JPH1044274A - Translucent polymer composite material used for load supporting structure and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woven fabric-reinforced translucent polymer composite material for a building used for a load supporting structure and a method for manufacturing it. SOLUTION: The translucent polymer composite material has a translucency of at least about 23% for a perpendicularly incident visible light. If the material receives a biaxial load at 1:1 of 25% or less of a uniaxial tensile break strength of woven fabric, a warp direction exhibits a value of a biaxial elongation larger than zero and smaller than 1.0%, and a weft direction exhibits a value of a biaxal elongation larger than the value of the biaxial elongation of the warp direction and smaller than 10%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composite used to construct a load-bearing structure for buildings. In particular, the present invention relates to fluoropolymer composites containing a reinforcing fabric that improves the translucency of the membrane for the load-bearing structure.

[0002]

BACKGROUND OF THE INVENTION Building and civil engineering engineers have used tensioned plastic or rubber coated fabrics as load bearing structures in architectural design for many years. A load bearing structure is a building component that is adapted to the application of external mechanical forces (or loads) without losing its physical integrity. A typical load bearing structure comprises a frame composed of arches and / or beams. Load-bearing structures incorporating the coated fabric were originally used in the design of air-supported shelters for moving exhibits and were used as housings for microwave antennas.

[0003] More recently, coated fabric load-bearing structures have been applied to tensioned prestressed members resulting from stretching of the coated fabric throughout the arches and beams of the structure. Evolved. As a prestressed member, the internal tension in the stretched fabric provides additional resistance to deformation when another load is applied to the structure.

[0004] In the earliest structures into which the coated fabric was incorporated, the coated fabric acted as a reinforcement to control the shape of the structure and to promote the load bearing properties of the structure. The most common coating materials include rubber, such as neoprene, and plastic, such as polyvinyl chloride or polyurethane. The most commonly used woven reinforcements were simple plain woven fabrics of nylon or polyester yarn.

[0005] In a typical example of a prior art coated fabric for a load-bearing structure, additives are incorporated into the coating material to protect the structure from the environment. For example,
Additives can be incorporated into the coated fabric to reduce the effects of ultraviolet light from sunlight on both the coating polymer and the fibrous reinforcement, thus improving the outdoor durability of the coated fabric. Such additives are:
While protecting the coated fabric from the environment, it also substantially reduces or eliminates the translucency of the coated fabric. Light is innumerably small gaps or openings in the coated fabric (so-called,
(A window in a woven fabric) to penetrate the coated fabric.

[0006] Additives or fillers fill these openings during the coating, and block the passage of light very significantly. Also, a flame retardant or a flame retardant plasticizer that can be used as a filler may collect dust from the surroundings on the surface, and further impede light transmission for a long time. For this reason, the earliest coated fabrics for load-bearing structures have been used only for applications that can tolerate low light transmittance. Due to the above-mentioned drawbacks with respect to light transmission, fire resistance and environmental durability, the use of these early coated fabrics was limited to "temporary" building structures.

[0007] In 1970, coated fabric composites for use in load-bearing structures were developed using special coating and fabric weave arrangements, changing the application from "temporary" structures. Expanded to permanent buildings. In particular, researchers have found that composites consisting of plain woven glass fibers and a perfluoroplastic (eg, polytetrafluoroethylene) coating are advantageous. Polytetrafluoroethylene (PTFE) is known to impart resistance to ubiquitous environmental elements (sunlight, water, oxidants) as well as fire. Researchers have combined the advantageous properties of PTFE with the preferred aspect of the strength / weight ratio of plain woven glass fibers to produce composites useful for permanent structures.

In 1973, load-bearing composites in which a plain woven glass fiber fabric was coated with a perfluoropolymer were used in a tensioned fabric structure. These composites did not incorporate additives to improve flame retardancy. These structural complexes are available from Chemfab, Merrimack, NH, USA.
b) ・ SHEER FI
LL, manufactured under the names I and II, transmitting less than 10% of incident visible light and maintaining adequate structural strength. Subsequent structural complexes, such as SHEER FILL® IIA manufactured by Chemfab Corporation, Merrimack, NH, USA, transmitted about 12% of the incident visible light. The development of this type of structure was initiated at the Institution of Struc- tures, June 4, 1980 in London.
uctural Engineers) Air-supported structures supported by Symposium on Air-Supported S
tructures: State-of-the-art). These materials still occupy the state of the art to date.

[0009] In addition to the primary desired properties of weatherability, non-combustibility, good light transmission and self-cleaning ability, load bearing structures incorporating the coated fabric composite are first and foremost a matter of importance. Need to function as construction material. Such structures need to be strong enough to withstand the various static and live loads encountered during use. Moreover, the fabrication and installation conditions for composites having favorable mechanical properties can create additional mechanical constraints that further narrow the range of key design parameters.

For example, a safety factor of 4 to 8 times is usually applied to the uniaxial tensile strength at break of a fabric reinforced composite used for a load supporting structure. That is, when designing a coated fabric composite for use in a load-bearing structure, engineers typically use a fabric having a uniaxial tensile breaking strength of at least four times the maximum load encountered by the structure. . In other words, the maximum design load is 25% of the uniaxial tensile strength at break.

[0011] Load bearing structures typically encounter three types of loads: installation loads, prestress loads, and live loads. As mentioned above, the load-bearing structure is
In a typical example, the maximum of these loads is designed to be 25% of the uniaxial tensile strength at break of the fabric.

[0012] The optic density of woven glass fiber fabrics that must ultimately meet the required safety factors at various loads
l density) substantially reduces the light transmission capacity of the woven fabric, especially after the reinforcing woven fabric has been coated with polytetrafluoroethylene. Moreover, clustering the glass fiber content into heavier, bulkier yarns to produce structures with larger gaps or windows results in woven products having undesirable morphologies that are not easily coated or laminated. Often. Despite overcoming the difficulties of the coating process, coated woven composites formed based on such relatively coarse reinforcing woven fabrics are not sufficiently easy to finely pattern structural panels. Often do not elongate.

Engineers have determined the ability of a coated fabric composite to function effectively in a load bearing structure by referring to the modulus curve for the coated fabric composite. The modulus curve plots the biaxial elongation of the composite for various biaxial loads applied to the composite. When constructing a modulus curve for a coated fabric composite, a technician applies several types of biaxial loads to the coated fabric composite and measures the biaxial elongation associated with each load. In a typical example, the technician applies a 1: 1 biaxial load (i.e., the loads in the warp and weft directions of the woven fabric are equal) when determining the biaxial elongation, but applies loads of different ratios. To determine the biaxial elongation associated with a particular load condition.

It is preferable to use a coated fabric composite which does not exhibit a negative biaxial elongation when subjected to an installation load, a prestress load and a biaxial live load for the load supporting structure. In fact, glass fibers exhibit good strength under tension but poor properties under compression. Therefore, negative biaxial elongation, equivalent to compression, is undesirable because it affects the effectiveness of using the composite in a load-bearing structure. To date, engineers have not successfully developed a coated fabric composite that exhibits high translucency and retains the ability to function effectively as part of a load bearing structure. Prior art composites with high translucency necessarily exhibit negative biaxial elongation values when subjected to installation, prestressing and live loads, or the properties of the prior art composites Shows a small total elongation that is too fragile to be easily installed in the intended application.

[0015]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a coated fabric composite having improved translucency and providing desirable tensile breaking strength and biaxial elongation characteristics to a load-bearing structure. It is to provide a manufacturing method thereof. Another object of the present invention is to provide a fabric having a uniaxial tensile strength at break of 2%.
Coated fabric composite which does not exhibit a negative biaxial elongation when subjected to an installation load, a prestress load and a live load in both directions of warp and weft under a load of 5% or less, and a method for producing the same Is to provide.

[0016]

The translucent polymer composite used in the load-bearing structure of the present invention is a composite obtained by coating a woven fabric with a polymer. The woven fabric is constructed according to a specific design that achieves improved translucency and achieves the desired tensile strength and associated biaxial elongation properties to make the composite useful for load bearing structures. .

[0017] The translucent polymer composite of the present invention comprises a woven fabric substrate comprising yarns arranged perpendicular to the warp and weft directions, and at least a woven fabric substrate provided on the substrate. With one type of polymer coating. The yarns of the woven fabric are woven in a mock leno pattern. Alternatively, if the number of threads in the weft direction is equal to or greater than about 1.25 times the number of threads in the warp direction, the threads can be woven in a plain weave pattern.

The composite of the present invention has a translucency of at least about 23% for normally incident visible light. Further, the composite of the present invention has a uniaxial tensile breaking strength of 25% of the woven fabric.
Under the following 1: 1 biaxial load (equal to warp and weft stress), a) biaxially greater than or equal to zero in the warp direction, and b) larger than the warp direction in the weft direction. Indicates the value of elongation.

In a preferred embodiment of the present invention, the composite according to the present invention is characterized in that the composite has a uniaxial tensile strength at break of 25% of the woven fabric.
When the following 1: 1 biaxial load is applied, the biaxial elongation values are 1.0% or less and 10% or less in the warp direction and the weft direction, respectively.

[0020] The woven fabric is most preferably based on glass fiber yarns to achieve the desired properties such as outdoor durability and fire resistance. The most preferred material for coating the woven fabric is tetrafluoroethylene (TFE),
Hexafluoropropylene (HFP), and a perfluoropolymer selected from the group consisting of homopolymers and copolymers of fluorovinyl ethers, including perfluoropropyl vinyl ether (PPVE) and perfluoromethyl vinyl ether (PMVE).

Another preferred class of polymers useful in the polymer matrix used in the improved architectural translucent composites is based on monomers including chlorotrifluoroethylene (CTFE) and vinylidene fluoride (VF ₂ ). As a homopolymer or as a copolymer with TFE, HFP, PPVE, PMVE, and ethylene or propylene. These fluoropolymers are sufficiently low in temperature so that they can be coated or laminated onto a woven substrate of low temperature capability yarns such as polyester or nylon. To melt or soften.

Other polymer matrices used to coat the woven fabric include polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and copolymers thereof with acrylic acid or acrylate or other vinyl ester monomers. It can be selected from the group consisting of polymers. In this case, if desired, an additional fluoropolymer layer can be provided (by coating or laminating) on the woven fabric coated with the polymer.

The present invention also relates to a method for producing a translucent polymer composite used as a building membrane.
The method comprises the steps of: a) producing a woven fabric by placing it orthogonal to the warp and weft directions; b) the composite comprising at least about 23% for normally incident visible light.
And i) greater than or equal to zero in the warp direction when the composite is subjected to a 1: 1 biaxial load of no more than 25% of the uniaxial tensile strength at break of the woven fabric; And ii) selecting the filament type, the number and diameter of the yarn, the number of threaded yarns, the crimping of the yarn, and the weaving pattern of the woven fabric so that the biaxial elongation value in the weft direction is larger than that in the warp direction. And c) coating the woven fabric with at least one polymer.

The additional steps in the above-described method of the present invention include:
If the woven fabric can withstand the temperature required to melt the polymer, then the step of melting the polymer coating on the woven substrate. If the woven substrate cannot withstand the temperature required to melt the polymer, the method of the present invention separately produces and melts the polymer film, and then divides the film into the woven substrate. Or laminating to a coated substrate.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred translucent composites suitable for the building structure of the present invention are about 10 to 30 threads / inch (25.4 m) in each of the warp and weft directions.
m). The warp and weft are arranged orthogonally.

The yarns of the woven fabric are preferably woven in a mock leno pattern. FIG. 1 shows a woven pattern of a 6 × 6 mock leno woven fabric. If the number of yarns in the weft direction is equal to or greater than about 1.25 times the number of yarns in the warp direction, the yarns can be woven in a plain weave pattern. FIG. 2 shows a woven pattern of a 2 × 2 plain woven fabric. FIG.
2 shows only the woven pattern of the woven fabric according to the present invention, and does not show the opening area actually existing in the woven fabric structure according to the present invention.

A coating of at least one polymer is provided on the yarns of the woven fabric. The coated woven fabric has a translucency of at least about 23% for normally incident visible light and is configured to provide a non-negative biaxial elongation.

When subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric, the biaxial elongation in the warp direction of the composite is greater than or equal to zero, and 0
% Is preferably not exceeded. The biaxial elongation in the weft direction of the composite at these levels is preferably greater than the biaxial elongation in the warp direction and does not exceed 10%.
The upper limit for biaxial elongation in the warp and weft directions is important. The reason is that beyond these upper limits, the composite becomes practically unuseful; that is, it becomes very difficult to form a load-bearing structure using the composite.

The coated woven composite according to the present invention has been found to have a substantially higher light transmission than that currently available. The composites of the present invention (see Tables 4 to 5 described below) have comparable weights (comparable w) shown in Tables 1 to 3.
eight) and transmits a significantly greater percentage of normally incident visible light, as opposed to those of the prior art plain woven comparative designs which have less favorable mechanical properties.

The uniaxial tensile strength at break of the composites shown in these tables is a function of the strength and number of individual glass fiber yarns woven into the reinforcement, and the crimp created on the yarns during the weaving process. . As the number of yarns in the woven fabric increases, the strength of the composite increases. However, as the crimp of the yarn increases by the weaving process, the strength of the woven fabric decreases. Therefore, the selection of an appropriate number of yarns and an appropriate crimp are important fundamentals in achieving the desired balance between strength and modulus.

Similarly, the elongation properties of the composite are affected by the amount of crimp combined with the number of yarns in each orthogonal direction. However, if a biaxial load is applied to the composite in which the woven reinforcement is used, the elongation in each direction is also a function of the relative load in each direction (ie, the warp or weft direction), Thus, it can be positive or negative as a function of the number of strikes, crimps and load ratio. In fact, glass fibers have good strength under tension, but have poor properties under compression, so negative elongation is undesirable. Therefore, the widespread use of glass fiber yarns imposes additional constraints on the number of allowable strikes and crimps in order to obtain positive elongation in both directions.

Furthermore, almost all of the light transmitted through the complex is "gaps" or "windows".
ows), and the size of these windows is determined by the number of threads and the number of crimps in addition to the diameter of the yarn. Usually, the light transmittance or translucency is substantially reduced.

Definitions of Terms in Tables Tables 1 to 3 show data on various conjugates of the prior art, and Tables 4 and 5 show data on conjugates of the present invention. The terms used in these tables, along with a brief description of the tests used to quantify the values shown in the tables,
explain.

[0034] Yarns are generally used for continuous strands of textile fibers, filaments or other materials in a form suitable for forming a textile fabric by knitting, weaving or other combined methods. Is a term. The yarn is in the following form: (1) a form in which several fibers are twisted (spun yarn),
(2) for use in a form in which a number of untwisted or twisted filaments are aligned, (3) in the form of a single untwisted or twisted filament, or (4) for use in fabric construction. In the form of narrow strips or materials, such as untwisted or twisted paper, plastic, film or metal foil.

The yarns are listed in these tables in the
n), which is a plied yar
The number of single yarns and the number of strands combined to form each successive unit of n) are shown. For example, in Table 3, NSP A9
6032a has a B150 4/2 yarn configuration, which starts with a beta size filament which is 1500 yards / pound (30.24 m).
/ G). Four single yarns are twisted together and called 4/0.
The termediate material is formed and then the two 4/0 intermediate materials are twisted to form a 4/2 configuration. This configuration can be compared with the configuration of the example of NSP A96053 shown in Table 4. In this example, two identical single yarns (B15
(0 1/0) is twisted to form an intermediate material called 2/0, and the four 2/0 intermediate materials are twisted to 2/4.
Forming a configuration.

The number of drives is the number of warp and weft yarns per inch of woven fabric, which corresponds to the number of rows and columns in the knitted fabric. The number of shots is
It is determined by placing a piece of woven fabric on a flat surface, removing unnatural creases, and counting the number of warp and weft yarns per inch (25.4 mm) of the woven fabric. As can be seen from Tables 4 and 5, the number of threads in the woven fabric according to the present invention ranges from about 10 to 30 threads per inch (25.4 mm) in the warp and weft directions. Also, numbers of shots outside of this range may be useful in the present invention.

Gauge is a general term for various types of equipment used to measure pressure or thickness.
The term "gauge" as used in describing the present invention means thickness as indicated in the table. The gauge is determined by a weight dial micrometer that is well known in the art.

The uniaxial tensile strength is the ultimate strength of the cross section of the woven fabric at the time of breaking when tensioned along either the warp or the weft. Generally, this value is different from the long-term holding strength of the material.

The test for measuring the uniaxial tensile strength at break is as follows. Cut three specimens in the warp direction, and
Each specimen is cut in the weft direction. These specimens are chosen so that the same group of yarn is not tested more than once. In the case of a warp oriented specimen, follow the warp and mark a point of at least 8 inches (203.2 mm); approximately 1 in parallel from this first warp (including the partial thread within the specimen). The second warp yarns separated by inches (25.4 mm) are similarly traced and marked. A similar method is used for the specimen in the weft direction to be generated.

Using a practical knife, the specimen is cut without damaging the thread of the specimen. Each specimen is
Place in a tensile tester set at a constant elongation rate of 2 ± 0.1 inches (50.8 ± 2.54 mm) / min. Using jaws 3 "(76.2 mm) apart from each other on the tensile tester, the specimen occupies a central location between the jaws and along the axis of the tensile tester. So that they line up,
Insert the specimen. While applying stress to the specimen, the load versus elongation is recorded. The peak load is read as the uniaxial tensile strength at break, and the average value of the test specimens tested in each direction is recorded.

[0041] Tensile strength (trapezoid) is the force required to initiate or continue a tear in a woven fabric under certain conditions and can be measured as follows. Three specimens are cut in the warp direction, and three specimens are cut in the weft direction. These specimens are chosen so that the same group of yarns is not tested more than once. In FIG. 3, each specimen is 3 ″ × 6 ″ (76.2 mm × 152.4 m).
m) The rectangular shape of the "warp" test, the longer dimension is aligned along the warp, and the "weft" test is aligned with the longer dimension along the weft. Using a template, add 3 ″ (7
6.2 mm) and 1 ”(2
5.4mm) and 4 "(101.6mm) base
Mark.

A 5/8 "(15.9 mm) long slit is cut perpendicular to the trapezoidal 1" (25.4 mm) base. This test specimen was weighed 12 ± 0.5 inches (304.8 ± 0.127 m
m) / min Place in a tensile tester set at a constant elongation rate. Use the jaws that are 1 "(25.4 mm) apart from each other in the tensile test, so that the trapezoidal marks are parallel to the jaws.
Insert the specimen. As the short side of the trapezoid is strongly stretched,
Center the slit between the clamps (half wa
y). The specimen is torn and the load versus time peak recorded. After tearing the specimen, read the values of the load of the five highest peaks and record the average of these peaks as the tear strength of the specimen (see FIG. 3).

Bow and skew are different drawbacks in the dimensional stability of woven fabrics. The bow-shaped warp is the degree to which the weft yarn in the central part of the woven fabric is deformed from its original shape under load, and the other distortion is
To the extent that the weft is deformed from one edge of the woven fabric to the other.

Light transmittance is a measure of the translucency of the composite of the present invention and can be measured as follows. 4 "x 6" (101.6mm x 152.4mm) from composite sample
Specimen was cut out at 720 ° F in an air circulation furnace.
16 at ± 10 ° F (382.2 ° C ± 5.55 ° C)
Heat bleaching for time (-0, +1 hour)
Prepare for the test by doing so. The specimen is cooled to room temperature before testing. The sample is tested using a visible light range spectrophotometer with a specular element and a wide field of view.

The measurement is carried out at three places on the specimen (one face faces the light source at two places and the opposite face faces the light source at one place) at intervals of 10 nm in the range of 400 to 750 nm. The average of the three readings is recorded for each wavelength. The average light transmittance% is 400, 450, 500, 550, 600, 65 in the visible region of the solar spectrum.
The light transmittance% at 0, 700 and 750 nm was assigned the following weighting factors: 0.0575, 0.123,
0.148, 0.145, 0.142, 0.143,
Calculated by summing the values obtained by multiplying by 0.135 and 0.106.

Using the open area as a predictor, the yarn-free plane area of the stiffener woven fabric (plana
r area) Find%. The opening area is given by the following equation: Opening area = (1− _Cw × _Dw ) × (1− _Cf × _Df ) ×
100 can be calculated. In the above equation, C _w and C _f are the numbers of warp and weft, respectively,
_w and D _f is the diameter of each warp and weft. The number of shots is obtained by the method described above. The "diameter" of a yarn is, in fact, the length of the major axis of the elliptical cross-section of the yarn resulting from the flattening of the yarn as it is tensioned in the weaving and coating process.

The yarn diameter is measured by direct microscopy or by extrapolating "diameter" data from similarly twisted yarns. The major axis diameters used in the calculations in the table below are as follows: Yarn Type Diameter (inches (mm)) B150 4/2 0.0300 (0.762) B150 4/3 0.0382 (0.970) B150 2/2 0.0193 (0.490) B150 2/4 0.0284 (0.721) B150 2/3 0.0246 (0.625)

Elongation is a measure of the deformation in the load direction caused by tensile forces. Depending on the application, a static test or a dynamic test can be used to measure the elongation at a specific load or elongation at tensile break. For certain applications, it is useful to measure the elongation of the woven fabric under biaxial as well as uniaxial loads. Typically, percent elongation is measured at a specific load, such as a prestressed load or a maximum load. The maximum biaxial stress is a load that is 25% of the uniaxial load that causes the woven fabric to break, as shown in the experimental data below.

The uniaxial load is measured as follows. Three specimens are cut in the warp direction, and three specimens are cut in the weft direction. In the case of the specimen in the warp direction,
Follow the warp yarn and at least 16 inches long (406.
Mark by a line on the surface at 4 mm).
A second warp parallel to the first warp (including the inner part of the specimen) and 1 inch (25.4 mm) away is similarly traced and marked. In the same manner, the weft direction specimen to be generated is marked by following the specimen. The specimen is then cut using a practical knife along the marked line and the tensile evalua
option). At this time, take care not to damage the yarn of the specimen. After cutting all specimens, place them on the table and mark them.

Using a steel ruler and divider,
1 "from 3" (76.2 mm) from the end of each specimen
Measure the 0 "(254.0 mm) section. Press the divider against the woven fabric, mark at a length of 10" (254.0 mm) and make a small hole. Mark this hole with a pen for quick identification. With the marked gauge length facing outward, one end of the specimen is fixed to the weight holding clamp, and the other end of the specimen is fixed to the clamp attached to the fixed rack. This step can be repeated for other specimens. After all specimens have been mounted on the rack, a 40 # weight is hung on each lower clamp. After one hour, the distance between the holes made in the specimen is measured. The measurement is performed with the specimen kept under load.

Using a divider, place the tip in the hole and measure the distance using a 1/100 increment. The elongation of each specimen is calculated by the following equation: uniaxial elongation% = [(L−L ₀ ) / L ₀ ] × 100. In the above equation, L is the length between holes after applying stress for one hour, and L ₀ is the initial length between holes. Record the average value of the specimens tested in each direction to one decimal place.

The biaxial elongation is measured as follows. FIG.
The specimens are cruciform with arms aligned with the warp and weft directions, respectively, of the fabric, as shown in FIG. The total length in each direction is 22.83 inches (580
mm) and the width of each arm is 6.30 inches (160 m
m). The corners of the specimen are rounded with a radius of 0.20 inch (5 mm). Each arm is provided with a slit halfway longitudinally from the central biaxial field to the end of the arm, and three specimens from a woven fabric section at least 2.95 inches (75 mm) from each fabric ear. Collect.

The tester simultaneously applies a load of 1: 1 ratio to the specimen in the warp direction and the weft direction. Loads in the warp and weft directions are applied from both sides of the specimen so that the center point of the specimen does not change.

When the specimen is mounted on the testing machine, a chuck clamp (chucking) is provided at a predetermined position on the cross arm where the warp direction and the weft direction are aligned with the testing machine.
clamps). The specimen is fixed so that no excessive stress acts on the specimen and no excessive wrinkling occurs. The specimen is gripped during the test so that a uniform force is applied in the warp and weft directions and that it is applied firmly enough to prevent slippage between the specimen and the clamp. .

The strain occurring in the biaxial field at the center of the specimen is measured simultaneously under load in the warp and weft directions. The distance between the initial elongation measurement points is between 0.79 inches (20 mm) and 3.15 inches (80 mm).

After each specimen is mounted on the tester, the stress-strain value is measured as follows (the load ratio and the load speed are maintained, regardless of whether a load is applied or not): (1) ) While maintaining a load ratio of 1: 1 in the warp direction and the weft direction in the axial direction, each axis is 0.16 inch / min (4 mm / min) and is 1/4 of the uniaxial tensile breaking strength of the woven fabric.
(25%) and record the load-elongation value as the first load cycle.

(2) Immediately after the load is applied, the load is reduced to 1/20 (5%) of the uniaxial tensile strength at break. The specimen is held at 1/20 (5%) of the uniaxial tensile strength at break for 5 minutes and then relaxed to zero load. (3) A load was again applied to the specimen at 0.16 inch / min (4 mm / min) to 1/4 (25%) of the uniaxial tensile strength at break.
The load-elongation value is recorded as the second weight cycle. The specimen is then immediately relaxed to zero load. This cycle is repeated once without a holding period, and the value of load-elongation is recorded as the third weight cycle.

The data for the three specimens is plotted on a graph and the elongation value at a particular comparison point is recorded. FIG. 5 is an example of a graph showing stress-strain data in the first and third load cycles. Comparative values of elongation (shown as strain in the graph) can be read from these graphs. The normal comparison point is the estimated installation (in
stallation) Load (39pli (6
96 kg / m)) and the prestress load after removing the hysteresis of the material (1 in the third load cycle).
1 pli (196 kg / m)) and the strain at the maximum biaxial test load after removing the hysteresis of the material. The values at these three normal comparison points are shown in the table.

Other specimens were tested at load ratios of 2: 1, 1: 2, 1: 0 and 0: 1. In each of these tests, the change in strain during the third load cycle was used to calculate the tensile modulus and Poisson's ratio of the material.

Comparative Test Results Tables 1, 2 and 3 illustrate the problems associated with prior art plain woven glass fiber woven fabrics, which have adequate overall tensile strength. However, the total light transmittance is limited, and even if the number of warp yarns and weft yarns is changed, the yarn does not have an appropriate elongation under a biaxial load. As a result, it has been difficult or impossible to avoid a negative elongation of the warp yarn.

As shown in Table 4, NSP A96037
a, NSP A96037b, NSP A96047
a, NSP A96047b, and NSP A960
In the example of 53, the use of a mock lenotype woven glass fiber woven fabric in the composite overcomes the limited translucency of the composite reinforced with the prior art plain woven fabric, as well as the end use Significantly greater light transmission can be readily achieved in practice than PTFE coated glass fiber woven products currently available for architectural applications. The elongation properties of the various embodiments shown in Table 4 indicate that composites using woven fabrics in the mock leno weave style can be patterned and installed in the same manner as plain woven products of the state of the art, and substantially more. Shows large translucency.

The data shown in Table 4 demonstrate the advantageous aspects of the composite, including the desired translucency and mechanical properties of the composite using a mock leno weave style fabric. These data show relatively high tensile break strength and positive (ie non-negative) biaxial elongation in the warp and weft directions. In particular, these complexes are 23.4-28.8%
And a biaxial elongation value of 0.04 to 0.42% in the warp direction when subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile breaking strength of the woven fabric. And in the weft direction, exhibit a biaxial elongation value of 0.70 to 3.17%. Thus, these composites exhibit excellent translucency and perform well mechanically in structures under tension.

The mock leno reinforcement according to the invention advantageously forms large size gaps or windows under the action of tension, thereby increasing translucency. Moreover, the elongation characteristics of this preferred type of woven fabric are advantageously superior to those of plain woven fabrics, apparently due to the fact that it is a mixed structural mixture of plain weave and satin weave modes.

According to a preferred embodiment of the composite of the present invention, the improved light transmission is approximately one-third greater than in currently available architectural PTFE / glass fiber fabrics, which are reinforced with a mock leno woven fabric. The composites of the present invention are achieved by using the disclosed composites and exhibit non-negative biaxial elongation properties in both warp or weft directions.

Table 5 shows data on composites using the plain woven fabric according to the present invention. Complex A9602 in Table 5
4a to 4c are specific examples in which the number of yarns driven in the warp direction is 1.25 times or more the number of yarns driven in the weft direction. These composites have translucency values of 21.6 to 25% and are subject to 1: 1 biaxial installation, prestress, and maximum loads of up to 25% of the uniaxial tensile strength at break of the woven fabric. In the case of these composites, these are 0.0-0.15 in the warp direction.
% Biaxial elongation value of 2.5 to 8.6 in the weft direction.
% Biaxial elongation value.

In Table 5, the complex NSP A9602
4d has a woven fabric yarn composition of 12 × 14 (warp × weft).
Therefore, the number of yarns driven in the weft direction is smaller than 1.25 times the number of yarns driven in the warp direction. The resulting composite exhibits a negative biaxial elongation value when subjected to a certain load. As explained above, negative biaxial elongation values make composites of such a configuration undesirable for use as load bearing structures.

[0067]

EXAMPLE 1 A preferred embodiment of the present invention having a translucency of at least about 23% was made to meet the targeted warp (w) and weft (f) tensile or break strengths. Things. Biaxial elongation did not show a negative stress value. Thus, the warp elongation (BEW) was greater than zero and the weft elongation (BEF) was greater than BEW.

In this way, 11 ° C.
A sy (ounce / (yard) ² ) (373 g / m ² ) glass fiber woven fabric was woven. The substrate was a 6 × 6 mock Leno weave consisting of B150 2/4 yarn in both warp and weft directions. The number of shots was 19 x 16.5 yarns / inch (12.5 cm) in both warp and weft directions. This substrate is referred to as NSP A96053 in the CHEMFAB style (shown in Table 4). This substrate was subjected to a heat cleaning treatment to remove the residual sizing agent. The substrate was then lubricated again by applying methylphenyl silicone oil (ET-4327 (trade name) obtained as an aqueous emulsion from Dow Corning, solids content 35%) onto it. The silicone oil is immersed in a two-zone coating tower having a dry zone temperature of 200-300 ° F. (93.3-148.9 ° C.) and a sintering zone temperature set at 550 ° F. (267.8 ° C.). By drying and drying, 4% by weight was applied to the substrate.
In the first coating process, only the yarn in the substrate is coated,
The windows remained open.

PTFE (T31 obtained from DuPont)
3A (trade name, applied at 53% solids) by immersing the substrate in a total of about 7.
A second coating of 5 osy (254 g / m ² ) was applied. The coating was dried and sintered in a two-zone coating tower having a drying zone temperature of 350 ° F (176.7 ° C) and a sintering zone temperature of 680 ° F (360.0 ° C).

A total of about 15 osy, using a formulation of T313A containing an additional 4% (wt% based on PTFE solids) of a surfactant (Triton X-100 from Union Carbide). A third coating (509 g / m ² ) was applied. The coating was deposited at 56.3% by several passes through a two-zone coating tower, dipping, drying and baking or sintering. The drying zone temperature was 350 ° F (176.7 ° C). The sintering zone temperature was 680 ° F. for the first, fourth and fifth passes.
(360.0 ° C.) and 600 ° F. (315.6 ° C.) for the second and third passes.

PFA dispersion liquid (T obtained from DuPont)
E-9946 (trade name), applied at 38% solids)
Was used to provide a top coat, thereby completing the composite. The topcoat is dipped, dried and sintered in a two-zone coating tower to provide about 1.5 osy (5
0.9 g / m ² ). Drying temperature is 350 ° F
(176.7 ° C.) and a sintering temperature of 680 ° F. (36 ° C.).
0.0 ° C).

The results of the physical tests performed on this composite are shown in Table 5, which shows that the composite has a translucency of 23.4% and the composite has a biaxial tensile strength at break of 25%. %
The biaxial elongation value under the following installation load, pre-stress load and maximum load is 0.04-0.
19%, indicating that it was 1.87 to 3.17% in the weft direction.

FIG. 5 shows the modulus curve of the complex NSP A96053. FIG. 5 is a curve for the first and third weight cycles. The curves for the second weight cycle fall within these first and third weight cycle curves. These curves show the three NSPs tested.
The biaxial elongation of one of the A96053 specimens is shown.

As can be seen from FIG.
Under a 1: 1 biaxial load of 40 pli (2500 kg / m) (about 25% of the woven "design" uniaxial tensile strength, which is slightly less than the actual uniaxial tensile strength shown in FIG. 5) In addition, the biaxial elongation is greater than or equal to zero in the warp direction and greater than the warp direction in the weft direction. This composite has high translucency properties, and structurally,
Sufficient for use in load bearing structures.

The present invention extends to all modifications and equivalents of the embodiments set forth in the specification and examples which fall within the scope of the appended claims.

[0076]

[Table 1]

[0077]

[Table 2]

[0078]

[Table 3]

[0079]

[Table 4]

[0080]

[Table 5]

[Brief description of the drawings]

FIG. 1 is a plan view of a woven pattern of a 6 × 6 mock leno woven fabric in an example of the composite of the present invention.

FIG. 2 is a plan view of a woven pattern of a 2 × 2 plain woven fabric in an example of the composite of the present invention.

FIG. 3 is an explanatory view showing an arrangement of a trapezoidal tear strength specimen during a test.

FIG. 4 is an explanatory view showing an arrangement of a biaxial elongation specimen during a test.

FIG. 5 is a graph showing a modulus curve of an example of the composite of the present invention.

Claims (36)

[Claims] 1. A translucent polymer composite used for a load-bearing structure, wherein the composite comprises a woven fabric substrate composed of yarns arranged orthogonally to a warp direction and a weft direction, and At least one polymer coating provided on the composite, wherein the composite has at least about 23 for normally incident visible light.
% Under a 1: 1 biaxial load of less than 25% of the uniaxial tensile strength at break of the woven fabric, a) greater than or equal to zero in the warp direction. B) a translucent polymer composite for a load-bearing structure, characterized in that it exhibits a biaxial elongation value greater in the weft direction than in the warp direction. 2. When the composite receives a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric, the biaxial elongation in the warp direction is 1.0% or less. The composite according to claim 1, wherein the composite is present. 3. The biaxial elongation value in the weft direction is 10% or less when the composite is subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric. 3. The composite according to claim 2, wherein 4. The composite according to claim 3, wherein said woven fabric is made of glass fiber yarn or polyester yarn. 5. The method according to claim 1, wherein the polymer coating is a fluoropolymer selected from the group consisting of chlorotrifluoroethylene (CTFE) monomer and vinylidene fluoride (VF ₂ ) monomer, as a homopolymer, or as TFE, HF.
The composite according to claim 4, which is contained as a copolymer of P, PPVE, PMVE, and ethylene or propylene. 6. The method according to claim 1, wherein the polymer film is made of tetrafluoroethylene (TFE), hexafluoropropylene (HF).
5. The composite according to claim 4, comprising P), and a perfluoropolymer selected from the group consisting of homopolymers and copolymers of fluorovinyl ethers including perfluoropropyl vinyl ether and perfluoromethyl vinyl ether. . 7. The method according to claim 1, wherein the polymer coating is polyvinyl chloride,
5. A polymer selected from the group consisting of polyvinylidene chloride, polyvinyl alcohol, and a copolymer thereof with acrylic acid or an acrylate ester or another vinyl ester monomer. Complex. 8. The composite according to claim 7, further comprising a fluoropolymer topcoat provided on said polymer coating. 9. A tensioned load-bearing membrane comprising a frame and the composite of claim 3 provided on the frame. 10. A translucent polymer composite used for a load-bearing structure, wherein the composite is arranged orthogonally to the warp direction and the weft direction, and is a woven fabric substrate made of yarn woven in a mock leno pattern. ,
And at least one polymer coating provided on the woven substrate, wherein the composite has at least about 23 for normally incident visible light.
% Under a 1: 1 biaxial load of less than 25% of the uniaxial tensile strength at break of the woven fabric, a) greater than or equal to zero in the warp direction. B) a translucent polymer composite for a load-bearing structure, characterized in that it exhibits a biaxial elongation value greater in the weft direction than in the warp direction. 11. When the composite receives a 1: 1 biaxial load of 25% or less of the uniaxial tensile breaking strength of the woven fabric, the biaxial elongation in the warp direction is 1.0% or less. The composite according to claim 10, wherein: 12. The biaxial elongation value in the weft direction is 10% or less when the composite receives a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric. The composite according to claim 11, wherein: 13. The composite according to claim 12, wherein said woven fabric is made of glass fiber yarn or polyester yarn. 14. The polymer film according to claim 1, wherein the polymer film is a fluoropolymer selected from the group consisting of a chlorotrifluoroethylene (CTFE) monomer and a vinylidene fluoride (VF ₂ ) monomer, as a homopolymer, or as TFE, HF.
14. The composite according to claim 13, which is contained as a copolymer of P, PPVE, PMVE, and ethylene or propylene. 15. The method according to claim 1, wherein the polymer film is made of tetrafluoroethylene (TFE), hexafluoropropylene (HF).
14. A composite according to claim 13, comprising P) and a perfluoropolymer selected from the group consisting of homopolymers and copolymers of fluorovinyl ethers, including perfluoropropyl vinyl ether and perfluoromethyl vinyl ether. . 16. The polymer coating is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and copolymers of these with acrylic acid or acrylate or other vinyl ester monomers. 14. The conjugate according to claim 13, comprising a polymer. 17. The composite according to claim 16, further comprising a fluoropolymer topcoat provided on said polymer coating. 18. A tensioned load-bearing membrane comprising a frame and a composite according to claim 12 provided on said frame. 19. The translucent polymer composite used for a load-bearing structure, wherein the composite is composed of yarns arranged orthogonally to the warp direction and the weft direction and woven in a plain weave pattern, wherein the number of wefts is set. A woven substrate equal to or greater than about 1.25 times the number of warp yarns, and at least one polymer coating provided on the woven substrate; At least about 23
% Under a 1: 1 biaxial load of less than 25% of the uniaxial tensile strength at break of the woven fabric, a) greater than or equal to zero in the warp direction. B) a translucent polymer composite for a load-bearing structure, characterized in that it exhibits a biaxial elongation value greater in the weft direction than in the warp direction. 20. When the composite receives a 1: 1 biaxial load of 25% or less of the uniaxial tensile breaking strength of the woven fabric, the biaxial elongation in the warp direction is 1.0% or less. 20. The conjugate of claim 19, wherein: 21. A biaxial elongation value in a weft direction of 10% or less when the composite is subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric. 21. The composite according to claim 20, wherein 22. The composite according to claim 21, wherein said woven fabric is made of glass fiber yarn or polyester yarn. 23. The polymer film according to claim 1, wherein the polymer coating is a fluoropolymer selected from the group consisting of chlorotrifluoroethylene (CTFE) monomer and vinylidene fluoride (VF ₂ ) monomer, as a homopolymer, or as TFE, HF.
23. The composite according to claim 22, which is contained as a copolymer of P, PPVE, PMVE, and ethylene or propylene. 24. A method according to claim 1, wherein the polymer film is made of tetrafluoroethylene (TFE), hexafluoropropylene (HF).
23. The composite of claim 22, comprising P) and a perfluoropolymer selected from the group consisting of homopolymers and copolymers of fluorovinyl ethers, including perfluoropropyl vinyl ether and perfluoromethyl vinyl ether. . 25. The polymer coating is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and copolymers of these with acrylic acid or acrylate or other vinyl ester monomers. 23. The composite of claim 22, comprising a polymer. 26. The composite of claim 25, further comprising a fluoropolymer topcoat provided on said polymer coating. 27. A tensioned load-bearing membrane comprising a frame and the composite of claim 21 provided on the frame. 28. In producing a translucent polymer composite for use in a load-bearing structure, a) producing a woven fabric by orthogonally arranging in the warp and weft directions; b) the composite comprises: I) a warp yarn when the composite exhibits a translucency of at least about 23% with respect to normally incident visible light and the composite is subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric; Ii) the filament type, number and diameter of the yarn; the number of threaded yarns; Shrinking; and selecting the woven pattern of the woven fabric; c) coating the woven fabric with at least one polymer; and then d) fusing each polymer coating; Polymer compound Method of manufacturing the body. 29. To produce a translucent polymer composite for use in a load-bearing structure, comprising: a) producing a woven fabric by placing it orthogonal to the warp and weft directions; b) the composite comprising: I) a warp yarn when the composite exhibits a translucency of at least about 23% with respect to normally incident visible light and the composite is subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric; Ii) the filament type, number and diameter of the yarn; the number of threaded yarns; Shrinking; and selecting the woven pattern of the woven fabric; c) separately producing and melting the polymer film; and then d) laminating the polymer film to the woven fabric; The method for producing a transparent polymer composite. 30. The warp direction biaxial elongation value of 10% or less when the composite is subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric. 30. The method according to claim 28 or 29, wherein the filament type, number and diameter of the yarns, the number of threaded yarns, the crimping of the yarns, and the weave pattern of the woven fabric are selected so as to form a composite. . 31. The method according to claim 31, wherein the composite exhibits a weft direction biaxial elongation value of 10% or less when the composite is subjected to a 1: 1 biaxial load of 25% or less of the uniaxial tensile strength at break of the woven fabric. 31. The method according to claim 30, wherein the filament type, number and diameter of the yarns, the number of yarns driven, the crimps of the yarns, and the weave pattern of the woven fabric are selected to produce a composite. 32. The method of claim 31, further comprising using glass fiber yarn or polyester yarn to produce said woven fabric. 33. The method of claim 1, further comprising using a fluoropolymer to coat the woven substrate, the fluoropolymer comprising a chlorotrifluoroethylene (CTFE) monomer and a vinylidene fluoride (VF ₂ ) monomer. From the group, as homopolymer or TFE, HFP, PPVE, P
33. The method according to claim 32, wherein the method is selected as a copolymer with MVE and eletin or propylene. 34. Use of a perfluoropolymer to coat the woven substrate, wherein the perfluoropolymer is tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and perfluoropropyl vinyl ether. 33. The method of claim 32, comprising a perfluoropolymer selected from the group consisting of fluorovinyl ether homopolymers and copolymers, including perfluoromethyl vinyl ether. 35. The polymer coating is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and copolymers thereof with acrylic acid or acrylate or other vinyl ester monomers. 33. The method of claim 32, comprising a polymer. 36. A translucent polymer composite for use in a load-bearing structure manufactured by the method according to claim 28 or 29.