JP2741102B2 - Packaging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention covers a tray containing food with a tubular film, replaces the air in the tube film with an inert gas, and further removes the opening edge of the film. The present invention relates to a packaging device that heats and shrinks a film after sealing.

(Prior Art) Conventionally, as shown in FIG. 7, when a tray 2 containing food 1 is hermetically packaged with a film 3, an inert gas is injected into the film in advance to suppress the spoilage of the food. Heat shrink the film.

(Problems to be Solved by the Invention) However, since the film in which the gas is sealed has insufficient heat shrinkage and remains in a swollen state, a needle hole is formed in the film in advance, and when the film is thermally shrunk, the needle hole is used. I try to exclude gas. Therefore, since this needle hole causes gas leakage, it is necessary to take a post measure such as attaching a label or the like to the hole.

(Means for Solving the Problems) In order to eliminate steps such as countermeasures against a needle hole, the present invention provides a carry-in conveyor for carrying trays containing foods at equal intervals in a column, and a conveying direction for each tray. Means for transferring the band-shaped film and forming the film into a tube around the tray; a pipe for supplying an inert gas into the tube film; and a rear end of the pipe in the film transfer direction. Means for reciprocating the sealer support block in the same direction as the film transport direction, and a means for squeezing and heating the tube film with a pair of upper and lower seal bars supported by the block. An air cylinder is installed on the block with a press plate provided at a lower end of a piston rod hanging down from the air cylinder, The air cylinder is operated so that the holding plate sinks below the upper edge of the tray in accordance with the timing of pressing the film by the two seal bars, and further, the film around each tray is heated and shrunk behind the block. Means are provided.

(Operation) A film is placed in a cylindrical shape around each of the trays conveyed by the carry-in conveyor by a tube-making means, and almost at the same time, an inert gas is supplied from the pipe into the tube film.

It moves by a certain distance integrally with the tube film,
The air cylinder provided in the block that repeats the reciprocating motion returning to the original position again, sinks the holding plate inside the tray at the timing when the pair of seal bars supported by the block presses the tube film, and After extruding the gas, heat seal the tube film with a seal bar.

Thereafter, when heat is applied to the package by the heat sealing means to shrink the tube film, since the inside of the tray is under a negative pressure, the residual gas around the tray moves into the tray due to the shrinkage of the film. After all, the film comes into close contact with the peripheral surface of the tray and at the same time tensions on the tray upper surface.

(Example) As shown in FIG. 1A and FIG.
A carry-in conveyor 10 for transporting a large number of trays T mounted in tandem is installed on the upstream side in the flow direction.

A pair of endless chains 11 are supported on a plurality of wheels 12 and 13 on both sides of the carry-in conveyor so as to be inclined downward in the direction of the flow of the film F. A number of clothespin type clamps (not shown) are attached to the chain to form a film transport belt 14. In short, both sides of the film are clamped by the clamp, and the film F is conveyed obliquely downward by the rotation of the chain 11. For this reason, a belt-like film is obliquely covered on the trays T transported in a row by the carry-in conveyor 10 from above.

The two foils 12 on the upstream side on both sides of the film transport belt are provided with cams for releasing the clamps for holding the film, and the two foils 13 on the downstream side are used to push open the clamps to release the film. Cams are provided, and when both side edges of the film F are released from the transport belt 14 at the downstream end of the film transport belt 14, a pair of V-shaped and rotating film squeezing belts 15 are disposed on both sides of the film. Pull the edge relatively towards the center.
Then, both sides of the film are guided between the gaps 17 between the two plates 16 provided downstream thereof, and a pair of roll-shaped center sealers 18 provided below the plate 16 as shown in FIG.
To weld both sides of the film, and form the film as a tube F0 around the tray T. Then, the film and the tray are transported by being sandwiched by the side sealers 24 from both sides. In short, this is the film cylinder means.

On the other hand, a cylindrical body 19 is installed in a hanging manner from between the V-shaped film drawing belts 15, and one end of the cylindrical body is connected to a vacuum pump (not shown), and flat air connected to an upper end of the cylindrical body. A suction duct 20 is arranged along the upper surface of the plate 16. For this reason, the inside of the tube film is made negative pressure by the suction force of the vacuum pump.

A gas supply pipe 21 is arranged along the side of the carry-in conveyor 10 in FIG. 1A, and one end of the gas supply pipe is connected to a gas cylinder (not shown), and the other end is connected to FIGS. 1B and 2. As shown in FIG. 2B, it is open on the upstream side of the seal bar 22 for the top sealer.

As shown in FIG. 2B, the top sealer 22 is composed of an upper seal bar 25 having a blade and a lower seal base 27 having a blade receiving groove 26 formed thereon.
Hook the belt 30 between 8, 29, and enable the seal bar to mesh with the gap 31 formed between the front and rear rolls,
The block 32 supporting the two rolls 28 and 29 is
5 and the seal table 27 are reciprocated in the directions of arrows A and B.

Further, air cylinders 35 and 36 are provided downward on frames 33 and 34 attached to the block 32 before and after the seal bar 25, respectively, and an air cylinder 35 on the upstream side of the seal bar is provided.
The piston rod is provided with a rod 37 in the lateral direction, and the downstream air cylinder 36 is provided with a plate 38 formed of urethane rubber.

The tube film F0 is swollen by the inert gas ejected from the gas supply pipe 21 while moving continuously, but behind the seal bar 25, the plate 38 is pressed against the upper surface of the tray T by the air cylinder 36. Is pushed out.

In the above case, the urethane rubber plate 38 is pushed into the tray T as shown in FIG. 5, and the gas inside the tray is discharged as much as possible, and the film is welded by the top sealer 22. Therefore, when the packaged product is carried into the heating tunnel 40 and the film is thermally contracted, the gas around the tray flows into the tray, and the film adheres to the peripheral surface of the tray as shown in FIG. Tension flat on the top.

Note that the rod 37 on the upstream side of the top sealer pushes down the film so that the film is peeled off without being welded to the seal bar 25.

(Effect) According to the present invention, in a device for arranging gas replacement by disposing a gas supply pipe 21 in a tube film transported over a tray, the gas supply pipe 21 is supported by a support block of the top sealer behind the top sealer 22. Immediately before sealing the tube film with the top sealer, the air cylinder pushes the plate 38 into the tray and pushes out the gas therefrom. Is sucked into the inside of the tray, and the film can be packaged so that the film is flat on the upper surface of the tray and in close contact with the entire surface of the tray.

[Brief description of the drawings]

1A and 1B are plan views of an embodiment of the present invention. 2A and 2B are side views of the previous figure. FIG. 3 is a sectional view taken along the line III-III in FIG. 2A. FIG. 4 is an explanatory view of gas replacement of a packaged product. FIG. 5 is a sectional view taken along line VV in FIG. FIG. 6 is a perspective view of a packaged product. FIG. 7 is a sectional view of a package. F: Film, T: Tray, 10: Loading conveyor, 14: Film transport belt, 15: Film squeezing belt, 18: Center sealer, 20: Air suction duct, 21: Gas supply pipe, 22: Top sealer, 36: Air Cylinder, 38 ... plate, 40 ... heating tunnel.

Claims (2)

(57) [Claims] 1. A loading conveyor for transporting trays accommodating foods at equal intervals in a column, means for transporting a band-like film in the transport direction of each tray, and forming the film into a tube around the tray. And a pipe for supplying an inert gas into the tube film, and a sealer support block is reciprocated in the same direction as the film transfer direction behind the pipe tip toward the film transfer direction and supported by the block. Means for pressing and heating the tube film with a pair of upper and lower seal bars, wherein an air cylinder is installed in the block behind the seal bar, and pressed against a lower end of a piston rod hanging down from the air cylinder. A plate is provided, and the holding plate is adjusted in accordance with the film pressing pressure by the both seal bars. A package for operating the air cylinder so as to sink into the tray from the upper edge of the tray by an amount corresponding to the excess gas volume around the lay, and further provided with means for heating and shrinking the film around each tray behind the block; apparatus. 2. The packaging apparatus according to claim 1, wherein the holding plate is formed of elastic urethane rubber.