JP3129463B2 - Shrink packaging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shrink wrapping apparatus used for manufacturing a shrink wrapper formed by thermally shrinking a wrapping film surrounding an object to be wrapped.

[0002]

2. Description of the Related Art Conventionally, to manufacture a shrink package, an intermediate package is manufactured by surrounding the object to be packaged with a heat-shrinkable film, and the intermediate package is passed through a shrink tunnel. Heat is applied to shrink the film and make it adhere to the package. However, the heat present during the heating causes the air present in the intermediate package to expand thermally, and the pressure at the time of the expansion causes the film to expand against the force of the film to shrink, causing the film to shrink. I can't let it.

[0003] Therefore, a very small through-hole is formed beforehand at a predetermined position of the film. This allows
When the intermediate package is heated, the air inside expands and tries to expand the film, but the expanded air is released to the outside through the vent holes for degassing, so that the film is smooth. Heat shrinks and adheres to the package.

[0004] As a packaging device for producing such a shrink package, for example, a normal pillow packaging device has a basic configuration, and as shown in FIG.
A punching device E provided with a piercing needle D around a rotating rod is arranged in the middle of drawing out the strip-shaped film C which is continuously pulled out from the bag making device B.
A shrink tunnel for heating and shrinking the film of the intermediate package is provided at the carry-out side end of the pillow packaging device. By using such a shrink wrapping device, after forming a through hole at a predetermined position of the strip-shaped film C, performing an ordinary wrapping process to produce an intermediate wrapper, and then passing the intermediate wrapper through a shrink tunnel. Heat shrinks the film to produce a shrink package.

[0005] The location of the through-holes formed in the strip film C, that is, the number of through-holes provided for one intermediate package, depends on the size of the package and the volume ratio between the packaged object and the internal space in the intermediate package. Therefore, each time the object to be packaged changes, it is necessary to determine the number of through-holes to be installed and adjust the installation position of the through-holes in the strip film C. Therefore, in the above-described hole punching device E, as shown in FIG. 10, a hollow rotary cylinder G is inserted into a rod F via a bearing H so as to correspond to a different package. Ring-shaped rotating body I divided into a plurality around
Are inserted, and in this state, the plurality of rotating bodies I are clamped and held between the pair of bolts J by fastening the bolts J attached to both ends of the rotating cylinder G. In this state, when the surface of the rotating body I is brought into contact with the belt-shaped film C, the rotating body I and the rotating cylindrical body G rotate due to contact resistance generated between the belt-shaped film C and the movement of the belt-shaped film C. When the perforating needle D inserted into the belt-shaped film C comes into contact with the band-shaped film C, a through-hole is formed in the band-shaped film C. The plurality of rotating bodies I include a plurality of rotating bodies I having a perforated needle D on the surface thereof (the number of needles provided is arbitrary) and a dummy having no such needle. Then, as described above, each time the form of the package changes, the bolt J is removed from the rotary cylinder G,
An arbitrary rotating body I (with or without a needle) is selected so that a through hole is formed at a predetermined installation position in the belt-shaped film C, and these are mounted on the rotating cylindrical body G, and then fixed via the bolts J. I do.

[0006]

However, in the above-described conventional shrink wrapping apparatus, every time the form of the package changes, the rotating body I must be selected and exchanged. Adjustment of the relative angular position of the perforating needle D is required, and such work becomes very complicated.

[0007] A shrink wrapper manufactured using the above shrink wrapping apparatus also has the following problems. That is, the shrink wrapped body has a through hole for venting (deaeration), and it is difficult to close the through hole in a subsequent process. This causes a problem that sealing performance is lacking. Therefore, for example, for the purpose of maintaining freshness and preventing discoloration of food when the packaged object is a living thing or food, etc., gas replacement packaging in which nitrogen gas or carbon dioxide gas is filled together with the packaged object in the package. Cannot be used for the package manufactured by the method described above. That is, even if the package is filled with nitrogen gas or the like, the nitrogen gas flows out through the through holes to the outside, and the effect of the gas is reduced. Furthermore, shrinkable films such as polyethylene and polypropylene, which are generally used in the past, have low gas barrier properties themselves, and the filled nitrogen gas and the like leaks from the film surface little by little to the outside. Becomes more noticeable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and has as its object to achieve good airtightness and to prevent the gas from leaking to the outside if the gas is filled with nitrogen gas or the like. Gana rather, yet to provide a shrink wrapping device for producing a sealing excellent in Sri <br/> ink package.

[0009]

To achieve the above object SUMMARY OF THE INVENTION In this onset bright, and with drawn out continuously a strip film comprising a low gas permeability material heat shrinkable good, the drawer Means for forming a tubular shape without providing a through hole for deaeration during heating on the way, a packaged material supply device for supplying a packaged product into a tubular film formed in the tubular shape, And a center sealing device arranged in the conveying path of the tubular film to seal the overlapped end of the tubular film, and a center sealing device disposed in front of the center sealing device in the traveling direction to seal the tubular film at predetermined intervals in a lateral direction. An end seal device for cutting, and a shrink tunnel disposed in front of the end seal device in the traveling direction and heating the intermediate package separated from the tubular film by the end seal device are provided. And, in the film biasing device for urging the disposed to the upper surface of the cylindrical film downwards between said end sealing apparatus and the shrink tunnel,
The center sealing device comprises a plurality of rollers for holding and heating the overlapped end of the cylindrical film, and a plurality of annular ridges are formed on a side peripheral surface of one of the plurality of rollers. Ri Na and the side peripheral surface of the other roller to form a flat surface with which the inter plurality several rollers
A plurality of centers extending longitudinally on the film passing through
-It forms a seal part .

[0010]

The belt-like film made of a material having good heat shrinkage and low gas permeability is continuously drawn out and formed into a cylindrical shape. No deaeration holes are formed. On the other hand, the articles to be packaged are sequentially supplied into the tubular film, and the articles are forward-transferred while the articles to be packaged are inserted in the tubular film. The package is sealed by the device, and furthermore, the end of the tubular film is sealed and cut in the lateral direction by the end sealing device to produce an intermediate package. At this time, in the center sealing device, the longitudinal end is
To form multiple center seals
Not only ensures a reliable seal, but also
Because it is not added , the amount of heating to the heat shrinkable film is kept low
Since the center seal portion is flat without being excessively shrunk, the end seal can be reliably performed.
Also, before the rear side in the traveling direction of the intermediate package is sealed / cut, the upper surface of the cylindrical film is urged downward by the film urging device, and then the predetermined position of the cylindrical film is adjusted by the end seal device. Sealed and cut, the intermediate package is separated from the tubular film and manufactured. In the intermediate package manufactured in this manner, the upper surface portion of the film is depressed inside, and the amount of gas present inside the intermediate package decreases. Then, by passing this intermediate package through the shrink tunnel, the film is heated and thermally contracted, so that the upper surface portion of the film becomes taut. At the same time, the gas present in the intermediate package expands thermally, but the expanded gas flows into the newly defined upper space side as the upper surface position of the film rises. Does not swell upward beyond a predetermined amount. In this way, a shrink package is manufactured. In addition, since the manufactured shrink wrapper is a completely sealed bag with no perforations formed, even if the wrapper is filled with nitrogen gas or the like for the purpose of maintaining the quality of the packaged object, the gas is not filled. The purpose of gas replacement is achieved for a long time without leakage to the outside.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a shrink wrapping device according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of the shrink packaging apparatus according to the present invention. As shown in FIG. 1, an end-sealing device 5 is disposed in front of a transport device 4 for transporting a package 3 in which articles 2 are stored in a tray 1 whose upper part is expanded at predetermined intervals. An original film 8 on which a belt-like film 7 is wound is disposed above the transport device 4, and a shrink tunnel 10 is disposed on the discharge end side of the end seal device 5.

As the belt-like film 7, a film material having low gas permeability, that is, good gas barrier property and high heat shrinkage, for example, BDF-2050 (manufactured by Cryovac) is used. Then, the band-shaped film 7 is formed into a cylindrical film by a bag-making device 14 disposed at an intermediate point of the conveying device 4 via a draw-out roller 12 and a plurality of tension rollers 13. A film 7 'is formed, and the articles to be packaged are sequentially supplied and stored in the cylindrical film 7', and are further transported.

The transport device 4 transports only the package 3 and sequentially feeds the package 3 into the cylindrical film 7 '. A second transporting device 16 is disposed adjacent to the unloading side of the first transporting device 15 and transports the packaged object 3 together with the tubular film 7 ′. Then, the first transfer device 1
Reference numeral 5 denotes an endless chain 18 provided on a pair of sprockets 17 and 17 ', and the endless chain 18
And fingers 19 arranged at predetermined intervals. Further, the second conveying device 16 is provided with a center seal device 20 for sealing the overlapped end portion 7a of the tubular film 7 'below the vicinity of the carry-in side.

The center seal device 20 heats and fuses the overlapped end 7a of the cylindrical film 7 'by pressing and heating the overlapped end 7a from both sides of the overlapped end 7a to heat and fuse the film joining surface. The structure is as shown in FIGS. That is, the heating roller 21 having a relatively large diameter,
It is composed of two small-diameter receiving rollers 22 arranged opposite to the heating roller 21 with the overlapping end 7a interposed therebetween. The reason why the two receiving rollers 22 and 22 are provided in this way is to reliably heat seal the overlapped end 7a. Then, three annular ridges 23 are formed on the side peripheral surface of the heating roller 21, and a cylindrical shape is formed between the three ridges 23 and the receiving rollers 22, 22 having flat side peripheral surfaces. The overlapping end 7a of the film 7 'is pinched and heated,
Heat is prevented from being applied to the entire surface of a, and the amount of heating of the film is reduced. That is, the film material 2 used
Because of its high heat shrinkability (shrinks to about 50 to 60% before shrinkage), if the heating amount is large, the polymerized end 7a shrinks too much and becomes rounded, increasing the thickness of the portion, and as it is, the post-process However, it is not possible to perform a completely sealed end seal, but by suppressing the amount of heating as described above, the center seal portion is flattened to ensure the end seal. The overlapped end 7a sealed by the center seal device 20 has a substantially flat shape in which three vertically extending seal portions 7a 'are formed as shown in an enlarged manner in FIG.

Further, in this embodiment, the heat generated from the heating roller 21 is applied to a portion of the cylindrical film 7 'located on the bottom side of the tray 1 to prevent the film portion from thermally contracting. A pair of left and right cooling plates 25 is disposed between the sealing device 20 and the cylindrical film 7 '. The cooling plate 25 includes a flat upper plate, a lower plate 26,
27 and a middle plate 28 having a meandering window hole 28a interposed between the two plates 26, 27.
Eight window holes 28a serve as cooling passages. A cooling water supply port 27 to the cooling water passage is provided at a predetermined position of the lower plate 27.
a and a discharge port 27b are formed.
7b via a connecting pipe 29 to a pump 30 and a tank 31
Are linked. Thereby, the cooling water circulates in a closed circuit constituted by the cooling water passage, the connecting pipe 29, the pump 30, and the tank 31. In this example, tap water is used as cooling water. Further, the overlapped end 7 of the tubular film 7 ′ is located in the gap between the two cooling plates 25, 25.
a is inserted and supplied between the rollers 21 and 22 located below the cooling plates 25 and 25.

In the present embodiment, the end seal device 5 uses a so-called box motion type end seal device, and the specific configuration is as shown in FIG. That is, it has a pair of upper and lower end sealers 35 and 36,
A cutting blade is built in the sealing surface of the upper end sealer 35. The both end sealers 35 and 36 are connected to the groove cams 37 and 37, and move forward with the end sealers 35 and 36 engaged with each other, and then rotate and move along a predetermined trajectory that moves backward while separating. It has become. Further, around the lower end sealer 36, there is provided an endless belt 40 extending over a number of fixed and movable pulleys 39a, 39b, and a cylindrical film 7 'on the upper conveying surface 40a of the endless belt 40. Is received and transported. The endless belt 4 formed around the lower end sealer 36
The space 40b of 0 is moved back and forth with the lower sealer 36 by moving the movable pulley 39b back and forth in synchronization with the front and rear movement of the lower sealer 36, thereby shortening the opening distance of the space 40b. The smooth movement of the tubular film 7 'and the like is achieved.

Further, according to the present invention, the front surface of the end sealer 35 in the traveling direction on the upper side of the end seal device 5 is provided with:
A film pressing member 43 as a film urging device is provided via a connecting plate 42. This film holding member 43
Is composed of a rectangular sponge, the shape of which is set smaller than the planar shape of the tray 1. The thickness of the film holding member 43 is set such that the lower surface of the film holding member 43 is located lower than the upper surface of the tray 1 when the end sealers 35 and 36 are engaged with each other, that is, when the upper end sealer 35 is located at the lowermost end. It is set. As described above, in the present embodiment, the end seal device 5 and the film holding member 43 are formed integrally, but it goes without saying that both may be separately configured.

The shrink tunnel 10 described above is disposed further forward in the direction of travel of the film holding member 43. The shrink tunnel 10 is a conventional one having a longitudinal section and a substantially gate-shaped opening with front and rear openings. A transport belt 45 is provided below the shrink tunnel 10 so as to transport the intermediate package 46 separated and manufactured from the cylindrical film 7 'by the end sealing device 5. An unloading conveyor 48 is provided near the unloading end of the transport belt 45, and is configured to unload the shrink wrapped body 50 that has been produced by heat shrinking through the shrink tunnel 10.

Next, the operation of the above-described embodiment will be described. First, the strip film 7 is continuously pulled out from the raw film 8 and guided to the bag making device 14 without forming a through hole in the strip film 7. Then, there, it is formed into a tubular shape to form a tubular film 7 '. On the other hand, the article to be packaged 1 is pushed by the finger 19, conveyed at predetermined intervals, and sequentially supplied into the tubular film 7 '. In this state (the state in which the article to be packaged 3 is stored in the cylindrical film 7 '), the film is conveyed on the second conveying device 16, and the overlapped end portions 7a of the cylindrical film 7' are interposed in the middle. Is heat-sealed while the heating roller 21 and the receiving roller 22 arranged on the left and right hold the same. At this time, the center seal device
Heat-sealed the overlapping end of the
Reduce the amount of heat applied to the film to reduce excessive shrinkage of the film.
Preventing.

When the sheet is further moved forward, the end seal device 5 heat seals and cuts the tubular film 7 'in the lateral direction at predetermined intervals to manufacture the intermediate package 46. At this time, before the end seal on the rear side in the traveling direction is performed, the upper surface of the cylindrical film 7 'is urged downward via the film pressing member 43 so as to be depressed inside (see FIG. 5). From that state, both end sealers 3
5 and 36 are rotated and engaged with each other to perform end sealing (see FIG. 6), thereby producing an intermediate package body 46 having a film whose upper surface is depressed as shown in FIG. That is, the amount of gas inside the intermediate package body 46 is reduced, and an extra film is provided in consideration of the thermal contraction of the tubular film 7 '. Since the film holding member 43 is formed of sponge, even if the film holding member 43
Even when the lower surface of the sheet abuts on the article 2, the film can be urged downward without damaging the article 2 in the tray 1. Therefore, by increasing the thickness of the sponge, the film suppressing member 43 moves downward while depressing the sponge portion in contact with the article 2 upward,
It is possible to urge the film portion located around the article 2 below the upper surface position of the article 2.

Next, the intermediate package 46 is supplied into the shrink tunnel 10 via the endless belt 40 and the conveyor 45. This shrink tunnel 10
Since the upper side has a particularly high temperature, the tubular film 7 'is thermally contracted, and particularly the upper surface portion is largely contracted. As a result, as shown in FIG. 8, the film portion located on the upper surface opening side of the tray 1 is in a taut state. At the same time, the gas present in the intermediate package 46 thermally expands, but flows into the newly defined upper space 51 as the film upper surface position rises, so that the film upper surface rises above the tray 1. It does not swell.

As a result, the shrink wrapping body 50 in which the tubular film 7 ′ is thermally contracted and adhered to the tray 1 is manufactured. Since the manufactured shrink wrapper 50 is a completely sealed bag having no through-hole, the nitrogen gas or the like filled in the shrink wrapper 50 may flow out to the outside by using a gas replacement device together. There is no. Moreover, since the gas barrier property of the used film material is good, it does not leak out from the film surface to the outside unlike the conventional package. Therefore, the nitrogen gas can be sealed in the package while utilizing the characteristics of the shrink package such that the article can be firmly fixed, and deterioration of the quality of the stored items can be prevented.

Further, since the heat shrinkability of the film is good, the ears 52 of the manufactured shrink wrapping body 50 are small and narrow as shown in the figure, so that the ears 52 are transported and displayed. The workability is improved without being in the way. Furthermore, when the tray 1 that expands upward as in this example is used, the ear 52 does not protrude from the edge of the tray 1, and the display effect is increased in addition to the workability described above.
The strength of the part also increases.

In the above-described embodiment, the article to be packaged 3 is configured by storing the article 2 in the tray 1, but the present invention is not limited to this, and the article is directly packaged without the tray 1. In addition, in the above embodiment, the height of the tray 1 is made larger than the height of the articles 2 to be stored. However, the relationship may be reversed or arbitrary. Needless to say, the film to be used is not limited to the above-described embodiment, and its heat shrinkage and the like also depend on the size and shape of articles, trays, etc., the amount of gas existing in the intermediate package, and the final amount. It is determined according to the relationship with the amount of space in the shrink wrapper, and is appropriately determined. further,
As the end seal device, a box motion type is described, but a rotary type that makes a circular motion around a rotation axis may be used, and other devices and components are not limited to the above-described embodiment. Various things can be applied.

[0025]

As described above, in the shrink wrapping apparatus according to the present invention, a strip film made of a material having good heat shrinkage and low gas permeability is continuously drawn out, and in the middle of the drawing, the strip film is drawn out. Enclosing the packaged object without forming a through hole for deaeration, and urging the upper surface of the tubular film downward before the intermediate package is manufactured by the film urging device. As a result, the intermediate package manufactured using the present apparatus is in a sealed state in which the upper surface portion of the film is depressed inside, and the amount of gas inside the intermediate package decreases. In the center seal device employed in the device of the present invention, a plurality of center seals extending in the longitudinal direction at the overlapping end of the cylindrical film are provided.
Not only ensures the center seal
In addition, since heat is not applied to the entire surface of the polymerization end, the amount of heat applied to the heat-shrinkable film is kept low, and the center seal portion is flat without excessive shrinkage, so that the end seal can be reliably performed. Then, by passing this intermediate package through the shrink tunnel, the film is heated and thermally contracted, so that the upper surface portion of the film becomes taut. At the same time, the gas present in the intermediate package expands thermally, but the expanded gas flows into the newly defined upper space side as the upper surface position of the film rises. Does not swell upward beyond a predetermined amount. Therefore, since the shrink package manufactured using the present invention is a completely sealed bag in which no through-hole is formed, it is assumed that the package is filled with nitrogen gas or the like for the purpose of maintaining the quality of the article to be packaged. However, the gas does not leak out, and the purpose of gas replacement is achieved for a long time. as a result,
Even if the package is filled with nitrogen gas or the like, the gas does not leak to the outside, so that it is possible to prevent deterioration of the quality of the stored items.

[Brief description of the drawings]

FIG. 1 is a side view showing a preferred embodiment of a shrink wrapping device according to the present invention.

FIG. 2 is a plan view showing the vicinity of a center seal device of the present embodiment.

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a side view showing the vicinity of the end seal device of the present embodiment.

FIG. 5 is a view for explaining the operation of the end seal device of the present embodiment.

FIG. 6 is a view for explaining the operation of the end seal device of the present embodiment.

FIG. 7 is a side view showing an intermediate package manufactured by the present apparatus.

FIG. 8 is a side view showing a shrink package manufactured by the present apparatus.

FIG. 9 is a side view showing a conventional example.

FIG. 10 is a diagram showing an example of a conventionally used hole punching device.

[Explanation of symbols]

REFERENCE SIGNS LIST 3 packaged object 5 end seal device 7 strip film 7 ′ tubular film 7 a overlapping end 10 shrink tunnel 14 bag making device 15 first transport device (means for supplying packaged material into tubular film) 20 center sealing device 43 Film holding member (film urging device)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-79270 (JP, A) JP-A-4-279422 (JP, A) Fully open 1974-2704 (JP, U) Really open 1975 13410 (JP, U) Japanese Utility Model Showa 60-50104 (JP, U) Japanese Utility Model Showa 62-65909 (JP, U) Japanese Utility Model Showa 48-26306 (JP, Y1) Japanese Utility Model Showa 49-19012 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65B 53/00-53/06

Claims (1)

(57) [Claims] 1. A belt-shaped film made of a material having good heat shrinkage and low gas permeability is continuously drawn out, and is formed into a cylindrical shape without providing a through hole for deaeration during heating during the drawing. Means for supplying an object to be packaged into the cylindrical film formed in the cylindrical shape, and a packaged end disposed in a conveying path of the cylindrical film and sealing a polymerization end of the cylindrical film. A center seal device, an end seal device disposed in front of the center seal device in the traveling direction, and an end seal device that seals and cuts the cylindrical film in a lateral direction at predetermined intervals; and an end seal device disposed in front of the end seal device in the traveling direction. A shrink tunnel for heating the intermediate package separated from the tubular film by the end seal device; and a connection between the end seal device and the shrink tunnel. And a film urging device disposed on the upper surface of the cylindrical film to urge the upper surface of the cylindrical film downward. consist of rollers, Ri Na formed on one flat surface of the side peripheral surface of the other roller to form a plurality of annular ridges on the side peripheral surface of the roller of the plurality of the rollers, which Between the plurality of rollers
A plurality of centers extending longitudinally through the film that has passed
A shrink packaging device characterized by forming a seal portion .