JPH01174671A - Durable membrane material - Google Patents

Abstract

PURPOSE:To provide the subject membrane material of high strength and high modulus, high in fatigue resistance to repeated load such as flex or crumpling action, suitable for tents etc., having a construction with multifilaments as both weft and warp, resulting in a specified crimp rate. CONSTITUTION:A base fabric with a tensile elongation at break of <=10% and elastic modulus of >=5,000kg/mm<2>, having a construction with multifilaments of p-aramid fiber as both weft and warp, resulting in a crimp rate determined by the equation (L is length of the final membrane material; L0 is length of weft or warp) of >=1.5% is processed by regulating such conditions as weaving density, tension during weaving and tension on the waterproofing layer (e.g. of urethane resin), thus obtaining the objective membrane material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a durable membrane material that is less fatigued by external mechanical forces.

[Prior Art] In recent years, membrane materials have been increasingly used in buildings, marine structures, etc., and along with this, in addition to general properties such as strength, weather resistance, and flexibility, membrane materials have also been developed to In order to maintain quality for a long period of time, there is a need for highly durable membrane materials that have a high modulus of elasticity and less fatigue under repeated loads. Conventionally, in order to meet these demands, membrane materials have been developed in which a waterproof layer is provided on a woven fabric made of glass fiber filaments or fibers such as rose aramid fibers, which have a lower elongation at break and a higher modulus of elasticity than ordinary synthetic fibers. There is.

[Problems to be solved by the invention] However, although these conventional membrane materials have low cutting elongation and high elastic modulus, they are subject to long-term twisting or repeated bending due to repeated loads caused by wind or waves. If exposed to heat, the strength of the membrane material will significantly deteriorate due to fatigue of the base fabric, or
Alternatively, even if the strength deterioration in either the vertical or horizontal direction is small, the strength deterioration in the other direction is large, and the membrane material may not have the durability against long-term mechanical fatigue. There was a problem.

An object of the present invention is to provide a highly durable membrane material that has high strength, high modulus of elasticity, and is less prone to fatigue due to repeated mechanical loads.

[Means for Solving the Problems] The present invention employs the following means to achieve the above object. That is, 1, (1) the tensile elongation at break is 10% or less and the elastic modulus is 5,000 kg/a
It consists of a base fabric and a waterproof layer composed of multifilaments of +m2 or more as warp and weft, and is characterized in that the crimp rate of the warp and weft, as determined by the following formula (1), is 1.5% or more. It is a durable membrane material.

Crimp rate (%) - Rini: j = One of the characteristics of the membrane material according to the invention is that it has a low tensile elongation at break and a high modulus of elasticity so that the membrane material and structures made of the membrane material do not easily deform due to external force loads.

In order to achieve this purpose, it is important to use a base fabric whose yarn is a multifilament having a tensile elongation at break of 10% or less and a modulus of elasticity of 5,000 kg/mm 2 or more.

Multifilaments with such characteristics include para-aramid fibers, high strength, high modulus polyethylene fibers,
Examples include high-strength, high-modulus polyvinyl alcohol fibers and glass fibers, but there are no restrictions on the material as long as the multifilament satisfies the above characteristics.

Another feature of the membrane material according to the present invention is that the crimp rate of the warp and weft yarns expressed by the following formula (1) is 1.5% or more.

Crimp rate (%>=L)/L] x 1oo... (1) In the formula, Lo indicates the length of a certain length of membrane material, and Lo indicates the length of the warp and weft yarns that make up the certain length of membrane material. ) In other words, when the above-mentioned fibers are repeatedly subjected to loads such as bending or fir, they tend to become fibrillated or fold, which reduces the strength of the fibers, which is undesirable in terms of the strength of the membrane material. .

When the membrane material is subjected to bending or fir loading, it is important that the deformation that occurs in the base fabric is not directly received by the multifilaments that make up the base fabric, but that the load is absorbed by movement within the structure of the base fabric. be. By adopting such a base fabric structure, the burden on the constituent multifilaments is reduced.

That is, the crimp rate of the warp and weft of the base fabric shown by the above formula (1) is 1.5% or more, more preferably 2.
．． It is important that it be 0% or more. If the crimp rate is less than 1.5%, if the membrane material is subjected to a load such as bending or fir for a long period of time, the strength of the membrane material will deteriorate significantly, making it unsuitable for use as a membrane material for structures. Even if the crimp rate satisfies this condition only in one direction, if the fatigue resistance in the other direction is poor, the membrane material will not exhibit desirable properties.

In order to make the crimp rate of the base fabric 1.5% or more, it is necessary to adjust the selection of the weave structure of the base fabric, the weave density, the tension during weaving, the tension during scouring, the tension during waterproof layer processing, etc. It is possible. In particular, weaving density and tension during weaving are important for adjusting the weaving crimp rate.

The weave structure of the base fabric referred to in the present invention may be any structure as long as the crimp rate is satisfied. Further, the base fabric may be a mixture of a plurality of the above-mentioned multifilaments by twisting, interweaving, or the like.

The waterproof layer referred to in the present invention is a flexible resin coating layer made of resin or rubber that is integrated with the base fabric, and is applied either on both sides of the base fabric or only on one side of the base fabric. Also good.

Materials for such a waterproof layer include synthetic resins such as vinyl chloride resin, acrylic resin, urethane resin, silicone resin, and polytetrafluoroethylene resin, natural rubber, ethylene-propylene copolymer rubber, butyl rubber, chlorosulfonated polyethylene, and silicone. Rubber-based materials such as rubber and fluororubber, and flexible resin coating layers in which these materials are mixed or laminated are preferred.

The present invention will be further explained below with reference to Examples.

[Example] Example 1 The tensile elongation at break was 3.4% and the elastic modulus was 7,400k (1/
Two glass fiber multifilaments having a diameter of 5 microns and a count of 75 mm 2 were twisted together at a twisting rate of 3.3 twists per inch, and were used as weaving yarns to weave in a plain weave structure.

At this time, the density, weaving tension, etc. were changed to create four types of woven fabrics with different warp and weft crimp rates.

Both sides of each of these fabrics were coated with a soft polyvinyl chloride film via a urethane adhesive layer by calendering.

Each processed fabric was tested using a Scotto-type fir testing machine in accordance with JIS K632B 5.3.8 at a pressure load of 1 kg.
After conducting the fir test, and then conducting the fir test, J
Tensile strength was measured by the strip method of ISA-10966, 12°1.

From these results, the strength retention rate compared to before the fir test was calculated.

The crimp rate was calculated by dissolving and removing the soft polyvinyl chloride film on the front and back sides of each coated fabric using tetrahydrofuran, cutting it to prepare a test piece, and using the above equation (1) to measure and calculate the crimp rate. The results are shown in Table 1 below.

From the above cloth 1, it can be seen that when the crimp rate is 1.5% or more in both the vertical and horizontal directions, the strength retention rate after the kneading test increases.

[Effects of the Invention] The durable membrane material of the present invention retains the characteristics of the yarn constituting the base fabric, and has high strength and high modulus of elasticity, as well as high fatigue resistance due to repeated loads such as bending or fir. Because of its excellent durability, it is effective for large membrane structures such as membrane structures, air houses, liquid tanks, livestock silos, and wave-dissipating structures, as well as tents, simple warehouses, and marine seats. Can be applied.

Claims (1)

[Claims] (1) Tensile breaking elongation is 10% or less, elastic modulus is 5,
It consists of a base fabric made of multifilaments of 000kg/mm^2 or more as warp and weft yarns, and a waterproof layer.
A durable membrane material characterized in that the warp and weft yarns each have a crimp rate of 1.5% or more as determined by the following formula (1). Crimp rate (%) = [(L_0-L)/L] x 100...
(1) (In the formula, L is the length of a certain length of membrane material, and L_0 is the length of the warp and weft yarns that make up the certain length of membrane material.)