JPS6036434Y2 - heat sealed container - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a heat-sealed container.

A method of sealing the lid of a container by heat sealing is widely used.

One of the properties required of such a lid is good sealing performance, and the other is that it is easy to open.

However, for example, if the heat-sealing part of the container body is made of polyethylene and the heat-sealing layer of the lid is also made of polyethylene, there is a problem that although the seal is completely fused and the seal is excellent, it cannot be opened easily. be.

Among the polyethylene materials mentioned above, additive-free polyethylene is said to be particularly hygienic for food packaging, so if the above problems can be solved, it has very high industrial applicability.

Therefore, an object of this invention is to provide a heat-sealed container that uses polyethylene as a heat-sealing layer and can be easily opened while maintaining good sealing performance.

In order to achieve this objective, this invention uses a metal foil, a resin layer mainly made of polypropylene, and a thickness of 1.
A lid material made of a polyethylene thin film layer of ~8 μm was heat-sealed to a container body having a polyethylene layer in the heat-sealed portion.

The polyethylene thin film layer of the lid and the polyethylene layer of the container body are completely fused and exhibit excellent sealing performance, while
The polyethylene layer of the lid material is very thin and the bonding force with the polypropylene layer is weak, so it easily breaks when the lid is pulled.
Can be opened easily.

Embodiments of this invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the lid material 10 is made by sequentially laminating a polypropylene resin layer 12 and an additive-free polyethylene thin film layer 13 on an aluminum metal foil 11.

Although the lamination method is arbitrary, for example, if polypropylene and additive-free polyethylene are co-extruded together with the metal foil 11, the lid material can be obtained in one step.

As shown in FIG. 2, a laminated film consisting of a polypropylene resin layer 12 and an additive-free polyethylene resin thin film layer 13 may be created in advance by co-extrusion or the like, and this may be bonded to the metal foil 11 with an adhesive 14. Alternatively, instead of the adhesive 14, a molar resin 15 such as polyethylene, polypropylene, or ionomer may be extruded between the laminated film and the metal foil 11, and the two may be bonded together by pressure.

The metal foil 11 is for providing the lid material 10 with barrier properties against air, water, light, etc., and the surface thereof may be laminated with paper, synthetic resin film, cellophane, etc.
Various treatments can be added, such as printing or overcoating for corrosion protection.

The polypropylene resin layer 12 serves as a cushion.
During heat sealing, it fills in the unevenness caused by the seams of the container body or the unevenness of the flange surface, plays an important role in maintaining the strength of the lid material, and also works together with the polyethylene thin film layer 13 to improve unsealability. It's helping me do that.

That is, as shown in FIG. 3, a polyethylene layer 21 is placed on the heat sealed part.
When the container body 20 provided with the above is heat-sealed with the lid material 10, the polyethylene layer 21 of the container body and the polyethylene layer 13 of the lid material are completely fused and exhibit excellent sealing performance, but compared to polyethylene and polypropylene, Because the bonding force is weak,
When the lid material 10 is pulled when the package is opened, the polyethylene thin film layer 13
Since the heat-sealed portion of the package is easily broken and peeled off from the polypropylene resin layer 12, the package can be easily opened.

FIG. 3 shows this state.

In order to obtain the above effects, it is desirable to set the thickness of the polyethylene thin film layer 13 between 1 and 8 microns.

If the thickness is less than 1 μm, the adhesive force will not be sufficient and pinholes will occur, which will have a negative effect on the sealing performance. If the thickness is more than 8 μm, it will not break easily and will be difficult to open.

The composition of the polypropylene resin layer 12 may be mainly composed of polypropylene, and for example, 45% or less polyethylene or 30% or less polystyrene may be mixed therein.

As mentioned above, the container of this invention has excellent sealing and opening properties, and at the same time, the polypropylene as the middle layer of the lid material acts as a cushion, making the container even better in sealing performance, and the strength of the lid material. Also, since it uses metal foil, it has good barrier properties.
It has many advantages.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views of the lid used in the container of this invention, and FIG. 3 is a cross-sectional view of the container of this invention in an unsealed state. 10... Lid material, 11... Metal foil, 12
...Polypropylene resin layer, 13 ... Curved polyethylene thin film layer, 14 ... Adhesive, 15 ...
...Resin, 20... Container body, 21...
・Polyethylene layer.

Claims (1)

[Scope of utility model registration request] Metal foil and resin layer mainly made of polypropylene and thickness 1~
A container made by heat-sealing a lid material made of sequentially laminated polyethylene thin film layers of 8 μm to a container body having a polyethylene layer in the heat-sealing part.