JPS59135114A - Heat sealing method - Google Patents

Abstract

PURPOSE:To prevent the erroneous adhesion of a pouch even if an inadequacy in pressure welding is present in a pair of belts, by shifting the pressure welding position of a pair of the belts during a time when the mouth end part of a pouch is repeatedly passed between heaters and contact bonding rollers while held between a pair of the belts. CONSTITUTION:The mouth end part of a pouch is passed between each pair of first heat pipes 1a, 1b, first pressure contact bonding rolls 4a, 4b, second heat bars 2a, 2b, second pressure contact bonding rolls 5a, 5b and cooling bars 3a, 3b while held between a pair of sheet belts 6a, 6b to be subjected to pressure welding. In this process, a pair of nip rolls 11a, 11b and a pair of guide rolls 12a, 12b are respectively provided between the first contact bonding rolls 4a, 4b and the second heat bars 2a, 2b to bypass a pair of the sheet belts 6a, 6b as well as to change the bypass lengths of both sheet belts 6a, 6b and the pressure welding position of both belts is changed before and after bypassing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of heat sealing the edges of the eyelets and the edges of the eyes using a belt method.

As a sealing device, a type using a sealing belt as shown in FIG. 1 is usually used. In Fig. 1, 1a, 1b are a pair of opposing first heat bars, usually made of brass, and electrical resistance heating elements 1.
A+ and lbl are built-in.

Second heat bars 2a and 2b are provided to ensure heat sealing, and similarly have built-in electric resistance heating elements 2a1 and 2b1.

Reference numerals 3a and 3b are a pair of cooling pars facing each other, and cooling pipes (for example, water cooling noise) 3a1 and 3bl are built therein. Between the first heat bar 1a, lb and the second heat bar 2a, 2b, and the second heat bar 2a
, 2b and the cooling pars 3a, 3b are provided with first crimping rolls 4a, 4b and second crimping rolls 5a, 5a, 4b, respectively.
5b, and the crimping roll is usually made of stainless steel.

6 a, 6. ,, b is a pair of seal belts, driving rolls 7a, 7b and guide rolls 8a, 8b.
Accordingly, between the first heat bar 1a and lbO, between the first pressure bonding rolls 4a and 4b, and between the second heat bar 2a and 2
b, between the second pressure rolls 5a, 5b, and between the cooling rollers 3a, 3b, and are arranged so as to move in the direction of the arrow in contact with each other and in opposition to each other. .

The mouth end of the pouch 9 filled with contents is placed on a conveyor (not shown) via a holder or is conveyed at the same speed as the seal belts 6a, 6b with both side edges gripped by grippers. 9a is a guide roll 8a
, 8b is sandwiched between the seal belts 6a and 6b, heated to a heat-sealable temperature and crimped twice while being conveyed together with the seal belts 6a and 6b, and heat-sealed. After that, the cooling bar 3a.

3b, it is cooled to a temperature lower than the heat-sealable temperature and sent to the next step.

The reason why heat sealing is performed twice is that if moisture from the contents adheres to the inner surface of the mouth end 9a, the heat sealing of the adhering part is likely to be incomplete in the first heat sealing. During the first heat seal, the moisture evaporates, so the second heat seal, 'y2' p
This is because the incomplete heat-sealed portion can be completely heat-sealed.

The seal belts 6a and 6b are usually made of stainless steel, and their width is equal to the width of the heat-sealed portion of the pouch mouth end 9a, which is usually about 10 wn. The thinner the material, the smaller the heat capacity and the higher the heating and cooling rate, so it is preferable, but if it becomes too thin, the strength will decrease, so the thickness is usually about 10 mm.
It is set at 0 to 300 μm, preferably around 150 μm.

By the way, each of the seal belts 6a, 6b has a loop shape, and this loop is formed by welding both ends of stainless steel silicone having the above-mentioned cross-sectional dimensions. However, since the thickness is thin, butt welding is impossible, and the overlap welded part 10 has a stepped portion 10a as shown in FIG. 5 mn
) is formed by lap welding.

Although it is possible to obtain a flat welded part by removing protruding parts such as beams after fusion welding by electron beam welding, etc., in this case, the welded part becomes brittle and easily breaks, making it impractical.

/-If there are 10 overlapping welds on Ruberto, the second
As shown in the figure, pressure rolls 4a and 4b (press rolls 5a and 5
The same applies to case b) The pressure bonding force is not applied satisfactorily, and as a result, the heat sealing strength of the relevant part is weak and it peels easily, and when internal pressure is applied during retort heat sterilization treatment, the relevant part peels off and the contents are damaged. It is easy to cause problems such as leakage, or the presence of pores from the beginning that allows outside air to enter the inside and cause the contents to deteriorate.

It is an object of the present invention to solve the problems of the prior art described above.

- In order to achieve distribution efficiency, the present invention is sequentially arranged from upstream to downstream. The eye end of the pouch is passed between each of a pair of opposing first heat pars, a 1.5th crimping roll, a pair of opposing second heat pars, and a second crimping roll. In the method of heat-sealing the mouth end by sandwiching and transferring the material between adjacent seal belts, the seal belt is bypassed on the exit side of the first crimping roll and/or the inlet side of the second crimping roll. , characterized in that the position of the seal belt that clamps the eye end is shifted between when the first crimping roll passes and when the second crimping roll passes. A method of heat sealing the mouth end is provided.

The present invention will be described below with reference to the drawings. In FIGS. 3 and 4, parts with the same reference numerals as those in FIG. 1 indicate similar parts.

In FIG. 3, nip rolls 11a and 11b are provided downstream of the first pressure rolls 4a and 4b along the path of the mouth end 9a of the nozzle 9.

Further, guide rolls 12a and 12b are provided apart from the path of the eye end portion 9a to the outside and symmetrically with respect to the path. Seal bell) 6 & is the first pressure roll 4
It is biased so that it exits the gap 4C between a and 4b and enters the gap 11c between the nip rolls 11a and 11b in contact with the outer circumferential surface 12a1 of the guide roll 12a. Similarly, the seat belt 6b is bypassed so that it exits the gap 4C and enters the gap lie in contact with the outer peripheral surface 12b1 of the guide roll 12b.

The distance between the gap portion 4C and the gap portion 110 is desirably smaller than the width (length in the transition direction) of the eye end portion 9a. This is to ensure smooth transition of the mouth end 9a and biting into the gap lie.

seal bell) 6a, 6b high l sos length c gap 4
-c1 outer peripheral surface 12al or 12b+ and gap 11
The difference p between the distance between the gap 4C and the gap lie is the distance between the point X and the point W in FIG. If the length of the portion where the loop portion is to be formed is 4, it is determined that the relationship p>II is satisfied. first pressure roll 4a,
A sealing bell) 6a which clamps the mouth end 9a when passing through 4b.

This is to create the following deviation between the position of the seal belts 6b and the positions of the seal belts 6a and 6b that clamp the mouth end portions 9a when passing through the second pressure rolls 5a and 5b.

That is, under the condition that the above-mentioned relationship is satisfied, positional deviation occurs, so that the sheet rolls 6a and 6b are present in the overlapping welding part 10, and therefore, when the first crimping rolls 4a and 4b pass, the stepped part -xy interval and z near 10a
Even if the heat-sealing of the opening end 9a corresponding to the section -w is incomplete due to insufficient pressure, the defective heat-sealing will be completed when passing through the second pressure rolls 5a + 5b. The completely heat-sealed portion is pinched by a normal seal belt portion that is apart from the stepped portion 10a and heat-sealed with sufficient pressure, so that it is restored to a completely heat-sealed portion.

In FIG. 4, nip rolls 21a, 21b and guide rolls 22a+22b are provided upstream of second pressure rolls 5a, 5b, and sealing bells 6a and 6b are bypassed. In this case as well, by arranging each roll in the same dimensional relationship as in the case of Fig. 3,
It is possible to prevent incomplete heat sealing from occurring due to the overlapping welded portion 10 of the seal belt.

Although not shown, the second pressure roll 5a in FIG.
Upstream of 5b, nip rolls 21a, 21b, as shown in FIG.
and guide roll 22a.

22 bli may be provided. In this case, the difference p' between the bypass length of the seal belt after leaving the first crimping rolls 4a, 4b and the length of the piping before entering the second crimping rolls 5a, 5b is expressed as p'. By setting the relationship such that >11 is satisfied, it is possible to prevent incomplete heat sealing from occurring due to the overlapping welded portion 10 of the seal belt.

The present invention is not limited to the above examples and drawings; for example, the nip rolls lla and llb may be disposed at the inlet side ends of the second heat pars 2a and 2b.

According to the present invention, the seal belt is bypassed on the outlet side of the first pressure roll and/or the inlet side of the second pressure roll, and the position of the seal belt that clamps the mouth end of the pouch is adjusted to the first pressure roll. Since the edges are heat-sealed in a shifted manner between when the first crimping roll passes and when the second crimping roll passes, even if there is an overlap weld on the seal belt, there will be no overlap weld. This has the effect of preventing incomplete heat-sealing from occurring due to the heat-sealed area.

[Brief explanation of drawings]

FIG. 1 is a plan view of an example of a conventional heat sealing device, FIG. 2 is an enlarged plan view of the vicinity of the first pressure roll in FIG. 1, and FIGS. 3 and 4 are views of the present invention. The first and second parts of the apparatus used for carrying out the heat sealing method of
FIG. 1a, 1b...first heat par, 2a, 2b...
Second heat roller, 4a, 4b...first pressure roll, 5a, 5b-second pressure roll, 6a,
6b... Seal belt, 9... Pouch, 9a...
・End of mouth.

Claims (1)

[Claims] (1) Each of a pair of opposing first heat bars, a first pressure roll, a pair of opposing second heat bars, and a second pressure roll, which are arranged sequentially from upstream to downstream. In the method of heat-sealing the eye ends by sandwiching and transferring the eye ends with a pair of opposing knobs Ic, the exit side of the first pressure roll and /''f, On the inlet side of the second pressure roll, the seal belt is bypassed so that the position of the seal belt that clamps the eye end is changed between when the first pressure roll passes and when the second pressure roll passes. A method of heat-soling the eye end of a pouch, which is characterized by making the pouch deviate between the edges.