JP2900095B2 - Packaging method and 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 packaging method in which a tray in which goods are placed is packaged with a film, the air in the film is replaced with an inert gas, and the film is heated and shrunk. About the method.

[0002]

2. Description of the Related Art It is known to flush an inert gas into a packaging bag and heat shrink the heat shrinking bag in order to prevent spoilage of commodities placed on a tray.

[0003]

However, the package obtained by such a method is a product in which the bag is rounded and inflated due to the presence of gas, and becomes an unstable product, and the gas is thermally expanded and the bag is damaged. Therefore, as shown in Japanese Utility Model Publication No. 53-20281, a hole for venting gas is formed in the bag.
As in 28327, the opening of the bag is not completely sealed, and the gas is discharged from the opening when the film is thermally shrunk, so that the product obtained by the conventional packaging method is not suitable for food packaging. There was a side.

SUMMARY OF THE INVENTION The present invention is a method for eliminating excess gas which makes a bag unstable while being completely sealed. The method comprises the steps of: feeding a strip of film supplied to a column tray which moves horizontally at equal intervals. While forming a tube around the tandem tray by means of a cylinder, meanwhile, while feeding an inert gas into the tube film from the tray loading side for the tube film, at the tip of the transport track where each tray moves, In a packaging method in which a tube film is sealed off between a state-of-the-art tray and a tray at the rear thereof, a holding block provided in an upper area immediately in front of the blocking seal portion in the transport direction of each tray is provided. While reciprocating according to the transport pitch of the tray, by a volume corresponding to the gas amount around the tray in the tube film. The holding block is pushed into the tray from the upper edge of the tray, and the pushing action removes the inert gas in the state-of-the-art tray in the tray loading direction with respect to the tube film, and seals off the tube film. The heat treatment shrinks the surrounding tube film.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus for carrying out the method of the present invention will be described below.

Although the detailed structure of the cylinder making mechanism is omitted in FIG. 1, the belt-shaped heat-shrinkable film 11 supplied via the roller 10 is connected to the tray 12 by the cylinder making mechanism. It is made into a tube. As this cylinder making mechanism,
For example, while holding both sides of the film with a large number of clamps, moving each clamp with a chain, winding the film around the tray, or using a kind of cylindrical form, the joint of the both sides of the film The parts are welded by the center sealer 13.

On the other hand, the trays 12 are successively supplied into the film 11 which is formed into a tube as described above, and each tray is sandwiched between a pair of side belt conveyors 14 from both sides.
The transport is performed by the transporting force of the side belt conveyor 14 which rotates by the power of No. 5. That is, as shown in FIG. 2, the pair of side belt conveyors 14 support the endless belt 18 on the frame 16 via the pulley 17, and the tray 12 is conveyed by the power transmitted to the belt 18 via the chain wheel 19. Things.

As shown in FIG. 1, a flat vacuum suction cylinder 21 having one end supported on a machine base 20 is disposed between the lower surface of the tray 12 and the film, and a plurality of suction holes 22 are formed at both end faces of the vacuum suction cylinder 21. The suction force of a vacuum pump 23 connected to one end of the cylinder is used to apply a vacuum suction force to each of the suction holes 22. For this reason, the air in the tubular film 11a is sucked in, and the film comes into close contact with the tray so as to wind once. In this case, a small hole is formed in the wall of the tray, and the air inside the tray is removed from this hole, and the gas around the tray is conveyed to the tray.
Since it can be inhaled , gas replacement , which will be described later, is improved.

Further, as shown in FIG. 2, a gas supply pipe 24 is disposed in a vacuum suction pipe 21. One end of the gas supply pipe is connected to a gas cylinder 25, and the other end 26 of the same gas supply pipe is connected to the vacuum suction pipe. The gas supply tube 24 extends beyond the end end 27 of the film 21 to the vicinity of the heated seal bars 29, 30 to flush an inert gas into a vacuum environment region in the film.

A guide rail 34 is provided above the tray moving area, behind heating seal bars 29, 30 provided above and below the tray moving area. The guide rail 34 is parallel to the moving direction of the tray 12, and includes an operation control mechanism 35 for reciprocating the air cylinder 33 along the guide rail 34.

The operation control mechanism 35 reciprocates the air cylinder 33 at a cycle corresponding to the moving pitch of the tray 12 and moves the air cylinder 33 in the same direction as the tray.
3 pushes down the holding block 31 fixed to the lower end via the piston rod 32.

As shown in FIG. 3, the holding block 31
It is composed of a plate 36 and a sponge rubber 37 provided on the lower surface thereof. Since the sponge rubber 37 is pushed into the tray 12 by the downward movement of the holding block 31, most of the inert gas in the tray is pushed out. Since the gas is discharged in the direction of the tray receiving port of the tube film, the pair of seal bars 29 and 30 immediately seal the tube film.

As shown in FIG. 2, the tube film has at least the slack of the volume in which the vacuum suction tube 21 was present. Therefore, as shown in FIG. 3, the sponge rubber 37 pushes out the gas inside the tray. The heating tunnel 40
When the film undergoes thermal shrinkage in the inside, the excess inert gas in the film slack portion around the tray is absorbed into the space previously formed inside the tray by the holding block 31 as described above, and as shown in FIG. As described above, the film 11 covering the upper edge portion of the tray 12 becomes flat and taut.

[0014]

According to the present invention, since the tube film is pushed down by the holding block 31 and the gas in the tray is pushed out excessively, the film is sealed, so that the film around the tray is absorbed into the tray so as to absorb the gas around the tray into the tray. It can be contracted and adhered. For this reason, unlike the conventional case, it is not necessary to seal the air vent hole formed in the film in advance with a label, or to heat-shrink the opening of the tube film in an incompletely sealed state, especially as a sanitary packaging for fresh food. effective.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA of the preceding figure.

FIG. 3 is an explanatory diagram of an operation of a holding block.

FIG. 4 is a perspective view of a packaged product.

[Explanation of symbols]

11-film, 12-tray, 14-side belt conveyor, 21 vacuum suction cylinder. 24--gas supply pipe. 31-Presser block. 35 operation controller. 40-
Heating tunnel.

Claims (4)

(57) [Claims] 1. A belt-like film to be supplied to each tray moving at equal intervals in a horizontal direction in a horizontal direction is formed into a tube around the vertical tray by a cylinder-making means, and from the tray carrying side for the tube film. A packing method in which the tube film is cut off and sealed between the most advanced tray and the tray at the rear thereof at the tip of the transport track along which each tray moves while feeding the inert gas into the tube film. The reciprocating movement of the pressing block provided in the upper region immediately in front of the blocking seal portion in the transport direction of each tray in accordance with the transport pitch of the tray while controlling the gas amount around the tray in the tube film. The holding block is pushed into the tray from the upper edge of the tray by a corresponding volume, and the pushing action causes A method of packaging, wherein the tube film is sealed off while the inert gas in the tray is removed in the tray carrying direction with respect to the tube film, and then the tube film around the tray is heated and shrunk. 2. The packaging method according to claim 1, wherein holes for gas distribution are formed in the wall surface of the tray. 3. Means for covering a plurality of trays moving at equal intervals in a column with a heat-shrinkable film supplied at the same speed as these trays in a cylindrical shape, and for integrally transporting the trays and the film. Gas supply means for flushing an inert gas into the cylindrical film by a gas supply pipe inserted and arranged in the cylindrical film; and a pair of upper and lower heating seal bars provided near an end end of the gas supply pipe In a packaging mechanism comprising means for sealing the cylindrical film so as to isolate each tray by means of heating, and a heating means for shrinking the film around the isolation tray, the sealing bar is provided in the conveying direction of the tray. A holding block arranged in the upper rear area so as to reciprocate in synchronization with the transport of the tray and to move downward toward the tray; A packaging device provided with an operation controller for removing gas corresponding to the volume of space around the tray from the inside of the tray by lowering the presser block immediately before sealing. 4. The packaging apparatus according to claim 3, wherein the holding block is formed by providing sponge rubber on the lower surface of the plate.