JPH09110017A - Formation method of picking lug for unsealing packaging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-shrinkable film which is hardly broken even if an unsealing picking lug integrally formed in the film, is pulled up with fingers. SOLUTION: An unsealing picking lug 1C is formed by welding of a specified length in the overlaid parts 1A, 1B through small protrusions 3a... ingrown into the overlaid parts 1A, 1B, by use of lateral sealers 3 (3A, 3B) in which small protrusions 3a... are scattered on the face met to the overlaid parts of a heatshrinkable film. When shrinking this film with heat, a tension to the peeling direction of the overlaid parts 1A, 1B welded together is given to the overlaid parts. In this way, continual small holes with a specified length are formed at the root side of the unsealing picking lug 1C separated from the ingrown positions (fusion holes 1a...) at the root side welded with the unsealing picking lug 1C. In this way, when pulling the unsealing picking lug, the package of the heat-shrinkable film is formed so as to be easily broken.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-shrinkable film (shrink wrapping) for wrapping a product to be packaged such as a container, and more specifically, to easily break the heat-shrinkable film when taking out a product to be packaged. In addition, the present invention relates to a method for forming an opening knob piece integrally formed with a heat-shrinkable film.

[0002]

2. Description of the Related Art Generally, when packaging an article to be packaged with a heat-shrinkable film, a heat-shrinkable film 1 is formed into a tubular shape with a former 12 as shown in FIG. The overlapping portions 1A and 1B (see FIG. 9) on the lower side of the formed film 1 are welded by the vertical sealer 13 to form the opening tab 1C having a predetermined width, and the opening tab 1C is formed on the tube. The film-shaped film 1D and the object to be packaged A are advanced, and the overlapping portions 1E and 1F of the tubular film 1D on the advancing side of the object to be packaged A are stacked.
Is melted by the horizontal sealer 14, and when the melted cylindrical film 1D and the packaged object A have advanced a predetermined distance, this time, the overlapping portion 1G of the cylindrical film 1D on the rear side of the packaged object A,
1H is melt-cut by the horizontal sealer 14 and the film bag 1I containing the object A to be packaged, the advancing side and the rear side of which are melted, is passed through the shrink tunnel 15 to heat-shrink the film bag 1I in the shrink tunnel 15. By
The packaged state of the heat shrink film 10 as shown in FIG. 10 is obtained.

[0003]

However, the packaging of the heat-shrinkable film 10 is such that the free end 1C "of the opening tab 1C.
Even if the side is picked up with a finger and pulled, the heat-shrinkable film only stretches and is durable and has a problem that it is difficult to tear. The present invention can easily break the heat-shrinkable film when the opening tab is picked with a finger and pulled, and moreover, a method for forming an opening tab of the packaging film which does not require significant modification of the packaging equipment. The purpose is to provide.

[0004]

In order to achieve the above-mentioned object, the present invention has an opening knob having a predetermined width integrally formed over a predetermined length on a heat-shrinkable film in which an object to be packaged is wrapped. The tabs are made by welding the overlapping parts of the film with a sealer before heat shrinking the heat-shrinkable film. Using a sealer having at least small protrusions scattered on the surface to be attached, the overlapping protrusions are welded to each other in a state in which a melting hole is formed in at least one of the overlapping portions by the small protrusions, and an opening knob having a predetermined width is opened. When a piece is formed and the film is heat-shrinked, a tensile force is applied to the welded overlapped portion in a direction of peeling it off, so that the root side of the overlapped portion formed with the melting holes is released. , In which so as to form an intermittent eyelet having a predetermined length at the base side of the opening for the tab.

By the above method, intermittent small holes are formed on the base side of the opening knob for a predetermined length. Therefore, when the opening knob is grasped by a finger and pulled, a crack is generated between the small holes and the heat shrink film. Is broken. In this case, the intermittent small holes of a predetermined length are formed based on the intervals of the small protrusions scattered on the sealer, so the pitch interval of each small hole is very small, which allows the heat shrink film to be easily broken. can do. Further, according to the method of the present invention, since the fusion holes are formed by the sealer in which the small projections are formed in a scattered manner, and the intermittent small holes are finally formed, the intermittent small holes are surely formed. Not only can it be manufactured in a simple manner, but it does not require any major modification to the packaging equipment, and its durability is good as equipment for making intermittent small holes.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a packaging equipment for explaining one embodiment of the present invention. Utilizing this packaging equipment, first, vinyl chloride, polypropylene, polyethylene or the like is used. A wide heat-shrinkable film 1 is formed into a tubular shape by a foamer 2 to enclose an object A to be packaged such as a traveling container, and the overlapping portions 1A and 1B on the lower side of the tubular film 1 are shown in FIG. Weld with a vertical sealer 3 as shown in. The vertical sealer 3 includes a pair of rotary rollers 3A and 3B.
, And the small protrusions 3a are formed on the entire circumferential surface of one rotating roller 3A in the circumferential direction and the axial direction, and the circumferential surface of the other rotating roller 3B is flat. Therefore, when the overlapping portions 1A and 1B on the lower side of the film 1 are pressed by the rotating rollers 3A and 3B, the small projections 3a of the rotating roller 3A are moved downward by the heat as shown in FIG. 3 (A). While overlapping the overlapping portions 1A and 1B, the overlapping portion 1
It bites into A and 1B, and the overlapping portions 1A and 1B are welded to each other (this welding location is a location indicated by a thick line in FIG. 3A). As a result of this welding, as shown in FIG. 3B, the small protrusions 3a of the rotating roller 3A are vertically and horizontally formed on the overlapping portion 1A.
An opening knob 1C having a predetermined width and having a large number of melting holes 1a corresponding to ... Is formed. The front end side of the opening tab 1C is cut into a predetermined width by a pressing force between the protruding blade 3b of the rotating roller 3A and the receiving surface of the rotating roller 3B as shown in FIG. 3 (A). Next, the tubular film 1D on which the opening tab 1C having the predetermined width is formed and the article A to be packaged advance, and the tubular film 1 on the advancing side of the article A to be packaged.
The superposed portions 1E and 1F of D are known swivel type horizontal sealers 4
The welding is cut by welding (hereinafter, welding cutting is referred to as fusing). Then, the tubular film 1D in which the overlapping portions 1E, 1F have been melted and the article A to be packaged advance, and at the time when the article A has advanced a predetermined distance, the tubular film 1 on the rear side of the article A to be packaged 1
The overlapping portions 1G and 1H of D are melted and cut by the horizontal sealer 4, whereby the film bag 1I containing the article to be packaged A is formed.
Is formed. Next, the film bag 1I containing the article A to be packaged, the advancing side and the rear side of which are melted and cut, is passed through the shrink tunnel 5, and the film bag 1I is thermally shrunk in the shrink tunnel 5. At this time, due to the heat shrinkage, as shown in FIG. 4, tensile forces F, F in the direction of separating them are applied to the welded overlapping portions 1A, 1B on the base side of the opening tab 1C, so that the root side Melting hole 1
a is peeled off and separated, as shown in FIG.
Intermittent small holes 6 of a predetermined length are formed on the root side of the. The detachment of the welded opening tab 1C on the base side can be released when the pulling forces F, F become larger than the welding force on the root side of the open tab 1C. It is necessary to select the material and thickness of the heat-shrinkable film 1, and adjust the clamping pressure of the sealer (particularly the clamping pressure on the root side of the overlapping portion) and the temperature inside the shrink tunnel 5.

In the above embodiment, with respect to the horizontal sealer 4 shown in FIG. 1, the overlapping portions 1E and 1F on the advancing side and the overlapping portions 1G and 1H on the rear side of the tubular film 1D are melted and cut. The horizontal sealer 4 shown in FIG. 6 may be used instead of the horizontal sealer 4. The horizontal sealer 7 has a pair of swivel dies 7A and 7B and a pair of swirl fusing dies 7C and 7D on the rear side of the swivel dies 7A and 7B.
Small projections 7a are formed vertically and laterally on the arcuate tip surface of the above, and the arcuate tip surface of the other swivel die 7 is flat. Therefore, when the rear overlapping portions 1G and 1H of the tubular film 1D are clamped by the pair of revolving dies 7A and 7B, the small projections of the revolving dies 7A are similar to those described in FIG. 3A. 7a ... due to the heat, the overlapping portion 1
While melting G and 1H, it bites into the overlapping portions 1G and 1H to weld the overlapping portions 1G and 1H together,
The small protrusions 7a of the swivel type 7A are arranged vertically and horizontally on the overlapping portion 1G.
The opening tab 1C 'having a predetermined width and having a large number of melting holes corresponding to the above is formed. In addition, the overlapping portions 1E, 1 of the rear end of the opening tab 1C 'and the subsequent tubular film 1D.
F is melted by the swirl molds 7C and 7D. For this reason, when the film bag 1I ′ containing the object A to be packaged in which the preceding opening tab 1C ′ is formed is passed through the shrink tunnel 5 and heat-shrinked, the film bag 1I ′ is overlapped as in the case described with reference to FIG. The root sides of the mating portions 1G and 1H are pulled, the melting holes on the root side are separated and separated, and intermittent small holes of a predetermined length are formed on the root side of the opening knob. In addition,
The horizontal sealer 7 forming the opening tab 1C 'may have a pair of swivel dies 7A, 7B on the rear side and a pair of swirl fusing dies 7C, 7D on the advancing side. The overlapping portions 1G and 1H are melted, and the overlapping portion 1
E and 1F are welded to each other over a predetermined width, and the opening tab 1
C'is formed, and finally an intermittent small hole having a predetermined length is formed at the base side of the opening picking piece 1C '. Further, the lateral sealer forming the opening tab 1C 'is not limited to the swivel type, but may be a pressing type that linearly advances and retreats with respect to the overlapping portion of the tubular film 1D. When a horizontal sealer that forms the opening tab 1C 'is used, the vertical sealer 3 may be replaced with a fusing-type vertical sealer 8 shown in FIG.

Further, in each of the above embodiments, the intermittent small holes 6 of a predetermined length are formed in a circle, but they are separated on the base side of the overlapping portions 1A, 1B (1G, 1H) ( The stripping amount may be reduced, and each small hole on the base side of the finally-opened opening tab 1C (1C ') may be formed in a semicircular shape such as a semicircular shape. (1C ')
When the film is picked up with a finger and pulled, a crack is generated from between the small holes and the heat shrink film can be easily broken. Further, if the cross-section of the small protrusions 3a ... (7a ...) is not limited to a circle, and if it is formed into a rhombus or an elongated shape, each small hole to be finally formed is also formed into a rhombus shape, an elongated shape or the like, and heat shrinkage occurs. The film can be easily broken. In each of the above embodiments,
Although one row of the fusion holes 1a on the base side of the overlapping portions 1A, 1B (1G, 1H) is separated at the time of thermal contraction, it goes without saying that the fusion holes on the base side of the overlapping portions 1A, 1B (1G, 1H) are separated. 1a
.. may be separated from each other to form intermittent rows of small holes 6 on the base side of the opening tab 1C (1C ′). Further, the welding force on the base side of the overlapping portions 1A, 1B (1G, 1H) is reduced or reduced to zero, and the overlapping portions 1A, 1B are
In order to facilitate the separation of the root side of (1G, 1H),
Whether the small protrusions 3a ... (7a ...) of the rotary roller 3A (swivel type 7A or pressing type) corresponding to the root side of the overlapping portions 1A, 1B (1G, 1H) are made small (FIG. 3).
(See dotted line P1 in (A)) or overlapping portions 1A, 1B
The rotating roller 3B corresponding to the root side of (1G, 1H)
The diameter (length) of the (turning type 7B or pressing type) may be made smaller (shorter) (see the chain double-dashed line P2 in FIG. 3A) or both of them may be adopted. Further, in each of the above-described embodiments, as the sealer that forms the melting hole 1a, the rotary roller 3A (swirl type 7A) having the small protrusion 3a (7a) on one side is used.
Or pressing type) was used, but both rotating rollers 3A, 3
B (swivel type 7A, 7B or pressing type) on the small protrusion 3a (7
a) may be formed so as to discriminate them in the axial direction (longitudinal direction). Further, in each of the above-described embodiments, the small holes 6 ... Are formed only on the root side of the overlapping portion 1A (1G) of the opening knob 1C (1C ′).
a is also formed in the overlapping portion 1B (1H), and both overlapping portions 1A, 1B (1G, 1G, 1C) of the opening tab 1C (1C ') are formed.
Intermittent small holes 6 ... May be formed on the root side of 1H).

[0009]

As described above, according to the present invention, since intermittent small holes are reliably formed on the base side of the opening picking piece over a predetermined length, the opening picking piece can be pulled with a finger. As a result, the heat-shrinkable film can be easily ruptured, the packaging equipment does not need to be significantly modified, and the durability is extremely good as equipment for making intermittent small holes for rupture.

[Brief description of the drawings]

FIG. 1 is a schematic side view of packaging equipment for explaining an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of welding a lower overlapping portion of a tubular film with a vertical sealer.

FIG. 3A is an enlarged cross-sectional view of a main part of FIG. 2, and FIG. 3B is an explanatory view showing a part of the opening tab.

FIG. 4 is a cross-sectional view of essential parts in a state in which a pulling force is applied to the opening tab of the film bag during thermal contraction.

FIG. 5 is an explanatory view showing a part of the opening tab after heat shrinking of the film bag.

FIG. 6 is a schematic cross-sectional view for explaining a horizontal sealer forming an opening knob.

FIG. 7 is a cross-sectional view of a vertical sealer that melts and cuts a lower overlapping portion of a tubular film.

FIG. 8 is a schematic side view showing a conventional packaging facility.

9 is a schematic sectional view of a vertical sealer portion of the packaging equipment of FIG.

10 is a perspective view of a heat-shrinkable film obtained by using the packaging equipment of FIG. 8 in a packaged state.

[Explanation of symbols]

 A Items to be packaged 1 Heat-shrinkable film 1A, 1B Lower overlapping portion of tubular film 1C Opening tab 1D Cylindrical film 1E, 1F Overlapping portion of tubular film on advancing side 1G , 1H Stacking part on the back side of tubular film 1I film bag 3 Vertical sealer 5 Shrink tunnel 3a Small protrusion 6 Small hole 7 Horizontal sealer 7a Small protrusion 1C 'Opening tab 1I' Film bag

Claims (1)

[Claims] 1. An opening tab having a predetermined width is integrally formed over a predetermined length on a heat-shrinkable film in which an object to be packaged is wrapped, and the opening tab is formed on the heat-shrinkable film before the heat-shrinking of the heat-shrinkable film. In the method for forming the opening tab of the packaging film, which is made by welding the overlapping portion with a sealer, using a sealer in which at least small projections are formed on the surface to be applied to the base side of the overlapping portion. The molten protrusion is formed in at least one of the overlapping portions by the small protrusions to weld the overlapping portion to form an opening knob having a predetermined width, and the heat-shrinkable film is welded to the opening portion. By giving a pulling force in the peeling direction to the overlapping portion, the root side of the overlapping portion in which the melting hole is formed is separated, and intermittent small holes of a predetermined length are formed on the root side of the opening knob. Opening for the tab formation process of the packaging film, characterized in that so as to formed.