BE1029772B1 - REINFORCEMENT FABRIC FOR SYNTHETIC MEMBRANES - Google Patents

Abstract

The present invention relates to an improved fabric for reinforcing synthetic membranes for use in roofing. The present invention further relates to roof covering comprising such fabric. The reinforcement fabric comprises an open scrim, the open scrim being a woven mesh, the open scrim comprising a plurality of spaced bundles of weft yarns in a first direction and a plurality of spaced bundles of warp yarns in a second direction approximately perpendicular to the first direction, the bundle of weft threads crossing the bundle of warp threads at nodes.

Description

1 BE2021/5738

REINFORCEMENT FABRIC FOR SYNTHETIC MEMBRANES

The present invention relates to an improved fabric for reinforcing synthetic membranes for use in roofing, for example reinforced roof foils of materials such as PVC, TPO or EPDM. The present invention further relates to roof coverings comprising such fabric.

State of the art

Such reinforcing fabrics can be formed by an open scrim (also called mesh) which may or may not be encapsulated in a thermoplastic or elastomeric coating. The fabric structure facilitates the encapsulation or coating process by providing larger gaps. Such reinforcing fabrics can be useful for roofing membranes, tents, tarpaulins, signs, banners, billboards and the like.

Such reinforcing fabrics for use in roofing are known from patent publication no. US 10,072,419 B2. When the roof covering is installed, the roof covering is nailed down by means of a kind of plugs. The disadvantage of such fabrics is that due to the upward force (Eng: uplift) as a result of wind load, the attachment points dare to tear out in case of extreme wind load.

Purpose of the invention

The present invention aims to obviate or at least limit the disadvantages described above and/or to provide improvements in general.

An object of the invention may be to provide a reinforcing fabric with improved tear resistance. A further object of the invention may be to provide a thinner reinforcing fabric with similar tear resistance, preferably with improved tear resistance. In addition, it may be an object of the invention to reduce the possible uplift under wind load.

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Description of the invention

This object is achieved according to the invention with a reinforcing fabric which has the technical features of one of the independent claims. To this end, the present invention relates to a reinforcing fabric for synthetic membranes for use in roofing. The invention further also relates to a coated reinforcing fabric or a roof covering comprising the foregoing.

In a first aspect of the invention, which may occur in conjunction with the other aspects and embodiments of the invention described herein, the invention comprises a roofing reinforcing fabric comprising an open scrim, the open scrim being a woven mesh, wherein the open scrim includes a plurality of spaced bundles of weft threads in a first direction and a plurality of spaced bundles of warp threads in a second direction approximately perpendicular to the first direction, the bundle of weft threads crossing the bundle of warp threads on nodes.

Each node comprises or consists of at least one pair of warp threads interwoven with at least two weft threads, each pair of warp threads interwoven with the bundle of weft threads in a half-cross leno weave, such that the warp threads only cross between adjacent bundles of weft threads. In the context of this description, the term "semi-crossed leno weave" refers to a leno weave of warp threads crossing each other only once between adjacent bundles of weft threads. Preferably, all warp threads are interwoven with the bundle of weft threads. Furthermore, in each node the weft threads are interwoven with the warp threads in a weave pattern, preferably a linen weave, twill weave or satin weave.

The inventor has found that such combination of half-crossed leno weave with a uniform weave, preferably a linen weave, twill weave or satin weave, between the crossings of the leno weave has a reduced weave compared to known woven structures, such as those disclosed in US 10,072,419

B2. The reduced weave is obtained by keeping the weave as limited as possible with the threads lying stretched in the plane, which reduces the elongation with possible uplift. This reduces the uplift under wind load by keeping the fabric as flat as possible.

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In addition, a fabric is also obtained with a thickness that is similar to the thickness of knitted scrims and is therefore thinner than a standard woven fabric.

As a result, the same resistance to wind load can be achieved with fewer attachment points when used as roofing material. On the one hand this is a cost saving in terms of equipment and on the other hand a cost saving in terms of the required working time of the installer.

In embodiments, which may occur in conjunction with the other aspects and embodiments of the invention described herein, said reinforcing fabric is an uncoated open scrim that is sufficiently bonded in some other way, for example by the bonding pattern or using melt fibers.

A first embodiment, which can occur in combination with the other aspects and embodiments of the invention described herein, relates to an aforesaid reinforcing fabric, wherein the at least two weft threads consist of two, three or four weft threads. In other words, there are always two to four weft threads between adjacent crossings of the leno weave. Preferably there are exactly three wefts between adjacent crossings of the leno weave.

The inventor has found that such a composition of warp and weft threads has a better tear resistance and that the best tear resistance is achieved in combination with a flatter structure.

A second embodiment, which may occur in combination with the other aspects and embodiments of the invention described herein, relates to an aforesaid reinforcing fabric in which successive bundles of weft threads are equidistant from each other and/or in which successive pairs of warp threads are spaced apart. are equidistant from each other. The inventor has found that such fabric has improved tear resistance.

A third embodiment, which can occur in combination with the other aspects and embodiments of the invention described herein, relates to an aforesaid reinforcing fabric, wherein the weft threads or the warp threads are at least partly formed of polyester, polypropylene, PP, polyvinyl alcohol, nylon, aramid, glass fiber polyethylene naphthalate, polyphenylene sulfide, PPS, basalt or carbon.

A fourth embodiment, which may occur in conjunction with the other aspects and embodiments of the invention described herein

4 BE2021/5738 an aforesaid reinforcing fabric, wherein the weft threads or the warp threads have a yarn titer of about 140 to 9900 dtex, preferably of about 280 to 2200 dtex. Warp threads and weft threads can differ in yarn titre. Either between warp and weft within the thread bundle or between weft and warp threads.

In a second aspect of the invention, which may occur in conjunction with the other aspects and embodiments of the invention described herein, the invention comprises a coated fabric for roofing.

The coated fabric comprises an aforesaid reinforcing fabric and a coating comprising a thermoplastic or elastomeric material, the coating being located along the length of the weft and warp yarns and located between the weft and warp yarns at the nodes. During the coating of the reinforcing fabric, a layer in the form of a paste is applied to one or both sides of the reinforcing fabric. Direct coating is one of the most widely used techniques and is based on applying one or more layers of thermoplastic or elastomeric material to the reinforcing fabric via a squeegee, knife-coating or roller (kiss-roll coating). However, the coating can be applied in various ways, for example using extrusion coating, pultrusion or impregnation via Foulard (Eng: padding).

An embodiment, which may occur in conjunction with the other aspects and embodiments of the invention described herein, involves an aforesaid coated fabric, wherein the coating has a weight between about | and 300% of the weight of the open scrim, preferably between about 20 and 100% of the weight of the open scrim.

In a third aspect of the invention, which may occur in conjunction with the other aspects and embodiments of the invention described herein, the invention comprises roofing material comprising an aforesaid reinforcing fabric.

Brief description of the figures

The invention will be explained in more detail below with reference to an exemplary embodiment shown in the drawing. Figure 1 shows an exploded schematic plan view of part of an open scrim for a reinforcement fabric according to an embodiment of the present invention.

Extensive description of the figures

The present invention will be described with respect to certain embodiments and with reference to certain drawings, but the invention is not limited thereto and is defined only by the claims. The drawings described are only schematic and non-limiting. In the drawings, the size of certain elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and relative dimensions do not necessarily correspond to actual practice of the invention.

In addition, the terms first, second, third and the like are used in the description and in the claims to distinguish between similar elements and not necessarily to describe a sequential or chronological order.

The terms are interchangeable under appropriate circumstances and the embodiments of the invention may be used in sequences other than those described or illustrated herein.

In addition, the terms top, bottom, over, under and the like are used in the specification and claims for illustrative purposes and not necessarily to describe relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein may be used in orientations other than those described or illustrated herein.

Further, the various embodiments, while referred to as "preferred forms", are to be construed as exemplifying how the invention may be practiced rather than as limiting the scope of the invention.

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The term "comprising" used in the claims is not to be construed as limited to the means or steps set forth below; the term does not exclude other elements or steps. The term should be interpreted as specifying the presence of said features, elements, steps or components referred to, but does not exclude the presence or addition of one or more other features, elements, steps or components, or groups thereof . The scope of the expression “a device comprising means A and

B' should therefore not be limited to devices consisting only of components A and

B exist. The meaning is that with respect to the present invention only components A and B of the device are recited, and the claim is further construed to include equivalents of these components as well.

The fabrics shown in the figures are reinforcing fabric, or elements therefor, for use in a roof covering.

Figure 1 shows an exploded schematic top view of a reinforcing fabric. The reinforcing fabric comprises a coated fabric having a first side and a second side. The coated fabric comprises an open scrim 10, the open scrim being a woven mesh, the open scrim including a plurality of spaced bundles of wefts 30, 50 in a first direction L and a plurality of spaced bundles of warp threads 40, 60 in a second direction B approximately perpendicular to the first direction, the bundle of weft threads intersecting the bundle of warp threads at nodes 20. The coated fabric further comprises a coating (not shown) of a thermoplastic or elastomeric material, wherein the coating is along the length of the weft and warp threads and is between the weft and warp threads at the nodes.

Each node consists of one pair of warp threads 41, 42 interwoven with three weft threads 31, 32, 33, the pair of warp threads 41, 42 interwoven with the bundle of weft threads 30 in a half-crossed leno weave, such that the warp threads only intersect crossing once between adjacent bundles of weft threads.

Consecutive pairs of warp threads 41, 42, each in a half-crossed leno weave, are equidistant from each other. As a result, the corresponding successive nodes will also be equidistant from each other in the first direction L. Furthermore, in each node, the three weft threads 31, 32, 33 are interwoven with the

7 BE2021/5738 two warp threads 41, 42 in a plain or linen weave pattern.

Consecutive weft threads 31, 32, 33 corresponding to the same node are equidistant from each other.

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Reference list 10. Open Scrim 20. Node 30, 50. Bundle of weft threads 31. First weft thread 32. Second weft thread 33. Third weft thread 40, 60. Bundle of warp threads 41. First warp thread 42. Second warp thread

Claims (15)

9 BE2021/5738 Conclusions A roofing reinforcing fabric, comprising: an open scrim, the open scrim being a woven mesh, the open scrim comprising a plurality of spaced bundles of weft threads in a first direction and a plurality of spaced bundles of warp threads in a second direction approximately perpendicular to the first direction, the bundles of weft threads crossing the bundles of warp threads at nodes, each node being formed by at least one pair of warp threads interwoven with at least two weft threads, the weft threads in each node being interwoven with the warp threads in a weave pattern, and each pair of warp threads interwoven with the bundle of weft threads in a semi-crossed leno weave, the warp threads crossing only between adjacent bundles of weft threads. Reinforcing fabric according to claim 1, wherein the weave pattern is a linen weave, twill weave or satin weave. Reinforcement fabric according to claim 1, wherein the at least two weft threads consist of two, three or four weft threads. 4. Reinforcing fabric according to claim 3, wherein in each node exactly one pair of warp threads is interwoven with exactly three weft threads. A reinforcement fabric according to any one of the preceding claims, wherein successive bundles of weft threads are equidistant from each other. A reinforcement fabric according to any one of the preceding claims, wherein successive pairs of warp threads are equidistant from each other. Reinforcement fabric according to one of the preceding claims, wherein the weft threads are at least partly formed from polyester, polypropylene, PP, polyvinyl alcohol, nylon, aramid, glass fiber or polyethylene naphthalate. 10 BE2021/5738 Reinforcement fabric according to one of the preceding claims, wherein the warp threads are at least partly formed from polyester, polypropylene, PP, polyvinyl alcohol, nylon, aramid, glass fiber or polyethylene naphthalate. A reinforcement fabric according to any one of the preceding claims, wherein the weft threads have a yarn titre of about 140 to 6600 dtex. A reinforcement fabric according to any one of the preceding claims, wherein the warp threads have a yarn titre of about 140 to 6600 dtex. A coated fabric having a first side and a second side, the coated fabric comprising: a reinforcing fabric according to any one of the preceding claims, and a coating comprising a thermoplastic or elastomeric material, the coating being along the length of the weft threads and the warp threads and is located between the weft and warp threads at the nodes. A coated fabric according to any one of the preceding claims, wherein the thermoplastic or elastomeric material is selected from the group consisting of polyvinyl alcohol, PVA, polyvinyl acetate, PVAc, ethylene vinyl acetate, EVA, polyvinyl chloride, PVC, styrene-butadiene rubber latex, SBR latex, acrylate , polyurethane, PU, Ethylene-acrylic acid, EAA, neoprene, and RFL. The coated fabric of claim 9 or claim 10, wherein the coating has a weight between about 10 and 300% of the weight of the open scrim. The coated fabric of claim 12, wherein the coating has a weight between about 15% and 100% of the weight of the open scrim. 15. Roof covering comprising a reinforcing fabric according to one of the preceding claims 1-10 or a coated fabric according to one of the preceding claims 11-14.