EP4151812A1

EP4151812A1 - Reinforcing fabric for synthetic membranes

Info

Publication number: EP4151812A1
Application number: EP22196462.0A
Authority: EP
Inventors: Willem VAN DAELE; Frank VERANNEMAN; Joost Wille; Bruno Devos
Original assignee: Sioen Industries NV
Current assignee: Sioen Industries NV
Priority date: 2021-09-20
Filing date: 2022-09-20
Publication date: 2023-03-22
Also published as: BE1029772B1; BE1029772A1

Abstract

The current invention embodies an improved fabric for reinforcing synthetic membranes for applications in roofing materials. The current invention also embodies roofing materials that contain this type of fabric. The reinforcement fabric encompasses an open scrim, whereby the open scrim is a woven mesh, whereby the open scrim encompasses a number of bundles of weft threads located at a distance from each other in a first direction and a number of bundles of warp threads located at a distance from each other in a second direction, approximately perpendicular to the first direction, whereby the bundle of weft threads crosses the bundle of warp threads at intersections.

Description

The current invention embodies an improved fabric for reinforcing synthetic membranes for applications in roofing materials, such as reinforced roof films of materials such as PVC, TPO or EPDM. The current invention also embodies a roofing materials that contains this type of fabric.

State of the Art of Technology

These types of reinforcement fabrics can be formed by a scrim (also called mesh) which may or may not be encapsulated in a thermoplastic or elastomer coating. The fabric structure makes the encapsulation or coating process easier by providing greater interim spaces. These types of reinforcement fabrics can be useful for roofing membranes, tents, tarpaulins, placards, banners, advertising signs and the like.
One of this type of reinforcement fabric for use as roofing material is known from patent publication no. US 10.072.419 B2 . In applying the roofing material, the roofing material is secured using a type of plugs. The disadvantage of these types of fabrics is that through the uplift as a result of wind load, the fixation points may tear out under extreme wind loads.

Objective of the invention

The current invention has the objective of overcome or at least limit the disadvantages described above and/or providing for general improvements. One objective of the invention may be to provide a reinforcement fabric with improved tear resistance. One further objective of the invention may be to provide a reinforcement fabric with equivalent tear resistance, preferably with better tear resistance, however. In addition, an objective of the invention may be to reduce the possible uplift under the wind load.

Description of the invention

This objective is achieved according to the invention with a reinforcement fabric that displays the technical features of one of the independent claims. In the current invention, this is a reinforcement fabric for synthetic membranes for application in roofing. The invention also comprises a coated reinforcement fabric or a roofing material including the former.
In a first aspect of the invention, which may occur in combination with the other aspects and embodiments of the invention described herein, the invention comprises a reinforcement fabric for roofing materials, having a scrim, whereby the scrim is a woven mesh, whereby the open scrim has a number of bundles of weft threads located at a distance from each other in a first direction, and a number of bundles of warp threads at a distance from each other in a second direction, approximately perpendicular to the first direction, whereby the bundle of weft threads cross the bundle of warp threats at intersections.
Each intersection comprises or is made up of at least one pair of warp threads woven into at least two weft threads, whereby each pair of warp threads is woven into the bundles of weft threads in a half-cross leno weave, such that the warp threads only cross each other between adjacent bundles of weft threads. Within the context of this description the term "half-cross leno weave" refers to a leno weave of warp threads that only cross each other once between adjacent bundles of weft threads. Preferably, all warp threads are woven into the bundle of weft threads. In addition, in each intersection, the weft threads are woven with the warp threads in a weave pattern, preferably in a linen weave, twill weave or satin weave.
The inventor has found that these types of combination of half-cross leno weave with a uniform weave, preferably a linen weave, twill weave or satin weave between the intersections of the leno weave has a reduced inweave compared to known weave structures, such as that published in US 10.072.419 . The reduced inweave is achieved by the keeping the inweave as limited as possible, whereby the threads are lie stretched within the plane which reduces the extension with possible uplift. Through this, the uplift is reduced during wind load because the fabric is kept as flat as possible.
In addition, a fabric is created with a thickness that is the same as the thickness of the knitted scrims and is thus thinner than a standard woven fabric. So it can be used as a roofing material with fewer fixation points with the same resistance to wind load. This is, on the one hand, a cost saving on material and on the other hand, a cost saving of the required work time of the installer.
In embodiments that can occur in combination with the other aspects and embodiments of the invention that are described herein, the aforementioned reinforcement fabric is an uncoated open scrim that is sufficiently bonded in another manner, such as through the weave pattern or using melt fibers.
Another embodiment, which may occur in combination with the other aspects and embodiments of the invention described herein, is an aforementioned reinforcement fabric, whereby 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 the adjacent intersections of the leno weave. Preferably there are exactly three weft threads between adjacent intersections of the leno weave. The inventor has found that this type of composition of warp and weft threads provide a better tear resistance and in combination with a flatter structure, the best tear resistance is achieved.
A second embodiment, which may occur in combination with the other aspects and embodiments of the invention that is described herein, is an aforementioned reinforcement fabric, whereby successive bundles of weft threads are located equidistant from each other and/or successive pairs of warp threads are located equidistant from each other. The inventor has found that this type of fabric has a better tear resistance.
A third embodiment, which may occur in combination with the other aspects and embodiments of the invention described herein, is an aforementioned reinforcement fabric, whereby the weft threads or the warp threads are at least partially made up of polyester, polypropylene, PP, polyvinyl alcohol, nylon, aramid, fiberglass, polyethylene naphthalate, PPS, basalt or carbon.
A fourth embodiment, which may occur in combination with the other aspects and embodiments of the invention described herein, is an aforementioned reinforcement fabric, whereby the weft threads or the warp threads have a yarn titer of approximately 140 to 9900 dtex, preferably of approximately 280 to 2200 dtex. Warp threads and weft threads may vary in yarn titer. Either between the warp and weft within the thread bundle or between the weft and warp threads reciprocally.
In a second aspect of the invention, which may occur in combination with the other aspects and embodiments of the invention described herein, the invention involves a coated fabric for roofing.
The coated fabric consists of an aforementioned reinforcement fabric and a coating consisting of a thermoplastic or elastomer material, whereby the coating is located along the length of the weft threads and the warp threads and is located between the weft and warp threads at the intersections. During the coating of the reinforcement fabric, a layer is applied in the form of a paste on one or both sides of the reinforcement fabric. Direct coating is one of the most used techniques and is based on the application of one or more layers of thermoplastic or elastomer material on the reinforcement fabric using a scraper, knife-coating or kiss roll coating. The coating can be applied in various ways, such as using extrusion coating, pultrusion or impregnation using padding.
One embodiment, which may occur in combination with the other aspects and embodiments of the invention described herein, is an aforementioned coated fabric, whereby the coating has a weight between approximately 1 and 300% of the weight of the open scrim, preferably between approximately 20 and 100% of the weight of the open scrim.
In a second aspect of the invention, which may occur in combination with the other aspects and embodiments of the invention described herein, the invention involves a coated fabric for roofing made up of an aforementioned reinforcement fabric.

Summary description of the figures

The invention will be described in detail below using the design example shown in the drawing.
Figure 1 shows an open schematic top view of a part of an open scrim for a reinforcement fabric according to one embodiment of the current invention.

Detailed description of the figures

The current invention will be described with regard to certain embodiments and with reference to certain drawings, but the invention is not limited to these and is only determined by the claims. The drawings described are only schematic and non-limiting. In the drawings, the size of certain elements are exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions are not necessarily consistent with actual practical embodiments of the invention.
In addition, terms such as "first, "second, "third" and the like in the descriptions and in the claims are used to differentiate between comparable elements are not necessarily to describe a sequential or chronological order. The terms are interchangeable under suitable circumstances and the embodiments of the invention may be applied in sequences other than those described or illustrated here.
In addition, the terms, "top", "bottom", "over", "under" and the like in the description and in the claims are used for descriptive purposes and not necessarily to indicate relative positions. The used terms are interchangeable under suitable circumstances and the embodiments of the invention may be applied in orientation other than those described or illustrated here.
Furthermore, the various embodiments, even though called "preferential types", are to be understood as a manner of example according to which the invention can be implemented, and not as a limitation to the range of the invention.
The term "comprising" used in the claims must not be interpreted as being limited to the elements or steps listed after them, as the term does not rule out other elements or steps. The term should be interpreted as specifying for the presence of the named features, elements, steps or components being referred to, but does not rule out the presence or addition of one or more other features, elements, steps or components of groups thereof. The range of the expression "a design comprising elements A and B" thus does not have to be limited to designs that only consist of components A and B. The meaning is that, with regard to the current invention, only the components A and B of the design are summed up, and the claim must be further interpreted to mean that they also contain equivalent of these components.
The fabrics shown in the figures are reinforcement fabrics or elements thereof for use in roofing.
Figure 1 shows an open schematic top view of a reinforcement fabric. The reinforcement fabric encompasses a coated fabric with a first and second side. The coated fabric encompasses an open scrim 10, whereby the open scrim is a woven mesh, whereby the open scrim encompasses a number of bundles of weft threads located at a distance from each other 30, 50 in a first direction L and a number of bundles of warp threads 40, 60 located at a distance from each other in a second direction B, approximately perpendicular to the first direction, whereby the bundle of weft threads crosses the bundle of warp threads at intersections 20. The coated fabric also encompasses a coating (not shown) of a thermoplastic or elastomer material, whereby the coating is located along the length of the weft threads and the warp threads and is located between the weft and warp threads at the intersections.
Each intersection encompasses one pair of warp threads 41, 42 woven with three weft threads 31, 32, 33, whereby the pair of warp threads 41, 42 is woven with the bundle of weft threads 30 in a half-cross leno weave, such that the warp threads cross each other only once between adjacent bundles of weft threads. Consecutive pairs of warp threads 41, 42, each in a half-cross leno weave, are located equidistant from each other. Through this, the corresponding consecutive intersections are equidistant from each other in the first direction L. In addition, in each intersection the three weft threads 31, 32, 33 are woven with the two warp threads 41, 42 in a smooth or linen weave pattern. Consecutive weft threads 31, 32, 33 corresponding to the same intersection are located equidistant from each other.

List of Reference Numbers

10.: Open Scrim

20.: Intersection

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

Reinforcement fabric for roofing material, encompassing:
an open scrim, whereby the open scrim is a woven mesh, whereby the open scrim encompasses a number of bundles of weft threads located at a distance from each other in a first direction and a number of bundles of warp threads located at a distance from each other in a second direction, approximately perpendicular to the first direction, whereby the bundle of weft threads crosses the bundle of warp threads at intersections,
whereby each intersection is formed by at least one pair of warp threads interwoven with at least two weft threads, whereby in each intersection the weft threads are interwoven with the warp threads in a woven pattern, and

whereby each pair of warp threads is interwoven with the bundle of weft threads in a half-cross leno weave, whereby the warp threads only cross each other between the bordering bundles of weft threads.
Reinforcement fabric according to claim 1, whereby the weave pattern is a linen weave, twill weave or satin weave.
Reinforcement fabric according to claim 1, whereby the at least two weft threads consist of two, three or four weft threads.
Reinforcement fabric according to claim 3, whereby in each intersection there is exactly one pair of warp threads interwoven with exactly three weft threads.
Reinforcement fabric according to one of the prior claims, whereby successive bundles of weft threads are located equidistant from each other.
Reinforcement fabric according to one of the prior claims, whereby successive bundles of warp threads are located equidistant from each other.
Reinforcement fabric according to one of the prior claims, whereby the weft threads are at least partially made up of polyester, polypropylene, PP, polyvinyl alcohol, nylon, aramid, fiberglass or polyethylene naphthalate.
Reinforcement fabric according to one of the prior claims, whereby the warp threads are at least partially made up of polyester, polypropylene, PP, polyvinyl alcohol, nylon, aramid, fiberglass or polyethylene naphthalate.
Reinforcement fabric according to one of the prior claims, whereby the weft threads have a yarn titer of approximately 140 to 6600 dtex.
Reinforcement fabric according to one of the prior claims, whereby the warp threads have a yarn titer of approximately 140 to 6600 dtex.
Coated fabric with a first side and a second side, the coated fabric encompassing:
a reinforcement fabric according to one of the prior claims; and

a coating consisting of a thermoplastic or elastomer material, whereby the coating is located along the length of the weft threads and the warp threads and is located between the weft and warp threads at the intersections.
Coated fabric according to one of the prior claims, whereby the thermoplastic or elastomer material is selected from the group consisting of polyvinyl alcohol, PVA, polyvinyl acetate, PVAc, ethylene vinyl acetate, EVA, polyvinyl chloride, PVC, styrenebutadiene rubber latex, SBR latex, acrylate, polyurethane, PU, ethylene-acrylic acid, EAA, neoprene and RFL.
Coated fabric according to claim 9 or 10, whereby the coating has a weight between approximately 10 and 300% of the weight of the open scrim.
Coated fabric according to claim 12, whereby the coating has a weight between approximately 15% and 100% of the weight of the open scrim.
Roofing material encompassing a reinforcement fabric according to one of the claims 1-10 or a coated fabric according to one of the claims 11-14.