JPH0444911A - Manufacture of easily openable sealed package - Google Patents

Abstract

PURPOSE:To make it possible to completely seal a container main body and a lid and still have easy openability at the time of opening by a method wherein on the internal peripheral edge of a flange of a container formed of a multi- layer sheet, numerous fine recessed parts are formed by ultrasonic process, and then the lid is heat-sealed. CONSTITUTION:A multi-layer sheet 1 which has a sealing layer on the surface is formed into a container with flange. In a part formed into a container shape in the continuous sheet, a content is filled, and a lid material 6 is placed over the sheet in which containers are formed, and heat-sealed. Container main bodies 12 and the lid material 6 are punched at the same time. Between a press to form containers from the multi-layer sheet 1 and a device which heat-seals the lid material and punches the containers and the lid material 6, an ultrasonic dispatcher 4 equipped with a horn with numerous fine protruding parts 13 in order to form fine recessed parts on the surface of a part which works as a flange of the container is provided. The ultrasonic dispatcher 4 has a structure by which ultrasonic process can be performed on the whole surface or a part of the sealing layer surface of the flange of the containers.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a packaging body in which a container is filled with contents in a molded state, a lid is rolled, and the container and lid are punched out at the same time. The present invention relates to a method for producing an easily openable sealed package in which the lid material can be easily opened in a continuous production method.

(Prior art) Conventional easy-to-open packaging is designed to maintain the seal strength between the container and lid within an appropriate range (usually 500-15C1Og/ l
5mm) and the seal interface is peeled off to open the seal (interface peeling type), and the seal can be opened by delaminating the gap between the seal layer on the flange side or lid side of the container and the layer adjacent to it. How to do it (delamination type)
are known.

In these methods, delamination type products have been frequently used because of the stable sealing performance and easy opening of the package with the lid material removed.

Various methods have been proposed for delamination-type easy-to-open packages in an attempt to make them more stable, such as cutting lines in the sealing layer and forming resin pools of resin in the sealing layer during heat sealing. ing.

As a continuous manufacturing method and apparatus for these easy-to-open packages, a device for forming a container, forming a score line in the sealing layer of the flange portion of the container, and sealing the lid material is disclosed in JP-A No. 63-096062. Publication, JP-A-63-1101
No. 08 and other publications have been proposed, but all of them involve making linear cut lines on the surface of the noon layer, and in such continuous equipment, it is very difficult to make the cut lines at accurate positions. Moreover, it is not easy to control the position of the sole of the lid material so that it does not overlap with these score lines, and it is not easy to obtain a package that has stable sealing properties and easy opening properties.

In addition, these proposed products are intended for containers that have already been formed, and are easy to open through continuous processes such as forming, filling, heat sealing, and punching.
It has been extremely difficult to obtain a package with sealing properties using conventional techniques.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems, completely and stably seals the lid material to the container body, and also allows for smooth and easy opening. Continuously packaged with different characteristics,
Moreover, it is an object of the present invention to provide a method for producing an easily openable sealed package that can be easily provided.

(Means for Solving the Problems) The present invention involves forming a multilayer sheet having a sealing layer on the surface into a container having a flange, forming the sheet continuously into a container shape, and filling the portion with contents. A method for producing a continuous package by covering the sheet formed from the container with a lid material, heat-sealing it, and punching out the container body and the lid material at the same time.In this method, a container is molded from a multilayer sheet. A horn is provided between a molding machine for heat-sealing the lid material and a device for punching out the container and the lid material, the horn having numerous minute convex portions for forming minute concave portions on the surface of the portion that corresponds to the flange portion of the container. This is a method in which an ultrasonic transmitter is provided and an easy-to-open sealed package is continuously manufactured.

The multilayer sheet for forming the container of the present invention has a sealing layer as its surface layer, and the lamination strength of the layer adjacent to this sealing layer and the sealing layer is 300 to 2000.
g/25mn+, and the thickness of the sealing layer is 10 to 70μ, for example, the sealing layer is made of polyethylene resin,
A simple two-layer structure consisting of a polypropylene resin may be used as the adjacent layer, and the adjacent layer may be a barrier layer of a saponified ethylene-vinyl acetate copolymer or a vinylidene chloride resin;
It may be a multi-layer sheet having a structure including a reinforcing layer of polypropylene resin, polyester resin, etc., and a layer of metal, paper, etc. as an intermediate layer.

These multilayer sheets are formed into a container, and the portion corresponding to the flange of the formed container is then subjected to ultrasonic treatment in that state. Container forming may be performed by a commonly used method, such as vacuum forming, vacuum pressure and air. Methods such as molding are used.

The ultrasonic treatment may be carried out either before the container is formed and filled with the contents (FIG. 1) or after the container is filled with the contents (FIG. 2).

Before the contents are filled, the horn of the ultrasonic transmitter is not contaminated by the contents, and maintenance of the ultrasonic horn is relatively easy.

Further, after filling the container with the contents, the dirt from the filled contents on the flange of the container is blown away by ultrasonic treatment, improving the heat sealability with the lid material and providing stable sealing.

In the ultrasonic transmitter, the treated surface of the horn is formed with minute convex portions for forming minute concave portions on the flange surface of the container, as shown in FIG. 6, and the pitch interval W of these minute convex portions is is preferably 0.3 to 0.8++on, and the height d of the minute protrusion is selected depending on the thickness of the sealing layer of the container, but as a guide, it is about 1 to 10 times the thickness of the sealing layer. is desirable.

The structure is such that this ultrasonic treatment can be applied to the entire surface of the sealing layer of the flange of the container or a portion thereof. In order to form such minute recesses on the entire surface or a part of the flange, the ultrasonic horn holder is used as a stand as shown in Figs. 5(a) and 5(a).
The supports shown in b) and (c) are made by using a stand.

A multilayer sheet is formed, the flange is subjected to ultrasonic treatment,
Fill the container with the contents, or perform ultrasonic treatment after filling the contents, and then heat seal the lid material. The heat sealing method uses a hot platen under normal conditions.

The heat-sealed series is punched out as individual packages in the next step, and easy-to-open sealed packages can be easily obtained in a continuous process.

(Function) In the package obtained by the manufacturing method of the present invention, the sole layer of the container body and the lid material are integrated with each other in a strongly bonded state, and the inside of the dot-like minute recesses formed on the flange surface. The structure is filled with the resin of the lid material, and the resin of the sealing layer is thick and thin on the flange surface, and the seal strength is distributed in Figure 7! As shown in Figure 2, it has a unique structure, and this seal structure provides stable pressure resistance against internal and external pressure when sealed, and when opened, it peels off as shown in Figure 7, resulting in smooth peeling between the eyebrows. In the innermost circumferential part of the flange part, it is easy to break with a slight force at the minute recess, and it is easy to obtain a continuous and completely opened part.

(Effects of the invention) The package produced by the method of the invention has excellent sealing properties,
Very good; Stable, smooth and easy-to-open packages can be obtained continuously, and positioning is very easy during the heat-sealing process, making it possible to produce highly productive, easy-to-open sealed packages. This is an easy manufacturing method.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams showing the manufacturing method of the present invention. Figure 1 shows the case where the contents are filled after ultrasonic treatment, and Figure 2 shows the case where the ultrasonic treatment is performed after filling the contents. . Fig. 3 is a perspective view of a package obtained by the apparatus of the present invention with the lid material partially peeled off, Fig. 4 is an enlarged view of the part subjected to ultrasonic treatment, and Fig. 5 is a receiver of the ultrasonic horn. 6 is an enlarged view of the ultrasonic horn, and FIG. 7 is an enlarged view of the container body and lid in an unsealed state. In the figure, 1: multilayer sheet, 2: sheet preheating device. 3: Vacuum pressure forming machine, 4: Ultrasonic processing machine. 5: Filling machine, 6: Lid material, 7: Heat sealing machine. 8: punching device; 9: lid material winding device after punching; 10: multilayer sheet winding device after punching; 14: Adjacent layers of the multilayer sheet forming the container body. 15: Sole layer of the multilayer sheet. 16: Ultrasonic horn head 17: The receiver of the ultrasonic horn indicates the stand.

Claims (2)

[Claims] (1) A package formed by forming a multilayer sheet with a sealing layer on the surface into a container with a flange, filling the container with contents, covering the container with a lid material, heat sealing, and punching out the container and lid material. In this manufacturing method, a container is formed from a multilayer sheet, and then a minute recess shape is formed all around the entire surface of the portion corresponding to the flange portion of the container or a portion of the inner periphery of the portion that will become the flange portion by ultrasonic treatment. A method for manufacturing an easily openable sealed package, which comprises forming an infinite number of pieces, filling the contents, heat-sealing the lid, and punching out the container and the lid at the same time. (2) A package formed by forming a multilayer sheet with a sealing layer on the surface into a container with a flange, filling the container with contents, covering the container with a lid material, heat sealing, and punching out the container and lid material. In this manufacturing method, a container is formed from a multilayer sheet, the contents are subsequently filled into the container molded part, and then the entire surface of the portion corresponding to the flange portion of the container or a part of the inner periphery of the portion that will become the flange portion is A method for manufacturing an easily openable sealed package, characterized in that a countless number of minute concave shapes are formed over the entire circumference by ultrasonic treatment, the lid material is heat-sealed, and then the container and the lid material are punched out at the same time.