JP3798459B2

JP3798459B2 - Turfgrass vegetation base

Info

Publication number: JP3798459B2
Application number: JP02599296A
Authority: JP
Inventors: 誠太田黒; 洋北川
Original assignee: Daiwabo Co Ltd; Daiwabo Holdings Co Ltd
Current assignee: Daiwabo Co Ltd; Daiwabo Holdings Co Ltd
Priority date: 1996-01-19
Filing date: 1996-01-19
Publication date: 2006-07-19
Anticipated expiration: 2016-01-19
Also published as: JPH09191763A

Description

【０００１】
【発明の属する技術分野】
本発明は、路面に植生する芝の植生基盤、詳しくは野外運動場やゴルフ場、競馬場の馬場あるいは走路等の砂地盤に植生している芝草の根を安定し、セルロース系捲縮短繊維が適度な保水性を持ち、生分解するにつれて空隙を生じ芝草の良好な成育を促すための芝草植生基盤に関する。
【０００２】
【従来の技術】
上記の広場や走路などの路面部分の基盤を補強するためには、例えば、特開昭５９−１３０９０９号公報のような可撓性のメッシュエレメントを砂と混合し基礎としたものや、例えば、杉の樹皮からなるチップ状物を砂と混合して施設し、路盤部分を補強したものあるいは、樹皮からなるチップのみを路面部分に散布施工したものなどがある。
【０００３】
さらに特開平３−２３３０２２号公報には多数の連続線条によるマット状網状物の裏面に吸水性不織布シートを接合したものを植生用網状体として使用する例が知られている。
【０００４】
【発明が解決しようとする課題】
しかしながら特開昭５９−１３０９０９号公報のように、可撓性のメッシュエレメントを砂と混合した場合には、砂とメッシュエレメントとの比重の違いから、砂のなかに均一にメッシュエレメントが分散した混合土が得られず、メッシュエレメントや砂の密な層と粗な層が発生して路面部分の基盤の均一な補強が得られず、路面の基盤強度の強い所と弱い所が発生し、このような路面部分の基盤を補強した地面に張芝をし、芝草を植生しても路面に発馬機などの重量物の輪荷重がかかれば路面の支持力が弱いために地盤が窪み、車輪や馬蹄が基盤層に沈んで基盤層の一部を破壊し、芝草が剥げるなどの不都合が発生する。
【０００５】
また、杉の樹皮からなるモスライトを砂と混合した植生層は、モスライトが砂中の過剰な水分を吸収し水分を保持するとともに、砂中の水分が減少すればモスライトの中の水分を発散させ砂中の水分を維持し、その水分による湿りとモスライトと砂粒との摩擦抵抗により砂粒の滑動を抑制しているが、路面部分の基盤の補強効果が乏しいために、この路面基盤に張芝をし芝草を植生しても、路面に重量物の輪荷重がかかれば地盤が窪みまたはときには芝草が剥がれるなどの不都合が発生する。
【０００６】
また、杉の樹皮からなるチップ状物を砂と混合させた場合には、上記チップ状物は砂中の過剰な水分を吸収するためにチップ状物が軟弱となり、基盤の補強効果が減少する恐れがある。
【０００７】
更に、樹皮から浸出するリグニンなどのヘミセルロースが、砂粒の粉塵と混じり合い、雨水などによって汚水として流出したり、あるいは、樹皮が重量物の荷重によって砕かれて微粉化し、そのために地盤の砂層や通水層の排水機能を低下させる恐れがある。
【０００８】
また前記の植生用網状体は発生した根が網状体の線条に絡み付くが、網状体内部の空隙率が不変であるため、根が成育するに従い通気性が悪くなり成育を阻害する欠点があった。しかし始めから空隙率を大きくとっておくと根の初期に線条体が絡みにくく、活着しにくいので施工地や成育条件に応じて網状体の空隙率を適当なものに選択せねばならなかった。
【０００９】
【課題を解決するための手段】
本発明は、直径０．１ｍｍ〜１．５ｍｍの熱可塑性合成重合体からなる繊維で１本のうち１個以上のループ状の捲縮を持つ捲縮短繊維（以下、この繊維を合成重合体捲縮短繊維と略す場合がある）を３０〜９０重量％と１本のうち１個以上のループ状の捲縮を持つセルロース系捲縮短繊維（以下、この繊維を単にセルロース系捲縮短繊維と略す場合がある）を７０〜１０重量％含み、隣接する捲縮短繊維及びセルロース系捲縮短繊維の各繊維の多くの接点が接着されている空隙率７０〜９５％の嵩高なマット状物である芝草植生基盤である。
【００１０】
また本発明の好ましい態様は、前記熱可塑性合成重合体からなる捲縮短繊維のうち少なくとも１種類が熱接着性繊維であり、各繊維の多くの接点がこの熱接着性繊維によって熱接着されている芝草植生基盤である。
【００１１】
更に本発明の好ましい別の態様は、熱接着性繊維が熱可塑性合成重合体からなる捲縮短繊維中に３０〜４０重量％含まれている芝草植生基盤である。
【００１２】
【発明の実施の形態】
本発明によるマット状の芝草植生基盤は、繊維間の空隙部に川砂、海砂、火山砂利あるいはスラグ等のいわゆる目土を充填して締め固めをして使用され、したがって形態的に安定で透水性と保水性に優れたものとなる。これらの特性を得るためには、繊維の太さやマットの空隙率や、保水性繊維の混在率が重要となる。即ち一般に、合成重合体繊維は吸水性が小さく基盤補強材としての機能をもたせ、セルロース系捲縮短繊維は補強材としてのほかにその吸水性を利用して保水材としての機能を持たせ、生分解することにより空隙を増加させ芝草の生育を促進するのに利用される。そこで、補強材としての合成重合体繊維はその直径が０．１ｍｍ未満のマットでは弾性が乏しく、砂の維持力が小さい。直径が１．５ｍｍを超える繊維のマットにおいては剛直性が強く、地面から繊維の一部が露出した時危険となる。また、セルロース系捲縮短繊維は２０デニール未満ではバルキー性がないので好ましくない。
【００１３】
また、マットの構造が極めて粗で空隙率が９０％よりも高いマットの場合には目土の充填は容易であるが、目土を拘束する力が弱く、路盤としての強度が低いため形態的に不安定となり、構造が密で空隙率が低いマットにおいては砂を拘束する力が強く形態的に安定であるが、目土を充填するのに特別な装置を必要とするなどの不都合が生じ、芝草植生基盤としての好ましい空隙率は７０〜９０％である。
【００１４】
そしてこの空隙は、マット全体に亘りほぼ均等に存続してその空隙の大きさもバラツキの少ないほど好適である。このような芝草植生基盤として好ましい嵩高なマット状物は、繊維の長さが合成重合体捲縮短繊維にあっては５０〜３００ｍｍであって、セルロース系捲縮短繊維にあっては２０〜２００ｍｍであって、伸長時の長さをＡ、張力開放時の長さをＢとしたとき、１．０＜Ａ／Ｂ＜３．０となるようなスパイラル状カールを有し、少なくとも１部にループ状カールを備えた立体捲縮状である合成重合体繊維または熱接着性繊維を３０〜９０重量％、セルロース系捲縮短繊維を７０〜１０重量％集積し、結合することによって得ることができる。
【００１５】
繊維の長さが合成重合体捲縮短繊維にあっては５０ｍｍ未満であると繊維の絡みのチャンスが少なく、横強度に不安を生じ、また３００ｍｍを超えると部分的に過度の絡みが生じてマットの構造が不均一になりやすく砂の拘束力の低下を招くことになる。また、セルロース系捲縮短繊維にあっても合成重合体捲縮短繊維と同様のことがいえる。
【００１６】
上記捲縮短繊維を形成する合成重合体としては、例えば、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリエチレン、ポリプロピレン等のポリオレフィン系、ポリエチレンテレフタレート等のポリエステル系、ナイロン６、ナイロン６６等のポリアミド系等の重合体若しくは上記の２種以上の共重合体あるいは、スチレン−ブタジエン共重合体やポリプロピレン−エチレン−ブテン共重合体等の共重合体を単独あるいは、２種以上を混合して使用することもできるが、耐圧性や曲げ強度あるいは耐久性等を考慮するとスチレン−ブタジエン共重合体とポリプロピレン−エチレン−ブテン三元共重合体を混合したものが好ましい。また、セルロース系捲縮短繊維としては、例えば椰子繊維、麻繊維、綿繊維等の天然繊維や、ビスコースレーヨン等の化学繊維が挙げられる。
【００１７】
また、マットを形成する繊維の混在率はマットの強度と保水性に影響を与える。即ち、合成重合体捲縮短繊維は３０〜９０重量％、好ましくは５０〜８０重量％であり、セルロース系捲縮短繊維は７０〜１０重量％、好ましくは５０〜２０重量％である。即ち、熱可塑性合成重合体からなる捲縮短繊維の混在率が３０重量％未満になると湿潤時にセルロース系捲縮短繊維の強度または接着剤による接着強度の低下を充分に補うことができず、マットの強度が低下する。また天然繊維が生分解をした後にマットが形状維持をするのに３０重量％以上必要である。
【００１８】
また、９０重量％を超えるとマットの強度は充分保てるが、合成重合体繊維は吸水率が小さく、保水率も小さいので芝草植生基盤としてはその機能が低下する。
【００１９】
したがって、合成重合体捲縮短繊維の好ましい混在率は３０〜９０重量％であり、セルロース系捲縮短繊維は７０〜１０重量％である。即ち、セルロース系捲縮短繊維が１０重量％未満であるとマット状芝草植生基盤の吸水性、保水性が低下し芝草の成育に必要な水分保持機能が低下する。また７０重量％を超えるとマット状の芝草植生基盤の吸水性、保水性は向上するが、セルロース系捲縮短繊維の接着剤での接着強力が低下し、芝草植生基盤として重要な機能のひとつであるマットの強度が低下し、また繊維の吸湿によるマットの形状安定性がへたりなどで低下し、目土の拘束力が低下し、発馬機などの重量物が芝草上に荷重されたときに芝草植生基盤を損傷することにつながる。したがって、その好ましい混在率は７０〜１０重量％である。
【００２０】
なお、マットを構成する繊維は上記の条件を満足していれば２種以上のものを混合して使用してもよい。また、マットの側面や底面に薄い透水性不織布などを貼着して目土の流出を防ぐなどの使用方法をとってもよい。
また、更に保水性を向上させるべく、マットに他の保水材、例えばアクリル酸ナトリウム塩等の高吸水性高分子材料を塗布し使用してもよい。
【００２１】
また、マットを形成する上で繊維を各繊維の交差点の接点で接着するための手段としてはゴム系の接着剤や、塩化ビニル系の接着剤等、従来から使用されているものを任意に用いることができる。このとき、接着剤の坪量は、繊維総量と同量以下で基盤を形成し、強度保持ができる範囲であれば特に限定されない。
【００２２】
また、合成重合体捲縮短繊維のうち少なくとも一種類の繊維を熱接着性繊維とし、これを熱接着させることにより各繊維の接点を接着することもできる。熱接着性繊維としては、ポリプロピレン、ポリエチレン等のポリオレフィン系、低融点ポリエステル等のポリエステル系からなる繊維を使用することができる。また、熱接着性繊維は熱可塑性合成重合体からなる捲縮短繊維中に３０〜４０重量％含まれていることが望ましい。
【００２３】
芝草植生基盤の厚みは５〜１００ｍｍがよい。５ｍｍ未満では植生基盤としての保水性、地盤補強力が低下し、１００ｍｍを超えると基盤補強施工コストが嵩むため不向きである。また、芝草植生基盤の目付は、基盤の厚みと空隙率を満足するものであれば、繊維の坪量を限定するものではない。
【００２４】
吸水性のセルロース系捲縮短繊維を７０〜１０重量％混在した芝草植生基盤は空隙率が高く保水性に優れ、砂中の過剰な水分を吸収し、水分の保持をするとともに、砂中の水分が減少すれば基盤中の水分を発散させ砂中の水分を維持し、その水分の湿りにより芝草の発根を促進させ、芝草の根は基盤を構成する合成重合体捲縮短繊維３０〜９０重量％に絡みあるいは基盤層を通り過ぎて成育するので芝草の滑動を抑制し、芝草の根切れ、根腐れを防ぐ。
【００２５】
また、ループ状の立体捲縮を付与された短繊維からなる空隙率の高い嵩高な芝草植生基盤は、基盤の空隙へ容易に充填した目土を捕捉し、植生層の垂直方向の耐荷重性を高めて重量物の支持力を確保し、垂直方向や水平方向への滑動を抑制して植生層の移動を防止し、さらに適度な空隙は芝草の根茎の成育を促進し、発達した芝草の根茎は基盤の繊維に絡まりあるいは通り抜けを許容し、丈夫な草根に成長させ、地盤補強に役立つ。そして、下層の整地地盤は植生層の排水を良好にして植生層に多量の水の滞留を防止して芝草の根腐れをなくする。
【００２６】
【実施例】
図１は、本発明の芝草植生基盤を例示した簡略断面図である。本発明の芝草植生基盤（１）は図示しているようにループ状カールを有する合成重合体繊維とループ状カールを有するセルロース系捲縮短繊維を混在させ各繊維の接点（５）を接着剤（４）で接着して形成される。
【００２７】
該芝草植生基盤（１）は、直径が約０．２５ｍｍ、平均長さが１５０ｍｍ、その大部分が半径約７〜１０ｍｍのループ状カールを１個以上有する非直線のポリ塩化ビニルの有端繊維３５重量％と、直径が約０．３０ｍｍ、平均長さが１２０ｍｍ、その大部分が半径約６〜１０ｍｍのループ状カールを１個以上有する非直線のポリ塩化ビニリデンの有端繊維３５重量％と、繊度が１００デニール、平均長さが約３０ｍｍ、その大部分が半径約６〜９ｍｍのループ状カールを１個以上有する非直線の椰子繊維３０重量％の混合繊維により構成され、各々の繊維が交差している接点（５）を接着剤を繊維総量の約８０重量％散布して、接着剤（４）によって接合されて空隙率９４％、厚み約３０ｍｍの畳大の形状をなしている。
【００２８】
上記芝草植生基盤（１）は次のようにして製造することができる。即ち上記した直径０．２５ｍｍ、平均長さ１５０ｍｍのポリ塩化ビニルの有端繊維３５重量％を、直径０．３０ｍｍ、平均長さ１２０ｍｍのポリ塩化ビニリデンの有端繊維３５重量％と、１００デニール、平均長さが約３０ｍｍの椰子繊維３０重量％とを混合し、その混合繊維を強撚機で撚りをかけてロープ状となしたのち巻取り、数日後解撚してスパイラル状の立体捲縮を有した繊維材料となす。
【００２９】
これをランダムウェバーを用いて見掛けの厚さが７０ｍｍの嵩高なマット状となし、ゴム系接着剤を上記繊維総量の約８０重量％を散布したのち厚さ約３０ｍｍになるように押圧しながら加熱処理して交絡している各繊維の接点（５）において接着し、空隙率９４％の本発明の基盤（１）を得た。
【００３０】
図２は本発明の芝草植生基盤を例示した簡略断面図である。本発明の芝草植生基盤（１）は図示しているように、基礎地盤（２４）、透水性シート（３１）、砂層（２１）からなる排水性構造の整地地盤（２５）の上に形成される。
【００３１】
グランドの下層に形成される上記基礎地盤（２４）は、本実施例においては、排水ドレーン（３０）を埋設しその周囲に砂利や砕石を配してフィルター層（２３）を形成し、その上に厚さ約２０ｃｍにわたり粒度６号からなる砕石による通水層（２２）を形成し、さらにこの通水層（２２）の上面に、ポリエステル繊維（６デニール×６４ｍｍ）からなる厚さ約３ｍｍ、目付約３５０ｇ／ｍ²のニードルパンチング不織布の透水性シート（３１）を敷設して形成されている。
【００３２】
次いで上記の基礎地盤（２４）の通水性シート（３１）上に、厚さ約４０ｃｍにわたり網野浜砂を散布敷設して砂層（２１）を形成し、しかるのち転圧ローラーを用いて押し固めて排水性構造の整地地盤（２５）となす。
【００３３】
本発明は、上記のようにして施工された基礎地盤（２４）の上に砂層（２１）が形成された排水性構造の整地地盤（２５）の上に、芝草植生と地盤補強となる空隙率の高い嵩高な芝草植生基盤（１）を敷設し、その空隙部（７）内へ目土（２８）として平均粒径２μｍ〜５ｍｍの土砂を充填し、しかるのち転圧ローラーを用いて押し固め植生層（２７）を形成し、芝草植生基盤（１）となしている。上記本発明の芝草植生基盤（１）の補強された植生層（２７）の上にマット状の張芝（２６）を展開敷設して植生し、３ヶ月間養生した結果芝草は順調に成育し、その芝草の上に発馬機を誘導設置したところ路面の沈みは数ｃｍに留まり、また誘導中の輪荷重のかかった部分はその輪荷重から開放されるとほぼ元通りに復帰した。
【００３４】
一方、比較のために植生層に芝草植生基盤（１）を敷設していない部分を造成しておき、その部分に上記と同様に芝草を植生し、３ヶ月間養生したところ芝草は順調に成育していたが、その芝草の上に発馬機を誘導設置した結果、路面の沈みは１０数ｃｍとなり、また誘導中の輪荷重のかかった部分はその輪荷重から開放されたのちにおいても、輪荷重による明らかな窪みの痕跡が残留していた。
【００３５】
【発明の効果】
このように、合成重合体捲縮短繊維と吸水性のセルロース系捲縮短繊維が混在した空隙率の高い、嵩高な芝草植生基盤は砂中の過剰な水分を吸収し水分の保持をするとともに、砂中の水分が減少すれば基盤中の水分を発散させて砂中の水分を維持し、その水分の湿りにより芝草の発根を促進させる。
【図面の簡単な説明】
【図１】本発明の芝草植生基盤を例示した簡略断面図である。
【図２】本発明の芝草植生基盤を例示した簡略断面図である。
【符号の説明】
１芝草植生基盤
２合成重合体繊維
３天然繊維
４接着剤
５接点
６繊維端部
７空隙部
２１砂層
２２通水層（砕石）
２３フィルター層（砂利、砕石）
２４基礎地盤
２５整地地盤
２６張芝
２７植生層
２８目土
３０排水ドレーン
３１透水性シート
４０芝草
４１草根[0001]
BACKGROUND OF THE INVENTION
The present invention stabilizes the vegetation base of turf vegetation on the road surface, in particular, the roots of turf grass vegetated on sand ground such as outdoor playgrounds, golf courses, racetracks or runways, and cellulosic crimped short fibers are suitable. The present invention relates to a turfgrass vegetation base that has water retention and creates voids as it biodegrades to promote good growth of turfgrass.
[0002]
[Prior art]
In order to reinforce the base of the road surface portion such as the above-mentioned square and runway, for example, a flexible mesh element such as JP-A-59-130909 mixed with sand, for example, There is a facility that mixes chips made of cedar bark with sand and reinforces the roadbed part, or a structure in which only chips made of bark are scattered on the road surface.
[0003]
Further, JP-A-3-233022 discloses an example in which a water-absorbing non-woven fabric sheet joined to the back surface of a mat-like net-like material having a large number of continuous filaments is used as a net for vegetation.
[0004]
[Problems to be solved by the invention]
However, as disclosed in JP-A-59-130909, when a flexible mesh element is mixed with sand, the mesh element is uniformly dispersed in the sand due to the difference in specific gravity between the sand and the mesh element. Mixed soil is not obtained, dense layers and coarse layers of mesh elements and sand are generated, and uniform reinforcement of the base of the road surface portion is not obtained, where strong and weak road base strength occurs, If the road surface is reinforced with ground and turf grass is vegetated, if the road surface is subjected to a heavy load such as a horse-running machine, the ground will be depressed because the road surface is weakly supported. Inconveniences such as wheels and horseshoe sinking into the base layer, destroying part of the base layer, and turf grass peeling off occur.
[0005]
In addition, the vegetation layer in which mossite made of cedar bark is mixed with sand absorbs excess moisture in the sand and retains it, and if the moisture in the sand decreases, it releases the moisture in the moss. Although the moisture in the sand is maintained and the sliding due to the moisture due to the moisture and the frictional resistance between the mossite and the sand grains is suppressed, the reinforcing effect of the road surface base is poor. Even if turf grass is vegetated, if a heavy load is applied to the road surface, inconveniences such as depression of the ground or sometimes peeling of the turf grass occur.
[0006]
In addition, when a chip-like material made of cedar bark is mixed with sand, the chip-like material absorbs excessive moisture in the sand, so that the chip-like material becomes weak and the reinforcing effect of the base is reduced. There is a fear.
[0007]
In addition, hemicellulose such as lignin that leaches out from the bark mixes with the dust of the sand grains and flows out as sewage due to rainwater, etc. There is a risk of reducing the drainage function of the water layer.
[0008]
In addition, the vegetation nets described above have roots that are entangled with the filaments of the nets, but since the porosity inside the nets is unchanged, there is a drawback that the air permeability becomes worse as the roots grow and the growth is hindered. It was. However, if the porosity is kept large from the beginning, the striatum does not easily get entangled at the beginning of the root, and it is difficult to establish it, so it was necessary to select an appropriate porosity for the mesh according to the construction site and growth conditions. .
[0009]
[Means for Solving the Problems]
The present invention is a fiber made of a thermoplastic synthetic polymer having a diameter of 0.1 mm to 1.5 mm, and is a crimped short fiber having one or more loop-like crimps (hereinafter referred to as a synthetic polymer fiber). Cellulose-based crimped short fibers (sometimes abbreviated as shortened staple fibers) having 30 to 90% by weight and one or more loop-shaped crimps in one (hereinafter, this fiber is simply abbreviated as cellulose-based crimped short fibers) Turf grass vegetation which is a bulky mat-like material having a porosity of 70 to 95%, in which a large number of contacts of adjacent crimped short fibers and cellulosic crimped short fibers are bonded to each other Is the foundation.
[0010]
In a preferred embodiment of the present invention, at least one of the crimped short fibers made of the thermoplastic synthetic polymer is a heat-adhesive fiber, and many contacts of each fiber are thermally bonded by the heat-adhesive fiber. Turfgrass vegetation base.
[0011]
Yet another preferred embodiment of the present invention is a turfgrass vegetation base wherein the heat-bondable fibers are contained in a crimped short fiber made of a thermoplastic synthetic polymer in an amount of 30 to 40% by weight.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The mat-like turfgrass vegetation base according to the present invention is used by filling the space between the fibers with so-called joint soil such as river sand, sea sand, volcanic gravel or slag, and is therefore morphologically stable and water permeable. It is excellent in properties and water retention. In order to obtain these characteristics, the thickness of the fiber, the porosity of the mat, and the mixing ratio of the water retention fibers are important. That is, in general, synthetic polymer fibers have a low water absorption and have a function as a base reinforcing material, and cellulosic crimped short fibers have a function as a water retaining material by utilizing their water absorption in addition to a reinforcing material. By decomposing, it is used to increase voids and promote the growth of turfgrass. Therefore, the synthetic polymer fiber as the reinforcing material has a poor elasticity in a mat whose diameter is less than 0.1 mm, and has a small sand retention force. A fiber mat having a diameter of more than 1.5 mm has high rigidity, which is dangerous when a part of the fiber is exposed from the ground. Cellulose-crimped short fibers are not preferable if they are less than 20 deniers because they do not have bulkiness.
[0013]
In addition, when the mat structure is extremely coarse and the porosity is higher than 90%, the filling of the joint is easy, but the force to restrain the joint is weak and the strength as a roadbed is low. In a mat with a dense structure and low porosity, the sand-binding force is strong and morphologically stable, but there are inconveniences such as requiring a special device to fill the joints. The preferable porosity as the turfgrass vegetation base is 70 to 90%.
[0014]
And it is more suitable that this space | gap continues substantially uniformly over the whole mat | matte, and the size of the space | gap has few variations. Such a bulky mat-like material preferred as a turfgrass vegetation base has a fiber length of 50 to 300 mm for synthetic polymer crimped short fibers, and 20 to 200 mm for cellulosic crimped short fibers. It has a spiral curl such that 1.0 <A / B <3.0, where A is the length when stretched and B is the length when tension is released. It can be obtained by accumulating 30 to 90% by weight of synthetic polymer fiber or thermoadhesive fiber in the form of three-dimensional crimps with a cylindrical curl and 70 to 10% by weight of cellulose-based crimped short fibers.
[0015]
If the length of the synthetic polymer crimped short fiber is less than 50 mm, there is little chance of entanglement of the fiber, and there is anxiety in the lateral strength, and if it exceeds 300 mm, excessive entanglement occurs in part. This structure tends to be non-uniform, resulting in a decrease in the binding force of the sand. The same can be said for the cellulose-based crimped short fibers as for the synthetic polymer crimped short fibers.
[0016]
Examples of the synthetic polymer that forms the crimped short fibers include, for example, polyvinyl chloride, polyvinylidene chloride, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polyamides such as nylon 6 and nylon 66, and the like. A polymer or a copolymer of two or more of the above, or a copolymer such as a styrene-butadiene copolymer or a polypropylene-ethylene-butene copolymer can be used alone or in admixture of two or more. In view of pressure resistance, bending strength, durability, etc., a mixture of a styrene-butadiene copolymer and a polypropylene-ethylene-butene terpolymer is preferred. Examples of the cellulose-based crimped short fibers include natural fibers such as coconut fibers, hemp fibers, and cotton fibers, and chemical fibers such as viscose rayon.
[0017]
The mixing ratio of fibers forming the mat affects the strength and water retention of the mat. That is, the synthetic polymer crimped short fiber is 30 to 90% by weight, preferably 50 to 80% by weight, and the cellulosic crimped short fiber is 70 to 10% by weight, preferably 50 to 20% by weight. That is, if the mixture ratio of the crimped short fibers made of the thermoplastic synthetic polymer is less than 30% by weight, the strength of the cellulose-based crimped short fibers or the decrease in the adhesive strength due to the adhesive cannot be sufficiently compensated when wet. Strength decreases. Further, 30% by weight or more is necessary for the mat to maintain its shape after the natural fiber is biodegraded.
[0018]
On the other hand, if it exceeds 90% by weight, the strength of the mat can be maintained sufficiently, but the synthetic polymer fiber has a low water absorption rate and a low water retention rate, so its function as a turfgrass vegetation base is lowered.
[0019]
Therefore, the preferable mixing ratio of the synthetic polymer crimped short fibers is 30 to 90% by weight, and the cellulosic crimped short fibers is 70 to 10% by weight. That is, when the cellulosic crimped short fibers are less than 10% by weight, the water absorption and water retention of the mat-like turfgrass vegetation base are lowered, and the water retention function necessary for turfgrass growth is lowered. If it exceeds 70% by weight, the water absorption and water retention of the mat-like turfgrass vegetation base will be improved, but the adhesive strength of the cellulosic crimped short fibers will decrease, which is one of the important functions of the turfgrass vegetation base. When the strength of a mat decreases, the shape stability of the mat decreases due to moisture absorption, the binding force of the joints decreases, and heavy objects such as horses are loaded on turfgrass Lead to damage to the turfgrass vegetation base. Therefore, the preferable mixing ratio is 70 to 10% by weight.
[0020]
The fibers constituting the mat may be used in combination of two or more if the above conditions are satisfied. Moreover, you may take usage methods, such as sticking a thin water-permeable nonwoven fabric etc. to the side surface and bottom face of a mat, and preventing the outflow of joint soil.
Further, in order to further improve the water retention, another water retention material such as a highly water-absorbing polymer material such as sodium acrylate may be applied to the mat.
[0021]
In addition, as a means for adhering the fibers at the intersections of the fibers when forming the mat, a conventionally used material such as a rubber adhesive or a vinyl chloride adhesive is arbitrarily used. be able to. At this time, the basis weight of the adhesive is not particularly limited as long as the base is formed with the same amount or less as the total amount of fibers and the strength can be maintained.
[0022]
In addition, at least one kind of the synthetic polymer crimped short fibers may be a heat-bondable fiber, and the contact of each fiber may be bonded by thermally bonding the fiber. As the heat-adhesive fiber, a fiber made of a polyolefin such as polypropylene or polyethylene, or a polyester such as a low melting point polyester can be used. Further, it is desirable that the thermoadhesive fiber is contained in a crimped short fiber made of a thermoplastic synthetic polymer in an amount of 30 to 40% by weight.
[0023]
The thickness of the turf grass vegetation base is preferably 5 to 100 mm. If it is less than 5 mm, the water retention and ground reinforcing power as a vegetation base will decrease, and if it exceeds 100 mm, the base reinforcement construction cost will increase, which is not suitable. Further, the basis weight of the turf grass vegetation base is not limited to the basis weight of the fiber as long as it satisfies the thickness and porosity of the base.
[0024]
Turfgrass vegetation base containing 70 to 10% by weight of water-absorbing cellulose-based crimped short fibers has a high porosity and excellent water retention, absorbs excess moisture in the sand, retains moisture, and retains moisture in the sand. Decreases the moisture in the base to maintain the water in the sand and promotes the rooting of turfgrass by the moistening of the water, and the root of the turf grass is 30-90% by weight of the synthetic polymer crimped short fibers constituting the base It grows through the entanglement or past the basement layer, so it prevents turfgrass from sliding, and prevents turfgrass root breakage and root rot.
[0025]
In addition, the bulky turfgrass vegetation base with a high porosity consisting of short fibers with loop-like three-dimensional crimps captures the fill soil easily filled in the base gap, and the vertical load resistance of the vegetation layer To support heavy objects, prevent vertical and horizontal sliding to prevent the movement of the vegetation layer, and moderate gaps promote the growth of turfgrass rhizomes. The rhizome allows entanglement or passage through the base fiber, grows into strong grass roots, and helps to reinforce the ground. And the lower leveled ground improves the drainage of the vegetation layer, prevents the accumulation of a large amount of water in the vegetation layer, and eliminates the root rot of turf grass.
[0026]
【Example】
FIG. 1 is a simplified cross-sectional view illustrating the turfgrass vegetation base of the present invention. The turfgrass vegetation base (1) of the present invention comprises a synthetic polymer fiber having loop curls and a cellulose-based crimped short fiber having loop curls, as shown in the drawing, and contacts (5) of the fibers are bonded to an adhesive ( It is formed by bonding in 4).
[0027]
The turfgrass vegetation substrate (1) has a non-linear polyvinyl chloride end fiber having at least one loop-shaped curl having a diameter of about 0.25 mm, an average length of 150 mm, and a radius of about 7 to 10 mm. 35% by weight, 35% by weight of a non-linear polyvinylidene chloride end fiber having one or more looped curls having a diameter of about 0.30 mm, an average length of 120 mm, and a radius of about 6 to 10 mm. , Composed of 30% by weight of non-linear insulator fiber having at least one loop-shaped curl having a fineness of 100 denier, an average length of about 30 mm, and a radius of about 6 to 9 mm. The intersecting contacts (5) are sprinkled with adhesive of about 80% by weight of the total amount of fibers, and joined by the adhesive (4) to form a tatami mat with a porosity of 94% and a thickness of about 30 mm.
[0028]
The turfgrass vegetation base (1) can be produced as follows. That is, 35% by weight of polyvinyl chloride end-ended fibers having a diameter of 0.25 mm and an average length of 150 mm are combined with 35% by weight of polyvinylidene chloride end fibers having a diameter of 0.30 mm and an average length of 120 mm, and 100 denier. 30% by weight of coconut fiber with an average length of about 30mm is mixed, the mixed fiber is twisted with a strong twister to form a rope, wound up, and untwisted several days later to form a spiral solid crimp And a fiber material having
[0029]
This is formed into a bulky mat shape with an apparent thickness of 70 mm using a random webber, and heated while pressing a rubber adhesive to a thickness of about 30 mm after spraying about 80% by weight of the total amount of the fiber. Bonding was made at the contact (5) of each fiber that had been treated and entangled to obtain a substrate (1) of the present invention having a porosity of 94%.
[0030]
FIG. 2 is a simplified cross-sectional view illustrating the turfgrass vegetation base of the present invention. As shown in the figure, the turfgrass vegetation base (1) of the present invention is formed on a leveling ground (25) having a drainage structure comprising a base ground (24), a water permeable sheet (31), and a sand layer (21). The
[0031]
In the present embodiment, the foundation ground (24) formed in the lower layer of the ground is embedded with a drainage drain (30), and gravel and crushed stone are arranged around it to form a filter layer (23). A water-permeable layer (22) made of crushed stone having a particle size of 6 is formed over a thickness of about 20 cm, and a thickness of about 3 mm made of polyester fibers (6 denier x 64 mm) is further formed on the upper surface of the water-permeable layer (22) It is formed by laying a water-permeable sheet (31) of a needle punching nonwoven fabric having a basis weight of about 350 g / m ² .
[0032]
Subsequently, Aminohama sand is spread and laid over the water-permeable sheet (31) of the foundation ground (24) over a thickness of about 40 cm to form a sand layer (21), and then pressed and compacted using a rolling roller. It becomes the leveling ground (25) of the sex structure.
[0033]
The present invention provides a void ratio for turfgrass vegetation and ground reinforcement on a ground leveling ground (25) having a drainage structure in which a sand layer (21) is formed on the foundation ground (24) constructed as described above. A high and bulky turfgrass vegetation base (1) is laid, and the void (7) is filled with earth and sand with an average particle diameter of 2 μm to 5 mm as the soil (28), and then compacted with a rolling roller. A vegetation layer (27) is formed, which is the turfgrass vegetation base (1). The mat-like turf turf (26) is developed and laid on the reinforced vegetation layer (27) of the turf grass vegetation base (1) of the present invention, and the turf grows smoothly as a result of curing for 3 months. When the horse was guided on the turf grass, the road surface sinked to a few centimeters, and the part of the wheel load that was being guided returned to its original state when released from the wheel load.
[0034]
On the other hand, for comparison, a portion where the turfgrass vegetation base (1) is not laid is created in the vegetation layer, and turfgrass is vegetated in the same manner as described above, and then cultivated for 3 months. However, as a result of guiding and installing the horse on the turf grass, the road surface sinks to a few tens of centimeters, and the part where the wheel load during guidance was released from the wheel load, There were obvious traces of dents due to wheel load.
[0035]
【The invention's effect】
In this way, the high porosity, bulky turfgrass vegetation base in which synthetic polymer crimped short fibers and water-absorbing cellulose-based crimped short fibers are mixed absorbs excess moisture in the sand and retains moisture. If the water content decreases, the water content in the base is released to maintain the water content in the sand, and the moistening of the water promotes the rooting of turfgrass.
[Brief description of the drawings]
FIG. 1 is a simplified cross-sectional view illustrating a turfgrass vegetation base according to the present invention.
FIG. 2 is a simplified cross-sectional view illustrating a turfgrass vegetation base of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Turfgrass vegetation base 2 Synthetic polymer fiber 3 Natural fiber 4 Adhesive 5 Contact point 6 Fiber edge part 7 Cavity part 21 Sand layer 22 Water flow layer (crushed stone)
23 Filter layer (gravel, crushed stone)
24 foundation ground 25 leveling ground 26 turf grass 27 vegetation layer 28 joint soil 30 drainage drain 31 permeable sheet 40 turf grass 41 grass root

Claims

30 to 90% by weight of one or more crimped short fibers each having one or more loop-like crimps made of a thermoplastic synthetic polymer having a diameter of 0.1 mm to 1.5 mm. includes a biodegradable cellulose crimped short fibers except for less than 20 denier with a loop-shaped crimps 70 to 10 wt%, of adjacent thermoplastic polymer crimped staple fiber and biodegradable cellulosic crimped short fibers A turfgrass vegetation base having biodegradability , which is a bulky mat-like material with a porosity of 70 to 95%, in which many contacts of each fiber are bonded.

2. At least one of the crimped short fibers made of the thermoplastic synthetic polymer is a heat-adhesive fiber, and many contact points of each fiber are thermally bonded by the heat-adhesive fiber. Turfgrass vegetation base with biodegradability as described.

3. The biodegradable turfgrass vegetation base according to claim 2, wherein the heat-bondable fiber is contained in a crimped short fiber made of a thermoplastic synthetic polymer in an amount of 30 to 40% by weight.

The biodegradable turfgrass vegetation base according to claim 1, wherein the length of the fibers is 50-300 mm for crimped short fibers made of a thermoplastic synthetic polymer, and 20-200 mm for biodegradable cellulose-based crimped short fibers.