Bag packaging method

Abstract

A bag packaging method by which a mouth portion of a thin plastic-made bag filled with articles can be sealed without creases is provided. A bag 4 filled with sliced bread 1 is conveyed by a blade conveyor 6. A mouth portion of the bag 4 is led between upper and lower two conveyor belts 20, 21. While a suction force acting on upper and lower sides of the mouth portion is applied from vacuum chambers 23, 24 through the conveyor belts 20, 21, air is blown from a sirocco fan 13 toward a mouth of the bag 4 so that the mouth portion of the bag 4 is opened. Two mouth spreader bars 30 having an interval between their distal ends narrowed are inserted into the bag 4 so opened. Then, the mouth spreader bars 30 have the interval widened to thereby spread the mouth portion flat. The mouth portion of the bag 4 spread flat is pinched and sealed by a sealer 50 without generation of creases.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a bag packaging method for producing a bag package of articles by sealing a mouth portion of a thin soft plastic bag filled with articles. [0003] 2. Description of the Prior Art [0004] A bag packaging method for producing a bag package by filling articles in a plastic-made bag and then sealing a mouth portion of the bag is widely practiced. However, while such a bag packaging method is carried out for packaging using a thick and comparatively strong plastic bag, under the present circumstances, such method is not practically used for packaging using a thin soft plastic bag. The reason therefor is that once the thin soft plastic bag is filled with articles, even if the mouth portion thereof is wanted to be sealed, the bag is very soft and weak so that it is extremely difficult to seal the mouth portion without generation of creases. [0005] For example, in a marketed package using a th...

AI Technical Summary

Benefits of technology

[0007] In view of the problems in the prior art, it is an object of the present invention to provide a bag packaging method by which a mouth portion of a thin plastic bag filled with articles to be packaged can be beautifully, securely and stably sealed without generation of creases.

[0008] In order to achieve the above-mentioned object, the present invention provides a bag packaging method comprising the steps of: while causing a suction force to act on both sides, opposed to each other, of a mouth portion of a bag filled with articles, opening the mouth portion of the bag by blowing air toward a mouth of the bag, inserting two mouth spreader bars having an interval between their distal ends narrowed into the bag so opened, causing the mouth spreader bars to have the interval laterally widened to thereby spread the mouth portion of the bag flat, and causing a sealer to pinch and seal the mouth portion of the bag so laterally spread.

[0009] While the air blowing toward the mouth of the bag according to the present invention may be continuously carried out, if the suction force is kept acting on the both sides of the mouth portion of the bag, the air blowing may be done only for a short time as a trigger to initiate the bag opening so that a later action to make the opening larger is carried out by the suction force acting from the both sides.

Problems solved by technology

However, while such a bag packaging method is carried out for packaging using a thick and comparatively strong plastic bag, under the present circumstances, such method is not practically used for packaging using a thin soft plastic bag.

The reason therefor is that once the thin soft plastic bag is filled with articles, even if the mouth portion thereof is wanted to be sealed, the bag is very soft and weak so that it is extremely difficult to seal the mouth portion without generation of creases.

Thus, as the mouth portion of the bag package using the thin plastic bag is not tightly closed by sealing, there is a problem that sweet smells come out of the bread or the like in the bag so that small insects are induced to enter the bag or dusts may come into the bag in the course of distribution.

Especially, while such small insects or dusts stick to the mouth portion of the bag, if the clip or tape binding the mouth portion is detached, there is a large possibility that the insects or dusts come into the bag.

However, the mouth portion of the bag is too weak to keep standing or, even if it is laid down, it is hardly spread flat without generation of creases.

Hence, sealing of the mouth portion is difficult.

However, in such sealing of the mouth portion, there are seen many shortcomings such that many creases are generated in the sealed portion of the bag mouth portion and heating for the sealing is not uniformly done because of the creases of the sealed portion so that the sealed portion may partially melt to be broken or the mouth portion may open because of the insufficient sealing.

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