JP3928184B2 - Flexible container bag joint structure - Google Patents

Description

【００１８】
【発明の効果】
以上述べたように、本発明においては本体布及び内張布に補強テープを貼着し、補強テープ同志を応力作用側に未接着部分を残して熱溶着し、これによって袋本体布と補強テープ、内張布と補強テープ及び補強テープ同志の剥離強度と増大することができ、その結果、フレキシブルコンテナ袋の角型形状を維持でき、従って、段積み強度を向上し、保管効率を向上させることができる等の効果を奏することができた。
【図面の簡単な説明】
【図１】本発明にかかるの袋本体と内張布との接合構造の断面図
【図２】本発明者の先の発明にかかる袋本体と内張布との接合構造の断面図
【図３】従来の袋本体と内張布との接合構造の断面図
【符号の説明】
１ 本体布 ２ 中間部材 ３ 内張布 ４ 未接着部
５、５’ 補強テープ[0001]
[Industrial application fields]
The present invention relates to a cubic or rectangular parallelepiped flexible container bag composed of a laminated sheet in which a thermoplastic resin film is laminated on both sides of a stretched woven fabric made of a thermoplastic resin, and a lining fabric provided inside the bag. It is related with the junction structure which improved the welding strength.
[0002]
[Prior art]
In a flexible container bag composed of a laminated sheet in which a thermoplastic resin film is laminated on both sides of a stretched woven fabric made of a thermoplastic resin, the bonding between the lining fabric provided in the bag and the bag body is flexible. This is a very important issue for container bags.
That is, flexible container bags used as powder or granular transport bags for food, grains, fertilizers, chemicals, synthetic resins, etc., have thermoplastic resin films on both sides of a stretched woven fabric made of thermoplastic resin. It is composed of a laminated sheet that is laminated, and a lining cloth for retaining the shape is welded to the even angle part inside the side wall of the bag body, and a suspension belt is provided on the side wall. Yes.
[0003]
By the way, as a laminated sheet constituting this flexible container bag, thermoplastics such as ethylene vinyl acetate copolymer (EVA tarpaulin), polyvinyl chloride (PVC tarpaulin) on both sides of a woven fabric made of multifilament yarn such as nylon or polyester. A resin layer is formed, or a polyethylene-based (PE cloth sheet) thermoplastic resin layer is formed on both sides of a woven fabric made of high-density polyethylene flat yarn. It is composed of a body cloth and a lining cloth. (Hereinafter, this laminated sheet is simply referred to as a main body cloth and a lining cloth.)
[0004]
Conventionally, when joining the bag body and the lining cloth or the like, as shown in FIG. 3, the thermoplastic resin layer of the bag body cloth 1 and the thermoplastic resin layer of the lining cloth 3 are directly welded. As a means, a high frequency welder is used when the laminated sheet is PVC tarpaulin or EVA tarpaulin, and hot air welding is used when the laminated sheet is PE cloth sheet.
[0005]
However, in the conventional bag body, the flexible container bag obtained by directly welding the bag body cloth and the lining cloth as shown in FIG. If the adhesive strength between the stretched woven fabric and the surface layer film (thermoplastic resin layer), the strength of the surface layer film and the welding strength are insufficient, a peeling trouble occurs. When the main body cloth and the lining cloth are peeled off, the original square shape of the bag is lost, and in the case of stacking storage, there is a risk of collapse.
Therefore, as shown in FIG. 2, the present inventor interposes an intermediate member (also referred to as a reinforcing tape) 2 having thermal adhesiveness at the joint between the main body cloth 1 and the lining cloth 3, thereby The intermediate member and the intermediate member are generally welded over the entire area of 40 to 50 mm wide, and the inner cloth and the intermediate member are welded leaving the non-bonded portion 4 at the end of the intermediate member at the peeling action side, and the peeling stress point is set to the inner cloth. It was found that the junction point B between the intermediate member and the intermediate member can be used to improve the peel strength and to improve the above-mentioned drawbacks.
[0006]
[Problems to be solved by the invention]
However, the inventor further improves the peel strength and does not cause troubles such as peeling of the thermoplastic resin film on both sides of the stretched woven fabric made of the thermoplastic resin constituting the bag body and the lining fabric. As a result of various investigations, the present invention has been completed. An object of the present invention is to provide a flexible container bag joining structure in which the welding peel strength between the bag body and its lining fabric is improved.
[0007]
[Means for Solving the Problems]
Gist of the present invention, in order to maintain the shape of the flexible container bag of rectangular shape, is stretched is welded to the inside of the side walls with composed of processed cloth formed by laminating a thermoplastic resin layer on at least one surface in the corner was lined with a cloth, the joint structure and the lining fabric and the body fabric of the side walls of the flexible container bag made of a main body fabric made of processed cloth formed by laminating a thermoplastic resins on at least one surface, said body the junction between the lining cloth and fabric, the body fabric and adhered each reinforcing tape in the lining cloth, welded, leaving an unbonded portion of these reinforcing tape between the peeling action end octopus It is the junction structure of the flexible container bag characterized by these.
[0008]
The operation of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a joining structure between a bag body and a lining cloth according to the present invention. In FIG. 1, a reinforcing tape 5 is attached to the bag body cloth 1 and a reinforcing tape 5 ′ is attached to the lining cloth 3. Then, when joining the main body cloth and the lining cloth, the reinforcing tape 5 and the reinforcing tape 5 ′ are welded while leaving the non-bonded portion 4 on the peeling stress acting side. By doing so, the point of application of the peeling stress is between the reinforcing tapes 5 and 5 ' from the point B which is the joining end portion of the lining cloth 3 and the intermediate member 2 in FIG. shift to the point a is a joint end, as a result, the peel strength is improved further, it was possible to eliminate the trouble caused in the joining structure between a conventional bag body fabric 1 and the lining cloth 3.
[0009]
Next, the present invention will be described in detail.
In the present invention, the main body cloth and the reinforcing tape and the lining cloth and the reinforcing tape are welded over the entire area of the reinforcing tape, and the reinforcing tapes are welded leaving an unbonded portion at the end portion on the side where the peeling stress acts. The size of the reinforcing tape is generally 40 mm to 50 mm wide, and the unbonded portion is about 2 to 20 mm from the end portion on the peeling stress acting side, and if it is less than 2 mm, there is no point in inserting the reinforcing tape in the unbonded portion. If it exceeds 20 mm, the width of the bonded portion between the intermediate member and the lining fabric becomes narrow, which may cause a difficulty in shear strength. The thickness of the reinforcing tape is 0.2 to 1.0 mm, preferably about 0.5 mm.
[0010]
Examples of the main body cloth and lining cloth that can be used in the present invention include flat yarn, monofilament yarn or multifilament yarn made of high-density polyethylene or polypropylene, high-density polyethylene, and other thermoplastic resins such as linear low-density polyethylene (LLDPE). Low density polyethylene on both sides of flat yarns, monofilament yarns or multifilament yarns blended or laminated with ethylene / vinyl acetate copolymer (EVA), polypropylene, etc., or multifilaments such as nylon and polyester. A heat-adhesive resin layer such as linear low density polyethylene, ethylene / vinyl acetate copolymer, polyvinyl chloride or the like is melt-extruded and formed into a processed cloth using a known method such as calendering. In this case, in particular, when mechanical strength is required, a composite cloth in which a plurality of layers of the above-described woven fabric or knitted fabric are laminated by an appropriate method may be used in which a heat-adhesive resin layer is formed on both surfaces.
Further, as the reinforcing tape, there is a surface layer that can be thermally bonded to the heat-adhesive resin formed on the surfaces of the main body cloth and the lining cloth, and the resin that can be heat-bonded between the reinforcing tapes used for both is used. For example, when the surface layer of the main body cloth and the lining cloth is a vinyl chloride porporin formed of polyvinyl chloride, a reinforcing tape made of a polyvinyl chloride sheet or a surface layer is used as the reinforcing tape. It is preferable to use a reinforcing tape formed of polyvinyl chloride. Therefore, in the case of the main body cloth and the lining cloth in which the surface layer is formed of linear low density polyethylene, the linear low density polyethylene sheet or the surface layer is formed of linear low density polyethylene as the reinforcing tape. It is preferable to use a reinforcing tape.
The main body cloth and the reinforcing tape, the reinforcing tape and the lining cloth, and the welding means of the reinforcing tape are conventionally used, for example, heat bonding with a bar, heat bonding with hot air, or surface resin using vinyl chloride or the like. In the case of tarpaulins, an adhesion method such as a high-frequency welder can be used.
[0011]
Next, the present invention will be specifically described with reference to examples.
In addition, the welding strength of the junction structure in an Example and a comparative example was tested and evaluated by the following test method.
Static load Suspend a load of 26 kgf on one side of the 3 cm sample width, leave it for 15 hours, and visually determine the peeled state of the joint. It was.
Dynamic load Grasp each of the joint part of the sample width of 3cm on the peel tester with a clip etc., peel off by applying a tensile force in the opposite direction at a tensile speed of 1mm / min, and measure the load when peeled off, kgf / 3cm Displayed.
[0012]
【Example】
Example 1
The main body cloth of the flexible container bag was composed of a polyethylene cloth sheet in which a LLDPE film having a thickness of 60 μm was laminated on both sides of a polyethylene cloth plain woven with a density of 15 deniers of 2000 denier high density polyethylene.
A composite polyethylene cloth in which two polyethylene cloths having the same structure as the polyethylene cloth constituting the main body as the lining cloth are adhered with a 50 μL LLDPE film, and both outer sides thereof are covered with a 60 μL LLDPE film. A sheet was used. A 600 μm LLDPE single sheet was used as the reinforcing tape.
The main body cloth and the lining cloth were heat-welded through the 45 mm width reinforcing tape. The main body cloth and the reinforcing tape and the reinforcing tape and the lining cloth were thermally welded over the entire width of 45 mm, and the reinforcing tapes were thermally welded leaving an unadhered part 10 mm wide from the end portion on the peeling action side of the reinforcing tape.
The static load and dynamic load at each temperature of the obtained joint were measured, and the results are shown in Table 1.
[0013]
Example 2
The main body cloth of the flexible container bag was composed of a polyethylene cloth sheet in which an LLDPE film having a thickness of 60 μm was laminated on both sides of a polyethylene cloth plain woven with a density of 15 deniers of 2000 denier high density polyethylene.
Two polyethylene cloths having the same structure as the polyethylene cloth constituting the main body as the lining cloth are adhered with a 50 μm thick LLDPE film, and further, both sides of the outer surface are 60 μm thick ethylene / vinyl acetate copolymer film. A composite polyethylene cloth sheet coated with is used.
[0014]
In addition, as a reinforcing tape, a 600 μm LLDPE single sheet is used on the main body cloth side, and a 600 μm ethylene / vinyl acetate copolymer film is used on the inner cloth side, and these reinforcing tapes are used for the main body cloth and the inner cloth. Heat welding was performed, and the reinforcing tapes were heat-welded leaving an unadhered portion having a width of 10 mm from the peeling action side end of the reinforcing tape.
The static load and dynamic load at each temperature of the obtained joint were measured, and the results are shown in Table 1.
[0015]
Comparative Example 1
The main body cloth and the lining cloth constituting the flexible container bag were respectively the polyethylene cloth sheet and the composite polyethylene cloth sheet shown in Example 1, and no reinforcing tape was used.
Table 1 shows the measurement results of the peel strength and shear strength of the joint obtained by welding under the welding conditions shown in Table 1.
[0016]
Comparative Example 2
The polyethylene cloth sheet and the composite polyethylene cloth sheet shown in Example 1 were used for the main body cloth and the lining cloth constituting the flexible container bag, respectively. The reinforcing tape used was an LLDPE film having a width of 45 mm and a thickness of 600 μm, adhered to the lining side leaving an unadhered portion of 10 mm, and the main body side was adhered to the front surface. Table 1 shows the measurement results of the peel strength and shear strength of the joint obtained by welding under the welding conditions shown in Table 1.
[0017]
[Table 1]

[0018]
【The invention's effect】
As described above, in the present invention, the reinforcing tape is attached to the main body cloth and the lining cloth, and the reinforcing tapes are heat-welded with the unbonded part left on the stress acting side, whereby the bag main body cloth and the reinforcing tape are bonded. , Can increase the peel strength between the lining fabric and the reinforcing tape and the reinforcing tape, so that the square shape of the flexible container bag can be maintained, thus improving the stacking strength and improving the storage efficiency It was possible to produce effects such as
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a bonding structure between a bag body and a lining cloth according to the present invention. FIG. 2 is a cross-sectional view of a bonding structure between a bag body and a lining cloth according to the inventors' previous invention. 3] Cross-sectional view of the joining structure of the conventional bag body and lining fabric [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body cloth 2 Intermediate member 3 Lining cloth 4 Unbonded part 5, 5 'Reinforcement tape

Claims (2)

To maintain the shape of the flexible container bag of rectangular shape, having a lining cloth is stretched is welded to the inside of the side walls with composed of processed cloth formed by laminating a thermoplastic resin layer on at least one surface in the corner In the joint structure between the main body cloth on the side wall of the flexible container bag and the lining cloth formed of a main cloth made of a processed cloth in which a thermoplastic resin is laminated on at least one surface, the main body cloth and the lining cloth the junction of the body fabric and adhered each reinforcing tape in the lining cloth, a flexible container, wherein the kite is welded to leave non-bonded portion of these reinforcing tape between the peeling action-side end portion Bag joint structure. The reinforcing tape adhered to the main body cloth and the lining cloth is a thermoplastic synthetic resin sheet that can be thermally bonded to the main body cloth and the lining cloth, and the reinforcing tapes are also a thermoplastic synthetic resin sheet that can be thermally bonded to each other. The joint structure of the flexible container bag of 1.

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