JP2003201638A - Mesh sheet for construction work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a mesh sheet for construction work which has high tenacity and excellent flexibility and ventilation free from dislocation of meshes. <P>SOLUTION: In this mesh sheet 1 in which weaving structure of warps 2 and wefts 3 comprises a set of three yarns, one of the three yarns is a multifilament 6 made of a thermoplastic resin and the other two yarns are monofilaments 7 made of a thermoplastic resin. The mesh sheet for construction work is constituted of a weaving system of a mock leno weave 4 or a plain weave 5 in which the multifilament 6 is arranged at the center and the monofilaments 7 are arranged at both the sides of the multifilament. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a mesh sheet for construction work.

[0002]

2. Description of the Related Art Conventionally, a mesh sheet for construction work is stretched on a scaffold around a building site such as a building and used to prevent falling of building materials such as bolts. Since there is a risk of burning, it is essential to impart flame retardancy, and it is necessary to have flexibility and excellent handleability in order to work in high places, and to prevent the scaffold from collapsing due to wind pressure. It is required to have appropriate ventilation so that it can be avoided.

Generally, a mesh sheet using monofilaments as warp and weft threads is inferior in flexibility due to the rigidity of the monofilament, and is difficult to fold and is handled as a mesh sheet for construction work in the spreading work at a construction site. There is an inconvenience that it is not good. Therefore, flexibility and foldability can be imparted by using a multifilament for the warp and weft yarns, but it is difficult to mix a flame retardant into the multifilament, and a mesh sheet is used in combination with a monofilament containing a flame retardant. I have no choice but to form.

In order to solve such a problem, the applicant of the present invention discloses in Japanese Unexamined Patent Publication No. 10-266577 that one of warp or weft is polypropylene multifilament and the other is polypropylene monofilament containing a flame retardant. A polypropylene mesh sheet is disclosed. However, the mesh sheet has problems such as poor flexibility in the monofilament direction and difficulty in folding, and there is also a problem that sufficient ventilation is not obtained.

[0005]

As described above, the mesh sheet for construction work is required to be flexible so that it can be easily folded and is easy to handle at the time of spreading work. Means that it is necessary to reduce the fineness of the warp and weft, and if the fineness is reduced, the strength as a sheet is reduced, and if the driving density is increased to improve the strength, the mesh spacing becomes smaller and the ventilation is reduced. There was a problem.

The present invention has been made in view of the above problems, and provides a mesh sheet for construction work which has high strength, flame retardancy, excellent flexibility, and excellent ventilation. The purpose is to

[0007]

In order to achieve the above-mentioned object, the mesh sheet for construction work of the present invention is a mesh sheet in which three woven structures of warp and weft are one set, of which three are One is a thermoplastic resin multifilament, the other two are thermoplastic resin monofilaments, and is composed of a woven or plain weave structure in which the multifilament is arranged in the center and the monofilaments are arranged on both sides thereof. It is something.

It is preferable that the mesh sheet for construction work has a wind force coefficient of 0.9 or less.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to FIGS.

In the present invention, the woven structure of the warp yarns 2 and the weft yarns 3 constituting the mesh sheet 1 is set to 3 sets,
It is composed of a dummy weave fabric 4 (see FIG. 1) or a plain weave 5 (see FIG. 2). One of the three is a thermoplastic resin multifilament 6 and the other two are a thermoplastic resin monofilament 7. The multifilament 6 is arranged at the center and the monofilaments 7 are provided on both sides thereof. It is used as a set of three arranged warps and wefts, and a space is formed between the warps 2 and the wefts 3 to form a gap 8 to produce a mesh sheet.

The mock-woven weave structure constructed as described above has 3
Of the set of warp and weft yarns, two yarns on both sides have a plain weave configuration, and the degree that the yarns in the center fly across the three yarns at the intersection point and the threads are tightened at the intersection point compared to the plain weave yarn. As a result, the hardness of the intersection is reduced and the flexibility is improved, and the width of the intersection is narrower than that of plain weave. Is characterized in that a woven fabric which is open and has many gaps can be obtained.

The total fineness of the thermoplastic resin multifilament is preferably 500 to 1500 decitex (hereinafter abbreviated as dt), and more preferably 600 to 1000 dt.
If the total fineness is less than 500 dt, the strength will be insufficient and 150
If it exceeds 0 dt, the flexibility is lowered, and the mesh interval is reduced, so that the ventilation property described later is lowered, which is not preferable.

The fineness of the thermoplastic resin monofilament is preferably 300 to 700 dt, and 400 to 600 dt.
Is more preferable. If the fineness is less than 300 dt, the strength becomes insufficient, and if it exceeds 700 dt, the flexibility is lowered, and the mesh interval is reduced, so that the ventilation property described later is lowered, which is not preferable.

It is preferable that the apparent striking density of the warp and the weft constituted as a set of three yarns is 3 to 10 yarns / 25 mm (actual number is 9 to 30 yarns / 25 mm). If the implantation density is less than 3 lines / 25 mm, it is difficult to obtain a predetermined strength, and if it exceeds 10 lines / 25 mm, the flexibility is reduced, and it is difficult to ensure sufficient mesh spacing, resulting in poor ventilation. It is not preferable. The construction work for the mesh sheet, the basis weight is preferably from 80~500g / ^{m 2,} and more preferably at 100 to 300 g / ^{m 2.}

In the present invention, it is preferable that the mesh sheet has a wind force coefficient of 0.9 or less, more preferably 0.8 or less, in a wind force coefficient measurement test described later. If the wind force coefficient exceeds 0.9, ventilation is deteriorated, and there is a problem that a scaffold or the like on which a mesh sheet for construction work is spread is collapsed by wind pressure at a construction site, which is not preferable.

Examples of the thermoplastic resin used in the present invention include polyolefins such as polyethylene and polypropylene, nylon, polyester and the like. Among them, polyolefin is preferable from the viewpoint of high strength, fiber moldability and low cost. As the polyolefin, specifically, high-density polyethylene, polypropylene and the like, which have excellent stretching effects and high strength, are preferable, and polypropylene is most preferable.

The polypropylene is a known polypropylene copolymer such as propylene homopolymer, ethylene-propylene block copolymer or random copolymer, or a mixture thereof, among which a high strength can be obtained. Propylene homopolymers are desirable for multifilaments, and those having an isotactic pentad ratio of 0.95 or more are preferably adopted.

In the present invention, it is preferable to add a flame retardant to impart flame retardancy. As the flame retardant, known flame retardants such as halogen-based, phosphorus-based, and inorganic-based flame retardants are used, but halogen-based flame retardants are preferable because they are excellent in processability at high temperatures, flame retardant effects, and are inexpensive, and especially bromine. Flame retardants are preferred.

Examples of the bromine flame retardant include aromatic bromine flame retardants such as tetrabromobisphenol A, decabromodiphenyl oxide, octabromodiphenyl oxide, bisdibromopropyl ether tetrabromosulfone, hexabrom cyclododecane and dibromoethyl dibromo. Examples thereof include alicyclic brominated flame retardants such as cyclohexane and liquid brominated flame retardants such as pentabromodiphenyl oxide and tetrabromodiphenyl oxide. These may be used alone or as a mixture of two or more kinds.
Of these, bisdibromopropyl ether tetrabromosulfone, which is suitable for imparting flame retardancy to polypropylene, is preferable.

It is preferable that the flame retardant is blended in an amount of 0.1 to 5% by weight based on the total weight of the mesh sheet. If the blending ratio is less than 0.1% by weight, the flame retardancy is insufficient, and if it exceeds 5% by weight, the flame retardant effect is not further improved and it is not economical.

In the present invention, in order to improve weather resistance, it is preferable to add a hindered amine light stabilizer and / or an ultraviolet absorber.

Examples of the hindered amine light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl)
Sebacate, tetrakis (2,2,6,6-tetramethyl-
4-piperidyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,3,4- Butane tetracarboxylate, 1- (2-hydroxyethyl) -2,
Polycondensate of 2,6,6-tetramethyl-4-piperidinol and diethyl succinate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane and 2,4-dichloro Examples thereof include polycondensation products of -6-tertiary octylamino-s-triazine.

As the ultraviolet absorber, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5'-methylenebis (2-hydroxy-4-methoxy) is used. Benzophenone-based UV absorbers such as benzophenone), 2- (2'-hydroxy-5'-methylphenyl)
Benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2 -(2'-hydroxy-3'-t-butyl
-5'-methylphenyl) -5-chlorobenzotriazole, 2,2'-methylenebis (4-t-octyl-6-benzotriazole) phenol and other benzotriazole-based UV absorbers, resorcinol monobenzoate, 2,4 -J
-t-butylphenyl-3'-5'-di-t-butyl-4'-hydroxybenzoate, hexadecyl-3-5-di-t-butyl
Examples thereof include benzoate-based UV absorbers such as 4-hydroxybenzoate.

In the present invention, the above flame retardant, light stabilizer,
It is preferable to add an ultraviolet absorber or the like to the monofilament before use.

The mesh sheet obtained as described above is cut into a predetermined size, and is used as the mesh sheet for construction work of the present invention by folding back the periphery or placing eyelets. It is preferable that the mesh sheet for construction work has a performance that passes the strength standard and the flameproof standard defined in JISA8952.

The thermoplastic resin used in the present invention includes an antioxidant, a dispersant, a lubricant, an antistatic agent, a pigment, an inorganic filler, an inorganic flame retardant, a cross-linking agent, within a range not departing from the gist of the present invention. You may mix | blend normally used additives, such as a foaming agent and a nucleating agent.

[0027]

As described above, the mesh sheet for construction work of the present invention is a mesh sheet having a weave structure of a plain weave or plain weave composed of a set of three warps and wefts, and has a predetermined size. For the fineness of the yarn required to give strength, the flexibility is provided by arranging one multifilament, and the thickness of the monofilament required for imparting flame retardancy is two monofilaments. By further improving the flexibility by comprising, the mesh sheet for construction work of the present invention obtained in this way has high strength, flame retardancy, flexibility, practical effect excellent in ventilation Is played.

[0028]

[Test method] 1. Wind force coefficient measurement test: Using a wind tunnel configured between a wind tunnel ceiling B and a wind tunnel floor C as shown in FIG. 3, a wind D is sent from one side of the wind tunnel and measured by a pitot tube E. In the wind speed test in which the wind force related to the mesh sheet 1 was measured by the wind tunnel balance A in the range of the wind speed, the wind force coefficient K calculated from the following formula was obtained. K: Wind force coefficient P: Wind force acting on the net (N) q: Velocity pressure (N / m ² ) A: Net area (m ² ) The velocity pressure q is V: wind speed (m / sec) ρ: air density (kg / m ³ ) 2. Stiffness: JIS L1096 (cantilever method) compliant 3. Flame retardance test: JIS A8952 compliant 4. Tensile test: JIS A8952 compliant

[0029]

EXAMPLES Example 1: Polypropylene (MFR = 20 g
/ 10 min., Density = 0.90 g / cm ³ , Tm = 15
8.0 ° C.) was used to form a total fineness of 760 dt / 100f multifilament 6. Next, polypropylene (MFR = 3.4g / 10min., Density = 0.90g /
cm ³ , Tm = 16.0 ° C.), 0.1% by weight of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate as a light stabilizer, 7% by weight of a masterbatch containing a flame retardant, etc., 0.5% by weight of (2′-hydroxy-3 ′ tert-butyl-5′-methylphenyl) 5chlorobenzotriazole (trade name: Tinuvin 326) as an ultraviolet absorber, and hydrotalcite (trade name: DHT-4) as an acid adsorbent.
A) 1 wt% and cyanine green pigment 1.9 wt% were blended to form a monofilament 7 having a single yarn fineness of 540 dt. The masterbatch containing a flame retardant, etc., comprises 60% by weight of a propylene-ethylene random copolymer, 15% by weight of bisdibromopropyl ether tetrabromosulfone, 1% of decabrom diphenyl oxide as a brominated flame retardant.
It is a mixture of 5% by weight and 10% by weight of antimony trioxide. The multifilament 6 thus obtained is arranged in the center, and the three filaments arranged on both sides of the monofilament 7 are used as a set for the warp 2 and the weft 3, and an apparent striking density 6 × 6/25 mm (actual number 18 × 18 / 25m
The mesh sheet 1 of mock weave structure 4 of m) was woven. The obtained mesh sheet 1 had a bending resistance in the longitudinal direction according to JIS-L-1096 (cantilever method) of 182 mm and good flexibility. The wind force coefficient is 4m / se.
Stable between 0.78 and 0.84 between c and 20 m / sec,
Ventilation was good. In addition, the mesh sheet for construction work formed from the above mesh sheet passed the flameproof standard of JIS A8952 with a flame contact number of 4 times in the flame retardancy test, and the tensile strength was 58.3 kgf / 3 cm in the longitudinal direction and the transverse direction. 56.6kgf / 3cm in either direction, JISA8952
It exceeds 50kgf / 3cm, which is the second class strength standard.

Example 2 The same procedure as in Example 1 was carried out except that the weave was plain weave (see FIG. 2). The plain weave tightened the intersections of the warp and weft yarns to make them bulky, and the mesh spacing was narrower than that of Example 1. The obtained mesh sheet had a longitudinal bending resistance of 218 mm according to JIS-L-1096 (cantilever method), and its flexibility was slightly lowered, but was practically sufficient. The wind force coefficient is 4m.
/ Sec to 20 m / sec was 0.82 to 0.88, and the ventilation was good.

[Brief description of drawings]

FIG. 1 is a plan view of a mesh sheet having a woven structure of a dummy weave according to an embodiment of the present invention.

FIG. 2 is a plan view of a mesh sheet having a plain weave structure according to another embodiment of the present invention.

FIG. 3 is a schematic diagram of a wind force test using a wind tunnel,
(A) is a front view in which a mesh sheet is attached to the wind tunnel balance, and (B) is a side view of an experimental apparatus in which the mesh sheet is attached to the wind tunnel.

[Explanation of symbols]

1 mesh sheet 2 warp 3 weft 4 imitation weave organization 5 plain weave 6 multifilament 7 monofilament 8 gap A wind tunnel balance B wind tunnel ceiling C wind tunnel floor D wind E Pitot tube

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4L048 AA15 AA20 AA24 AA48 AA53                       AB07 AB10 AB13 BA07 BA14                       CA11 CA12 DA30

Claims (2)

[Claims] 1. A mesh sheet comprising three warp and weft woven structures, one of which is a thermoplastic resin multifilament and the other two are thermoplastic resin monofilaments. And a mesh sheet for construction work, which is composed of a woven structure of a dummy weave or plain weave in which the multifilaments are arranged in the center and the monofilaments are arranged on both sides thereof. 2. The mesh sheet for construction work according to claim 1, which has a wind force coefficient of 0.9 or less.