JPH0211313Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multilayer bag, and more particularly to a multilayer bag in which a synthetic resin tubular film or a synthetic resin film is interposed between layers along the entire circumference as one layer of the bag. Traditionally, cement. Milled grains. Multi-layer bags for storing feed, etc. are made with a synthetic resin tubular film or synthetic resin film interposed between the layers around the entire circumference of the bag to prevent moisture from clumping together. However, since these moisture-proof materials are 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 serious problems for the pack car that inflates the bag when filling the stored items. becomes.

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

That is, the present invention is a multilayer bag made by cutting diagonal score lines at a plurality of locations on the surface of a synthetic resin tubular film interposed as one layer of the bag.

The bag material of this invention is paper. Resin cloth. Laminated paper made by laminating paper and resin cloth. A longitudinally stretched thermoplastic resin film is slit to a certain width. Laminated paper made by simultaneously laminating yarn, horizontally stretched film, and paper, etc. Also, as a material for the synthetic resin film interposed between the layers, polyethylene. A thermoplastic resin film such as polypropylene is selected depending on the purpose of use and is 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 base paper and a synthetic resin tubular film interposed between the two layers of base paper.

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 to form a cylindrical body, leaving a longitudinal glue margin in each according to a conventional method.
When a multilayer bag 7 is made by providing a valve port 4 like a cement bag and performing vertical perforations 5, 5', diagonal cut lines 6, 6, 6, etc. are made on the surface of the synthetic resin tubular film interposed between each base paper. is cut into pieces at appropriate intervals and lengths.

The present case is as follows, and since diagonal cut lines are formed on the surface of the synthetic resin film, the air that is blown in at the same time as the stored items passes through the machine-sewn seam holes above the diagonal cut lines. It is completely discharged from the bag. Conventionally, this type of synthetic resin film has been provided with pinballs, vertical cut lines, gaps for degassing, etc. to vent the air inside the bag, but each of these had advantages and disadvantages, but the synthetic resin film of the present invention has advantages and disadvantages. The large number of diagonal score lines 6, 6, 6, etc. cut into the surface are, for example, vertical score lines.Since the synthetic resin film is stretched in the vertical direction, the vertical score lines are horizontally cut due to the internal pressure of the bag. In contrast, in the case of a diagonal cut line, even if the synthetic resin film is stretched vertically, the entire cut of the diagonal cut line becomes curved due to the internal pressure of the bag. Because of this formation, air escape is extremely good. Therefore, even if the bag is a multilayer bag in which a synthetic resin tubular film is interposed between the paper layers for the purpose of moisture proofing, by providing this diagonal cut line, the air that is inserted at the same time as the stored items can be sufficiently removed and stored in the bag. Even when storing items in a flat pile, the bag shape does not swell into a drum shape and can be stacked neatly and flatly.
Furthermore, the present invention provides a multilayer bag that does not tear during handling of the bag during filling or immediately after packaging, and has a practically effective 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. FIG. 4 is an enlarged longitudinal sectional front view of FIG. In the figure, 1 is the outermost layer base paper, 2 is the innermost layer base paper, 3 is the synthetic resin tubular film, 4 is the valve opening,
5, 5' are perforated, 6, 6, 6 are diagonal cut lines,
7 indicates a multilayer bag.

Claims (1)

[Scope of utility model registration request] A multilayer paper bag comprising a synthetic resin tubular film or a synthetic resin film interposed between the layers around the entire circumference as one layer of the bag, and diagonal score lines are cut at a plurality of locations on the surface of the synthetic resin film.