JPS6140646Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a vertical sealing device for a laminate film tube that can be suitably applied to a packaging device for hygienically and economically filling and packaging liquids or viscous materials.

BACKGROUND ART Conventionally, as packaging means for automatic bag making and automatic bag filling using a film roll supply method, means generally called "vertical pillow" and "horizontal pillow" have been developed and are widely used.

However, this vertical seal in many cases is
Since the film is heat-sealed by overlapping both edges of the film so that the inner surfaces are in contact, a dorsal fin-like part is formed at the overlapping part of the vertical seal, which not only results in a lot of wasted film. When the contents are liquid, it is difficult to obtain sufficient pressure resistance, and the packaging design is not satisfactory. Therefore, if the vertical sealing is done by heat-sealing by overlapping both edges of the film so that the inner and outer surfaces are in contact, so-called "envelope pasting", there will be no wastage of the film, and sufficient pressure resistance can be obtained. Many people skilled in the art have thought and researched that there is a significant improvement in terms of strength and pressure resistance.
When using a multilayer film having multiple properties such as gas barrier properties and excellent heat sealing properties, as shown in Fig. 4, a high barrier film intermediate layer 7 with which it is undesirable for the contents to come into contact with each other for hygienic reasons is necessary. At present, it has not yet been put into practical use for packaging liquids and viscous substances because it can come into direct contact with the side edges.

In view of the current situation, the present invention has been proposed to provide an intermediate film on the side edge end surface of the film located inside the overlapping portion of the film when laminated films having at least three layers are overlapped in an envelope-like manner to form a cylinder. It is possible to provide a vertical sealing device for a laminate film tube that avoids exposure of the layer and prevents contact between the contents and the intermediate film layer of the laminate film. This will be explained in detail according to examples.

In the figure, reference numeral 1 denotes a guide roll that guides a laminate film (composite film) 2. 3 is a cylindrical seal holder whose surface is coated with an anti-adhesive material such as polytetrafluoroethylene, in which the laminate film 2 is held at both edges by a special positioning mechanism so that the inner surface of one side is in contact with the outer surface of the other. The sheets are stacked like envelopes and fed intermittently so that the overlapped portion is fed without wrinkles and the position of the overlapped portion is accurately determined. Reference numeral 4 denotes a vertical heat seal bar placed near the seal holder 3, which is constantly heated and may be intermittently pressed against the seal holder 3 via a laminate film, and which is constantly heated.
The seal holder 3 may be brought into contact with the laminate film 2 and heated intermittently.

As shown in FIG. 3, a step is provided at a portion of the seal holder 3 to which the vertical heat seal bar 4 is pressed. The convex side 5 formed by providing this step is in a position where it can press the inner side edge of the overlapped portion of the laminate film 2. It is also possible to provide a step on the vertical heat seal bar 4. A protrusion may be provided instead of the step.

In this way, by providing a step or a protrusion on the seal pedestal 3 or the vertical heat sealing bar 4, the resin such as polyolefin constituting the innermost layer 6 of the laminate film 2 is vertically heated during vertical heat sealing of the laminate film 2. Heat seal bar 4
Under the action of heat and pressure of middle layer 7
will be completely covered. The preferred size of the convex side of the step and the protrusion differs depending on the total thickness and structure of the laminate film, as well as the melting point, specific heat, fluidity, etc. of each layer of the laminate film.

The laminate film 2, which has been vertically sealed by the seal holder 3 and the vertical heat seal bar 4, is sent downward as shown in FIGS. 1 and 2. Reference numeral 9 denotes a known intermittent feeding mechanism, and the intermittent feeding mechanism 9
A first lateral heat seal bar 10, a second lateral heat seal bar 11, and a cutter 12 are arranged at predetermined intervals.First, bottom sealing is performed by the first lateral heat seal bar 10, and at the same time One stage of feeding is performed, and then the contents are degassed and filled by the filling pipe 13, then top-sealed by the first lateral heat-sealing bar 10, passed through the second lateral heat-sealing bar 11, and finally delivered to the cutter 12. The cutting operation is performed intermittently.

As is clear from the above description, the vertical sealing device according to the present invention has a cylindrical seal holder or a vertical heat seal bar that has a protruding portion that can press the inner side edge of the overlapping portion of the laminate film. Since the convex side or protrusion of the step is provided, the surface pressure against the inner side edge during heat sealing is high, which induces a phenomenon of resin in the innermost layer of the laminate film, eliminating corners on the side edge end face. The intermediate film layer is completely coated, making it possible to prevent contact with the contents, and the effect is even more pronounced when used in the manufacture of container-shaped products that have a spout, etc. attached in the previous process. obtain.

[Brief explanation of the drawing]

The drawings show one embodiment of the vertical sealing device according to the present invention, and FIG. 1 is a front view of the packaging device to which the present invention is applied, FIG. 2 is a side view thereof, and FIG. 4 is an enlarged sectional view of a sealed portion obtained by a conventional vertical sealing device, and FIG. 5 is an enlarged sectional view of a sealed portion obtained by a vertical sealing device of the present invention. . 1: Guide roll, 2: Laminate film,
3: Film guide, 4: Vertical heat seal bar,
5: Convex side of step, 6: Innermost layer, 7: Middle layer,
8: outermost layer, 9: intermittent feeding mechanism, 10: first lateral heat seal bar, 11: second lateral heat seal bar, 12: cutter, 13: filling pipe.

Claims (1)

[Scope of utility model registration request] A cylindrical seal pedestal is formed by overlapping both side edges of a laminate film composed of at least three layers in an envelope-like manner to form a cylindrical shape for travel guidance. In a vertical sealing device consisting of a heat seal bar, the inner side edge of the overlapping part of the laminated film, which is run in a cylindrical shape, is placed on either the cylindrical seal holder or the vertical heat seal bar. 1. A vertical sealing device for a laminate film tube, characterized in that the end face of the innermost layer of the inner side edge is provided with a stepped convex portion that can be pressed against the inner surface of the laminate film superimposed on the outside.