JP2874962B2 - Method for producing easily openable sealed package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a packaged product obtained by filling a container with a container in a molded state, sealing a lid, and punching the container and the lid at the same time. The present invention relates to a method for producing an easily-openable sealed package in which a lid material can be easily opened in a continuous production method.

(Prior art) The conventional easy-open package has a sealing strength between the container and the cover material in an appropriate range (usually 500 to 1500 g / 15 mm) by changing the composition of the resin constituting the seal layer of the container or the cover material. ), The seal interface is peeled off and the seal is opened (interface peeling type), or the container is opened by delamination between the seal layer on the flange side or lid material side and the layer adjacent thereto. A method (delamination type) is known.

In these methods, a delamination type package has been frequently used because of its stable sealing property and easy opening property as a package in which a lid material is sealed.

Various methods have been proposed for the delamination type easy-open package, such as making a cut line in the seal layer in order to obtain a more stable one, or forming a resin pool of the resin in the seal layer during heat sealing. ing.

JP-A-63-096062 discloses an apparatus for forming a container, forming a cut line in a seal layer of a flange portion of the container, and sealing a lid material as a continuous production method and apparatus for these easily openable packages. And Japanese Patent Application Laid-Open No. 63-110108, all of which propose a linear cut line on the surface of the seal layer. In such a continuous apparatus, the cut line is placed at an accurate position. It is very difficult to insert, and it is not easy to control the sealing position of the lid material so as not to be caught by these cut lines, and it is not easy to obtain a package having stable sealing property and easy opening property. Was.

In addition, these proposals are intended to be once molded as a container, and obtain a package having an easy-opening property and a sealing property by a continuous process such as molding, filling, heat sealing, and punching. This was very difficult with the prior art.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems and completely and stably seals and seals a lid on a container body, and has a smooth easy-open property when opened. Continuously
Another object of the present invention is to provide a method of manufacturing an easily-openable sealed package that can be easily provided.

(Means for Solving the Problem) In the present invention, a multilayer sheet having a seal layer on its surface is formed into a container having a flange, and a portion of the continuous sheet formed into a container shape is filled with contents. In a method of manufacturing a continuous and continuous package body, which is formed by simultaneously punching a container body and a lid material after covering and heat-sealing the lid material on the sheet formed with the container, a molding machine and a lid material for molding the container from the multilayer sheet are used. Heat-sealed between the container and the punching device for the cover material, provided with an ultrasonic transmitter having a horn having a myriad of micro convex portions for forming micro concave portions on the surface of the portion corresponding to the flange portion of the container, This is a method for continuously and consistently producing an easily openable sealed package.

The multilayer sheet for molding the container of the present invention has a sealing layer as its surface layer, and the lamination strength between the layer adjacent to the sealing layer and the sealing layer is 300 to 2000 g / 25 m.
m, the thickness of the seal layer is 10 to 70 μm. For example, a simple two-layer structure composed of a polyethylene resin for the seal layer and a polypropylene resin for the adjacent layer may be used. It may be a barrier layer of a polymer saponified or vinylidene chloride-based resin, a reinforcing layer of a polypropylene-based resin, a polyester-based resin, or the like, or a multilayer sheet having a structure in which a metal, paper, or the like is laminated as an intermediate layer.

These multilayer sheets are formed into a container, and a portion corresponding to the flange portion of the formed container is continuously subjected to ultrasonic treatment as it is. Container forming may be performed by a commonly used method, such as vacuum forming, vacuum pressurized air. A method such as molding is used.

The ultrasonic treatment is carried out before the container is filled with the contents (FIG. 1) or after the contents are filled (FIG. 2).

Before filling the contents, the horn of the ultrasonic transmitter is not stained with the contents, and the maintenance of the ultrasonic horn is relatively easy.

Further, after the contents are filled, the dirt due to the contents filled in the flange portion of the container is blown off by the ultrasonic treatment, so that the heat sealing property with the lid material is improved and the stable sealing property is obtained.

In the ultrasonic transmitter, the processing surface of the horn is formed with minute projections for forming minute recesses on the flange surface of the container as shown in FIG. 6, and the pitch interval w of these minute projections is The height d of the projections of the minute projections is preferably selected according to the thickness of the sealing layer of the container, but is preferably about 1 to 10 times the thickness of the sealing layer as a guide.

This ultrasonic treatment has such a structure that it can be performed on the entire surface of the sealing layer of the container flange or on a part thereof. In order to form a minute concave portion on the entire surface or a part of such a flange, an ultrasonic horn cradle as shown in FIG.
This is achieved by using a cradle as shown in (b) and (c).

A multilayer sheet is formed, the flange portion is subjected to ultrasonic treatment, the contents are filled, or the contents are filled, ultrasonic treatment is performed, and then the lid material is heat-sealed. The heat sealing method may be of a type using a hot plate under ordinary conditions.

A series of these heat-sealed packages are punched out as individual packages in the next step, and easily openable sealed packages can be easily obtained continuously in a continuous process.

(Function) The package obtained by the production method according to the present invention is integrated with the sealing layer of the container body and the lid member firmly adhered to each other, and the inside of the point-like minute concave portion formed on the flange surface is formed. It has a structure filled with resin for the lid material, the flange surface has a thin resin for the sealing layer, and has a unique structure as shown in FIG. 7 where the strength of the sealing strength is distributed. This seal structure provides stable pressure resistance against internal pressure and external pressure when sealed, and when opened, it comes into a peeled state as shown in FIG. 7 to cause smooth delamination. By the way, it is possible to easily and continuously obtain a material that is broken by a small force and easily opened completely.

(Effects of the Invention) The package produced by the method of the present invention has excellent sealing properties, and provides a very stable, smooth and easy-to-open property in a continuous manner. Is very easy, and a highly productive easy-opening sealed package can be obtained very easily.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are schematic views showing a manufacturing method of the present invention. FIG. 1 shows a case where contents are filled after ultrasonic treatment, and FIG. The case where ultrasonic treatment is performed is shown. FIG. 3 is a perspective view of the package obtained by the apparatus of the present invention in a state where a cover material is partially removed, FIG. 4 is an enlarged view of a portion subjected to ultrasonic treatment, and FIG. 5 is a receiving portion of an ultrasonic horn. FIG. 6 is an enlarged view of the ultrasonic horn, and FIG. 7 is an enlarged view showing an opened state of the container body and the lid member. In the figure, 1: Multi-layer sheet, 2: Sheet preheating device, 3: Vacuum pressure forming machine, 4: Ultrasonic treatment machine, 5: Filling machine, 6: Lid material, 7: Heat sealing machine, 8: Punching device, 9: Roller for punching lid material after punching, 1
0: Multilayer sheet winding device after punching, 11: Package, 12:
Container body, 13: micro-recess formed in the flange of the container, 1
4: adjacent layer of the multilayer sheet forming the container body, 15: sealing layer of the multilayer sheet, 16: ultrasonic horn head, 17: pedestal of ultrasonic horn.

Claims (2)

(57) [Claims] 1. A multi-layer sheet having a seal layer on its surface is formed into a container having a flange, the container is filled with the contents, the container is covered with a cover material, heat sealed, and the container and the cover material are punched out. In the method for manufacturing a package, a container is formed from a multilayer sheet, and then the entire surface of a portion corresponding to the flange portion of the container or a part of the inner periphery of the portion to be the flange portion is formed into a micro concave shape over the entire circumference by ultrasonic waves. A method for producing an easily-openable hermetically sealed package, comprising forming a countless number of pieces by processing, filling the contents, heat-sealing the lid, and punching out the container and the lid at the same time. 2. A multi-layer sheet having a sealing layer on its surface is formed into a container having a flange, the contents are filled in the container, a lid is placed on the container, heat sealing is performed, and the container and the lid are punched out. In the method of manufacturing a package, a container is formed from a multilayer sheet, the contents are subsequently filled into a container forming portion, and then the entire surface of the portion corresponding to the flange portion of the container or the inner peripheral portion of the portion to be the flange portion is formed. A method for producing an easily-openable hermetically sealed package, comprising: forming an infinite number of minute concave portions over the entire circumference by ultrasonic treatment; heat-sealing the lid material; and punching out the container and the lid material simultaneously.