JPH02142421A - Subsoil for plant culture - Google Patents

Abstract

PURPOSE:To obtain the subject subsoil having a structure prepared by heat bond of a crumb-shaped staple composed of a synthetic fiber and adhesive, capable of ready control of water absorption properties, water retention characteristics, water permeability and root spread properties, requiring no precise control of characteristics of the raw fiber and suitable for raising of seedlings or cultivation of vegetables, flowering trees and shrubs, etc. CONSTITUTION:A crumb-shaped staple (preferably bulk no. 30-130g/l) composed of a synthetic fiber such as a polyester, polyamide, DP or vinyl chloride and a heat bond (m.p. is preferably 20 deg.C or more lower than that of the above- mentioned synthetic fiber. e.g., copolyester containing the third copolymerization component or PE) is heat bonded to provide the objective subsoil having the prescribed structure.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a medium for cultivating plants, particularly green vegetables, flowering trees, etc.

This invention relates to an artificial plant cultivation medium (hereinafter simply referred to as an artificial medium) suitable for raising and cultivating all kinds of plants.

[Prior Art] Natural soil has generally been used as a conventional artificial culture medium.

However, soil management is becoming more complex, especially in areas around cities, due to soaring land prices, environmental pollution, an imbalance of soil nutrients due to chemical fertilizers, and problems with continuous cropping.

Under these circumstances, cultivation methods using artificial culture media have been studied for several years with the theme of high quality, high yield, and labor saving, and recently, hydroponic cultivation using rock wool as a culture medium has become a hot topic. ing.

The artificial culture medium is mainly made of mineral fibers and has excellent water absorption and water retention properties, but due to its low water permeability, it is susceptible to root rot depending on the type of plant, and in terms of the working environment, contact with short fibers can cause problems. Health management issues such as skin disorders and respiratory disorders due to dust are coming to the fore.

In response to this, artificial culture media made from synthetic fibers have recently been considered.For example, a method has been proposed in which a carded web made of short fibers and heat-adhesive fibers is laminated and subjected to compression heat treatment to create a block body. (For example, JP-A-62-11
5217).

However, this type of artificial culture medium has poor water absorption and water retention properties.

In order to control various characteristic values such as water permeability, “
l! Fiber retention properties such as the thickness and length of the navy blue, and the strength of the crimp must be strictly controlled, which can cause losses of 1 to 100%.

Further, in the direction of compression perpendicular to the fiber axis, rooting properties are extremely low, while in the direction of the fiber axis, water permeability increases, causing problems such as the surface layer of the culture medium tends to dry out.

[Problems to be Solved by the Invention] The problem of the present invention is to solve the above-mentioned problems of the prior art, and to freely change the properties of plants such as water absorption, water retention, and water permeability depending on the type of plant. Another object of the present invention is to provide an artificial culture medium with excellent rooting properties.

Furthermore, the problem of the present invention can be solved by an artificial medium having a structure in which crumb-like short fibers made of synthetic fibers and a thermal adhesive are thermally bonded.

Hereinafter, the configuration of the present invention will be specifically explained.

That is, examples of the synthetic fibers in the present invention include polyester-based, polyamide-based, polypropylene-based, vinyl chloride-based, vinylidene chloride-based fibers (including unstretched fibers thereof). The fineness, fiber length, cross-sectional shape, etc. of the fibers are not particularly limited, but for the artificial culture medium of the present invention, for example, the single fiber fineness is about 1 to 20.
The denyl range is preferably used.

On the other hand, the thermal adhesive includes a third component of a fibrous material (including composite fibers) having thermal adhesive properties, such as polyester, polyethylene, and polypropylene.

A film-like material can be used as the cloth, but it is desirable that the melting point of these materials is about 20'C or more lower than that of the synthetic fibers.

The mixing rate of the thermal adhesive is usually 1 to 9% by weight, preferably 2 to 7% by weight per synthetic fiber. On the other hand, if the content of the thermal adhesive exceeds 9% by weight, the medium will become hard and rooting properties will decrease.

If it is less than 1% by weight, shape shrinkage during irrigation becomes large and water permeability tends to decrease.

After the synthetic fibers and the thermal adhesive are mixed, they are crushed into short crumb-like fibers by suitable crushing means.

As shown in FIG. 1, small fluffs are formed in the crumb-like short fibers. Of this hairball, the shape.

Those with a large density are suitable for creating an artificial medium with a high liquid phase ratio, while those with a small shape and density are suitable for creating a soft artificial medium with a high gas phase ratio.

The crushed state of the crumb-like short fibers is bulk N (130 to 13
It is best to control it within the range of 0 g/l, preferably 40 to 8(]+#. If the bulk number is less than 30 g/l, the density becomes too small and shape shrinkage during irrigation increases; If the number exceeds 130 g#l, the density becomes too large and the medium becomes hard, which tends to cause problems such as reduced rooting ability.

The bulk number of the crumb-like short fibers mentioned here means that the crumb-like short fibers are put into a sieve of about 4 meshes and are about 15 to 20 cm.
Container 1g from a height of m (Wo.

g) After sieving and removing excess crumb-like short fibers by cutting with a scalpel, the total weight of the container and crumb-like short fibers W
1 (g) is measured and calculated using the following formula.

Bulk Nα((]/Ω＞　=W1−W.

The above-mentioned crumb-like short fibers are made into an arbitrary shape as an artificial medium and then thermally bonded to form a molded product.The density of the molded product is within the range of 0.02 to 0.11 (J/cm3). is preferable. If the density of the molded product is less than 0.02 (1/cm3), the gas phase rate increases and the water permeability becomes high;
If it exceeds 11 (1/Cm3), it may become too hard and problems such as reduced rooting properties may occur.

In addition, other characteristic points of the artificial culture medium of the present invention other than those mentioned above include the mixing ratio of the thermal adhesive mentioned above, the bulk NO1 indicating the pulverized state of crumb-like short fibers, and the block body (i.e. 0
The liquid phase ratio of the artificial medium by independently controlling the density of each (artificial medium).

It is possible to arbitrarily control the vapor phase ratio and the feel of the block body.

In addition, the artificial culture medium of the present invention includes the above-mentioned synthetic medium! In addition to the Ii fibers and the thermal adhesive, natural fibers or artificial fibers may be mixed in an amount of less than about 50% by weight, if necessary.

Next, a manufacturing example of the above-mentioned artificial medium will be explained.

That is, in the artificial culture medium of the present invention, synthetic fibers and a thermal adhesive are mixed in advance in a desired usage ratio, and then crushed into crumb-like short fibers using a pulverizer. In this case, it is preferable to use a crusher of the type that uses a fixed blade and a cutting edge that rotates at a relatively low speed to press and shear. Further, it is desirable to remove as much fine powder as possible from the crumb-like short fibers obtained after pulverization.

The above-mentioned crumb-like short fibers have a desired shape, e.g.

Using a molding machine that can form cylinders, squares, continuous mats, bed shapes, etc., the hot air temperature is approximately 100 to 200.
An artificial culture medium can be prepared by forming a block by thermally adhering the thermal adhesive components in a hot air dryer at .degree. C., or by cutting the block into a desired shape or size.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples.

In this example, the water absorption, water permeability, liquid phase ratio, gas phase ratio, and tenacity of the blocks (ie, 9 artificial medium) were determined by the following methods.

Water absorption: Measure the weight of a block sample of approximately 750 cm3 (Vl) (wl, g>. Hold the sample in water several times by hand to expel any remaining air, absorb enough water, then take it out and leave it for 10 minutes. Measure the weight after (draining) (w2.y>.

2 Wl Water absorption ffi (g/Cm3) = x100 Water permeability, liquid phase rate and gas phase rate: After the water absorption sample was left for 24 hours when the above water absorption amount was measured, the volume (v2, cm3 > and weight (W3
．． g).

2 W3 It is assumed that water permeability (%) = ×100.

vinegar.

Tomatoes are sown on the root-prone niblock sample, allowed to germinate, and the root-propagation condition is determined by M3.

O: Good ×; Bad Example 1 Drawn polyester yarn waste (6d) as a raw material for synthetic fibers
It was cut into a length of about 5 cm. This raw material was placed in a bag and crushed in hot water at 50 to 60'C, and after washing and removing oil and dirt, it was dehydrated using a centrifugal dehydrator.

On the other hand, low melting point polyester fibers (melting point: 130°C) cut into approximately 4 cm pieces were used as the thermal adhesive and mixed with the raw material fibers in the proportions shown in Table 1.

This mixed fiber was pulverized into a crumb shape using a final type pulverizer model IXNM349. The crumb-like short fibers of the crushed wheat were taken out of the system via a cyclone through an air duct. At this time, the powder that had been pulverized to a bulk NQ of 30 (g/, 1!) or less was removed using a MultiCron.

This crumb-like short fiber was placed in a box (10xlOx 7.5cm) made of wire mesh (#2/l, 8 meshes).
A block body was produced by heat treatment for 60 minutes in a hot air dryer controlled at 170±5°C.

For comparison, the mixed m fibers of the polyester drawn yarn waste and low melting point polyester fibers were made into a carded web using a mixing and batting machine, and the obtained carded ware was laminated and compressed to give approximately 1.
It was heat-treated in a hot air dryer at 70°C to form a block body.

The evaluation results of the obtained blocks are shown in Table 1.

Regarding the water absorption amount of the block body, the product of the present invention is characterized in that there is no difference in water absorption amount between the vertical direction and the horizontal direction of the block body. On the other hand, in the block body cited as a comparative example, there is a large difference in water absorption between the vertical and horizontal directions in relation to the fiber axis direction.

Table 1 Example 2 (Example of artificial medium with high liquid phase ratio) Undrawn polyester yarn waste (approximately 156) and low melting point polyester fiber (melting point: 130°C) were mixed at a mixing ratio of 3 weights of low melting point polyester fiber. %), and then crushed for about 5 minutes to crush bulk No. It was made into crumb-like short fibers of 90(]/I.

When this crumb-like short fiber was molded in the same manner as in Example 1, a block body with a liquid phase ratio of 75% was obtained.

Example 3 (Example of artificial medium with high gas phase ratio) Undrawn polyester yarn waste (about 156) and low melting point polyester fiber (melting point: 130°C) were mixed at a ratio of 7% by weight of low melting point polyester fiber. The mixture was mixed with cotton and crushed for about 5 minutes to obtain crumb-like short fibers with a bulk Nα of 60 a#).

When this crumb-like short fiber was molded in the same manner as in Example 1, a block body with a gas phase ratio of 25% was obtained.

[Effects of the Invention] Since the artificial culture medium of the present invention is a thermally bonded structure of short crumb-like fibers made of synthetic fibers and a thermal adhesive, it has the following effects.

■It is easy to control the water absorption, water retention, water permeability, and rootability of the artificial medium.

■ By adopting crumb-like short fibers for the raw material fibers, there is no need to strictly control the conventional raw material fiber characteristics (e.g., fiber thickness, length, crimp strength, etc.), and the use of waste yarn as the raw material fibers. It also becomes possible.

■It is easy to mold the artificial culture medium into any shape and size.

■In terms of plant cultivation, it can be expected to improve the working environment, achieve labor savings, improve the quality of harvested products, and increase revenue.

[Brief explanation of the drawing]

FIG. 1 is a photograph of crumb-like short fibers used in the artificial culture medium of the present invention. Procedural amendment speech and behavior type) 1, 6. -2 Date of Heisei

Claims (2)

[Claims] (1) A plant cultivation medium having a structure in which short crumb-like fibers made of synthetic fibers and a thermal adhesive are thermally bonded. (2) The crumb-like short fibers in claim (1) are bulk No. A plant cultivation medium having a concentration of 30 to 130 g/l.