JPH08187035A - Mulching mat - Google Patents

Abstract

PURPOSE: To obtain a mulching mat which can cover crop plants around their roots to maintain the air permeation, moisture permeation, light screening and heat retaining at suitable levels, respectively by admixing a thermoplastic resin to woody fibers, melting the resin and forming a mat of a prescribed bulk density. CONSTITUTION: Woody fibers are mixed with natural fibers such as linen at a specific ratio and the mixture is used as a main material. This main material is mixed with a thermoplastic resin such as polyester, which is biodegradable and melts at 100-150' deg.C, then the resin is molten to give this mulching mat having a bulk density of 0.07-0.12g/cm<3> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mat for mulching which is preferably used for growing seedlings of fruit trees and vegetation and preventing weeds in the fields of horticulture and civil engineering in a broad sense.

[0002]

2. Description of the Related Art Conventionally, in order to adjust the growth of crops such as horticultural crops and vegetables and to increase the sweetness of fruits, for example, straws such as rice straw and wheat straw are spread near the base of the crops as straws. The method of laying and adjusting the temperature and humidity around it has been implemented. This straw has a light-shielding effect (shade effect) and appropriate breathability, so even when it is hot in summer and direct sunlight is strong, heat dissipation due to evaporation of water is moderately promoted, and the ground temperature is always below open field. To hold.

[0003]

However, from the viewpoint of preventing weeds, the seeds of the weeds easily penetrate through the gaps between the straws and the roots of the weeds cannot be prevented. There was a problem that it might become a hotbed. Further, in recent years, it has become difficult to obtain straw, and it takes time and labor to lay the straw, resulting in poor workability.

[0004] On the other hand, mulching mats made of plastic sheets are also used, but the plastic film has poor air permeability, so heat dissipation is poor, and the ground temperature becomes too high in the summer to hinder the growth of seedlings. Further, since it is poor in water permeability, root submergence work such as providing a groove at the base is required to replenish the seedlings with water, which is troublesome. Furthermore, since it is durable and resistant to corrosion, there is a problem that soil will be contaminated if it is left as it is after use. Especially, in recent years, regulations on abandonment of plastic materials have become strict, so the end of the growing season of crops Have been collected. However, this recovery work requires a great deal of labor, and even if the recovered material is incinerated, there are pollution and other problems.

From the above, it is excellent in handling workability as a mat for mulching, and further achieves the original purpose of mulching during the growing period of crops, fulfills the mulching function, and then remains in the soil even if left unattended. As a mulching mat having a property of being naturally decomposed by the action, a mulching mat in which natural plant fibers such as hemp are woven with a needle punch has been developed. However, the mat for mulching has a fast microbial degradability of half a year to one year, and the mulching effect for the period of 3 years or longer required for fruit trees and vegetation trees cannot be expected.
In addition, hemp itself is a valuable resource, so it is expensive, and as for the weed-preventing effect, weeds with rough needles have the problem that weeds grow in a short time and the effect is small.

In view of the above problems, the present invention is easy to obtain raw materials, is excellent in workability at the time of arranging the raw materials at the root of a crop, and has a mulching period required depending on the kind of each crop. The present invention also provides a mulching mat having a weed-preventing effect that is retained and does not cause any trouble in disposal after use.

[0007]

Means for Solving the Problems That is, the mat for mulching according to the present invention has a wood fiber as a main raw material, and a thermoplastic resin is added to and mixed with the main raw material, and the thermoplastic resin is melted to obtain a bulk density. Is formed in a mat shape of 0.07 to 0.12 g / cm ³ .

Further, a mixture of wood fibers and natural fibers in a predetermined ratio is used as a main raw material, and a thermoplastic resin is added to and mixed with the main raw material, and the thermoplastic resin is melted to obtain a bulk density of 0. It is formed by being formed in a mat shape of 07 to 0.12 g / cm ³ .

The thermoplastic resin is biodegradable.

Here, as the wood fiber, a scrap material generated when lumbering lumber, a dismantled material generated when a building is dismantled, etc. are made into chips and further defibrated by a defibrator or the like to form a fiber. It can be used. Since this wood fiber is a natural polymer, it is finally decomposed by microorganisms while maintaining durability against microorganisms for a relatively long period of time.

The thermoplastic resin may be any resin as long as it is harmless to food hygiene, such as polyester, and its property may be fibrous, powdery or liquid. In addition to improving the air permeability of the mulching mat, the addition amount is small, so that it is fibrous (especially, the diameter is 2 to 10 denier and the length is 5 to 20 mm.
Fiber) is preferred. The addition amount of the thermoplastic resin is preferably 5 to 20 parts by weight from the viewpoint of strength and price, and the melting condition of the thermoplastic resin is 10 at 100 to 150 ° C.
Heating and melting for about 60 seconds is suitable.

As the natural fiber mixed with the wood fiber, hemp or the like can be used.

The bulk density of the mat for mulching is 0.
If it is less than 07 g / cm ³ , the breathability and water permeability are good, but the light-shielding properties are poor, and the mats for mulching are not strong enough to be handled, and the buds of germinated weeds are mats for mulching. It will break through and grow up. On the contrary, the bulk density of the mat for mulching is 0.12.
When it is larger than g / cm ³ , the light-shielding property and the handling property are excellent, but the air permeability and the water permeability are deteriorated, so that the growth of crops is hindered.

[0014]

With the above-mentioned constitution, in the present invention, by covering the root of the crop, the air permeability, water permeability, light shielding property and heat retaining property are appropriately maintained. Moreover, since the bulk density of the mat for mulching is 0.07 to 0.12 g / cm ^3, it prevents the buds of germinated weeds from breaking through the mat for mating and growing at the same time. It acts so as to impart appropriate handling properties.

Further, by appropriately mixing the natural fibers with the wood fibers, the microbial decomposition of the main raw material of the mat for mulching acts to accelerate according to the mixing ratio.
That is, when the main raw material of the mat for mulching is only wood fiber, the decomposition required period is 3 to 4 years, while, for example, about 20 parts by weight of hemp is mixed with 100 parts by weight of wood fiber. If so, the time required for decomposition is shortened to about 2 to 2.5 years, and if 50 parts by weight of hemp is mixed with 100 parts by weight of wood fiber, the time required for decomposition is shortened to about 1 to 1.5 years. .

Further, by using the biodegradable thermoplastic resin, not only the main raw material but also the thermoplastic resin is decomposed by the microorganisms, so that the artificial disposal after use becomes unnecessary.

[0017]

Example 1 100 parts by weight of thermomechanical pulp (wood fiber) obtained by defibrating wood chips with an Asplund defibrillator was mixed with a thermoplastic resin (Melty 4080 composite adhesive fiber manufactured by Unitika Ltd.). ]) 15 parts by weight and then uniformly mixed, and a basis weight of 0.7 kg /
A mat for matting having a thickness of 7 mm and a bulk specific gravity of 0.1 g / cm ³ was obtained by matting to m ² and heating and pressing at 140 ° C. for 50 seconds.

Comparative Example 1 In Example 1, a mixture of a wood fiber and a thermoplastic resin was matted with a fleece molding machine to a basis weight of 0.35 kg / m ² , which was heated and pressed at 140 ° C. for 50 seconds to give a thickness. 7m
A mat for mulching having m and a bulk specific gravity of 0.05 g / cm ³ was obtained.

Comparative Example 2 In Example 1, a mixture of a wood fiber and a thermoplastic resin was matted with a fleece molding machine to have a basis weight of 1.05 kg / m ² , which was heated and pressed at 140 ° C. for 50 seconds to give a thickness. 7m
A mat for mulching having m and a bulk specific gravity of 0.15 g / cm ³ was obtained.

Example 2 Mulching having a thickness of 7 mm and a bulk specific gravity of 0.1 g / cm ^{3 under} the same conditions as in Example 1 except that 50 parts by weight of hemp was added to 100 parts by weight of thermomechanical pulp as wood fiber. Got a mat for.

Example 3 Under the same conditions as in Example 1, except that a thermoplastic resin having biodegradability (“NBF (KK)” manufactured by Daiwa Boshoku Co., Ltd.) was used, the thickness was 7 mm and the bulk specific gravity was 0. .1 g / cm ³
A mat for mulching was obtained.

Next, the mulching mat thus obtained is laid on the ground to observe the growing condition of crops, the condition of weeds generation, the biodegradability of the mulching mat, and the like. In contrast, the results are shown in Table 1.

[0023]

[Table 1]

As is clear from Table 1, in Examples 1 to 3 as compared with Comparative Examples 1 and 2 and the needle-made hemp mat, weeds did not occur, and the mat for mulching decomposed within about 3 years,
The handling property of the mulching mat was also good.

[0025]

As described above, according to the present invention,
A wood fiber is used as a main raw material, a thermoplastic resin is added to and mixed with the main raw material, and the thermoplastic resin is melted to form a mat-like having a bulk density of 0.07 to 0.12 g / cm ^3. Therefore, by covering the roots of crops, breathability, water permeability, light-shielding properties and heat retention properties are appropriately maintained, and since the bulk density of the mat for mulching is 0.07 to 0.12 g / cm ³ , This prevents the germination of germinated weeds from breaking through the mulching mat to grow, and at the same time provides the mulching mat with appropriate handling properties, thus preventing overgrowth of weeds and promoting crop growth. It is possible to provide a mulching mat which is capable of easily obtaining raw materials and has excellent workability when arranged at the root of a crop. In addition, since wood fiber, which is the main raw material, is decomposed by microorganisms in the soil and naturally corrodes, it is not necessary to collect it after mulching like a mulching mat made of plastic sheets, and it takes time and effort for recovery and disposal after collection. There is no complexity in processing. Furthermore,
Since the wood fiber, which is the main raw material, contains a large amount of cellulose, which is relatively slowly biodegraded, it is more durable than the mulching mat made of natural fibers and a relatively long-term mulching effect is obtained.

A main raw material is a mixture of wood fibers and natural fibers in a predetermined ratio. A thermoplastic resin is added to the main raw material and mixed, and the thermoplastic resin is melted to obtain a bulk density of 0. Since it was formed by forming a mat shape of 07 to 0.12 g / cm ³ , covering the roots of the crops made it breathable, water permeable,
The light-shielding property and heat-retaining property are appropriately maintained, and since the bulk density of the mat for mulching is 0.07 to 0.12 g / cm ³ , the buds of germinated weeds break through the mat for mulching and grow. At the same time, the mulching mat is provided with appropriate handling properties, which makes it possible to prevent the overgrowth of weeds and promote the growth of crops. It is possible to provide a mat for mulching which is excellent in workability when the mat is arranged. In addition, since wood fiber and natural fiber, which are the main raw materials, are decomposed by microorganisms in the soil and naturally corrode, there is no need to collect them after mulching like a mulching mat made of plastic sheets. There is no complexity of later disposal processing. Moreover, wood fiber, which is one of the main raw materials, contains a large amount of cellulose, which is relatively slow in biodegradation, so it is more durable than a mat for mulching consisting only of natural fibers, and has a relatively long-term mulching effect. Is obtained. Moreover,
By appropriately mixing wood fibers with natural fibers, the microbial decomposition of the main raw material of the mulching mat is accelerated according to the mixing ratio thereof, so that the mulching period of the mulching mat can be arbitrarily selected.

Further, when the thermoplastic resin having biodegradability is used as the thermoplastic resin, in addition to the above effects,
By using a biodegradable thermoplastic resin, not only the main raw material but also the thermoplastic resin is decomposed by microorganisms, and there is no need for artificial disposal after use. There is no problem in disposal.

Claims (3)

[Claims] 1. A mat-like material having a bulk density of 0.07 to 0.12 g / cm ³ obtained by using wood fiber as a main raw material, adding a thermoplastic resin to the main raw material and mixing and melting the thermoplastic resin. A mat for mulching formed by forming. 2. A main raw material is a mixture of wood fibers and natural fibers in a predetermined ratio. A thermoplastic resin is added to and mixed with the main raw material, and the thermoplastic resin is melted to obtain a bulk density of 0. A mat for mulching formed by forming a mat shape of 07 to 0.12 g / cm ³ . 3. The mat for mulching according to claim 1 or 2, wherein the thermoplastic resin has biodegradability.