JPH0686442U - Pressing pile for mulching material - Google Patents

Abstract

(57) [Summary] [Purpose] To make the mulching material using a burlap sheet biodegrade in time with the biodegradation. [Structure] A mulching material press pile 2 applied to a biodegradable mulching material 1, which is integrally provided at a pile body 3a having a sharp tip and a base end portion of the pile body 3a. The pile body 3a has a head portion 4b larger than the cross-sectional shape of the pile body 3a. The pile body 3a and the head portion 4b are both made of biodegradable thermoplastic plastic. This thermoplastic may be poly-ε-caprolactone, polyethylene succinate or poly-β.
Aliphatic polyesters such as hydroxyalkanoates have been used.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a retaining pile for a mulching material that is friendly to the global environment.

[0002]

[Prior art]

 When planting plants such as trees and flowers, the mulching method is often adopted. In a broad sense, the mulching method is a general term for a cultivation method that has been performed since ancient times, in which the root wrinkles of cultivated plants are covered with straw, grass, etc. In addition, the mulching method is an extremely excellent cultivation method because the soil is modified by the corrosion and decomposition.

In recent years, colored synthetic resin films have come to be used as covering materials (mulching materials), and the use of such films promotes an increase in soil temperature and suppresses the generation of weeds. However, when synthetic resin films are used as mulching materials, they do not corrode at all and therefore cannot be expected to function as compost. There are many problems such as the need to separately consider the treatment of mulching materials.

For this reason, mulching materials that have recently been mass-produced using natural materials are in the limelight (for example, the product name “Greening Mat” manufactured by Koizumi Seima Co., Ltd. is jute fiber 100). % Is a mulching mat made from natural thread material). Such marching mats are completely decomposed by microorganisms in the soil and returned to the soil one to two years after being laid at a predetermined place, so that the soil is similar to the mulching materials such as straw and grass that have been used since ancient times. It can also contribute to the reforming of slag and is expected to spread in the future.

After such a mulching material is laid in a predetermined place, it is usually pressed by a pressing pile so as not to be scattered by wind or the like. In the past, this retaining pile used wood chips, bamboo chips, or metal fittings that had its tip sharpened at home, but because of its productivity and retaining effect, it is made of mass-produced and commercially available plastic. It is common to purchase and use retaining piles. As such a plastic retaining pile, for example, one disclosed in Japanese Patent Publication No. 55-15727 is known.

[0006]

[Problems to be solved by the device]

 By the way, when the above plastic retaining piles are used, even if one or two years have passed and the burlap mulching material is completely corroded, only the above retaining piles remain without corrosion. It has become. Therefore, there is a problem that environmental protection cannot be achieved unless the remaining retaining pile is removed and a predetermined treatment is performed separately.

[0007] Therefore, in recent years, a material that can be completely decomposed by microorganisms when it is buried in soil for a long period of time, that is, a pile made of a biodegradable material has attracted attention. ing. As a pressing pile using such a biodegradable material, for example, the one disclosed in JP-A-4-66030 can be mentioned. In the pile disclosed in this publication, a composition comprising at least one base material selected from soil, carbon and ceramics and at least one binder selected from proteins and polysaccharides is pressure-molded under heating. Since the above proteins and polysaccharides are inherently biodegradable in the soil, the piles will collapse and return to the original soil after being buried in the soil for a long time.

However, in the pressing pile disclosed in Japanese Patent Laid-Open No. 4-66030, first, the base material such as soil, carbon, or ceramic is crushed to a predetermined particle size, and then the protein or polysaccharide is crushed. It is necessary to mix the following binders, knead and knead these mixtures, press-mold using a predetermined mold, and then heat them. Since it has to go through many processes, it has a disadvantage that the manufacturing is troublesome and the process cost is high.

Further, the obtained retaining pile is not necessarily strong in terms of strength because it is formed in a state where the particulate base materials are bonded to each other by utilizing the thermosetting property of protein or polysaccharide. Instead, it has the drawback that it is often damaged when hit with a hammer or the like to hold it down. Further, since the protein or polysaccharide is a thermosetting substance, it cannot be manufactured by an injection molding method suitable for mass production by heating and melting, and there is a problem that the manufacturing cost increases.

Furthermore, the decomposition rate of proteins and polysaccharides is extremely high, and biodegradation occurs in about two months. Therefore, when jute is used as a mulching material, the mulching material is biodegraded. Compared with the required one to three years, the biodegradation period of piles is too short and there is the inconvenience of being unbalanced. As a result, a new retaining pile must be driven into the mulching material once every two months. After all, such a pile is not very convenient as a retaining pile for mulching materials.

The present invention has been made to solve the above problems, and when a burlap sheet is used as the mulching material, the raw material and the pace of the mulching material are measured. The purpose is to provide a retaining pile for mulching material that biodegrades together.

[0012]

[Means for Solving the Problems]

 The pressing pile for mulching material according to claim 1 of the present invention is a pressing pile for mulching material which is applied to marching material having biodegradability, and a pile body having a sharp tip and It is composed of a head that is larger than the cross-sectional shape of the pile body that is integrally provided at the base end of the pile body, and that both the pile body and the head are formed of a biodegradable thermoplastic plastic. It is characterized by being present.

The pressing pile for mulching material according to claim 2 of the present invention is the pressing pile for mulching material according to claim 1, wherein the thermoplastic plastic having biodegradability is an aliphatic polyester. It is characterized by being.

The pressing pile for mulching material according to claim 3 of the present invention is the pressing pile for mulching material according to claim 2, wherein the aliphatic polyester is poly-ε-caprolactone or polyethylene succinate. And poly-β-hydroxyalkanoate, or a copolymer thereof.

[0015]

[Action]

 According to the pressing pile for mulching material according to claim 1, the pressing pile has a cross-sectional shape of a pile main body having a pointed tip and a pile main body integrally provided at the base end of the pile main body. Since it is composed of a larger head, by driving the pile main body of the retaining pile into the mulching material that has been laid, the head plays a role of preventing the mulching material from falling, and the mulching material is also protected by strong wind. There is no such thing.

Further, since both the pile body and the head are made of biodegradable thermoplastic, they are corroded and decomposed by the action of microorganisms when they are continuously buried in the soil, and as a result, they are separated. There is no need to pull out the stake. Further, like ordinary thermoplastics, mass production can be easily performed by a manufacturing method such as injection molding, which contributes to reduction in manufacturing cost due to mass production.

In the pressing pile for mulching material according to claim 2, the biodegradable thermoplastic plastic is aliphatic polyester, and the pressing pile for mulching material according to claim 3 is The aliphatic polyester is in particular any one of poly-ε-caprolactone, polyethylene succinate and poly-β-hydroxyalkanoates or their copolymers. All of these are decomposed by microbes within a year or two, so they are biodegraded in tune with the mulching material that uses jute as the raw material, and disappear at almost the same time, leaving one of them inconvenient. It can be avoided.

[0018]

【Example】

 FIG. 1 is a perspective view illustrating a state in which a pressing pile for a mulching material according to the present invention is applied. As shown in this figure, the retaining pile 2 according to the present invention is applied to a mulching material 1 having biodegradability. The mulching material 1 is a covering material used in a so-called covering cultivation method of covering and cultivating the periphery of a plant being planted, and a thin sheet made of synthetic resin is usually used, but in the present invention, In consideration of environmental protection, a mulching material 1 having biodegradability is used.

Biodegradability refers to the property of being completely decomposed by the action of microorganisms when the substance itself is buried in soil. Since this decomposition causes composting, the biodegradable mulching material 1 is extremely convenient for plant growth. In this example, as the mulching material 1, 100% jute fibers were used, and a 10 mm thick mulching mat obtained by compression molding short fibers (trade name “green mat, manufactured by Koizumi Seima Co., Ltd.” )) Has been applied. Since burlap fibers are unquestionably natural products, they are inherently biodegradable.

In the example shown in FIG. 1, the mulching material 1 is formed in a circular shape having a diameter of 1 m to 2 m, and a cut 11 is cut from the circumferential portion toward the central portion, and at the central portion, Has a through hole 12 formed by making a cut with a cross. Such a mulching material 1 is attached to the tree W through the spread cut 11 and positioned so that the trunk enters the through hole 12.

After the soil around the tree W is covered with the mulching material 1 in this way, a plurality of the pressing piles 2 according to the present invention are inserted into the soil while penetrating the peripheral portion of the mulching material 1. It is embedded. Since the mulching material 1 is reliably fixed on the soil by burying the pressing piles 2 as described above, it does not turn even if it is fanned by strong wind.

As shown in FIG. 2 showing the first example, the pressing pile 2 according to the present invention has a pile body 3 having a sharp tip embedded in soil, and a base body of the pile body 3. It is composed of a head 4 that is larger than the cross-sectional shape of the pile body 3 that is integrally provided at the end.

What kind of material the push-pile 2 is made of is an extremely important issue to be solved in order to protect the environment, and in the present invention, the push-pile 2 is used. Both the pile body 3 and the head 4 are made of biodegradable thermoplastic.

Here, the outline of the biodegradable plastic will be briefly described. First of all, degradable plastics are generally said to be "plastics that decompose under natural conditions without harming the natural environment," although a strict definition has not yet been established. There is. The degradable plastics are further classified into photodegradable plastics that are decomposed by ultraviolet rays and biodegradable plastics, which is the problem here.

As described above, the biodegradable plastic is defined as “a plastic that is completely reduced to the natural world by the involvement of microorganisms in the process of decomposition”. . Briefly explaining the mechanism of biodegradation, the primary decomposition process in which plastic is first decomposed by a degrading enzyme secreted by microorganisms and then decomposed, and biopolymers are made from substances decomposed by the metabolic action of microorganisms and carbon dioxide, methane , The complete decomposition process of producing water, etc. progresses in time series, and the biodegradable plastic is naturally reduced.

A plastic that can progress to the complete decomposition process is called a complete decomposition type plastic, and a plastic that only advances to the primary decomposition process is called a biodegradable plastic. The latter bio-degradable type is like a fully degradable plastic blended with a normal degradable plastic such as polyethylene or polypropylene, in which the fully degradable plastic is completely and naturally reduced. Therefore, it is said that ordinary plastics become powdery decay products, and these decay products remain without being decomposed, so that secondary pollution eventually occurs and the problem cannot be solved. Therefore, when it comes to biodegradable plastics, the theory is that it does not include biodegradable plastics, but refers only to fully degradable plastics.

Therefore, in the present invention, the above-mentioned completely decomposable plastic that is completely reduced to the natural world is applied to the retaining pile 2. By doing so, the retaining pile 2 driven into the soil is completely decomposed by the action of microorganisms with the passage of time, which is convenient for environmental protection.

By the way, examples of biodegradable completely decomposable plastics include those obtained from starch, cellulose, chitin, chitosan, etc., which are natural high molecules, as well as polyhydroxybutyrate, polyhydroxyvalerate, etc. Examples thereof include biopolymers that are fermented synthetic resins by microorganisms and synthetic polymer resins such as aliphatic polyesters represented by polycaprolactone and polyvinyl alcohol.

Of these biodegradable, completely degradable plastics, there is considerable strength, that they can be melt extruded and can be commercialized by injection molding, that is, they have thermoplasticity. Taking this into consideration, the aliphatic polyester is selected for the retaining pile for the mulching material of the present invention.

Among such aliphatic polyesters, poly-ε-caprolactone, polyethylene succinate or poly-β-hydroxyalkanoate is preferable. This is because these aliphatic polyesters sufficiently satisfy the above-mentioned conditions of high strength and thermoplasticity, and require a longer period of time for biodegradation than other fully degradable plastics. This is because it is as long as 1 to 2 years, and it is possible to keep pace with the biodegradation of mulching material 1 made of jute.

Incidentally, in this example, a biodegradable plastic mainly composed of poly-ε-caprolactone manufactured by Unitika Ltd. is used.

Regarding the biodegradation rate, a copolymerized product of the above poly-ε-caprolactone, polyethylene succinate and poly-β-hydroxyalkanoate, or a copolymer of these with the above polyhydroxybutyrate or polyhydroxyvalerate It is possible to easily determine the product as a function of the mixing ratio by varying the composition ratio of the product and testing the biodegradation rate of each of the obtained copolymer products. Once the above function is obtained, it becomes possible to design the resin of the retaining pile 2 according to the biodegradation speed of various mulching materials 1.

As described above with reference to FIG. 2, the above-mentioned retaining pile is basically composed of the pile body 3 embedded in the soil and the head 4 for preventing the mulching material 1 from coming off. If necessary, the minimum required configuration will be established, but various variations are possible for easier burying operation of the pile body and for more stable burying. Hereinafter, various variations of the shape and structure of the retaining pile 2 according to the present invention will be described with reference to FIGS.

FIG. 3 is a perspective view showing a pressing pile 2a of the second example. As shown in this figure, in the pressing pile 2a of the second example, the head 4a thereof is formed in a cross shape in plan view. With such a shape of the head portion 4a, the pressing pile 2a can be grasped with the fingers in the shape of the cross from above, and as a result, it is possible to use a striking jig such as a hammer. By rotating the push-down pile 2a forward and backward around the pile body 3, it can be easily buried in the soil, which is convenient. In FIG. 3, the shape of the head 4a is a dozen, but the shape is not limited to the cross shape, and may be a star shape or a polygon shape.

FIG. 4 is a perspective view showing a pressing pile 2b of a third example. In the pressing pile 2b of this example, the head portion 4b is formed in an elliptical shape, and a grip portion 41 formed by standing a flat plate in the longitudinal direction is provided above the head portion 4b. The pile body 3a is composed of an inverted triangular first flat plate pile 31 and an inverted triangular second flat plate pile 32 provided so as to intersect with the first flat plate pile 31. An inverted quadrangular pyramid retaining piece 33 is fixedly provided at the intersection of the first flat plate pile 31 and the second flat plate pile 32.

Since the pressing pile 2b of the third example is configured as described above, by grasping the grasping portion 41 by hand and swinging the head portion 4b on the horizontal plane, a hammer is eliminated. Also, the retaining pile 2b can be easily buried in the soil.

Further, since the pile main body 3a is provided with a retaining piece 33 of an inverted quadrangular pyramid, once the pile body 3a is embedded in the soil, the retaining piece 33 causes the pile main body 3a to move upward. It is possible to effectively prevent the person from rising.

FIG. 5 is a perspective view showing a pressing pile 2c of a fourth example. In the case of the retaining pile 2c of this example, the head 4c is set in a circular shape. Then, a grip portion 41 similar to that of the third example is provided on the upper portion of the head portion 4c so as to project. The pile body 3b has a spiral structure including a core shaft 34 and a spiral portion 35 formed around the core shaft 34. Therefore, the pile main body 3b can be embedded in the soil very easily by tightening the screw by gripping the grip portion 41 by hand and rotating the grip portion 41 around the core shaft 34 in only one direction.

The combination of the pile main bodies 3, 3a, 3b and the heads 4, 4a, 4b, 4c in the above first to fourth examples is arbitrary, and the head 4 is attached to the pile main body 3b. a may be adopted, or the head 4 may be applied to the pile body 3a.

As described in detail above, the retaining piles 2, 2a, 2b, and 2c of the present invention use the completely degradable biodegradable plastic as the material thereof, and therefore, are embedded in the soil. After a certain period of time in the stored state, it is completely decomposed by the action of microorganisms and returned to the natural world without harming the natural environment.

Further, by devising various shapes of the pressing piles 2, 2a, 2b, 2c as described above, the burying operation can be easily performed, and once burying, the staking does not easily come out. As a result, the mulching material 1 can be more stably pressed.

[0042]

[Effect of device]

 As described above, the mulching material retaining pile of the present invention is a mulching material retaining pile applied to biodegradable mulching material, which has a pointed tip body and the pile body. It is composed of a head that is larger than the cross-sectional shape of the pile main body integrally provided at the base end of the main body, and both the pile main body and the head are made of biodegradable thermoplastic plastic. Is.

Therefore, when the retaining pile is buried in the soil for a long period of time, it is decomposed by the action of microorganisms to be decomposed by corrosion, and it is not necessary to pull out the pile after use, which is convenient for simplifying the mulching work.

Further, similar to ordinary thermoplastics, mass production can be easily performed by a manufacturing method such as injection molding and, as a result, mass production can contribute to a reduction in manufacturing cost, which is a great effect in terms of production. .

If an aliphatic polyester such as poly-ε-caprolactone, polyethylene succinate, and poly-β-hydroxyalkanoate is used as the above-mentioned biodegradable thermoplastic plastic, all of these can be used for 1 to 2 years. Since it is biodegraded by microorganisms in a year, it is decomposed in tandem with the mulching material that uses jute as its raw material, and disappears at about the same time, and it is necessary to remove the other separately because one remains. This is convenient because it is possible to avoid inconveniences such as occurrence.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a state in which a pressing pile for a mulching material according to the present invention is applied.

FIG. 2 is a perspective view showing a pressing pile of the first example.

FIG. 3 is a perspective view showing a second embodiment of a retaining pile.

FIG. 4 is a perspective view showing a pressing pile of a third example.

FIG. 5 is a perspective view showing a pressing pile of a fourth example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mulching material 11 Cut 12 Through hole 2, 2a, 2b, 2c Pushing pile 3, 3a, 3b Pile body 31 First flat plate pile 32 Second flat plate pile 33 Retaining piece 34 Core shaft 35 Spiral part 4, 4a, 4b 4c head 41 gripping part W tree

Claims (3)

[Scope of utility model registration request] 1. A push-down pile for a mulching material applied to a biodegradable mulching material, the pile main body having a pointed tip, and a pile integrally provided at a base end portion of the pile main body. A retaining pile for a mulching material, comprising a head having a larger cross-sectional shape than the main body, and the pile main body and the head are both made of a biodegradable thermoplastic. 2. The retaining pile for a mulching material according to claim 1, wherein the biodegradable thermoplastic is an aliphatic polyester. 3. The aliphatic polyester is poly-ε-caprolactone, polyethylene succinate and poly-.
The retaining pile for a mulching material according to claim 2, which is one of β-hydroxyalkanoates or a copolymer thereof.