JP2000129646A - Sandbag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sandbag having biodegradable property, which is excellent environmentably having sufficient mechanical strength by weaving a flat yarn consisting of biodegradable plastic to form woven fabric, and sewing the woven fabric to form the sandbag. SOLUTION: A sandbag 1 is formed such that a ground fabric consisting of a biodegradable fabric is sewed by a machine sewing thread to be made in the form of a bag, and a cover ground fabric 3 consisting of the biodegradable woven fabric is cylindrically sewn by the machine sewing thread on the opening part of the body ground fabric 2 of the bag to form a charge port 4. A hanging belt 5 consisting of the biodegradable woven fabric is sewn on the outer peripheral wall of the body ground fabric 2 to fold one end thereof so as to sew to the ground fabric 2, and a hanger 6 is formed. Furthermore, the charge port 4 is tied on the cover ground fabric 3 to attach tie string 7 consisting of the biodegradable woven fabric for sealing the bag 1. Thereby the sandbag is used for a temporary bank or the like, even when it is left as it is, performance as the sandbag can be held for a few years, and thereafter, since it is decomposed, bad influence is not exerted on an environment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a biodegradable composition,
The present invention relates to a sandbag having excellent environmental properties and sufficient mechanical strength.

[0002]

2. Description of the Related Art Sandbags have conventionally been used mainly for manual emergency measures, such as for temporary embankments or for preventing water from entering a house in the event of a natural disaster such as a typhoon or heavy rain.
Therefore, its size (capacity) is at most 10-20.
It was about kg. Materials used for sandbags include water resistance, corrosion resistance,
Weather resistance, mechanical strength, and the like are required, and a woven fabric made of filaments or split yarns of a polyolefin resin such as polyethylene is used as the material.

On the other hand, as a large-sized bag, there is a flexible container (generally abbreviated as "FIBC") used for transporting and storing powder and granules. The capacity of the flexible container is usually about 500 to 3000 kg.
A temporary embankment method using this flexible container as a sandbag has been proposed, for example, in Japanese Patent Application Laid-Open No. 8-49225.

[0004]

However, in the above-mentioned method, when the temporary flexible container (large bag) is to be removed, the material is deteriorated, and the strength of the slinger is reduced, and it is impossible to lift the slug. High in nature. If the bag is left as it is, the bag is damaged due to deterioration due to ultraviolet rays or repeated waves due to seawater, and the damaged cloth floats on the sea. This piece of cloth made of polyolefin etc.
Since it is not naturally decomposed, has a low specific gravity, and does not sink in the sea, it affects fisheries and the like, and further causes environmental problems such as impairing the coastal landscape.

[0005] The present invention has been made to solve the above problem, and has an object to provide a sandbag having biodegradability, excellent environmental properties, and sufficient mechanical strength.

[0006]

The sandbag according to the present invention is characterized in that a flat yarn made of biodegradable plastic is woven into a woven fabric, and the woven fabric is sewn. Further, the biodegradable plastic is preferably an aliphatic polyester.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a perspective view showing an example of a sandbag of the present invention,
FIG. 2 is a perspective view showing a state in which contents such as sand, soil, crushed stone and the like are filled in the sandbag of FIG. A sandbag 1 is formed by sewing a main body base cloth 2 made of a biodegradable woven fabric with a sewing thread to form a bag, and a lid base cloth 3 made of a biodegradable woven cloth is provided at an opening of the bag-shaped main base cloth 2. Is sewn in a tubular shape with a sewing thread to form an input port 4. On the outer peripheral wall of the main body fabric 2,
Four suspending belts 5 made of a biodegradable woven fabric are sewn, and one end of each of the suspending belts 5 is folded and sewn to the opening of the main body base fabric 2 to hang the suspender 6.
Are formed. Further, a tie string 7 made of a biodegradable woven cloth is attached to the lid base cloth 3 for filling the contents such as sand, soil, crushed stone, etc., and then binding the input port 4 to seal the sandbag 1. I have.

[0008] The biodegradable woven fabric is, as shown in FIG.
The flat yarn 8 made of biodegradable plastic is used for the warp yarn and is woven by a conventional loom such as a sluser loom or a circular loom. Flat yarn 8
Since it is excellent in mechanical strength, productivity, handleability, etc., it can be suitably used for the woven fabric of the sandbag of the present invention.

[0009] The driving density of the biodegradable woven fabric should be at least such that it does not permeate the contents such as sand, soil, crushed stone, etc. In order to maintain the mechanical strength of the sandbag 1 high,
It is better to have as high a density as possible. In particular, since the main base fabric 2 is required to have enough strength to withstand the weight of the contents, the driving density of the main base fabric 2 may be higher than the driving density of the lid base fabric 3. preferable. For example, when a 3000 denier flat yarn is used, the driving density of the main base fabric 2 is preferably in the range of 10 to 18 yarns / inch and 10 to 20 yarns / inch in length. Is 5
The range is preferably 9 to 9 lines / inch and 5 to 9 lines / inch in width.

Further, since the suspension belt 5 is also required to have enough strength to withstand the weight of the contents, the driving density of the suspension belt 5 is substantially equal to the driving density of the main base fabric 2. Preferably. On the other hand, the driving density of the tying string 7 is substantially the same as the driving density of the lid base cloth 3. Further, a string made of biodegradable natural fiber may be used instead. The fineness of the flat yarn 8 used for the biodegradable woven fabric is preferably 1800 to 3800 denier from the viewpoint of mechanical strength, productivity, handleability, and the like.

The biodegradable plastic may be any plastic that can be decomposed by bacteria or bacteria in the ground or in the water (in the sea), and may be any of a natural polymer or a chemically synthesized polymer. For example, aliphatic polyesters (ε-caprolactone, condensates of dicarboxylic acid and glycol, etc.), polysaccharides (starch, dextrin, chitosan), polyhydroxy acids, polyorthoesters, polydepsipeptides, polypeptides, polyβ-hydroxybutyrate , Starch and other synthetic resins (ethylene-vinyl alcohol copolymer, modified polyvinyl alcohol, polyethylene, etc.). Among them, aliphatic polyesters are preferably used because they have excellent biodegradability, excellent mechanical strength, and higher specific gravity than water.

Specific examples of the aliphatic polyester include:
"Biopole" (Product name: Monsanto Japan Co., Ltd.)
), "Bionore" (trade name: manufactured by Showa High Polymer Co., Ltd.)
Among these, “bionole” is particularly excellent as a raw material of the flat yarn 8 because it has excellent biodegradability and high strength. In addition, aliphatic polyesters such as bionoles have low calories burned (about half that of polyethylene), and can be easily incinerated even if used sandbags 1 are incinerated, and harmful gases such as hydrogen chloride. There is no occurrence.

The flat yarn 8 according to the present invention may contain an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant,
Additives such as waxes, coloring agents, crystallization accelerators, antistatic agents, flame retardants, inorganic fillers and the like may be added. Examples of the antioxidant include hindered phenol antioxidants such as p-tert-butylhydroxytoluene and p-tert-butylhydroxyanisole, and sulfur-based antioxidants such as distearylthiodipropionate and dilaurylthiodipropionate. Agents and the like. Examples of the heat stabilizer include triphenyl phosphite, trilauryl phosphite, trisnonyl phenyl phosphite and the like.

Examples of the ultraviolet absorber include pt-butylphenyl salicylate, 2-hydroxy-4-methoxy-
2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone and the like. As the lubricant, monoamide type of higher fatty acid, fatty acid amide, synthetic silica, calcium stearate, zinc stearate,
Barium stearate, sodium palmitate and the like can be mentioned. Examples of the antistatic agent include N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallyl sulfonate, and alkyl sulfonate.

Examples of the flame retardant include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentabromophenylallyl ether and the like. Examples of the inorganic filler include calcium carbonate, silica, titanium oxide, talc, mica, barium sulfate, and alumina. Examples of the crystallization promoter include polyethylene terephthalate, poly-transcyclohexanedimethanol terephthalate, and the like.

The flat yarn 8 is manufactured by melt-extruding a biodegradable plastic by a known extrusion molding method such as an inflation method to form a film, slitting the film, and then stretching the film. Melt extrusion of biodegradable plastics is performed by circular dies,
It can be performed using a known molding machine equipped with a T die and the like. The extrusion temperature is generally between 170 and 230C, preferably between 180 and 210C. As the stretching method, a known stretching method such as a hot roll stretching method can be used. The stretching temperature is 80 to 110 ° C, preferably 90 to 105 ° C, and the stretching ratio is 3 to 9 times, preferably 4 to 8 times.
The strength of the flat yarn 8 can be adjusted by the stretching ratio, and the strength can be increased by increasing the stretching ratio. However, when the stretching ratio is too high, the stretching tends to be easily broken. The relaxation temperature is 90 to 120 ° C, preferably 95 to 110 ° C, and the relaxation rate is 5 to 20%.
Preferably it is 8 to 15%.

The sewing thread used for the sandbag 1 is desirably biodegradable. As the material, for example, the above-mentioned biodegradable plastics and natural fibers such as hemp yarn and cotton yarn are preferable. Among them, hemp yarn is suitably used in view of strength and cost.

In such a sandbag, a flat yarn made of a biodegradable plastic is woven into a woven fabric, and the woven fabric is sewn. It has excellent mechanical strength. The decomposition rate of the sandbag of the present invention varies depending on the environmental temperature and the place, but is usually decomposed in 2 to 3 years. The sandbag of the present invention has a bag-like shape, and can be filled with soil, sand, crushed stones, and other contents therein, and can be sealed at the input port. However, the present invention is not limited to this.

[0019]

The present invention will be described below in detail with reference to examples. The test method in this example was performed using the following method. (Mechanical strength of woven fabric) The tensile strength and elongation of the woven fabric were measured according to JIS L 1096.

(Soil performance test) JIS Z1651
(Flexible container), a lifting test and a drop impact test were performed. -Hanging test Sandbags (bulk specific gravity 1.5) are filled into sandbags by 1.2 tons, and the sandbags are suspended by four fulcrum hooks, and the bottom surface of the bag is 3 m in height.
, And immediately suspended to 0 m. This operation was repeated 30 times. Next, the sandbag was lifted to 3 m, allowed to stand for 5 minutes, and then hung to 0 m. Subsequently, the above-described test was repeated with two diagonal hooks suspended from the hook, and it was confirmed whether there was any leakage of the contents or damage to the sandbag.・ Drop impact test Using the sandbags for which the lifting test has been completed, the bottom of the bag is dropped once from a position of 0.8m height onto a firm flat floor (asphalt road) to leak the contents and prevent the sandbags from falling. Checked for damage.

(Evaluation of biodegradability) Woven specimen (size:
(30 cm × 30 cm) was set in a pot submerged at a water depth of about 3 m at Yawata Coast, Ichihara City, Chiba Prefecture, and evaluated by weight retention (%) after immersion for 24 months.

(Production of flat yarn) Bionole # 1
001 (manufactured by Showa Polymer Co., Ltd.) was extruded at an extrusion temperature of 200 ° C. by an inflation method and cooled to obtain a film. This film was slit to a specified width, and the stretching ratio was 6.5 times, the stretching temperature was 95 ° C., the relaxation rate was 10%, and the relaxation temperature was 9
Hot roll stretching was performed at 5 ° C. to obtain 3000 denier flat yarn.

(Manufacture of Woven Fabric) A woven fabric was obtained by weaving the above-described flat yarn as a warp yarn using a sluser loom. The driving density of the base fabric and the woven fabric for the hanging belt is 13 × 14.
(Books / inch), and the density of the lid base fabric and the woven fabric for the tying string was 7 × 7 (books / inch). The tensile strength and elongation of the obtained woven fabric were measured. Table 1 shows the results
Shown in The specific gravity of the woven fabric was 1.2. further,
The biodegradability was also evaluated, and the results are shown in FIG.

[0024]

[Table 1]

(Manufacture of sandbags) As shown in FIG. 1, a sandbag having a main body base portion having a height of 10,000 mm, a lid base fabric portion having a height of 600 mm, and a sandbag having a diameter of 900 mm was sewn. A hemp thread (No. 16/3) was used for the sewing thread. A sandbag performance test was performed on the obtained sandbags. In both the lifting test and the drop impact test, no leakage of the contents and no damage to the sandbag were observed.

From the above results, the sandbag of this embodiment is:
It can be seen that it has biodegradability while maintaining excellent strength.

[0027]

As described above, the sandbag of the present invention is made by weaving flat yarn made of biodegradable plastic into a woven fabric and sewing this woven fabric. And has sufficient mechanical strength. Therefore, even if the sandbag of the present invention is used for a temporary embankment or the like and left as it is, the performance as a sandbag can be maintained for several years, and it is completely decomposed thereafter, which has an adverse effect on the environment. Has no effect. In particular, when aliphatic polyester is used as the biodegradable plastic,
Furthermore, because of its excellent biodegradability and mechanical strength, and its specific gravity is heavier than water, the pieces of cloth that are broken from sandbags for temporary shore embankments sink into the sea, It does not adversely affect the coastal landscape. The sandbag of the present invention is particularly suitable for temporary embankment in beach nourishment work,
By using such a sandbag, the removal of the temporary embankment becomes unnecessary, and the cost and labor for beach nourishment work can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a sandbag according to the present invention.

FIG. 2 is a perspective view showing a state in which the contents are filled in a sandbag according to the present invention.

FIG. 3 is a perspective view showing an example of a woven fabric used for a sandbag according to the present invention.

FIG. 4 is a graph showing the biodegradability of a woven fabric used for a sandbag according to the present invention, in which the vertical axis represents weight retention (%) and the horizontal axis represents immersion time (months).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sandbag 2 Body base cloth (woven cloth) 3 Lid base cloth (woven cloth) 5 Suspension belt (woven cloth) 7 Tied string (woven cloth) 8 Flat yarn

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyoo Ishii 4-1 Nihonbashi Kobunacho, Chuo-ku, Tokyo Heisei Polymer Co., Ltd. (72) Inventor Tetsuya Ishida 4-1 Nihonbashi Kobunacho, Chuo-ku, Tokyo Heisei Polymer F term in reference (reference) 2D018 AA06 4L035 BB32 BB89 BB91 CC07 DD20 EE20 FF02 4L048 AA20 AA42 AB28 BA01 BA02 CA01 CA02 CA15 DA30

Claims (2)

[Claims] 1. A sandbag made by weaving a flat yarn made of biodegradable plastic into a woven fabric and sewing the woven fabric. 2. The sandbag according to claim 1, wherein the biodegradable plastic is an aliphatic polyester.