JP6160609B2 - Sand movement prevention method in sand - Google Patents

Description

  The present invention relates to a method for suppressing the movement of sand in sandy areas such as desert areas, sand dunes, and coasts, and for growing plants.

  As a typical example of a place where the ground surface is widely covered with sand, such as desert areas, dunes, coasts, etc., where the sand moves violently due to wind power etc. There is a fluid dune zone to play. The desertification in this area is said to have been expanded by cashmere goats and overgrazing sheep, and the flow of sand that had buried plants. Sand carried by the wind is said to be the cause of dust and even yellow sand, and there is an increasing demand to reduce the damage caused by rolling up sand from this area.

In this area, the amount of precipitation is high as a desert area and the groundwater level is high, so it is considered that greening is possible by suppressing sand flow near the ground surface due to strong winds and fixing sand. As a technique for doing this, a technique called Kusakagata has been used for a long time.
This greening method called the “Kusakata” is one of the sand control methods using straws and branches. A grid line is drawn on the sand surface at intervals of 1 to 1.5 m, and a scoop is drawn along the grid line. This is a method of digging a ditch using a paddle and standing straw or the like in the ditch. However, it is difficult to procure straw and the like, and it is bulky, so it is difficult to transport it locally (it is necessary to transport it on the ground). Furthermore, since straw etc. deteriorates, it is replaced in 2 to 3 years. There was a problem in maintenance and management after installation.

  Patent Document 1 describes a construction method in which a plurality of cylindrical knitted fabrics are crossed and installed on the sand ground to suppress sand movement. However, the work of packing sand into the cylindrical knitted fabric is difficult, and rain It is difficult to pack wet sand into a tubular knitted fabric after falling. Also, because the sand surface that is installed has a concave structure, if you plant a plant immediately after installation, the plant will fall down, and it will be necessary to plant the plant for a while after installation, or seeds and sand will be put together in a tubular knitted fabric There was also a problem that buds did not come out of the knitted fabric.

  Patent Document 2 describes a method in which a plurality of cylindrical knitted fabrics are arranged and seeds and seedlings are transplanted between them, but the work of filling the cylindrical knitted fabric with sand is heavy and the sand is clogged. It is difficult as an actual work to arrange the tubular knitted fabrics in parallel.

Japanese Patent Application Laid-Open No. 2008-291636 Japanese Unexamined Patent Publication No. 2010-227093

  An object of the present invention is to provide a sand movement prevention method that prevents sand movement or plant growth, is light in weight, easy to transport even in desert areas, etc., has good workability in installation, and reduces the burden on workers. It is also to provide a method that makes it possible to grow plants in a place covered with sand.

The present invention is to solve the above-described problems, and includes the following configurations (1) to (10).
(1) Using a net composed of monofilaments as a sand movement prevention material, with a part of the net buried in the sand and a part of the net standing on the sand A method for preventing sand movement, comprising installing the net.
(2) The sand movement preventing method according to (1), wherein at least one bent portion is formed by bending an intermediate portion of the net with a sand ground side as a mountain, and the bent portion is buried in sand.
(3) The sand movement preventing method according to (1) or (2), wherein the height of the other part of the net is 5 to 30 cm from the sand surface.
(4) The sand movement preventing method according to any one of the above (1) to (3), wherein the net softness by the Gurley method is 20 to 150 mN.
(5) The sand movement preventing method according to any one of (1) to (4), wherein the pressure loss of the net at a wind speed of 5 m / min is 50 to 300 Pa.
(6) The fineness of the monofilament is 300 to 600 dTex (decitex), and the mesh of the net is 0.5 to 5 mm, according to any one of (1) to (5), Sand movement prevention method.
(7) The method for preventing sand movement according to any one of (1) to (6), wherein the monofilament contains polylactic acid.
(8) A plurality of the nets are installed on the sandy ground so as to cross each other in the vertical direction and the horizontal direction when viewed from above, as described in any one of (1) to (7) Sand movement prevention method.
(9) On the sandy ground, a plurality of the nets are installed in the vertical direction or the horizontal direction when viewed from above, and when the net is installed in the vertical direction, the sand movement prevention material other than the net is installed in the horizontal direction. Alternatively, the sand movement preventing method according to any one of (1) to (7), wherein when the net is installed in a horizontal direction, the net is installed so as to intersect in the vertical direction.
(10) The plant seed is buried in sand in the vicinity of the net before or after being partially buried in sand before or after part of the net is buried in sand. )-(9) The sand movement prevention method according to any one of (9).

  In the present invention, since the material for preventing sand movement is light, transportation to the site is easy, and in work for preventing sand movement, there is an effect that workability is excellent particularly after rainy weather. Further, the installation work of the sand movement preventing material becomes easy, and at the same time, plant vegetation is also possible.

FIG. 1 is a sectional view showing a state of the sand movement preventing method of the present invention. FIG. 2 is a plan view showing an example of net arrangement in the sand movement preventing method of the present invention.

The sand movement prevention method of the present invention uses a net composed of monofilament (hereinafter also referred to as “the net of the present invention”) as a sand movement prevention material, and a part of the net is buried in the sand, The sand is prevented from moving by being installed with the other part standing on the sand surface.
The net is hard enough to be self-supporting. When a part of the net of the present invention is buried in sand and fixed, the rest of the net coming out of the sand ground (that is, the other part of the net) is against the sand ground. In the vertical direction, the sand moved by the wind stays on the net protruding from the sandy ground, preventing the sand from spreading.

  As for the direction in which the net of the present invention is buried, when the movement of sand is suppressed against wind blowing in a certain direction such as a westerly wind, it is preferable to prevent the sand from moving by standing upright in the direction of the wind.

  As a method of installing the net in a state where a part of the net is buried in sand and the other part of the net is stood on the sand ground, a sheet-like net is set up in a direction perpendicular to the sand ground. To fill the sand, part of the sheet-like net to the sand ground and other part of the net to the sand ground at the same time, or after the part of the sheet-like net to the sand ground A method of standing a part of the floor on a sandy ground is mentioned. An appropriate width from the viewpoint that the time required for installing the net can be shortened in a state where a part of the net is buried in sand and the other part of the net stands on the sand surface. Set up a roll-shaped net with a length to the required length, push part of the net into the sand with a scoop, etc., and place the net by placing sand on the indented part if necessary It is preferable.

  Alternatively, the net may be formed with a bent portion with the sand ground side as a mountain, and the bent portion may be buried in sand. The place where the bent portion is formed in the net is not limited as long as it can be installed in a state where a part of the net is buried in sand and the other part of the net stands on the sand ground, but the longitudinal direction of the net An intermediate part along the line is preferred. In the present invention, the “intermediate portion” refers to a portion between opposite ends of the net. That is, the place where the bent portion is formed is not limited as long as both ends in the width direction of the net can be installed on the sandy ground, and the substantially central portion in the width direction of the net, a 1/3 portion, etc. It can be selected as appropriate. One bent portion may be provided for one net, or two or more bent portions may be provided.

FIG. 1 is a sectional view showing a state of the sand movement preventing method of the present invention, and shows an example in which a bent portion is provided at a substantially central portion in the width direction of the net.
When a part of the net 1 is pushed into the sand 3 so as to be in the state shown in FIG. 1, the bent portion 1a is formed by bending the substantially center part of the net so that the lower side (sand ground side) is a mountain. The bent portion 1a is pushed into the sand 3. Then, since both ends of the net can be made to stand evenly with respect to the sand ground, the wind speed can be further reduced, and the scattering of sand can be suppressed, which is preferable.

In order to suppress sand flow and scattering, it is possible to install a plurality of monofilament woven nets as shown in FIG.
When an intersection is provided to make a square with a fixed interval, it is also possible to fix the intersection by embedding a pile of about 1 cm in diameter made of wood or the like at the intersection.

  Specifically, a plurality of the nets of the present invention are installed on the sandy ground so as to cross each other in the vertical direction and the horizontal direction when viewed from above (in plan view). Thus, by arranging the net of the present invention in a square shape, the sand can be prevented from moving against winds from all directions.

  In addition, when installing with an intersection, the direction varies depending on the wind direction of the installation location, but a net composed of the monofilament of the present invention is installed perpendicular to a direction where the wind is strong in a certain direction such as a westerly wind, and other winds are weak It is also possible to make a square by installing a sand movement prevention material other than the net of the present invention as an object of another form in the direction. Examples of the sand movement-preventing material other than the net of the present invention include a material in which a cylindrical knitted fabric made of polylactic acid fibers is filled with sand, wheat straw, and branches having an appropriate length.

  Specifically, a plurality of the nets of the present invention are installed in the vertical direction or the horizontal direction when viewed from above (in plan view) on the sand ground, and the sand movement preventing material other than the net of the present invention is attached to the nets. When installed in the vertical direction, it is installed in the horizontal direction, or when the net is installed in the horizontal direction, installed in the vertical direction. In this way, by using different sand movement preventing materials depending on the strength of the wind, the sand movement preventing materials can be installed in places where it has been difficult to install conventionally.

  When installing squares with a constant interval, the interval between squares is preferably 0.5 to 2 m. If the distance between the squares is 0.5 to 2 m, it is possible to suppress the scattering of sand.

  When a net is constructed by burying a part of the net composed of the monofilament of the present invention, other nets coming out of the sand surface to suppress the scattering of sand by passing the net and reducing the wind speed of the wind. The height of a part (the rest of the net) is preferably 5 to 30 cm from the sand surface, and the height of the other part of the net is 10 to 20 cm in order to suppress sand scattering in a stronger wind region. More preferably.

  Further, when part of the net is embedded in the sand, it is necessary to fix the net so that it does not move due to wind, and it is preferable to embed the net in the ground by about 5 to 20 cm in the depth direction.

Moreover, it is preferable to plant seeds when installing a net as a method of simultaneously proceeding greening while suppressing sand movement. The plant seeds are preferably buried in the sand in the vicinity of the net before or after the part of the net is buried in the sand.
Specifically, when a net is laid on the ground and a part is pushed into the sand, seeds are seeded above or below the net and buried together with the net. In this case, the seeds can be reliably transported to the soil layer containing water, so that germination can be made more reliable. After germination, the shoots and roots grow from the stitches of the net, so there is no problem in plant growth. . In FIG. 1, plant seed 2 is buried in the sand above the net. Alternatively, the net is buried in sand, and after standing, seeds and seedlings are buried between the nets. If seeds are planted above or below the net, the net will get in the way even if animals such as goats and sheep try to eat buds. Furthermore, since roots cannot be eaten, desertification can be suppressed, which is preferable.

There are no particular restrictions on the type of species, but plants that can withstand harsh climates such as dryness, extreme cold, and extreme heat in the desert are preferred, and plants that are used as livestock feed when plants are established are preferred. For example, when used in China, they are Shayanagi, Shashin, Shamai, and Sheep.
By promoting greening at the same time, for example, in a net made of polylactic acid (PLA), it is almost completely biodegraded and disappears in 5 to 10 years after installation. Will prevent sand movement.

Next, the configuration of the net of the present invention will be described.
The net of the present invention is composed of a monofilament. The monofilament is preferably made of a thermoplastic resin such as polyethylene terephthalate, polyamide, polypropylene, or polylactic acid, and preferably contains a resin that can be biodegraded after installation. In particular, a net composed of monofilament containing polylactic acid which is a typical biodegradable resin is preferable. Nets composed of monofilaments containing polylactic acid are unlikely to deteriorate with respect to ultraviolet irradiation, and the deterioration of nets composed of monofilaments can be suppressed even under intense ultraviolet irradiation environments in the desert.

  For example, when polylactic acid is used in the net, the molecular weight of polylactic acid is preferably in the range of 100,000 to 200,000 in terms of weight average molecular weight (Mw). If it is 100,000 or less, a polylactic acid monofilament having sufficient strength cannot be obtained, so that thread breakage occurs frequently at the time of creating a net, resulting in poor productivity. In addition, when 200,000 or more polylactic acid is used, the spinning temperature rises during spinning, and thermal degradation during spinning proceeds. Therefore, yarn breakage occurs during net production, making production difficult. Mw of polylactic acid is a value in terms of polystyrene measured by gel permeation chromatography (GPC) using chloroform as a solvent.

  The polylactic acid may be a copolymer. The lactic acid copolymer is obtained by copolymerizing a lactic acid monomer or lactide and another component copolymerizable therewith. Examples of such other components include dicarboxylic acids having two or more ester bond-forming functional groups, polyhydric alcohols, hydroxycarboxylic acids, lactones, and the like, and various polyesters and various polyesters composed of these various components. Examples include ether and various polycarbonates. For the purpose of increasing the molecular weight, a method of increasing the molecular weight using a small amount of a chain extender, for example, a diisocyanate compound such as hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, or aliphatic using a carbonate compound A method for obtaining polyester carbonate may be used.

  Furthermore, an additive such as an antioxidant or particles may be contained as long as the properties of the lactic acid polymer are not impaired. When polylactic acid fiber yarn is used, in the present invention, it is also preferable that the carboxyl terminal amount of the polylactic acid fiber is 10 equivalent / t or less. When the carboxyl terminal amount is 10 equivalent / t or less, hydrolysis of polylactic acid fiber can be suppressed. As a method for reducing the carboxyl terminal amount of the polylactic acid fiber to 10 equivalent / t or less, at the raw material resin stage, for example, condensation reaction type compounds such as aliphatic alcohols and amide compounds, carbodiimide compounds, epoxy compounds, oxazoline compounds, oxazines An addition reaction type compound such as a compound or an aziridine compound may be blocked by reacting with the carboxyl terminus of polylactic acid. If the latter addition reaction type compound is used, polylactic acid is melt-spun because there is no need to discharge extra by-products out of the reaction system, such as end-capping by dehydration condensation reaction of alcohol and carboxyl group. At this time, since an addition reaction type compound can be added, mixed and reacted, it is advantageous for obtaining a reaction product having a practically sufficiently high molecular weight, heat resistance and hydrolysis resistance.

  Among the above addition reaction type compounds, a method of adding a carbodiimide compound to polylactic acid is preferable. By blocking the reaction active terminal of the polylactic acid polymer or the oligomer contained therein with a carbodiimide compound, the reaction active terminal in the polymer is inactivated and hydrolysis of polylactic acid is suppressed. As the carbodiimide compound, for example, a polymer obtained by polymerizing a diisocyanate compound as described in Japanese Patent Application Laid-Open No. 11-80522 is preferably used. Among them, a polymer of 4,4′-dicyclohexylmethane carbodiimide or tetramethyl is used. A polymer of xylylene carbodiimide or a polymer whose end is blocked with polyethylene glycol or the like is preferable.

  Epoxy compounds are also preferable as endblockers for polylactic acid. The required durability can be obtained by using polylactic acid end-capped with an epoxy compound. In particular, it is preferable to contain a trifunctional or higher functional epoxy compound and to react the trifunctional or higher functional epoxy compound with at least a part of polylactic acid. More preferably, a trifunctional or higher functional epoxy compound is reacted with at least a part of the terminal of polylactic acid. The trifunctional or higher functional epoxy compound has three or more epoxy groups in one molecule of the compound. The reason for having 3 or more epoxy groups per molecule of compound is that when melt kneading with polylactic acid, part of it reacts with polylactic acid, and the remaining epoxy group when melt molding is performed again. Furthermore, the molecular weight is increased by reacting with polylactic acid, and the durability of the final molded product can be dramatically improved. In addition, the epoxy compound has a slower reaction rate with respect to polylactic acid than other terminal reactive substances such as carbodiimide compounds. Therefore, if the substance added to polylactic acid is an epoxy compound, the molecular weight of polylactic acid does not become extremely large, so that the structure in which all the epoxy groups react with polylactic acid is difficult to form, and unreacted in the polylactic acid short fiber. It becomes easy to have a structure in which an epoxy group remains.

  The trifunctional or higher functional epoxy compound used in the present invention is more preferably a compound having at least one glycidyloxycarbonyl group or N- (glycidyl) amide group in one molecule.

  The epoxy compound is a compound in which the reaction active terminal of the polylactic acid polymer and the oligomer contained therein is blocked with an epoxy compound, thereby inactivating the reaction active terminal in the polymer and suppressing hydrolysis of polylactic acid. The reaction active terminal has a hydroxyl group and a carboxyl group, but the epoxy compound is excellent in the blocking property of the carboxyl group. The addition amount of the epoxy compound is determined with respect to the carboxyl end amount. Furthermore, since residual oligomers such as lactide also generate a carboxyl end by hydrolysis, it is preferable to make it not more than twice the total carboxyl end amount of not only the carboxyl end of the polymer but also those derived from the remaining oligomer or monomer. . It is preferable that the total carboxyl terminal concentration is 10 equivalents / t or less with respect to the whole polylactic acid because the hydrolysis resistance can be remarkably improved.

  The content of polylactic acid is preferably 50% by mass or more, further 80% by mass or more, and further 90% by mass or more with respect to the entire net.

  Moreover, you may blend an inorganic substance, such as an ultraviolet-resistant improver and titanium, with a thermoplastic resin.

  The fineness of the monofilament used in the net of the present invention is preferably 200 to 800 dTex (decitex). When a monofilament having a fineness of less than 200 dTex is used, the number of nets increases, which increases the cost and is not suitable. In addition, when a monofilament having a fineness exceeding 800 dTex is used, the net becomes hard, and it is difficult to wind and transport the net in a roll shape. The fineness of the monofilament is more preferably 300 to 600 dTex.

  The strength of the monofilament used in the net of the present invention is preferably 2.5 to 5.5 cN / dTex (centinewton / dtex).

  The net of the present invention needs to receive wind resistance by setting up the net when part of it is buried in sand. Therefore, since the net needs a certain hardness, the net is preferably made of a woven fabric. As the configuration of the woven fabric, plain weave, twill weave, satin weave, or the like can be used, but the plain weave is preferable because it can be a fabric having higher hardness.

  In order to stand a net composed of monofilaments, moderate hardness is required, and the bending resistance according to the bending repulsion A method (Gurley method) described in JIS L1096 is preferably 20 to 150 mN. Within the above range, when a part of the net is buried in the sand, the remaining part of the net coming out of the sand surface becomes independent without being tilted. A more preferable range of the bending resistance by the Gurley method is 40 to 100 mN.

  In addition, when a net composed of monofilaments is erected and refilled, the wind speed can be reduced moderately when the wind passes through the net stitches, and sand contained in the wind is accumulated between the nets to collect and sand. The movement of can be suppressed more. Therefore, the mesh of the present invention is preferably 0.5 to 4 mm square because an appropriate pressure loss can be obtained. Here, the mesh means a square. The mesh of the net is more preferably 1 to 3 mm square.

  In addition, the pressure loss for reducing the wind speed is obtained by measuring the differential pressure of the net at a wind speed of 5 m / min and setting it as the pressure loss. The pressure loss of the net composed of the monofilament containing polylactic acid of the present invention is A range of 50 to 300 Pa is preferable. If the pressure loss is small, the wind speed does not drop when passing through the net, so the sand movement prevention is weak. On the other hand, if the pressure loss is large, the wind resistance is large and the net is overturned or blown by the wind. The movement prevention effect becomes unstable. The pressure loss of the net is more preferably 70 to 200 Pa.

  As a factor of the anti-UV deterioration characteristic of the net composed of monofilament, when the deterioration test by the sunshine weather meter test based on JIS B 7753 (2007) is performed, the breaking strength retention after 450 hours is 70% or more. It is preferable. If the bursting strength in the test is 70% or more, the form can be maintained for 3 years or more even in the intense ultraviolet rays of the desert. The burst strength is more preferably 80% or more.

EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these Examples.
Note that the parameters appearing in the above description are values measured as follows.

A. Weight average molecular weight of polylactic acid Polylactic acid net was dissolved in a chloroform solution to obtain a measurement solution. This was measured by gel permeation chromatography (GPC) (solvent: chloroform), and the weight average molecular weight was determined in terms of polystyrene.

B. Tensile strength, tensile elongation Measured according to JIS L 1013: 1999 8.5.1.
With the sample loosely tensioned, it was attached to the grip of a tensile tester (Orientec “Tensilon” (registered trademark) UCT-100) with a grip interval of 20 cm, and the test was performed at a constant speed extension of 20 cm / min. It was. Read the elongation when the initial load is applied as looseness (mm), pull the sample further, measure the load and elongation (mm) when the sample is cut, and use the following formula to determine the tensile strength (tensile strength) and elongation The rate (tensile elongation) was calculated. The number of tests was 10, and the average value was calculated.
Tb = SD / F0
Here, Tb: tensile strength, SD: strength at the time of cutting, and F0: positive fineness of the sample.
Elongation rate (%) = [(E2-E1) / (L + E1)] × 100
Here, E1: Looseness (mm), E2: Elongation at the time of cutting (mm), and L: Grazing interval (mm).

C. The surface of the net stitch was observed with a magnifying glass, and the average was obtained with n = 10.

D. Pressure loss Using a measuring machine of type 3 described in JIS B9908, the differential pressure measured by installing two nets on the net installation part so as not to leak air is measured.
The measurement area is 176.7 cm ² (150 mmφ).

E. Bending softness A value obtained by a bending repulsion A method (Gurley method) described in JIS L1096.

F. Ultraviolet light deterioration test According to the method of JIS B 7753, using a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.) under the conditions of one cycle of irradiation 180 min / rainfall 12 min, black panel temperature 63 ° C., humidity 50% Rh Irradiation for 450 hours was carried out. Tensile strength was measured before and after irradiation to determine the retention rate (%) of breaking strength. The average value was obtained by setting n number to 5.

G. Workability When constructing sand movement prevention materials in the desert, the work amount per person (10 minutes) was evaluated in the following three stages.
A: The construction area per person is 7 m ² or more, and the workability is very excellent.
A: The work area per person is 5 m ² or more, and the workability is excellent.
X: The work area per person is less than 5 m ² and the workability is inferior.

H. Sand movement prevention effect Sand movement prevention materials were installed in the desert and the sand movement situation one year later was summarized and evaluated in the following four stages.
A: Sand movement prevention material is not buried in sand, and the sand movement prevention effect is very high.
◯: Part of the sand movement prevention material is buried in the sand, but the sand movement prevention effect is high.
(Triangle | delta): Although part of sand movement prevention material is buried in sand or the sand surface of the center part in a square becomes concave, the sand movement prevention effect is a little inferior.
×: No sand movement prevention effect.

[Production of polylactic acid]
(A) Production Example 1 (Production of polylactic acid)
Polymerization of lactide produced from L-lactic acid with an optical purity of 99.5% in the presence of bis (2-ethylhexanoate) tin catalyst (lactide to catalyst molar ratio = 10000: 1) at 180 ° C. for 160 minutes in a nitrogen atmosphere To obtain a polylactic acid resin P1. The resulting polylactic acid had a weight average molecular weight of 180,000.

(B) Production Example 2 (Production of polylactic acid)
Polymerization of lactide produced from L-lactic acid with an optical purity of 99.5% in the presence of bis (2-ethylhexanoate) tin catalyst (lactide to catalyst molar ratio = 10000: 1) at 180 ° C. for 140 minutes in a nitrogen atmosphere To obtain a polylactic acid resin P2. The resulting polylactic acid had a weight average molecular weight of 145,000.

[Example 1]
The polylactic acid resin P1 obtained in Production Example 1 was melt-spun and stretched to obtain a 420 dTex monofilament. The obtained polylactic acid monofilament had a strength of 3.5 cN / dTex and an elongation of 35%.
A net was prepared with a rapier loom so that the obtained monofilament had a width of 2 m, a length of 400 m, and a mesh of 1 mm × 1 mm. Then, it melt-cut with a melting iron to a width of 0.5 m to create a net as a sand movement prevention material. The net pressure loss was 186 Pa, the bending resistance was 84 mN, and the strength retention in the UV degradation test was 85%.
The obtained net is buried in 100 m ² of almost flat sand ground so that the center of the net is buried so as to be perpendicular to the strongest wind direction, and the height of the net is set to 5 to 15 cm from the sand ground and installed at intervals of 1 m. did. Workability at the time of installation of in workers four people, very good and 18.0m ^2/10 minutes, was the evaluation of the "◎".
Although the state after one year was confirmed, the sand movement preventing material was not buried in the sand, and a high sand movement preventing effect was obtained.

[Example 2]
Using the same net as in Example 1, a part of the net is buried in a substantially flat sand ground 100 m ² as shown in FIG. 2 so that the height of the net is 10 to 20 cm from the sand ground and intersects perpendicularly. Were installed in a grid with a pitch of 1 m. Workability at the time of installation of in workers four people, very good and 9.5m ^2/10 minutes, was the evaluation of the "◎".
Although the state after one year was confirmed, the sand movement preventing material was not buried in the sand, and a very high sand movement preventing effect was obtained.

Example 3
A net was obtained in the same manner as in Example 1 except that the mesh was 2 mm × 2 mm. The pressure loss of the net was 80 Pa, the bending resistance was 40 mN, and the strength retention in the ultraviolet deterioration test was 83%.
The obtained net | network was installed in the grid | lattice form of a 1-m space | interval so that it may cross | intersect orthogonally to 100 m ² of the substantially flat sand ground of a dune. Workability at the time of installation of in workers four people, 8.0m very good and the ^2/10 minutes, was the evaluation of the "◎".
Although the state after one year was confirmed, a phenomenon in which some sand movement prevention materials were buried in the sand was observed, but a high sand movement prevention effect was obtained, and the evaluation was “◯”.

Example 4
The polylactic acid resin P2 obtained in Production Example 2 was melt-spun at a spinning speed of 4000 m / min to obtain 106 dTex, 26-filament semi-drawn yarn. Two of these were stretched and false twisted to obtain a 1 heater false twisted yarn of 167 dTex, 52 filaments. A cylindrical knitted fabric was prepared using this with a kettle diameter of 3.5 inches and a 22 gauge circular knitting machine.
The sand dunes are arranged in a grid of 1m intervals so that the nets intersected perpendicularly to the windy direction, and the sand stuffed cylindrical tubular fabric intersected perpendicularly to the windy direction. It was installed on 100 m ² of almost flat sand. Workability at the time of installation of in workers four people, 5.0m ^2/10 minutes, was the evaluation of the "〇".
One year later, the cylindrical knitted fabric was partially buried in sand and the inside of the lattice was slightly concave, but a high sand movement preventing effect was obtained, and the evaluation was “◎”.

Example 5
A net was obtained in the same manner as in Example 1 except that the mesh was 3 mm × 3 mm. The net pressure loss was 52 Pa, and the bending resistance was 22 mN.
The obtained net | network was installed in the grid | lattice form of a 1-m space | interval so that it may cross | intersect orthogonally to 100 m ² of the substantially flat sand ground of a dune. Workability at the time of installation, since the stiffness of the net is low, but Standing how the net was bad also push the net with a shovel, workability 5.8m ^2/10 min, a rating of "〇" It was.
The state after one year was confirmed, but some net materials were buried with soil, and the sand movement prevention effect was “◯”.

Example 6
The net was installed in the same manner as in Example 2, but before embedding part of the net in the soil, the net was spread to a predetermined length, and seeds of sheep were planted in the center of the upper surface of the net. The center part was pushed into the ground, and the seeds were buried in the soil as shown in FIG.
Workability at the time of installation of in workers four people, very good and 8.8m ^2/10 minutes, was the evaluation of the "◎".
The state after one year was confirmed, but the sand movement prevention material was not buried in the sand, and sheep shiba germinated from between the V-shaped nets, and a very high sand movement prevention effect was obtained. ◎ ”and a greening effect was also obtained.

Example 7
A net was installed in the same manner as in Example 2, and seeds of pear were planted on the sand in a grid with a pitch of 1 m.
The state after one year was confirmed, but the sand movement prevention material was not buried in the sand, and the pear was germinated from inside the lattice, and a very high sand movement prevention effect was obtained. It was also possible to obtain a greening effect.

Example 8
A 420 dTex monofilament made of polyethylene terephthalate was obtained. The obtained monofilament had a strength of 4.7 cN / dTex and an elongation of 40%.
A net was prepared with a rapier loom so that the obtained monofilament had a width of 2 m, a length of 400 m, and a mesh of 1 mm × 1 mm. Then, it melt-cut with a melting iron to a width of 0.5 m to create a net as a sand movement prevention material. The net pressure loss was 173 Pa, the bending resistance was 78 mN, and the strength retention in the ultraviolet deterioration test was 70%.
The obtained net is buried in 100 m ² of almost flat sand ground so that the center of the net is buried so as to be perpendicular to the strongest wind direction, and the height of the net is set to 5 to 15 cm from the sand ground and installed at intervals of 1 m. did. Workability at the time of installation of in workers four people, very good and 18.0m ^2/10 minutes, was the evaluation of the "◎".
Although the state after one year was confirmed, the sand movement preventing material was not buried in the sand, and a high sand movement preventing effect was obtained.

[Comparative Example 1]
Using only the material in which the cylindrical knitted fabric made of polylactic acid used in Example 4 was filled with sand, it was installed in a grid shape with a pitch of 1 m so as to intersect perpendicularly to a substantially flat sand ground 100 m ² . Workability at the time of installation of in workers four people, inferior in workability and 5.0m ^2/10 minutes, was the result of "×".
Although the state after one year was confirmed, a part of the sand was buried in the sand or the sand surface at the center of the square was concave, but the effect of preventing sand movement was inferior, resulting in a “△” result.

[Comparative Example 2]
A commercially available long-fiber non-woven fabric (100 g / m ² basis weight) composed of polyethylene terephthalate multifilaments was cut to a width of 50 cm and wound up to a length of 400 m. The pressure loss of the long-fiber nonwoven fabric was 452 Pa, the bending resistance was 0.81 mN, and the strength retention in the ultraviolet deterioration test was 70%.
The long fiber nonwoven fabric is buried in 100 m ² of almost flat sand ground so that the vicinity of the center of the long fiber nonwoven fabric is buried so as to be perpendicular to the strongest wind direction, and the height of the net is 5-15 cm from the sand ground. installed. Workability at the time of installation of in workers four people, very good and 18.0m ^2/10 minutes, was the evaluation of the "◎".
Although the state after one year was confirmed, the long-fiber nonwoven fabric was broken by the wind or a part was blown by the wind, and the sand movement preventing effect was not obtained, and the evaluation was “x”.

  Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on Sep. 10, 2012 (Japanese Patent Application No. 2012-198111), the contents of which are incorporated herein by reference.

1: Net 1a: Bending part 2: Plant seed 3: Sand (ground)

Claims (10)

  A net made of monofilament is used as a sand movement prevention material, and the net is installed in a state where a part of the net is buried in the sand and the other part of the net stands on the sand. A method for preventing sand movement.   2. The sand movement preventing method according to claim 1, wherein at least one bent portion is formed by bending an intermediate portion of the net with a sand ground side as a mountain, and the bent portion is buried in sand.   The sand movement prevention method according to claim 1 or 2, wherein the height of the other part of the net is 5 to 30 cm from the sand surface.   The sand movement prevention method according to any one of claims 1 to 3, wherein the bending resistance of the net according to the Gurley method is 20 to 150 mN.   The sand movement prevention method according to any one of claims 1 to 4, wherein a pressure loss of the net at a wind speed of 5 m / min is 50 to 300 Pa.   6. The sand movement prevention according to claim 1, wherein the fineness of the monofilament is 300 to 600 dTex (decitex), and the mesh of the net is 0.5 to 5 mm. Method.   The said monofilament contains polylactic acid, The sand movement prevention method as described in any one of Claims 1-6 characterized by the above-mentioned.   The sand movement prevention method according to any one of claims 1 to 7, wherein a plurality of the nets are installed on the sandy ground so as to cross each other in the vertical direction and the horizontal direction when viewed from above. .   On the sandy ground, a plurality of the nets are installed in the vertical direction or the horizontal direction when viewed from above, and a sand movement prevention material other than the net is installed in the horizontal direction when the net is installed in the vertical direction, or The sand movement preventing method according to any one of claims 1 to 7, wherein when the net is installed in the horizontal direction, the net is installed so as to intersect in the vertical direction.   The plant seeds are buried in the sand in the vicinity of the net before or after the part of the net is buried in the sand. The method for preventing sand movement according to any one of claims 9 to 10.

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