JPS591954Y2 - multilayer bag - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multilayer bag, and more specifically, to a moisture-proof multilayer bag in which a synthetic resin tubular film or a synthetic resin film is interposed between layers around the entire circumference as one layer of the bag.

Conventionally, multi-layer bags for storing cement, milled grains, feed, etc. have been made with synthetic resin tubular film or synthetic resin film wrapped around the entire circumference as one layer of the bag in order to prevent the contents from clumping. Moisture-proofing is expected by interposing the material between the layers, but since this moisture-proof material is interposed on the entire wall, the air that is blown into the bag at the same time as the stored items is extremely insufficient, causing the bag to swell when filled with stored items. This will seriously impede the packer.

The present invention provides a multilayer bag that overcomes the drawbacks of conventional products.

That is, the present invention involves cutting notch-like tongues at multiple locations on the surface of the synthetic resin tubular film that is interposed as one layer of the bag, and the tongues are bent and interposed between the layers of the bag so that the surface of the synthetic resin tubular film is It is a multi-layered bag with gaps between the bag materials.

The bag materials of this invention are paper, resin cloth, laminated paper made by laminating paper and resin cloth, slits made of longitudinally stretched thermoplastic resin film to a certain width, and laminated layers made by simultaneously laminating yarn, horizontally stretched film, and paper. The material for the synthetic resin film interposed between the layers, such as paper, is a thermoplastic resin film such as polyethylene, polypropylene, etc., selected depending on the purpose of use, and combined with the bag material described above to form a multilayer bag.

An embodiment of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a partially cutaway front view showing an example of a multilayer bag according to the present invention, which is a multilayer bag with two layers of paperboard and a synthetic resin tubular film interposed between the two layers of cardboard.

A synthetic resin tubular film 3 is interposed between the outermost layer base paper 1 and the innermost layer base paper 2, and they are polymerized in different steps according to a conventional method, leaving a joint glue margin for each layer, to form a cylindrical body, and the Pulpro 4 is made into a cylindrical body like a bag for cement. When the multi-layer bag 7 is made by machine sewing 5, 5' on the top and bottom, cut-out tongues 6, 6. The tongue pieces 6,6.
6 etc. are necessarily bent and interposed between the layers so as to maintain a gap 8 between the synthetic resin film surface and the paper surface.

The tongue pieces to be cut are most preferably cut at both folds and near the upper mouth, but are not limited thereto, and may be cut at any location such as the body of both walls.

It is most desirable for the tongue to be in the shape of an eye, but any appropriate shape may be used as long as the cut tongue can be bent.

The main idea is as follows, air is blown in at the same time as the stored items, and tongues cut into the synthetic resin film surface are bent and interposed between the synthetic resin film surface and the paper surface to maintain a gap between the layers. Because of this structure, the air that is inserted at the same time as the stored items is sufficiently extracted from the gap between the layers of the bag, and even when the stored items are stored in the bag and stored as offspring, the bag does not swell into a drum shape. , can be seeded in an orderly manner.

Moreover, when making bags by placing a long roll of synthetic resin film on a base paper table in a conventional bag-making machine that is commonly used, a ■-shaped tooth pattern is applied to the surface of the synthetic resin film, making it easy to produce bags with the desired length. It is an object of the present invention to provide a multilayer bag that does not break during handling during filling or immediately after packaging, and has a practically advantageous effect.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an example of a multilayer bag according to the present invention, Fig. 2 is an enlarged cross-sectional plan view taken along line A-A' in Fig. 1, and Fig. 3 is a cross-sectional view taken along line B-B' in Fig. 1. Enlarged longitudinal plan view of
FIG. 4 is an explanatory diagram of the main parts. In the figure, 1 is the outermost layer base paper, 2 is the innermost layer base paper, 3 is a synthetic resin tubular film, 4 is pulp processing, 5, 5' are sewing machine stitches, 6, 6.6 are notched tongue pieces, 7 is a In the multilayer bag, 8 indicates a gap, respectively.

Claims (1)

[Scope of utility model registration request] In a multilayer bag in which a synthetic resin tubular film or a synthetic resin film is interposed between the layers around the entire circumference as one layer of the bag, notch-shaped tongue pieces are cut at multiple places on the surface of the synthetic resin film, and the tongue pieces are A multilayer bag characterized in that the is folded and interposed between the layers.