JPH07107260B2 - Drain material for civil engineering - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (i) Purpose of the invention Industrial field of application The present invention relates to a drainage material used for civil engineering, that is, a flat plate that is embedded in the soil mainly vertically to improve the soil. The present invention relates to a drainage material for civil engineering, which is a material in the shape of a soil, which allows only moisture in the soil to pass through and is sucked up to the surface of the earth for drainage.

Conventional technology and its problems Conventionally, as a typical drainage material for civil engineering, there is a hard type product in which non-woven fabric is laminated on both sides of a plastic core body. Kosho 58
As can be seen in JP-A-3090 and JP-B-58-29372, a heat-fusible powder was used as the adhesive.

That is, before laminating the non-woven fabric and the core body, the powder of the heat-fusible synthetic resin such as polyethylene or ethylene-vinyl acetate copolymer resin is sprayed over the entire bonding surface of the non-woven fabric in advance in the fiber gap of the non-woven fabric. It was dispersed and fixed, and this was heat-fused to the core and bonded.

However, this powder is apt to be formed into a film by heating at the time of heat fusion, and the part which is not laminated, that is, the part of the non-woven fabric covering the concave portion of the core body is also formed into a film due to the melting of the powder, and the water permeability is remarkable. The problem is that it is impaired.

Therefore, attempts have been made to solve this drawback by reducing the size of the heat-fusible powder or reducing the amount of spraying, but in each case, a new problem that the adhesive strength becomes weak occurs and the problem is solved. Has not reached.

The present invention has been made to solve the above-mentioned problems, and does not adversely affect the adhesive strength between the plastic core body and the nonwoven fabric, but rather covers the concave portion of the core body even though the adhesive strength is increased. It is intended to provide a drainage material for civil engineering in which the non-woven fabric portion does not impair its water permeability.

(B) Structure and action of the present invention The inventors of the present invention examined the use of heat-fusible fibers as an adhesive between the nonwoven fabric and the core body, and integrated it with the nonwoven fabric in the form of a spider web to bond it to the core body. It has been found that the adhesive strength is improved and the water permeability of the non-woven fabric is not lowered.

Means for Solving the Problems The constitution of the present invention is a drain material in which a non-woven fabric is laminated on both sides of a core body having concavo-convex grooves formed on the entire surface, and a heat-fusible fiber is attached to the laminating face side of the non-woven fabric. Is laminated in the form of a spider web, and the above-mentioned pasting is obtained by the heat-fusible fiber, and a drain material for civil engineering, characterized by the above.

Action Since the present invention has the above-mentioned configuration, the non-woven fabric portion covering the groove groove portion of the core body, only the spider web-shaped heat-fusible fiber is present, the water permeability of this portion is not impaired, Moreover, since the ridges of the core body and the non-woven fabric are bonded in a continuous line by the fibers entwined in the shape of a spider web, the adhesive strength is improved.

The core body of the present invention is one in which concavo-convex groove grooves having a U-shaped cross section, a U-shaped cross section, a V-shaped cross section, etc. are formed on the entire surface. The depth and width of the groove are both 1-4 mm.
It has become something of a degree.

The weight of the non-woven fabric laminated on both sides of this core is 20
It is preferably about 50 g / m ² and acts as a filter that separates earth and sand and allows only water to pass through.

When a non-woven fabric having a dense and dense two-layer structure in which the outer side is dense and the inner side is coarse is used, the separability of soil and sand is improved and an excellent effect of preventing clogging is obtained.

As an adhesive for bonding the non-woven fabric and the core body, the greatest feature of the present invention is that the heat-fusible fiber is used in the form of a spider web, and the material of the heat-fusible fiber is, for example, ethylene / vinegar. Bi-copolymer resin, low melting point polyethylene resin,
A low softening point polyamide resin, etc. can be used. Any hot melt resin can be used as long as it makes the plastic core and the non-woven fabric adhere well and has a much lower softening point (usually 20 to 50 ° C lower). Is.

As a means for laminating these heat-fusible fibers on the nonwoven fabric in the form of a spider web, a method of forming a hot melt resin such as the above by a hot melt spray of blowing hot air onto one surface of the nonwoven fabric, or a hot melt resin is a melt blow method. A preferred method is to make a non-woven fabric by the method of heating and fusing to one surface of the base non-woven fabric.

As the heat-fusible fiber, for example, a thin-sheath type composite fiber of polypropylene and polyethylene may be used,
Such heat-bondable fibers may be formed into a spider web and laminated on a non-woven fabric.

The process of laminating the heat-fusible fibers on the non-woven fabric in the form of a spider web may be performed at the same time when the core body and the non-woven fabric are bonded together, or may be processed in advance before the bonding.

The weight of the spider web-shaped laminated portion of the heat-fusible fiber is 5 to 35.
A ratio of g / m ² is preferable, and even if the weight is considerably increased, it does not become a film by heating, so the water permeability is not adversely affected, and the adhesive strength is greatly improved.

The bonding of the core body and the non-woven fabric in the present invention is achieved by heat-sealing the heat-fusible fibers in a state of being entwined in the shape of a thin cobweb, and the adhesive force is large because they are bonded by continuous lines. It is improving. In addition, the spider web-like shape is maintained in the part that is not adhered, that is, the part that covers the concave part of the core, the film formation phenomenon like the powder described above does not occur, and the water permeability of the nonwoven fabric is not impaired at all.

Example 1 On one surface of a base non-woven fabric having a basis weight of 30 g / m ^{2 made} of polyester short fibers, hot-melt air was blown with hot air while hot-melting a hot-melt resin by ethylene-vinyl acetate copolymerization (hot-melt spray), 20 g / cobweb-shaped. It was deposited at a rate of m ² .

On the other hand, the core has a thickness of 0.5 mm and is made of low-density polyethylene, and has a U-shaped cross section with a depth and width of 2 mm.
The plastic board which has the uneven groove of 3 was used.

The non-woven fabric was laminated on both sides of this plastic boat at a laminating temperature of 220 ° C. while sandwiching it between two hot rolls so that the sprayed surface was in contact with the core body, and a drain material for civil engineering was obtained.

Example 2 A hot-melt spray was applied to the nonwoven fabric surface in Example 1 immediately before sandwiching it between rolls and contacting with the core, and otherwise the same conditions as in Example 1 were used to obtain a drainage material for civil engineering.

Example 3 On one surface of the same base non-woven fabric as in Example 1, a spider web-like thermo-adhesive non-woven fabric of low melting point polyethylene having a weight of 25 g / m ² obtained by a melt-blowing method was heat-fused to be integrated with the base non-woven fabric. Let

This was laminated in the same manner as in Example 1 on both sides of the same plastic board as in Example 1 so that the heat-adhesive non-woven fabric surface was in contact with the core, and a drain material for civil engineering was obtained.

Example 4 As a non-woven fabric having a coarse and dense two-layer structure, the coarse layer has a basis weight of 10 g / m ^{2 and} is made of a heat-adhesive fiber of polypropylene / polyethylene thin / saya composite fiber, and the dense layer has a basis weight of 20 g / m ^2. A non-woven fabric consisting of low density polyethylene fibers thinner than the layers was produced.

This was laminated at the laminating temperature of 138 ° C. in the same manner as in Example 1 so that the rough layer side was in contact with the core on both sides of the same plastic board as in Example 1 to obtain a drain material for civil engineering.

Comparative Example 30 g / m ² of hot-melt resin powder of ethylene-vinyl acetate copolymer (average particle size 30 μ) was coated on one side of the same non-woven fabric substrate as in Example 1.
Was sprayed and heated to adhere.

A laminated civil engineering-like drain material was obtained in the same manner as in Example 1 except that the powder-dispersed surface was in contact with the core on both sides of the same plastic board as in Example 1.

With respect to the above Examples and Comparative Examples, the water permeability, adhesiveness and clogging property were examined.

Here, the water permeability was determined according to the JIS-A1218 constant water level permeability test, and the value calculated by the following equation was used as the water permeability coefficient.

k; Permeability coefficient (cm / sec) Q; Permeability (cm ³ ) t; Time required for permeability (sec) h; Head difference (cm) L; Sample length (cm) A; Permeability cross section (cm ² ) At this time, the water permeability is the water permeability in the direction perpendicular to the surface of the nonwoven fabric.

The adhesiveness was measured by measuring the peel strength between the board and the non-woven fabric using Tensilon.

Table 1 shows the measurement results of the water permeability and the adhesiveness.

From this table, the example of the present invention is compared with the comparative example of the prior art,
Both of them have excellent water permeability and further have a great improvement in adhesive strength.

For clogging, place a perforated plate on the water passage as shown in Fig. 1,
On top of that, the non-woven fabrics of Examples and Comparative Examples were laid, and further collected at the shore of Lake Biwa, Kinohama Town, Moriyama City, Shiga Prefecture, dried and crushed.
The soil (about 63μ or less) that had passed through a 0 mesh sieve was packed and the water permeability was measured intermittently while continuously supplying water.

The results are shown in Table 2.

From this table, it is recognized that the examples of the present invention are excellent also in the anti-clogging property that maintains the water permeability.

C. Effect of the Invention The present invention is as described above, and has an excellent effect that the adhesive does not become a film and the water permeability of the drain material is not impaired in laminating the core body and the nonwoven fabric, and Since they are adhered in a continuous line, the adhesive strength is improved compared to the conventional point adhesion, and the durability and the like have a good result.

Further, if the spider web-shaped laminate is obtained by hot melt spraying or is formed by a non-woven fabric by a melt blow method, the drain material of the present invention can be produced very efficiently.

Furthermore, when the heat-bonding fiber made of a composite fiber is used as the heat-fusible fiber, it is possible to simultaneously laminate the core body and the nonwoven fabric on the nonwoven fabric, and it is possible to simplify the manufacturing process.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a means for measuring clogging in Examples and Comparative Examples. (W) …… Supply water, (o) …… Overflow water, (t) …… Test soil, (s) …… Sample (nonwoven fabric), (Q) …… Permeability

Claims (4)

[Claims] 1. A drain material in which a non-woven fabric is laminated on both sides of a core body having concavo-convex grooves formed on the entire surface, wherein heat-fusible fibers are laminated in a spider web shape on the laminating face side of the non-woven fabric, A drainage material for civil engineering, characterized in that the above-mentioned lamination is obtained by this heat-fusible fiber. 2. The drainage material for civil engineering according to claim 1, wherein the spider web-like lamination is obtained by hot melt spraying. 3. The civil engineering drain material according to claim 1, wherein the spider web-shaped laminated portion is a non-woven fabric of a melt blow method. 4. The civil engineering drain material according to claim 1, wherein the heat-fusible fiber is a heat-adhesive fiber made of a composite fiber.