-called sandwich laminated composite film having a composite configuration.

Since the materials used for the tape of the present invention are all the same type of polypropylene resin, the combination of such materials as the corona discharge treatment, the application of an anchor coat agent, etc., which are usually required in the case of the combination of different types of materials. Since activation treatment of the film surface is not required, it is advantageous in terms of production cost.

The tape for an automatic banding machine of the present invention is used in an automatic banding machine by slitting the composite film having the above-mentioned film structure into a width of 10 to 60 mm, preferably 20 to 50 mm, winding it around a paper tube. . The tape of the present invention has a low saturated electrostatic voltage because of a small generation of static electricity due to friction when the tape passes through the narrow gap of the arch-shaped guide rail of the strapping machine at a high speed while contacting the guide rail. Because of the good performance, no running failure due to the generation of frictional static electricity occurs.

Although the reason for this is not clear, when producing a composite film, for example, when laminating by a so-called dry lamination method in which a film is adhered using a two-component polyurethane resin adhesive as in a conventional method, the adhesive Slip agents such as higher fatty acid amides and alkylene bis fatty acid amides, which are added to improve the slipperiness of the film, as well as organic solvents used to dilute the agent and curing agents for the adhesive, and the chargeability of the film It is considered that the amount of these additives existing on the surface of the composite film after lamination is reduced because the nonionic or ionic surfactant added to improve the surface roughness is drawn into the inside of the film. Since slip and antistatic properties are exhibited by the presence of these additives on the film surface, dry lamination composite films tend to impair the runnability of the banding machine. Seem.

On the other hand, since the tape of the composite film of the present invention does not need to use any adhesive or anchor coating agent, the heat-sealing property of laminating without the above-mentioned phenomenon of additives due to a curing agent or an organic solvent can be obtained. It seems that the biaxially stretched polypropylene film exhibits excellent running performance without impairing the inherent slip and antistatic performance of the biaxially stretched polypropylene film.

In addition, since the tape of the present invention has excellent running performance, it is not necessary to spray a dusting agent on the composite film for improving the slipperiness of the tape, and the tape is not applied to guide rails or the like generated thereby. The problem that the stinging agent accumulates and adheres to the packaged object or scatters in the air to pollute the environment is eliminated.

As the polypropylene resin, propylene homopolymer, propylene-ethylene random copolymer,
A propylene-ethylene block copolymer resin or the like is used.

Since the tape is bound by superposing the front and back surfaces of the tape in an envelope-attached state and heat-sealing the tape, the front and back surfaces of the tape need to have heat-sealing properties.

Heat-sealable biaxial stretching in which a heat-sealable layer such as a thin polyethylene or polyethylene-propylene copolymer is provided on one side by co-extrusion or coating in order to impart heat-sealability to both sides of the composite film. A polypropylene film is placed such that the heat-sealable layer is outside the composite film.

As a heat sealing method, an impulse sealing method is generally employed.

In the tape of the present invention, the tape penetrates the tape along the edge line by 0.4 to 2.0 mm, preferably 0.6 to 1.0 mm inside both or one edge line of the tape. By providing fine scars penetrating at least the biaxially stretched polypropylene resin layers on both sides, it is possible to cut the bound tape by the force of fingers and open the package.
The tape of the present invention has a relatively good tear propagation property.
When the application position of the fine scar is smaller than 0.4 mm,
The tape is likely to be cut due to the tightening force at the time of bundling, and unintended cutting of the tape is likely to occur in the distribution process of the packaged goods.
On the other hand, when the thickness is 2.0 mm or more, it becomes difficult to cut by finger force.

The shape and arrangement of the scars are such that a number of short cuts longer than the width are arranged in a row at an angle within ± 45 ° with respect to the vertical direction of the tape edge line. However, the present invention is not limited to this as long as it has a tape tearing start function.

The size of the scar is preferably 1.0 mm or less in length, particularly preferably 0.5 mm to 0.1 mm. The width of the scar group provided with the fine scar is not particularly limited as long as it has a tear initiation function, and is 0.5 to 3.0 mm, preferably 1.0 to 2.0 m.
m is good.

[0027] The fine scar is described in, for example, Japanese Patent Application Laid-Open No. 3-2793.
The method is applied by a method of pressing a composite film using a tool having fine projections as described in Japanese Patent Publication No. 0-0. Specifically, the laminated wide-width composite film is provided with two fine scratches spaced at an interval corresponding to twice the inner distance from the edge line at a pitch corresponding to a plurality of rows of a predetermined tape width, It is manufactured by slitting the center of the interval between two scars with a slitter and winding it on a paper tube.

In this case, the scar may be a scar penetrating the entire laminated film, or a scar penetrating only the heat-sealable biaxially stretched polypropylene resin film layers on both sides excluding the extruded polypropylene resin layer of the adhesive layer. Good. Alternatively, as another scar applying method, a scar is previously applied only to a biaxially stretched polypropylene resin film which is difficult to cut with the force of fingers, and then the heat-sealing resin layer is formed on the film. To obtain a biaxially oriented polypropylene resin film,
This may be utilized in the production of the tape of the present invention.

Next, the tape of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the tape of the present invention. The composite film 1 is composed of one heat-sealable biaxially oriented polypropylene film 2-1 and the other heat-sealable biaxially oriented polypropylene film 2-2 and an extruded polypropylene of the intermediate layer. It is composed of a resin layer 5. In the heat-sealable biaxially oriented polypropylene films 2-1 and 2-2, the thin heat seal layers 3-1 and 3-2 are arranged on one side of the biaxially oriented polypropylene film layers 4-1 and 4-2, This state is commercially available as a single-sided heat-sealable biaxially oriented polypropylene film. The heat-sealable biaxially oriented polypropylene films 2-1 and 2-2 may be of the same type or different, but the rigidity of the tape,
The same type in terms of curl and the like, the biaxially stretched film layer has a thickness of 20 to 100 μm, preferably about 30 to 50 μm,
The heat-sealing layer has a thickness of 1 to 15 μm, preferably 2 to 5 μm. The intermediate polypropylene resin layer 5 is extruded into a film form from a T-die of an extruder, and heat-sealable biaxially oriented polypropylene films 2-1 and 2- of both outer layers are formed.
2 is adhered. The thickness of the polypropylene resin layer 5 is 10
５０50 μm, preferably about 20 to 35 μm. The binding of the tape is performed by heat-sealing the heat-sealing layers 3-1 and 3-2 in an envelope-attached state with an impulse sea or the like with the surfaces thereof facing each other.

FIG. 2 is a diagram of a wound tape obtained by winding the tape of the second invention. As shown in the enlarged view of FIG. 3, the wound tape 6 has fine scratches 7 penetrating the tape along the edge line at a position X away from the edge line of the tape. The tape provided is wound around a paper tube. In FIG. 2, the scar 7 is provided on both sides of the tape, but may be on one side.

[0031]

Example 1 A non-heat-sealed surface of a single-sided heat-sealed type biaxially stretched propylene film FOH having a thickness of 40 μm manufactured by Nimura Chemical Industry Co., Ltd. was put through a T-die of an extruder to a thickness of 25 μm.
m of the polypropylene resin was extruded to obtain a composite film having a total thickness of 105 μm.

This composite film was slit to a width of 30 mm and wound around a paper tube to a length of 200 m. This wound tape was hung on an automatic banding machine Tepit W manufactured by Uchida Yoko Co., Ltd., and a cardboard box having a length of 15 cm, a width of 30 cm and a height of 15 cm was bound. The tying was done 100 times in a row and 3
Repeating the bundling for 100 times and then bundling 100 times in total was repeated a total of three times. In all cases, the tape ran smoothly on the guide rail and was bound without any problem.

The tape was charged at 23 ° C. × 5
When measured by a JIS L-1094B method in a 0% RH atmosphere, the saturation charged voltage was 42 V, and the charged voltage after 30 seconds was 36.
It was V.

Example 2 An example of a tape provided with a fine scar inside the edge line using a disc-like scar applying tool manufactured by the method described in Example 1 of JP-A-3-27930. explain.

On the outer peripheral surface of a metal disk having a diameter of 80 mm and a thickness of 6 mm, a height of 0.45 mm with a blade width of 0.5 mm is set so that the length direction is perpendicular to the circumferential direction of the disk. The tip having a sharp fine tip has a pitch of 0.5 mm in the thickness direction of the disk and a pitch of 3.0 m in the circumferential direction of the disk.
The row group arranged in three rows so as to be m is defined as one row, and two rows are arranged at an interval of 1.5 mm.

The composite disk of Example 1 was passed between rubber-coated receiving rolls, which were arranged at intervals of 30 mm, with the metal disks placed at an interval of 30 mm, and the film was pressed between the disk and the receiving rolls. A wide composite film was obtained in which two 1.5-mm-wide scars were arranged in the longitudinal direction of the composite film at an interval of 1.5 mm on both sides thereof with a width of 30 mm therebetween.

Then, the center of the 1.5 mm gap between the two scar groups of this wide film is slit and wound around a paper tube, so that the tape is taped along the edge line to 0.75 mm inside the both edge lines of the tape. To obtain a wound tape provided with fine scars penetrating through.

This tape was bound in the same manner as in Example 1. However, the running property of the tape was not a problem at all, and the tape was not cut by the tape tightening tension at the time of binding. The tied tape could be easily cut by pinching and twisting with a finger. Also united cardboard box 100
Approximately 2000 km on a Takkyubin (registered trademark) truck
There was no trouble that the tape was cut during transportation.

Comparative Example 1 The same single-sided heat-sealing type biaxially stretched propylene film having a thickness of 40 μm as in Example 1 with the non-heat-sealing surfaces facing each other and a two-component polyurethane-based adhesive having a thickness of 23 μm was used. Laminated on both sides of biaxially stretched polyester film by dry lamination method, total thickness 1
A 10 μm composite film was obtained.

The composite film was slit to a width of 30 mm and wound around a paper tube to a length of 200 m. When the tape was wrapped with an automatic banding machine in the same manner as in Example 1, the running property was quite poor, and the first time was tied three times and stopped running on the guide rail. I could only run. When the antistatic spray was applied to the vicinity of the guide rail, the tape that stopped running began to run several times, and the cause of the running failure is considered to be the large electrification due to the friction between the tape and the guide rail.

The saturated charging voltage of this tape measured in the same manner as in Example 1 was 675 V, and the charging voltage after 30 seconds was 64.
5V was much different from the tape of Example 1.

A tape in which a dusting agent was sprayed on the surface of the composite film in the final step of dry lamination to improve the slipperiness of the tape was almost the same as above, and the running property was not improved.

[0043]

The tape of the present invention runs stably with an automatic banding machine, and when a fine scar is formed inside the edge line of the tape, the tape is easily cut and bound with the force of a finger. Can be opened.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tape of the present invention.

FIG. 2 is a partially enlarged view of the easy-cutting tape of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Composite film 2-1 and 2-2 Heat-sealable biaxially-stretched polypropylene film 3-1 and 3-2 Heat-seal layer 4-1 and 4-2 Biaxially-stretched polypropylene film layer 5 Polypropylene resin layer 6 Winding tape 7 Fine scar

Claims (2)

[Claims] 1. A biaxially stretched propylene resin film having a heat seal layer is disposed so that the heat seal layer surface is on the outside, and the two films are bonded by an extruded polypropylene resin layer. Tape for automatic banding machines. 2. A fine scar which penetrates a biaxially stretched propylene resin film layer along at least one edge line is densely provided inside the edge line of the tape. The tape for an automatic banding machine according to claim 1.