JPS6028726B2 - How to seal a bag filled with contents - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sealing a bag filled with contents such as a liquid or a liquid containing solids.

・Conventionally, it has been common practice to heat-seal the mouth of a bag filled with contents, and in this case, there are air-free packaging that seals by contacting the contents, and air-free packaging that seals by contacting the contents, and air-free packaging that seals by contacting the contents. There is air-containing packaging that provides a seal.

In the former type of air-free packaging, the air content inside the bag after sealing can be reduced to almost 0, but when heat-sealing, the air content inside the bag can be reduced to almost 0. The bag must be pressed, which requires pressing the bag with high pressure, and there is a high incidence of seal failure due to the contents, especially solids, getting caught in the sealing part. There was a problem in that the flat seal bar shape could not be applied to liquids with large solid contents. In the latter type of air-containing packaging, the bag is heat-sealed at a position far above the top surface of the contents, so the sealed bag has a high air content.
There was also a problem that the length of the bag was longer than in the case of air-free packaging. This invention solves the above-mentioned problems and
The air content of sealed bags is lower than that of conventional air-containing packaging, and the length of the bag is approximately the same as that of conventional air-containing packaging. In particular, it does not allow the solid matter inside to get caught in the seal, and requires less pressure than conventional air-containing packaging, which reduces the incidence of seal failures and creates a seal with a good appearance. It is an object of the present invention to provide a method of sealing a bag filled with contents, which can be performed.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Figure 1, 1 is a bag made of two sheets made of plastic film, a laminate of plastic film, a laminate of plastic film and aluminum foil, etc., and has a certain degree of flexibility and elasticity. It is.

This bag is continuously formed by successively heat-sealing the lower end and both side edges of the two sheets, and at a position where at least one side twill of the two sheets is not sealed, an automatic filling machine (not shown) is used to form the bag. A predetermined amount of the contents 2 from a liquid or a liquid containing solids is filled into a portion of the bag 1 from a nozzle. Further, in FIG. 1, reference numeral 3 denotes a pair of seal bars, and these seal bars 3 are disposed with their lower edges substantially touching the top surface of the bag 1 immediately after filling with the contents 2. A notch 3 for forming an unsealed portion is provided at the lower end of both ends in the width direction, that is, at a position opposite to both lower corners.
a are provided on the opposing surfaces, respectively. Reference numeral 4 denotes a pair of pressure rolls, and these pressure rolls 4 are arranged above the seal bar 3 and a little apart from them.

Reference numeral 5 denotes a spot seal bar provided in the notch 3a of the seal bar 3. A total of four spot seal bars 5 are provided, and a deaeration needle 6 is slid into each spot seal bar 5 on one side. It is penetrated so that it can move.

7 is an auxiliary seal bar, and a bag 2 is placed below the seal bar 3.
It is arranged so as to face the lower end of both sides of the bottom.

8 is a deaeration plate disposed between the seal bar 3 and the auxiliary seal bar 7. As shown in FIG. 1, after filling the bag 1 with the contents 2, as shown in FIG. Seal tightly.

Next, as shown in FIG. 3, the seal bar 3 is advanced together with the auxiliary seal bar 7. When the bag 1 is pressed by advancing the seal bar 3, the volume of air inside the bag 1 between the upper surface of the contents 2 and the press roll 4 decreases during the pressing process, and the air in this space is pressurized. The bag 1 stretches and swells a little, and the top surface of the contents 2 descends. Therefore, the bag 1 is pressed and sealed by the seal bar 3 with a position slightly above the upper surface of the lowered contents 2 as the lower edge, and this part is pressurized and heated by the seal bar 3 to seal it. Therefore, bag 1
is heat-sealed at a position slightly distant from the upper surface of the descending content 2, so that the solid matter in the content 2 is not bitten by this heat-sealed part, and the content 2 is not viscous. Even if the liquid is high, the part to which it adheres will not be heat-sealed, so even if the pressure applied by the seal bar 3 is reduced to a low pressure, a strong and reliable seal can be achieved.
The incidence of seal failures can be reduced to virtually nothing. Further, corresponding to the notches 3a of the seal bar 3, as shown in FIG. 4B, notched unsealed portions 10 are formed at the lower ends of both side ends of the heat-sealed portion 9. After heat-sealing the bag 1 as described above, the pressure roll 4 is moved back and opened as shown in FIGS. As shown in FIGS. 5a and 5b, the heat-sealed portion 9 inside the bag 1 is removed by retracting the degassing needle 6 and advancing the degassing plate 8 to press the bag 1 from the outside.
The air is removed from the gas phase section la below the bag 1, and the bag 1 is returned to its shape before heat sealing. Thereafter, as shown in FIGS. 6a and 6b, the spot seal bar 5, which had been retracted, is moved forward and the deaeration needle 6 is pulled out, so that air enters the bag 1 through the needle hole lb formed in the bag 1. Perform the first stage of heat sealing to prevent intrusion. At the same time, the deaeration plate 8 and the seal bar 3 are moved back and then the spot seal bar 5 is also moved back. Furthermore, the bag 1 is lowered one pitch and the same sealing operation as described above is performed, but when the bag 1 is lowered one pitch, the unsealed part 10 that has been heat-sealed in the first stage with the spot seal bar 5 is moved to the auxiliary seal bar. 7, the auxiliary seal bar 7 is moved forward simultaneously with the seal bar 3 to heat seal the second stage of the unsealed portion 1 and heat seal the entire unsealed portion 10. As mentioned above, it is difficult to seal the entire unsealed part 10 on the outer peripheral side of the degassing port, which is made up of the needle hole lb from which the degassing needle 6 is removed, in one go, so the sealing is done in two stages. However, by varying the shape of the spot seal bar 5, as shown in FIG. , and a first stage heat-sealed portion 11a, such as a thin line in the bottom width direction that is in contact with the lower surface of the heat-sealed portion 10,
11b, 11c, and 11d, and by appropriately configuring the shape of the auxiliary seal bar 7, FIGS.
, c and d, at least the unsealed portion 10
Heat-seal the entire part to form the second heat-sealed part 12.
, and together with the heat-sealed portion 9 by the seal bar 3, form a heat-sealed portion whose lower edge is in a straight line.

In addition, regarding the heat sealing of the unsealed part of the first stage mentioned above, the one in Fig. 7b is one in which a /tch is inserted from the side into the side green part of the bag 1 to form a degassing port lc consisting of a notch. and
Even if this is done, the notch blade will not be contaminated with the contents 2, and if the upper green sides of the heat-sealed part 9 are raised in an arc shape by the seal bar 3 as shown by the chain line in FIG. This is preferable because less air remains when filling the product.

In the present invention, it is preferable to perform degassing from the unsealed portion and from both ends in the width direction of the bag using a degassing needle, and the pressing member may be a pressing rod or a pressing plate instead of the pressing roller.

Furthermore, the present invention can be applied to cases where the contents include powders and granules in addition to liquids and liquids containing solids.

As explained above, the present invention uses a pressing member to press and seal the portion of a bag filled with contents above the top surface of the contents, and in this state, the position substantially touching the top surface of the contents is defined as the lower edge. Press with the seal bar, and at this time, the air pressure in the area between the sealing part by the pressing member inside the bag and the top surface of the contents is increased to push down the top surface of the contents, and the top surface of the contents and the seal bar are pressed down. Since the pressing part is separated from the seal bar and the pressing part is heat-sealed, the lower edge of the seal bar is placed at substantially the same height as in conventional fish packaging, that is, before the bag is pressed. The bag can be heat-sealed at the position where it makes contact with the top surface of the contents, and at the time of sealing, the seal part is separated from the top surface of the pressed contents, so the contents, especially solids, will not get caught. .

In addition, in the present invention, when performing the above-mentioned heat sealing,
Heat seal the heat-sealed portion with the seal bar so that a small notch-shaped unsealed portion remains at the lower corner in the bag width direction, and then open a deaeration port by inserting a deaeration needle into the unsealed portion of the bag. The air is removed from the bag through the gas phase below the heat-sealed bag, and a seal is created to prevent air from entering through the degassing port.Then, the entire unsealed area is heat-sealed and the lower green area is removed. Since it is formed on a straight seal part,
It is possible to reduce the amount of air inside the bag to the same extent as conventional air-free packaging, and while it only requires pressing the seal bar at a lower pressure than conventional air-free packaging, the unsealed area is divided into two stages. Coupled with heat-sealing the entire area,
It is possible to perform a strong and reliable seal, reduce the incidence of seal failure, prevent the contents from getting caught in the sealed part, and ultimately seal the entire unsealed part. Since the green is in a straight line, it has the effect of providing a product that not only looks better than simply blocking the vent, but also can reliably prevent air from entering through the vent.

[Brief explanation of drawings]

1 to 3 are side sectional views showing the sealing process according to an embodiment of the present invention in the order of steps, and FIGS. 4a to 6a and 4b to 6b are seals according to the same embodiment. A side sectional view and a front view of the same bag showing the subsequent degassing process of the bag in the order of steps, and FIGS. 7a, b, c, and d are different embodiments showing the sealed state of the first stage of the unsealed part Front view of part of
FIGS. 8a, b, c, and d are front views of parts of the unsealed portions corresponding to FIGS. 7a, b, c, and d after the second stage of sealing. 1...bag, la...gas phase section, lb...
...needle hole, lc...deaeration port, 2...contents, 3...
Seal bar, 3a... Notch, 4... Press roll (pressing member), 5... Spot seal bar, 6...
... Degassing needle, 7... Auxiliary seal bar, 8...
... Degassing plate, 9... Heat sealed part, 10... Unsealed part, 11a, 11b, 11c, 1id... First stage heat sealed part, 12... Second stage heat sealed part. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. A portion of the bag filled with contents above the top surface of the contents is pressed with a pressing member to seal it, and in this state, the bag is pressed with a sealing bar with the lower edge at a position substantially in contact with the top surface of the contents, The pressure of the air in the bag between the top surface of the contents and the pressing member is increased to push down the top surface of the contents so that a small notch-shaped unsealed portion remains at the lower corner in the bag width direction of the heat-sealed portion. Heat-seal with a seal bar, and then form a degassing port in the unsealed portion of the bag to evacuate from the gas phase below the heat-sealed bag to form a seal that prevents air from entering through the degassing port. A method for sealing a bag filled with contents, characterized in that the entire unsealed portion is then heat-sealed to form a sealed portion with a straight lower edge.