FI3899118T3 - Membrane for a textile architecture - Google Patents

Description

Membrane for textile architecture

The invention relates to a membrane for textile architecture, comprising a fabric layer with warp threads and weft threads with a thread linear density of the warp threads and the weft threads of at least 550 dtex each, plus at least one coating layer applied to the fabric layer, the fabric layer being formed with a float of the weft threads over at least four warp threads.

JP 2016-124204 A specified a non-combustible generic fabric formed of inorganic material.

Such a fabric can be used to make membranes for construction purposes, thus a structural component.

JP 2017-159483 specified another generic fabric made of inorganic material, which is claimed to be suitable for construction purposes.

In architecture, the use of relatively strong fabrics as a material for building envelopes, for example, has become established practice. These fabrics are also called membranes or textile membranes in technical jargon. In addition to strength, a specific elongation behaviour and other material characteristics, such membranes must above all also have a high weathering resistance.

Textile membranes are commonly coated with a polymer, usually a polyvinyl chloride (PVC), to increase their weathering resistance. The coating is applied on both sides. A lacquer layer is then applied to the polymer coating in order to further increase the weathering resistance.

So far, fabrics woven on the basis of appropriately strong threads or yarns in a plain weave or Panama weave, e.g. a 2/2 Panama weave, have been used for the making of textile membranes. The use of these weave types for textile membranes has the advantage that sufficient coverage and strength for coating can be achieved with a low setting (thread density). The advantage is a simpler and faster (in terms of weaving time) production without special weaving machines. The disadvantage is the limited feasibility, which depends on the thread density, and thus the limits of the strengths.

In spite of per se excellent properties of known textile membranes, it has become apparent that there is a need to further improve the durability of such products. Furthermore, with regard to mechanical properties for certain applications, it has also proved to be a disadvantage that elongation in the warp direction on the one hand and the weft direction on the other hand exhibit relatively large differences, which requires adequate positional alignment of a textile membrane with regard to the stresses in the installed condition and/or the consideration of this direction-dependent inhomogeneity of the material properties during the planning stage already.

It is the purpose of the invention to specify a textile membrane of the type mentioned at the beginning, which leads to a higher weathering resistance with approximately the same elongation behaviour in warp and weft.

This task is solved with a membrane according to claim 1.

Within the scope of the invention, it was realized that several improvements can be achieved by forming a generic textile membrane with an atlas weave or a variation thereof or, in general, with a float of the weft yarns over at least four warp yarns as defined. Firstly, in contrast to a plain weave or Panama weave, the warp and weft threads show considerably fewer crossing points and/or longer floats, and as a result of this a higher thread density can be selected without any problems. The atlas weave or an alternative design with suitable float optimises the fabric structure and therefore also positively influences a thickness of the — at least one — coating layer and, above all, it avoids the thin spots in the coating layer(s) that occur with highly structured fabrics. Secondly, the formation of the fabric layer with, in particular, an atlas weave also means that differences of elongation in the warp direction and in the weft direction are significantly smaller than with a plain weave or Panama weave. The reason for this is again that the warp and weft threads have considerably fewer enlacements, and therefore the elongation behaviour in the warp and weft direction decreases accordingly. Furthermore, an atlas weave offers the additional advantage that, due to the multiple skipping of the warp threads, the thread density in the warp and weft direction can be increased compared to both plain weave and

Panama weave, meaning that the mechanical properties can be increased at the same thickness. Finally there are also advantages in terms of haptics, as the surface (warp effect on the right side of the fabric, weft effect on the left side) is significantly smoother than has been the case up to now, for textile membranes with plain weave or Panama weave.

For a textile membrane, the thread linear density may be at least 1000 dtex, preferably 1100 dtex or more.

For the foregoing reasons, it is preferred for the weft threads to be passed over at least four, better still five to seven, warp threads. In particular, in order to achieve the desired properties as discussed in the foregoing paragraph, five- and eight-end atlas weaves may be used, i.e. the weft threads may be passed over four or seven warp threads before they are re-integrated. In general, the floats of the warp and weft threads can be passed over, for example, at least four up to, for example, seven to nine (warp) threads, depending on the choice of weave repeat and a pitch number. In a classic atlas weave, for example, the threads can float from at least four (five-end) to seven (eight-end) or more warp and weft threads depending on the selected weave repeat and the pitch number. Similar effects can be achieved through variants of the atlas weave (for example, reinforced atlas weaves).

As a rule, the warp threads and/or the weft threads are each formed from a multifilament yarn. In particular, both the warp threads and the weft threads are formed from a multifilament yarn. Multifilament yarns have the reguired strength. Multifilament yarns can furthermore be of the spinneret-dyed type, unless the textile membrane is to be kept in white anyway. The warp threads and/or the weft threads may be formed in particular from polyester, in particular spun. Preferably, both the warp threads and the weft threads are formed from a polyester, since an appropriate choice of material ensures durability and the achievement of desired mechanical properties. In principle, however, monofilament yarns can also be used. Alternative plastics are also possible, for example acrylates or polyethylene derivatives.

The thickness of the membrane can generally be selected within a wide range, depending on the weight class and the reguired strength. It is advantageous if the membrane has a thickness of 500 um to 1300 um, preferably 600 um to 1200 um, in particular 700 um to 1000 um. In the corresponding thickness range, it is possible on the one hand to achieve a required strength, and on the other the textile membrane is not so thick as to cause architectural difficulties during installation or to require special constructions. In particular, a thickness range of 700 um to 1000 um has proven to be the optimal range.

The basis weight of the membrane is at least 600 gm, preferably 700 gm? to 1800 gm”.

The corresponding basis weights are in turn determined by the type of requirement in architectural use. In this respect, for the thickness of the textile membrane explained above, it is also necessary to take into account the required strengths and ease of design in the context of architectural use.

The fabric layer can be provided with a coating on both sides. In particular, the coating can be formed from PVC coating layers. These coating layers are preferably applied to both sides of the fabric layer, although it is also possible to apply a PVC coating layer to an outer side of the fabric layer only, namely to the side which is subjected to weathering in later use.

A lacquer layer may be applied to each PVC coating layer to finish off the outer side of the textile membrane. The lacquer layer may be made up of several layers, in particular including a liner layer and on top of it a topcoat layer on the outside.

A textile membrane according to the invention can be used in all conceivable architectural applications. Any built structure such as buildings or parts of buildings can be formed with or from a membrane according to the invention. Preferably, a textile membrane is used as a material for a building envelope, for example in stadiums, air domes, tents or the like. An application as an awning may also be a preferred use.

Further features, advantages and effects of the invention will be apparent from the execution example shown below. The referenced drawings show:

Fig. 1 a schematic representation of an atlas weave (five-end, A 4/1 3);

Fig. 2 a schematic representation of a cross-section of a membrane according to the invention;

Fig. 3 a light microscopic image of a membrane according to the invention (atlas five-end);

Fig. 4 a light microscopic image of a state-of-the-art membrane (Panama 2/2);

Fig. 5 a diagram illustrating elongation measurements.

Fig. 1 shows a fabric layer 2 as an atlas weave. As can be seen, the fabric layer has 2 warp threads 21 and weft threads 22. The weft thread 22 passes under four warp threads 21 before this weft thread 22 passes over a warp thread 21, then it passes under four warp threads 21 again. The individual crossing points (binding points) of the weft threads 22 with the warp threads 21 are offset from each other (pitch number).

A corresponding fabric layer 2 is a central. i.e. middle, component of a textile membrane 1, which is shown schematically in a cross-section in Fig. 2. The membrane 1 features a fabric layer 2 of an atlas weave type. In particular, this can be a five- or eight-end atlas weave. The central fabric layer 2 is surrounded on both sides by a PVC coating layer 3. The PVC coating layers 3 are in turn covered on the outside by lacquer coating layers 4, which seal the textile membrane 1 on the outside. This results in a multi-layer structure of the textile membrane 1. The individual PVC coating layers 3 can be applied in several goes. If applied in several goes, the individual PVC coating layers 3 can also have at least partially different compositions. For example, inner PVC coating layers 3, which adjoin the central fabric layer 2, can have a different composition to facilitate an intimate bond than outer PVC coating layers 3, which are then adjoined by the lacquer coating layers 4. Typically, the PVC coating layers 3 have titanium dioxide and/or other white or coloured pigments in particular, in addition to the usual auxiliary substances and additives such as plasticisers, stabilisers or fillers and flame retardants. However, the PVC coating layers 3 are formed without phthalates. Membrane 1 is usually between 600 um and 1200 um thick.

Fig. 3 and Fig. 4 illustrate the advantages of a five-end atlas weave in a textile membrane 1 versus a state-of-the-art Panama weave 2/2. As can be seen in Fig. 3, a weft thread 22 first passes over a warp thread 21 and then under four warp threads 21, until finally the weft thread 22 is again passed over a warp thread 21. In contrast, as Fig. 4 shows, the weft thread 22 of a Panama weave 2/2 is much wavier, as it is passed over two warp threads 21 much more often and then back under two warp threads 21. Due to this significantly greater waviness of the weft thread 22 in the finished state, there is considerably less leeway for the application of the PVC coating layers 3 in view of the restrictions with regard to the thickness of the textile membrane 1. In other words, the PVC coating layers 3 cannot be formed with the same thickness as with an atlas weave according to Fig. 3. In this respect, it was a surprising discovery that the required strengths can also be achieved with an atlas weave, and in addition it has clear advantages with regard to the formation of a thicker PVC coating layer 3, as a result of which better weathering resistance can be achieved. Expressed differently, it can also be said that the same mechanical properties are achieved with a thinner (raw) fabric, due to an increased warp and weft density.

Due to the course of the weft yarns 22 with less waviness — as Fig. 3 shows in comparison to

Fig. 4 — the elongation behaviour is also clearly improved. Fig. 5 shows the corresponding measurement results. As can be seen, a Panama weave 2/2 produces a significantly greater difference between the warp threads 21 and the weft threads 22 than an atlas weave.

Overall, a textile membrane 1 with an atlas weave according to the invention can optimise the thickness of a PVC coating layer 3 while achieving the required strengths and satisfying other architectural parameters, but at the same time it has an improved elongation behaviour due to its less pronounced asymmetry. Finally, it also has an improved light transmission behaviour and good haptic properties, as the outer surface is significantly smoother than the current state of the art.

Claims (12)

Patent Claims 1. A film (1) for a textile structure, comprising a fabric layer (2) with warp threads (21) and weft threads (22) whose respective linear density of the warp threads (21) and weft threads (22) is at least 550 dtex, and at least one of the coating layer (3), which is spread over the fabric layer (2), whereby the fabric layer (2) is formed in such a way that the weft threads (22) run over at least four warp threads (21), characterized in that the warp threads (21) and the weft threads (22) consist of synthetic material. 2. Film (1) according to claim 1, characterized in that the fabric layer (2) is formed with a satin bond. 3. Film (1) according to claim 1 or 2, characterized in that the linear density is at least 800 dtex, for example 1,000 dtex, preferably 1,100 dtex or more. 4. — A film (1) according to one of claims 1-3, characterized in that the weft threads (22) run over 5-7 warp threads (21). 5. — A membrane (1) according to one of claims 1-4, characterized in that the warp threads (21) and/or the weft threads (22) are each preferably formed from a multifilament thread. 6. — A film (1) according to one of claims 1-5, characterized in that the warp threads (21) and/or the weft threads (22) are made of polyester. 7. — A film (1) according to one of claims 1-6, characterized in that the thickness of the film (1) is 500-1,300 µm, preferably 600-1,200 µm, especially 700-1,000 µm. 8. — A film (1) according to one of claims 1-7, characterized in that the square mass of the film (1) is at least 600 gm, preferably 700-1,800 gm". 9. — A membrane (1) according to one of claims 1-8, characterized in that the fabric layer (2) is equipped with a coating on both sides. 10. The film (1) according to claim 9, characterized in that the coating is formed from PVC coating layers (3). 11. The film (1) according to claim 10, characterized in that a lacquer coating layer (4) has been applied on top of each PVC coating layer (3). 12. A piece with a film according to one of claims 1-11.