JPS61232116A - Continuous packaging method and device by stretch film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention involves continuously pulling out a stretch film from a roll of raw material, holding both ends of the film under tension, and covering the object to be packaged. The present invention relates to a continuous wrapping method and apparatus using a stretch film, which is made by wrapping the film around the side of an object so that both edges thereof are brought into close contact with each other, and then cutting and sealing the film at the front and back of the object to be packaged.

(Prior art) In the conventional continuous wrapping method using stretch film, the film is continuously pulled out from a raw roll and is stretched slightly while passing through guide rolls perpendicular to the roll to prevent slack from occurring in the length direction. (for example, 1% or less), and then the central part of the film is stretched to a length by a pair of tension guide rolls provided on both sides of the upper part of the conveyance path of the packaged items, each inclined slightly downward and forward toward the conveyance path side. The stretched film is stretched in both the direction and the lateral direction, and both side edges of the stretch film are clamped by a film clamping belt disposed at a downward slope with respect to the traveling direction of the conveying path, and the film is stretched in the lateral direction. The container is moved forward in this state to cover the sides of the object to be packaged and seal the front and back as described above.

This conventional packaging method using stretch film evolved from the horizontal billow packaging method, which was developed for non-stretchable packaging materials, and the excellent elastic properties of stretch film have not been fully utilized. However, attention was paid only to the point that the stretch film was wrapped with enough tension to prevent wrinkles. Therefore, in the conventional wrapping method using stretch film, the film is only slightly stretched in the longitudinal and lateral directions by the guide rolls and tension guide rolls, and the total stretching rate is 1 to 2% at most. It was about.

(Problems to be Solved by the Invention) The present invention focuses on the excellent elongation properties of the stretch film itself, and by stretching this film sufficiently beforehand within a range that does not exceed its elastic limit and packaging, it is possible to An object of the present invention is to provide a method and apparatus for continuous wrapping using a stretch film, which can significantly reduce the amount of stretch film used, and provide a tighter package with stronger residual stress than conventional methods.

(Means for Solving the Problem) In the continuous wrapping method using a stretch film according to the invention of Application No. 1, before pulling out the stretch film from the original roll and covering the object to be packaged, the stretch film is stretched five times in the length direction. % or more within a range that does not exceed the elastic limit, and the subsequent packaging process is carried out while maintaining this stretched state.

The elastic limit of stretch film varies over a relatively wide range depending on the type of film, but it is preferable to stretch it to a point relatively close to the elastic limit, but at a stretching rate of 5%.
If the amount of film used is less than 1, the effect of significantly reducing the amount of film used for the same package cannot be achieved.

Preferably, after stretching in the length direction as described above, the film is also stretched in the width direction, and in this case as well, the stretching is done as much as possible without exceeding the elastic limit of the stretch film.

In the apparatus according to the second invention of the present application for achieving the above method, a first driving roller and a second driving roller are disposed between the raw roll and the transport means for covering the stretch film on the packaged object. rollers are provided and the stretch film is run between these drive rollers. And the second
The circumferential speed of the first drive roller is set to be 5% or more higher than the circumferential speed of the first drive roller, and the difference in circumferential speed is set within a range that does not exceed the elastic limit of the stretched stretch film. Further, the transfer means is made to run at a speed that is approximately equal to or slightly faster than the circumferential speed of the second driving roller.

By arranging the first drive roller and the second drive roller in close proximity, it is possible to reduce the degree of shrinkage in the width direction when the stretch film is stretched in the length direction. The distance between both drive rollers should be 1 cm or less.

(Embodiments) Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an apparatus of the present invention equipped with stretch film stretching means, in which a stretch film original roll 1 is rotatably supported above a rotating roller 2 and an autorotating roller 3, and a stretch film 4 is drawn out by the rotational drive of the autorotating roller 3 and is enlarged as detailed below while passing through the guard roller 5 between the first drive roller 6 and the second drive roller 7 for enlargement, Next, it is guided to a pair of tensioning guide rolls 8-8. The guide roll 8-8 is disposed above the conveyance path for the packaged object 9, with its tip inclined downward from both sides toward the center and toward the rear in the traveling direction. A pair of upper and lower film holding belts 10 are provided on both sides of the guide roll 8-8 in the forward direction of travel.
-10 are provided, and these belts 10-10 are inclined downward in the forward direction of travel. A conveying means 11 for carrying the packaged article 9, which has articles placed on a tray, is provided at the rear of the film holding belt 10-10 in the traveling direction of the belt 10-10. A feed claw 13 attached to each of the boxes pushes the packaged object 9 forward. A plurality of chain conveyors 14 are provided in series with the conveying means 11 and driven at the same speed as the film holding belts 10-10. sent. This chain conveyor 14 is arranged horizontally, and while the article 9 to be packaged is conveyed on this chain conveyor 14, a belt 10-1 is arranged downwardly and inclined forward.
The stretch film 4 held by the 0 is gradually placed on the article 9 to be packaged.

In front of the film holding belt 10-10, there is a guide means 15 for converging both side lines of the stretch film, which has come to be located below the object 9, to the center of the object 9.
Further, in front of the guide means 15, a pressure roller 16 is provided to bring the edges of the converged stretch film into close contact with each other. In front of this pressure roller 16 is a guide roll 17 for bending the end edges of vertical stretch films that are in close contact with each other on the lower surface of the object to be packaged, and attaching it to the lower surface of the tray of the object to be packaged 9. and a pressure roll 18 are provided, respectively.

Further, in front of the pressure roller 18 in the traveling direction, a packaged object 9 is provided.
One cutter means is provided for sequentially cutting the stretch film 4 at the front and rear ends of the packaged object 9, and the edges of the stretch film that are continuous with the front and rear ends of the cut article 9 are cut by a vacuum means or the like (not shown). The package 9 is bent downward by a well-known edge folding means, and then tightly sealed to the bottom surface of the tray of the packaged items 9.

According to the present invention, in the continuous wrapping method and apparatus using a stretch film as described above, the stretch film 4 is stretched before being placed on the article 9 to be packaged.

FIG. 2 shows an enlarged view of the stretch film stretching means of the present invention, in which the first drive roller 6 and the second drive roller 7 are vertically separated and arranged, and the stretch film is wound in an S-shape. The first drive roller 6 and the roller 3 that pulls out the stretch film from the raw roll 1 should rotate at approximately the same speed, or the first drive roller 6 should be rotated slightly faster to the extent that the film does not become slack. . Further, in order to prevent the film from being substantially stretched between the second driving roller 7 and the film holding belt 10-10,
Either the film holding belt 10 should have approximately the same speed as the film holding belt 10.
-10 is set to be slightly faster than the circumferential speed of the second drive roller 7.

In order to prevent the film from slipping between the first driving roller 6 and the second driving roller 7, it is preferable to use a rubber baking roller or other appropriate means. In the present invention, the circumferential speed of the second driving roller 7 is set higher than the circumferential speed of the first driving roller 6, and the stretching of the stretch film 4 is performed during this time, so that the length of the stretch film is increased by this difference in circumferential speed. 5% in the direction
The goal is to make it possible to stretch the film further, and to keep the stretching rate within a range that does not exceed the elastic limit of the stretch film. The purpose of this difference in circumferential speed of the re-driving rollers 6, 7 is to make it possible to stretch the stretch film as close to its elastic limit as possible;
Considering the stretching speed of the film, the strength of the film after stretching, etc., it is preferable to keep the upper limit of the stretching ratio at about 50%.

On the other hand, when this enlargement rate is less than 5%, sufficient economic effects cannot be achieved.

Further, preferably, by arranging the first drive roller 6 and the second drive roller 7 close to each other, the distance (f) between both rollers that the stretch film spans can be reduced to 1 c.
m or less, more preferably about 1 to 4III. By placing the rollers 6.7 in close proximity in this manner, the film between the rollers is sufficiently stretched in the length direction, while shrinkage in the width in the transverse direction is minimized.

FIG. 3 shows an apparatus for stretching a stretch film in the width direction in the method according to the present invention, and the apparatus is used in FIGS. 1 and 2 to fully stretch the stretch film 4 in its length direction, and then It is an enlargement. In this device, a pair of upper and lower clamping conveyor belts 20-20 are provided on the left and right sides along the traveling direction, with the interval gradually increasing in the direction of travel. The width of the film is gradually enlarged as the film progresses. This clamping conveyor belt 20-20 is provided between the second driving roller 7 and the film clamping belt 10-10, which is disposed in a downwardly inclined manner, as shown in the first embodiment.
It is preferable to perform stretching in the width direction after stretching in the length direction. However, if necessary, this nip conveyor belt 20- instead of the second drive roller 7
20 may be provided so that stretching in the length direction and stretching in the width direction may be performed simultaneously between the first drive roller 5 and this clamping conveyor belt 20-20.

The degree of stretching in the width direction is to be such that it does not exceed the elastic limit of the stretch film in the width direction, but the stretching rate should be 10% or less, taking into consideration the stretching speed in the film width direction.

FIGS. 4(A) and 4(B) show another embodiment of the device for stretching the stretch film shown in FIG. 3 in the width direction. A series of lower roller groups 22-22 are arranged below the series of upper roller groups 21-21, and each lower roller group 22-2
2 is partially inserted into the upper roller group 2l-21fil. Pinch rollers 23-23 are provided at both ends of the upper and lower roller groups 21 and 22, respectively, and both end edges of the stretch film 4 are connected to these pinch rollers 23-23.
23 and passes between the groups of upper and lower rollers 21 and 22, the intermediate portion thereof is stretched into a waveform from above and below. After passing through this device, the stretch film 4 is stretched in the lateral direction and sent to the next stage, a film holding belt 10-10, which is disposed at a downward slope. Note that the degree of stretching in the lateral direction is the same as in the embodiment shown in FIG. 3 above.

Next, in the first embodiment of the present invention shown in FIGS. 1 and 2, the ratio (X) of the circumferential speed of the second drive roller to the circumferential speed 1 of the first drive roller was variously changed, Average elongation rate (Y) in the length direction of the film between both rollers, average shrinkage rate (Z) in the width direction of the film, tension condition of the film after packaging (A), and rupture status of the film after packaging (B) ) are shown in the table below. The stretch film used was a PVC stretch film manufactured by Nippon Carbide Industries Co., Ltd. under the trade name [Hinissoft 0M5J, and the thickness was 18μ, which is said to be the thinnest limit in manufacturing technology.
belongs to.

As is clear from the above table, from the above experimental results of the present invention, when the stretching rate of the stretch film reaches 60%,
Signs of film breakage were observed, and from a safety standpoint, it seems that the upper limit for the stretching rate is about 50%.

(Effects) As described above, according to the stretch film packaging method and apparatus according to the present invention, the stretch film is stretched by 5% in the length direction before being pulled out from the original roll and covering the object to be packaged. As described above, the film is stretched within a range that does not exceed its elastic limit, and the subsequent packaging process is carried out while maintaining this stretched state. This makes it possible to effectively utilize the film and save more than 5% of the film, significantly reducing packaging costs. can be reduced. In addition, the stretch film stretched in the present invention has a large residual stress, so it has better tension after being wrapped over the packaged item, compared to conventional packaging that is not fully stretched. The appearance of things also becomes better. Furthermore, since the apparatus implementing the presentation method of the present invention requires only the addition of a first drive roller and a second drive roller to a conventional apparatus, there is no need to modify the main components of the conventional packaging machine. It is extremely simple and can produce great effects.

[Brief explanation of the drawing]

Figure 1 is a side view showing the entire device of the present invention, and Figure 2 is a side view showing the entire device of the present invention.
A side view showing an enlarged view of the essential parts of the present invention in the device shown in the figure;
FIG. 3 is a perspective view showing an example of a device for stretching a stretch film in the horizontal direction, and FIGS. 4 (A) and (B) are side and front views showing other examples of stretching the stretch film in the horizontal direction, respectively. It is. 1... Original fabric roll 4... Stretch film 6... First drive roller 7... Second drive roller 9... Packaged object 10...Film holding belt patent applicant Omori Machine Industry Co., Ltd. Agent
People Patent Attorney - Kensuke Iro Figure 2

Claims (4)

[Claims] (1) Continuously pull out the stretch film from the original roll, hold both ends under tension, and cover the item to be packaged.
In a packaging method, the stretch film is wrapped around the side of the packaged object so that both side edges thereof are brought into close contact with each other, and then the film is cut and sealed at the front and rear of the packaged object. Before pulling out the stretch film from the original roll and covering the object to be packaged, the stretch film is stretched by 5% or more in the length direction within a range that does not exceed the elastic limit, and this stretched state is maintained during subsequent packaging. A continuous packaging method using stretch film characterized by carrying out a process. (2) After the stretch film is stretched in the length direction, it is also stretched in the width direction, and the stretching in the width direction is kept within a range that does not exceed the elastic limit of the stretch film. Continuous packaging method using the described stretch film. (3) a roll of stretch film, a means for transporting the stretch film pulled out from the roll through a guide roll while holding both side edges of the stretch film under tension;
A means for conveying a packaged object that runs between the transfer means, a guide means for wrapping the stretch film around the sides of the object, a means for bringing the both side edges of the stretch film into close contact with each other, and a means for bringing the stretch film into close contact with the sides of the object to be packaged. In a continuous wrapping device for stretch film, which comprises a cutter means for cutting the stretch film, and a means for sealing the front and rear opening ends of the cut stretch film, there is a gap between the raw roll and the transport means. A first drive roller and a second drive roller are disposed, the stretch film is run between these drive rollers, and the circumferential speed of the second drive roller is set to 5% of the circumferential speed of the first drive roller. In addition, the peripheral speed difference is set within a range that does not exceed the elastic limit of the stretched stretch film, and the transfer means is set at a peripheral speed approximately equal to or slightly equal to the peripheral speed of the second driving roller. A continuous wrapping device using stretch film that is characterized by running at a high speed. (4) The distance between the first driving roller and the second driving roller over which the stretch film is stretched is set to 1 cm or less. Continuous wrapping equipment using stretch film.