JP2005295934A - Agricultural net - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive agricultural net that is easy to homogenize to soil, has high water absorption and water retention, and does not generate toxic gas even when incinerated.
SOLUTION: selected from conifer pulp, manila hemp pulp, sisal hemp pulp, flax pulp, cotton pulp, linter pulp, cannabis pulp, jute pulp, trilobum pulp, persimmon pulp, husk pulp, lint pulp, bamboo pulp, kenaf pulp and bagasse pulp An agricultural net comprising a string of base paper made from at least one kind of pulp.
The base paper preferably has a basis weight of 20 to 80 g / m ² and is made by a circular paper machine.
[Selection] Figure 1

Description

  The present invention relates to an agricultural net effective for farm products such as fields, paddy fields, or fruit trees, for example, for preventing birds, insects, preventing weeds from growing, preventing wind, shielding light, and preventing animals.

There are various types of agricultural nets depending on the purpose of use. Recently, insect nets have been used effectively to avoid the damage caused by pests of vegetables, especially leafy vegetables, in pesticide-free or reduced pesticide cultivation. ing.
As conventional agricultural nets, those that are constructed in a net shape by knitting ropes and strings using natural fibers such as hemp and straw, and those that use synthetic fibers such as polyethylene, nylon, polyester, etc. are common, In particular, the former natural fibers such as hemp and straw are flammable and easily corrode even when buried in the soil, but currently there are few raw materials to produce, and the latter synthetic fibers have a negative impact on the environment when burned when discarded. There is a concern about the generation of gas, and there is a problem that it does not corrode in the soil. There are various proposals for solving this problem, and typical ones include the following patent publications.

JP-A-6-185062, JP-A-11-275987, JP 2000-32852 A, JP 2001-346456 A, JP 2001-352844 A,

  Briefly explaining the contents of the above-mentioned patent publication, Japanese Patent Application Laid-Open No. 6-185062 discloses a vegetation formed from a material which has been subjected to antibacterial treatment on a net body made of plastic fibers such as nylon and modified to be corrosive Although the net is used, the plastic body is used for the net body, so it has a problem of generating toxic gas when it is burned, and it is difficult to decompose in the soil. Moreover, it did not have sufficient water absorption and water retention necessary for vegetation.

The one described in JP-A-11-275987 is a biodegradable net formed by molding a lactone resin alone or a biodegradable resin composed of a lactone resin and another biodegradable resin. Since it is used, the cost is high.
Japanese Patent Application Laid-Open No. 2000-32852 discloses a mixed paper obtained by mixing biodegradable thermoplastic synthetic staple fibers and plant fiber for papermaking at a certain ratio, or a layer not including a biodegradable thermoplastic synthetic staple fiber layer. Although a biodegradable thermoplastic synthetic short fiber layer bonded to one side of the sheet by joining together is described, a cost increase is inevitable because a biodegradable thermoplastic synthetic short fiber is prepared.
JP-A-2001-352844 describes an agricultural net knitted with warps and wefts, using monofilaments or tape yarns, having grid-like eyes, and using warps and wefts with starch. Polylactic acid used as a raw material, and the product described in Japanese Patent Application Laid-Open No. 2001-346456 is an agricultural net in which warp and weft are knitted, and one of warp and weft is a flat yarn. It has a grid-like eye, and warps and wefts are made from biodegradable materials, especially polylactic acid made from starch, and hygroscopic in that polylactic acid made from starch is used selectively. There is a problem that the cost is slightly high.

  The present invention has been made in view of the above circumstances, does not generate toxic gas even when burned, has a good soil assimilation property even if embedded in the soil as it is, the thickness of the string, the mesh The purpose is to provide an agricultural net at a low cost that is manufactured from paper string that can be applied according to the purpose by arbitrarily setting the size and stitch structure, and has essential water absorption and water retention. It is what.

The present invention has been made as a result of intensive studies to solve the above problems,
The invention of claim 1 includes softwood pulp, manila hemp pulp, sisal hemp pulp, flax pulp, cotton pulp, linter pulp, cannabis pulp, jute pulp, trifoam pulp, persimmon pulp, crust pulp, lint pulp, bamboo pulp, kenaf pulp and bagasse pulp An agricultural net comprising a paper string made of a base paper made from at least one kind of pulp selected from the above, wherein the basis weight of the base paper is 20 to 80 g / m. an agricultural net according to claim 1, characterized in that the ^2.
The invention according to claim 3 is the agricultural net according to any one of claims 1 to 2, wherein the base paper is made by a circular net paper machine, and the invention according to claim 4 The agricultural net according to any one of claims 1 to 3, wherein the aspect ratio of the tensile strength measured according to JIS P 8113 of the base paper is 5-15. The invention according to claim 5 is the agricultural net according to any one of claims 1 to 4, wherein the paper string net is formed of a knotless net, and the invention according to claim 6 6. The agricultural net according to claim 1, wherein the base paper contains a wet paper strength enhancer, and the invention according to claim 7 provides the wet paper strength. The enhancer is polyamide epichlorohydrin resin, epoxy resin, melamine resin The agricultural net according to claim 6, comprising at least one selected from fat, urea-based resin, dialdehyde starch, polyacrylamide and polyethyleneimine.

Since the agricultural net of the present invention is made of a specific pulp, it has an assimilation property in the soil during its disposal, and therefore has an ecological and ecological advantage. By adjusting the thickness, physical strength, and stitch spacing of the vertical and horizontal straps that make up the agricultural net, it can be manufactured arbitrarily from those with extremely small openings to those with large openings, and Depending on the purpose, the thickness and strength of the string, the porosity of the mesh can be changed, and favorable characteristics such as air circulation (including windproof), light projection rate, humidity adjustment, etc. can be given, and further if necessary By impregnating herbicides, insect repellents, and animal repellents, it is possible to provide an agricultural net that can easily achieve these purposes.
And the agricultural net of the present invention is corroded and soiled within a certain period of time by burying it together with other burying treatments such as weeds, residual roots, etc. in the site where it was used after the period to be used. Since it is reduced, no harmful gas is generated, and it is not necessary to carry, incinerate, etc. in response to the aging of farmers, and it is possible to provide an agricultural net with excellent handleability.

The present invention will be described in detail below.
Base papers constituting the present invention are softwood pulp, manila hemp pulp, sisal hemp pulp, flax pulp, cotton pulp, linter pulp, cannabis pulp, jute pulp, cocoon pulp, persimmon pulp, crust pulp, lint pulp, bamboo pulp, kenaf pulp and At least one kind of pulp selected from bagasse pulp is used as a raw material. Various softwood pulps such as kraft pulp and sulfite pulp can be applied as the softwood pulp.
The pulp may be bleached pulp or unbleached pulp. Moreover, the tensile strength required for the paper string can be maintained by adjusting the raw material so that at least 70% or more of the pulp raw material becomes the above pulp.
In this case, these pulps may be used alone or as a mixture of several kinds.
As other pulp that can be mixed with the above-mentioned pulp, various pulps such as hardwood pulp, esparto pulp, straw pulp and the like, and waste paper pulp can be blended within a range that does not impair the strength of the paper.
These pulps are subjected to a beating process using a beater such as a beater, and then used as raw material for base paper.

The degree of the beating process is set according to the use of the agricultural net manufactured from the twisted paper string, and it is necessary to advance the beating when trying to obtain a high-strength paper string. In this case, increasing the blending ratio of Manila hemp is effective for obtaining a high-strength paper string.
The base paper of the present invention may contain additives such as a wet paper strength enhancer, various fillers, sizing agents, and yield improvers, if necessary.
In particular, the wet paper strength enhancer is effective in preventing deterioration of paper strength due to rainwater for a certain period of time when an agricultural net made from the paper string net of the present invention is used. In this case, the wet paper strength enhancer is not particularly limited, but at least selected from polyamide epichlorohydrin resin, epoxy resin, melamine resin, urea resin, dialdehyde starch, polyacrylamide and polyethyleneimine. One type can be suitably applied to the present invention.
As the sizing agent, in addition to the rosin type, an internal sizing agent such as alkyl ketene dimer and alkenyl succinic anhydride, and various synthetic polymer surface sizing agents can be used.
Furthermore, the yield improver is added to reduce the loss of pulp and filler in the paper machine and improve the yield of papermaking. For example, organic polymer electrolytes such as polyacrylamide and aluminum sulfate are representative. The inorganic salts are applicable to the base paper of the present invention.

Production of the base paper constituting the present invention is carried out by making a papermaking raw material slurry in which the above raw materials are blended at a predetermined ratio with a wet paper machine.
The wet paper machine for making the base paper of the present invention is not particularly limited, such as a long net and a circular net paper machine, which are applied to general paper making technology, but has sufficient tensile strength necessary for the paper string net. In order to ensure, it is preferable to use a circular net paper machine.
The basis weight of the base paper of the present invention is preferably ²⁰ to 80 g / m ² , more preferably 30 to 50 g / m ² . If the basis weight is less than 20 g / m ² , it is easy to cut at the time of twisted paper, and if it exceeds 80 g / m ² , the rigidity becomes high and it is difficult to twist.

  In addition, the base paper constituting the present invention is a single-layer paper composed of 100% of one kind of pulp selected from the plurality of pulps or a mixed paper of the plurality of pulp components, and two to three layers of paper. A paper configuration may be used. The base paper of the present invention preferably has a tensile strength aspect ratio of 5 to 15 in a normal state according to JIS P8113. If the aspect ratio of the tensile strength is less than 5, there is a risk of paper breakage when slitting into a tape-like shape from the base paper during the manufacture of paper strings. -It is not preferred because there is a risk of tearing in the vertical direction when slitting into a sphere.

  The base paper obtained by the above process is processed into a paper string by slitting it into a tape having a width of 5-50 mm and a winding length of about 500 m, cutting it into a tape, setting it in a twisting machine and twisting it. The The paper string used in the present invention is preferably used alone from the viewpoint of cost, but some may be knitted and used as necessary. The thickness of the paper string is not particularly limited, but a diameter of about 1 to 10 mm is preferable from the viewpoint of ease of handling.

In order to create the agricultural net of the present invention using the paper string obtained in the above process, it is necessary to use a knitting netting machine to knit a knotted net or a knotless net by a normal net manufacturing technique. Good.
The agricultural net of the present invention is particularly preferably knitted into a knotless net. By knitting into a knotless net, the knot-free connection is flat and the weight is light and not bulky. Therefore, seeds, fertilizers, etc. are attached when growing from seed sowing in agriculture. It is also possible to affix paper, etc., which has the effect of improving the workability. In addition, since the mesh is accurate and has no drop, the appearance is good when applied to agricultural nets. Furthermore, the knotless net is more susceptible to fraying than the knotted net, and therefore has the advantage of being easy to homogenize to the soil when used in an agricultural net.
In addition, when supplying the agricultural net of the present invention as a knotted net, it is preferable to impregnate paper string with oil or the like in advance.

  Examples of a knotless network applicable to the agricultural net of the present invention are given as FIGS. That is, FIG. 1 is called a penetration type and has a structure in which the yarns of two mesh yarns cross each other, and the mesh yarn has a structure extending linearly through the connecting portion. FIG. The mesh yarn is crossed 2 to 3 times, and the mesh yarn has a zigzag structure. Fig. 3 shows a tortoiseshell type 2 yarn mesh yarn 3 to 4 times. The net yarn has a structure that extends linearly through the connecting portion. FIG. 4 is called a Russell net, which is a net made by a so-called “lace net”, and FIG. It is called koji net (ordinary moji net), twisted warp yarns, and weft yarns are used as meshes between them. FIG. 7 is a diagram in which yarns are simply crossed with a woven mesh, and these are all embodiments of the agricultural net of the present invention.

In the present invention, various uses can be developed by arbitrarily adjusting the thickness of the paper string and the size of the mesh.
The agricultural net of the present invention may be coated or impregnated with a resin component for the purpose of imparting water resistance or improving physical strength, if necessary. In this case, the application or impregnation of the resin component may be performed in advance on a stage before processing into a net, that is, on a paper string or base paper.

The agricultural net of the present invention may be used by covering it with a crop, for example, in a tunnel shape, removing it after harvesting the crop, collecting it, and embedding it in the soil at a predetermined place. In addition, when used as an orchard for bird protection, it may be spread using an appropriate support or the like.
In addition, when using an agricultural net carrying a herbicide in advance, lay it at the base of the crop where it is not desired to increase weeds. In this case, as long as there is an agricultural net, it will be weeded and if left as it is, it will be decomposed and returned to the soil after a predetermined period of time.
Furthermore, since the atmosphere such as temperature, humidity and light can be adjusted by selecting the opening density of the net, it can be spread on vegetables and flower buds and used as a garden net.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
A domestic slurry of unbleached kraft pulp (NUKP) produced in Japan was beaten to 60 ° SR to prepare an aqueous slurry, and a wet paper strength enhancer made of polyamide epichlorohydrin resin (made by Showa Polymer Co., Ltd., trade name “Polyfix 301”). )) Was added to the aqueous slurry so as to be 2% to prepare a papermaking raw material. The raw material was applied to a circular paper machine to prepare a base paper having a basis weight of 30 g / m ² .
When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 8.6 kg / 15 mm, the transverse direction was 1.6 kg / 15 mm, and the aspect ratio was 5.4. .
Next, this base paper was slit into a tape with a width of 40 mm using a bobbin winder, and this was set on a twisting machine and twisted 28 times / 30 cm to produce a paper string having a diameter of 3 mm. . The strength of the paper string was 15 kg as measured by JISZ1518.
This paper string was subjected to a commercially available knitting netting machine to produce a knotless net having a through-hole type and a small opening ratio as shown in FIG.
The resulting knotless net was impregnated with a herbicide to obtain an agricultural net of the present invention, which was used by laying it in a portion where weeds such as the roots of crops were not desired to grow. As a result, the herbicidal effect was confirmed while the form of the agricultural net was present, and it was further confirmed that the agricultural net was assimilated into the soil after leaving it for a predetermined period.

Example 2
A base paper was prepared under the same conditions as in Example 1 except that 80% by weight of NUKP and 20% by weight of Manila hemp pulp were mixed and beaten at 60 ° SR to prepare an aqueous slurry.
When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 11.8 kg / 15 mm, the transverse direction was 2.1 kg / 15 mm, and the aspect ratio was 5.6. .
Using this base paper, an agricultural net of the present invention comprising a paper string and a paper string net was produced under the same conditions as in Example 1.
The obtained agricultural net was covered with a Chinese cabbage field in a tunnel and fixed with an anchor pin. As a result, Chinese cabbage was able to grow and be harvested without being attacked by pests. After the Chinese cabbage was harvested, the agricultural net was removed, discarded in another predetermined place, and left to stand.

Example 3
An aqueous slurry was prepared by beating domestic softwood unbleached kraft pulp (NUKP) to 50 ° SR, and a wet paper strength enhancer made of polyamide epichlorohydrin resin (trade name “Polyfix 301”, manufactured by Showa Polymer Co., Ltd.). )) For the aqueous slurry. A papermaking raw material was prepared by adding 5%. The raw material was applied to a circular paper machine to produce a base paper having a basis weight of 41.5 g / m ² .
When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 13.1 kg / 15 mm, the transverse direction was 1.9 kg / 15 mm, and the aspect ratio was 6.8. .
Using this base paper, a paper string was prepared under the same conditions as in Example 1, and an agricultural net of the present invention consisting of a paper string net having a higher aperture ratio than Example 1 was prepared.
When the obtained agricultural net was stretched and used on the ceiling of a flower cultivating house, an insect-repellent effect was exhibited in combination with moderate heat retention and high air permeability, and it was confirmed that florets grew smoothly. In addition, after harvesting the florets, the agricultural net was removed, discarded and left in another place, and it was degraded and homogenized with soil.

Example 4
An aqueous slurry was prepared by beating domestic softwood unbleached kraft pulp (NUKP) to 50 ° SR, and a wet paper strength enhancer made of polyamide epichlorohydrin resin (trade name “Polyfix 301”, manufactured by Showa Polymer Co., Ltd.). )) For the aqueous slurry. A papermaking raw material was prepared by adding 5%. The raw material was applied to a circular paper machine to produce a base paper having a basis weight of 42 g / m ² .

When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 13.1 kg / 15 mm, the transverse direction was 1.9 kg / 15 mm, and the aspect ratio was 6.8. .
Using this base paper, a paper string was prepared under the same conditions as in Example 1, and an agricultural net of the present invention consisting of a paper net having a lower aperture ratio than Example 1 was prepared.
The obtained agricultural net was laid in a tunnel shape in a pesticide-free Komatsuna field and used as an insect repellent net.
Seventeen days after the netting of the insect repellent was harvested, Komatsuna was harvested, and its weight, presence / absence of pests, leaf color, etc. were observed. In addition, when the insect repellent net was used, it was left as it was without being recovered, and it was confirmed that it was decomposed in the soil.

Comparative Example 1
A net (product name: # Cremona 300; manufactured by Kuraray Co., Ltd.) made of single yarn vinylon spun yarn with wire number 20 was prepared and laid in a tunnel shape in a field of pesticide-free Komatsuna under the same conditions as in Example 4. And used as an insect repellent net.
As a result, the insect repellent effect was the same as in Example 4, but after use, the product was left as it was without being recovered, but remained in the field as garbage without being decomposed into the soil.

Comparative Example 2
A mixed pulp of 60% by weight of unbleached kraft pulp (LUKP) and 40% by weight of unbleached kraft pulp (NUKP) made of hardwood from foreign countries is beaten to 55 ° SR to create an aqueous slurry, and polyamide epichlorohydrin is made into this A wet paper strength enhancer made of resin (made by Showa Polymer Co., Ltd., trade name “Polyfix 301” was added so as to be 2% with respect to the aqueous slurry to prepare a papermaking raw material. A base paper having a basis weight of 26.9 g / m ² was prepared by applying to a paper machine.
When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 5.1 kg / 15 mm, the transverse direction was 1.7 kg / 15 mm, and the aspect ratio was 3.0. .
Next, this base paper was slit into a strip of 40 mm width with a bobbin winder, and this was set on a twisting machine and twisted 28 times / 30 cm to create a paper string having a diameter of 3 mm. However, paper breaks frequently occurred, making it difficult to create a string, and thus an agricultural net.

  Since the agricultural net of the present invention is made of natural organic fibers, it can be used in a wide range of agricultural fields based on the effects described above.

The top view of the agricultural net which consists of a penetration type no knot net concerning the present invention The top view of the agricultural net which consists of a staggered type knotless net concerning the present invention The top view of the agricultural net which consists of a tortoiseshell type no knot net concerning the present invention The top view of the agricultural net which consists of a knotless net which consists of a Russell net concerning the present invention The top view of the agricultural net | network which consists of a knotless net | network which consists of a normal net according to this invention The top view of the agricultural net | network which consists of a knotless net | network which consists of an improved maple net which concerns on this invention The top view of the agricultural net which consists of a knotless net which consists of a woven net concerning the present invention

Claims (7)

  At least one selected from conifer pulp, manila hemp pulp, sisal hemp pulp, flax pulp, cotton pulp, linter pulp, cannabis pulp, jute pulp, miso pulp, birch pulp, cocoon pulp, lint pulp, bamboo pulp, kenaf pulp and bagasse pulp An agricultural net comprising a paper string made of pulp made from pulp. ^2. The agricultural net according to claim 1, wherein the base paper has a basis weight of 20 to 80 g / m < ² >.   The agricultural net according to any one of claims 1 to 2, wherein the base paper is made by a circular net paper machine.   The agricultural net according to any one of claims 1 to 3, wherein the aspect ratio of the tensile strength measured by JIS P 8113 of the base paper is 5-15.   The agricultural net according to any one of claims 1 to 4, wherein the paper string net is composed of a knotless net.   The agricultural net according to any one of claims 1 to 5, wherein the base paper contains a wet paper strength enhancer.   The wet paper strength enhancer is made of at least one selected from polyamide epichlorohydrin resin, epoxy resin, melamine resin, urea resin, dialdehyde starch, polyacrylamide and polyethyleneimine. Agricultural net as described in.

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