JPS635A - Heat seal method of packaging vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for heat-sealing packaging containers used for foods such as genuine leather cans, puddings, and jelly, and in particular, a method for heat-sealing packaging containers used for food products such as genuine leather cans, puddings, and jelly. This invention relates to something that can reliably prevent the outer peripheral edge of the material from turning over.

(Prior Art) As a conventional structure of this type of container and its heat-sealing method, there is, for example, the one shown in FIG. In FIG. 4, reference numeral 1 denotes a plastic container body constituting a packaging container. The joint portion of the flange 11 is curved 12 in an R shape.

Reference numeral 2 denotes a plastic lid material that is heat-bonded to the opening of the container body 1 by heating means such as heat sealing, and is used to keep the contents airtight.

(Problems to be Solved by the Invention) However, in the conventional heat sealing method described above, as schematically shown in the rjSJ diagram, the pedestal 3
3' supporting surface 33a' and joining surface 38a' of heating plate 38'
Since they are mutually flat surfaces, it is physically difficult to achieve perfect parallelism, and it is impossible to apply a uniform pressing force to the lid member 2 over the entire width W of the annular flange 11. In some cases, the pressing force applied to the outer peripheral edge of the lid member 2 becomes insufficient, causing a problem in that the outer peripheral edge turns over after sealing is completed.

Therefore, when the outer peripheral edge of the lid material 2 is turned up, it not only spoils the appearance of the product and reduces its commercial value, but also
If water gets mixed in and remains in the gap between the folds G during boil sterilization or retort sterilization, it causes various problems such as mold growth in the remaining part or the residual water rotting and producing a bad odor. .

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional example, and its purpose is to limit only the inner peripheral edge of the joint surface of the lid member that contacts the annular flange of the container body. Rather, the purpose is to prevent the outer circumferential edge of the lid material from turning over after sealing is completed by reliably heat-bonding the outer circumferential edge to the annular flange.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for heat sealing a packaging container in which a lid member is heat-bonded to an annular flange of a container body under a predetermined pressure. A first heat-sealing step in which the inner peripheral edge of the joint surface of the lid material that contacts the annular flange is heat-bonded to the annular flange, and a first heat-sealing step that heat-bonds the entire surface of the joint surface of the lid material that contacts the annular flange to the annular flange. , a second heat-sealing step is performed in which heating and bonding is performed by applying a pressing force to the outer peripheral edge of the joint surface of the lid material relatively higher than the pressing force to the inner peripheral edge.

(Function) In the present invention having the above configuration, in the first heat sealing step, the inner peripheral edge of the bonding surface of the lid member that contacts the annular flange of the container body is reliably heat bonded to the annular flange. First, in the second heat-sealing step, the pressure on the outer peripheral edge of the bonding surface of the lid is relatively higher than the pressure on the inner peripheral edge to heat-bond the lid. Therefore, not only the inner circumferential edge of the cover is double-jointed, but also the outer circumferential edge of the cover is reliably heat-bonded to the annular flange due to the increased contact surface pressure.

(Example) The method of heat sealing a packaging container according to the present invention will be explained below based on the illustrated example. Fig. 1 shows a filling/sealing device for a packaging container implemented in the present invention. Furthermore, FIG. 2 shows the first heat sealing step, and FIG. 3 shows the second heat sealing step. Reference numeral 1 denotes a plastic container body constituting a packaging container, and this container body l is formed by integrally providing an annular flange 11 on the outer periphery of the top of a bottomed body 10, and a joint between the body 10 and the flange 11. is curved 12 in an R shape. Reference numeral 2 denotes a plastic lid material that is heat-bonded to the opening of the container body 1 by heating means such as heat sealing, and is used to keep the contents airtight. Reference numeral 31 denotes a sprocket provided on the primary side and the secondary side inside the device main body 30, and an endless chain 32 that moves intermittently is wound around both sprockets 31 and 31.
A plurality of pedestals 33 are attached to the outer periphery of 2 at a predetermined pitch. Reference numeral 34 denotes a cup supply section provided on the primary side of the apparatus main body 30, from which the aforementioned container bodies are appropriately supplied into each pedestal 33 on the chain. The container body in each pedestal 33 is filled with contents in the next filling step 35.

When the filling of the contents is completed, the opening of the container body is covered with a plastic lid material 37 supplied from a reel 36, and this lid material sequentially passes through the first station and the second station, thereby closing both stations. heating plate 3
It is heat sealed in two steps onto the plastic annular flange of the container body while being pressurized by 8.39. The lid material that has been further heat-sealed in two stages is cooled in the next cooling press step 40, and then punched out to a predetermined size in a final trimming step 41 to form a packaging container for the final product.

By the way, in the method for heat-sealing packaging containers according to the present invention, the heating plate 38 in the first heat-sealing step is integrally provided with a jetty 38b on its joint surface 38a, and @W I of the jetty 38b is a container. The width is smaller than the width of the joint surface of the lid 2 that contacts the annular flange 11 of the main body 1, and the jetty 38b corresponds to the inner peripheral edge of the joint surface of the lid 2 (Fig. 2). ), therefore, the inner peripheral edge of the lid member 2 is on the support surface 33a of the pedestal 33,
It is heated while being pressurized by the jetty 38b of the heating plate 38, and the contact surface pressure is dramatically increased at this time, so that the annular flange 11 of the container body and the inner peripheral edge of the lid member 2 are reliably joined by heat.

Next, the joint surface 39a of the heating plate 39 in the second heat sealing step is the support surface 33 of the pedestal 33 that holds the container body l.
It is inclined at a predetermined angle θ (0.5° to 5″) with respect to a, and the direction of inclination is such that the outer edge of the joint surface 39a approaches the support surface 33a (see Fig. 3). ), Therefore, when the joint surface 39a of the heating plate 39 is brought into pressure contact with the support surface 33a of the pedestal 33, the annular flange ll sandwiched between the support surface 33a and the joint surface 39a
The upper lid material 2 is ripened while being pressurized by a heating plate 39. In this case, the joint surface 39a of the heating plate 39
is inclined toward the outer edge, so that the pressing force on the outer peripheral edge of the joint surface of the lid member 2 that contacts the annular flange 11 is relatively higher than the pressing force on the inner peripheral edge. Therefore, not only the inner circumferential edge of the cover 2 is double heat-bonded, but also the outer circumferential edge of the cover 2 is reliably heat-bonded to the annular flange 11 due to the increased contact surface pressure.

Furthermore, in the heat-sealing method for a packaging container according to the present invention, the container main body l is held in the fitting recess 33b of the pedestal 33, but the inner peripheral upper edge of the pedestal surrounding the fitting recess 33b is The portion 33c is constituted by a curved surface having a radius of curvature larger than the radius of curvature of the curved portion 12 on the outer periphery of the container body corresponding to the inner upper edge 33c of the pedestal. Therefore, in the first and second heat sealing processes, the heating plate 38°3 with respect to the pedestal 33
9 is closed, the upper inner peripheral part 13c of the pedestal
Since the curvature of is larger than the curvature of the curved part 12 on the outer circumference of the container, the inner upper edge part 33c and the curved part 12 do not interfere with each other. Since the annular flange 11 of the main body can be placed horizontally without tilting to the left or right, the sealing accuracy of the lid material can be improved.

Moreover, if the inner circumferential upper edge portion 33c and the curved portion 12 do not interfere with each other, the outer circumference of the container body l may be damaged.
In addition, since cracks do not occur, the life and durability of this type of packaging container can be improved.

(Effect of the invention) Since the present invention consists of the above configuration and operation,
It is necessary to reliably heat-bond not only the inner peripheral edge of the joint surface of the lid material that contacts the annular flange of the container body, but also the outer peripheral edge thereof to the annular flange. Curling of the outer peripheral edge can be prevented.

Therefore, it not only improves the appearance quality of the product, but also has various effects such as eliminating mold and bad odors.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the method for heat sealing a packaging container according to the present invention, and FIG. The figure is an enlarged view of the main part of section A in FIG. 1, FIG. 3 is an enlarged view of the main part of section B in FIG. 1, and FIG. 4 is a sectional view showing a conventional example. Explanation of symbols l...Container body 2...Lid lO...Body part 11...Annular flange 2...Curved part 33...Base 33a...Supporting surface
33b...Fitting recess 33c...Inner circumference upper edge 3
8... Heating plate 38a... Joint surface 38b... Jetty (protrusion) 39... Heating plate 39a... Inclined joint surface Figure 2 Wl 2 Supervision ← -1 Figure 3 3b No. 41゛4 33b'

Claims (1)

[Claims] In a method for heat sealing packaging containers in which a lid material is heat-bonded to an annular flange of a container body under a predetermined pressure, the inner peripheral edge of the joint surface of the lid material that contacts the annular flange is heat-bonded to the annular flange. a first heat sealing step;
While heating the entire surface of the lid material that contacts the annular flange to the annular flange, the pressure on the outer peripheral edge of the joint surface of the lid material is relatively higher than that on the inner peripheral edge. A method for heat-sealing packaging containers, comprising a second heat-sealing step.