KR20120083901A - Coated light fabric, in particular for a flight sail - Google Patents

Abstract

The present invention is a lightweight fabric consisting of a continuous warp and weft yarn and coated on one or both surfaces with polyurethane, the bare fabric having a coverage rate TC of 1.8 to 4, preferably 2.6 to 3.2. Wherein the polyurethane is made of polyether and polycarbonate having a 100% elongation tensile stress of 5 MPa or less and the impregnation rate is at least 10% by weight, preferably 12 to 30% by weight, more preferably Is 15 to 25% by weight, and the fabric relates to a lightweight fabric having a weight of 25 to 40 g / m 2 including the coating. The invention also relates to a method of making such a fabric. The invention can be used especially for flight sails, in particular for paragliders.

Description

Coated light fabric, in particular for a flight sail

The present invention relates to lightweight fabrics formed with continuous warp and weft yarns and coated on one or both surfaces with polyurethane. Such lightweight fabrics are particularly applicable to the field of flying sails. The invention also relates to a method of making such a fabric.

In the field of flying sails, such as paragliders, fabric manufacturers have been struggling to combine light weight, low porosity and durability for a considerable time. This equation is difficult to solve because porosity reduction is usually very close to weight gain. In practice, porosity depends on the density of the fabric, ie the number of warps and wefts per surface unit. Porosity also depends on the presence of a coating that somewhat closes the pores of the fabric. The coating is indispensable and occupies a negligible portion of the weight of the coated fabric, ie the flight sail.

Since such coatings are essential for imparting the required porosity, they must be durable. Durability concepts can cover a variety of criteria, for example UV stability and hydrolysis stability, and more generally stability with respect to atmospheric conditions and moisture. Hydrolytic stability should be considered as the most important factor in preserving porosity over time.

The coating is also important for imparting proper stiffness in the bias direction.

Currently, flying sails such as paragliders use polyester-based polyurethane (PU) as the coating material. Such coatings have relatively good UV resistance, but have limited durability relative to hydrolytic stability. The weight of the lightest coated fabric produced in this way is close to 45 g / m 2.

Higher weight is obtained by yarn density, the choice of coating material and the combination of thickness and weight of the coating, which allows the production of fabrics with hydrolytic stability and acceptable levels of porosity. However, it is too heavy to be used for manufacturing high performance flying sails.

FR 2 840 625 is a diagonally-stabilized fabric consisting of ripstop-type weaves comprising warp and weft interlaced with stabilizing strips and zones. Explain. Such woven fabrics are coated with an aqueous mixture of polyurethane and silicone. The physical and chemical properties of the polyurethane are not specified and the weight of the fabric is 45 g / m 2.

EP 0 305 888 describes a textile material formed from a substrate impregnated with a water repellent and coated with a layer of polyurethane resin modified with polysiloxane. The modified resins are prepared by the reaction of siloxane polymers with basic components of polyurethanes, isocyanates and diols (polytetramethylene glycol, polyether diols, ring-opening lactone diols, polycarbonate diols). The weight of the fabric is greater than 40 g / m 2.

EP 2 184 399 describes a textile material for paraglider comprising a fabric coated with a layer of urethane-silicone copolymer resin on the base of polyester fibers. This material is said to have a weight of 21 to 100 g / m 2. The examples illustrate weights of 45 g / m 2 or even greater.

EP 0 552 374 describes textile materials that can be used in the manufacture of boats, paragliders, or parachute sails. This material includes polyurethane, silicone resins, and polyester fabrics that can potentially be coated with a resin that can be selected from them without any additional accuracy or any preference for the properties of the polyvinylchloride. This treatment is clearly stated that the textile material does not need to be treated with a resin and the weight of the uncoated or coated fabric may be 20 to 100, preferably 30 to 50 g / m 2. The examples illustrate 25, 48 or 85 g / m 2 polyethylene terephthalate fabric coated with polyurethane resin.

JP 2000234272 is a synthetic having a base of polyamide warp and weft yarn and can be selected from these without any additional accuracy on the physicochemical properties of acrylic resins, polyurethane resins, silicone resins, polyamide resins, polyester resins, polyimide resins Describes a paraglider sail fabric that can be coated with resin.

Prior art has not identified the essential criteria that enable the optimization of both the weight and porosity of the coated fabric as well as the mechanical properties of the coated fabric to obtain a fabric that enables the production of improved flight sails. Thus, the prior art failed to identify coverage TC as an essential criterion. The prior art also did not confirm the importance of selecting the physicochemical properties of the coating resin. The prior art has not been able to combine these criteria to obtain fabrics of particularly low weight up to 40 g / m 2 including a coating. The prior art also could not combine these different criteria to obtain an optimal level of air permeability for the reduced weight.

It is therefore an object of the present invention to propose a coated fabric which combines light weight, porosity and durability, in particular moisture stability.

Another object of the present invention is also to provide a fabric having suitable rigidity in the bias direction.

Another object of the present invention is to provide a method for producing such a fabric.

Other additional objects will appear by reading the specification of the present invention.

The present invention particularly relates to polyether-based or polycarbonate-based polyurethanes, which consist of continuous warp and weft yarns, one or both of which have a 100% elongation tensile stress (measured according to standard DIN 53504) of 5 MPa or less. It relates to a light weight fabric coated and comprising a coating having a weight of 25 to 40 g / m 2, preferably 31 to 36 g / m 2 and a coverage TC of 1.8 to 4, preferably 2.6 to 3.2.

According to one embodiment, the polyurethane has a 100% elongation tensile stress of 4 MPa or less, preferably 3 MPa or less. Thus, the tensile strength may be 1 to 5, 4 or 3 MPa.

The coverage TC is the coverage of the fabric obtained from the weaving process before any calendering or similar process. The TC is calculated as follows:

TC = (number of filaments / ㎝ × one diameter of the filament) + _slope (filament diameter × 1 number of one filament) _wefts,

The diameter of the filament is expressed in cm.

The TC value used in the present invention corresponds to a value that gives the fabric a sufficiently closed structure, which is emphasized by calendering, which, on the one hand, reduces the impregnation rate of the coating material to obtain a low porosity suitable for the application of the fabric. And consequently makes it possible to limit the final weight of the coated fabric on the other hand.

According to one embodiment, the dry impregnation rate of the coating material is at least 10% by weight, in particular 10-30% by weight, preferably 12-30% by weight, more preferably 15-25% by weight. The dry impregnation rate is the weight ratio of dry coating (particularly PU and crosslinking agent) to the coated fabric and represents the dry / crosslinked coating weight present in the final fabric.

In one embodiment, the fabric of the invention is characterized by rigidity in the bias direction. Incline direction bias is 45 degree direction with respect to the inclination. The weft direction bias is 45 ° direction with respect to the weft yarn. Elongation% is measured under a load of 3 pounds (lbs, 1.36 kg) applied in the bias direction. This elongation characterizes the fabric stiffness in the bias direction. The standard used is NF EN ISO 13934-1: Test specimens are made 50 mm wide and 300 mm long. The jaw of the dynamometer is moved 200 mm apart and the measurement is made at a speed of 100 mm / min.

In one embodiment, the fabric according to the invention has an elongation of 10% or less with a warp and weft direction bias under 3 lbs. This elongation can thus be 1 to 10%, preferably 3 to 10%, more preferably 5 to 10%.

According to one embodiment, the lightweight fabric has an air permeability of 20 L / m 2 / min or less under a pressure of 2000 kPa when measured according to standard NFG 07111 (when measuring a surface of 100 cm 2).

According to one embodiment, the lightweight fabric comprises warp and / or weft yarns having a dtex of 11-44 dtex and a DPF (decex per filament) of 1-4.

According to one embodiment, the weight of the bare fabric is 20 to 33 g / m 2, preferably 24 to 28 g / m 2.

According to one embodiment, the weight of the coated fabric is 25 to 40 g / m 2, preferably 31 to 36 g / m 2.

According to one embodiment, the fabric comprises 30 to 50 warp / cm and 30 to 50 weft / cm.

According to one embodiment, the fabric comprises a yarn in which the filament has a DPF (decex per filament) of 1-3.

In one embodiment, the lightweight fabric of the present invention is obtained by coating with a polyurethane aqueous dispersion. The coating can have any one of the aforementioned properties.

The invention also relates to a process for producing a coated lightweight fabric as follows:

(a) A fabric having a coverage TC of 1.8 to 4, preferably 2.6 to 3.2, is used and the TC is calculated as follows:

TC = (number of filaments / cm × 1 filament) _warp + (number of filaments / cm × 1 filament) _weft ,

(b) one or both surfaces of the fabric are coated with a polyether-based or polycarbonate-based polyurethane having a 100% elongation tensile stress (measured according to standard DIN 53504) of 5 MPa or less, and the dry impregnation rate Is at least 10% by weight, preferably 12 to 30% by weight, more preferably 15 to 25% by weight,

(c) the fabric is heated until the coating is dry / crosslinked,

(d) The fabric is recovered to have a weight of 25 to 40 g / m 2 including the coating.

According to one embodiment, the polyurethane has a 100% elongation tensile stress of 4 MPa or less, preferably 3 MPa or less. Thus, the tensile stress may be 1 to 5, 4 or 3 MPa.

According to one embodiment, the fabric comprises a warp and / or weft having a dtex of 11 to 44 dtex and a DPF (decex per filament) of 1 to 4 dtex.

According to one embodiment, the fabric is calendered before being coated in step (b). The calendering crushes the fabric and unfolds the yarn as well as the filament component, which contributes to closing the pores of the fabric and reducing the porosity.

According to one embodiment, the calendering is performed between a calendering tool, a cylinder, or a roller and a jack. The surface of the fabric through which the calendering tool passes is called the calendering surface and is smooth compared to other surfaces.

According to one form, the coating is carried out on the calendering surface. Machining can be applied on a smooth surface in advance to improve the catching of the polymer. This may be a physical treatment or a chemical treatment. This may be, for example, a chemical treatment that imparts a functional group of a property that reacts with the group of the polymer to form a chemical bond.

According to another form, the coating may be carried out on another non-smooth surface. The impregnation rate varies depending on the surface of interest and it is understood that this impregnation rate is higher on non-smooth surfaces, which allows one skilled in the art to manipulate the amount and weight of the coating. It is also possible to coat both surfaces.

According to another embodiment, the calendering is performed between two calendering tools, cylinders or rollers. Both surfaces of the fabric are smoothed. One or two surfaces are then coated with or without the processing described above.

The calendering is preferably carried out at temperatures of 150 to 250 ° C, preferably 180 and 210 ° C. The calendering is preferably carried out at a pressure of 150 to 250 kg, preferably 180 to 230 kg. The rotation speed of the calender may be 1 to 30 m / min, preferably 10 to 20 m / min.

According to one embodiment, the weight of the fabric used in step (a) is 20 to 33 g / m 2, preferably 24 to 28 g / m 2.

According to one embodiment, the weight of the fabric obtained from step (c) is 25 to 40 g / m 2, preferably 31 to 36 g / m 2.

According to one embodiment, the fabric used comprises 30 to 50 warp / cm and 30 to 50 weft / cm.

According to one embodiment, the fabric used comprises a yarn having filaments of 1 to 3 DPFs (decex per filament).

In one embodiment, the lightweight fabric of the present invention is obtained by coating with an aqueous dispersion of polyurethane.

In one embodiment, the lightweight fabric of the present invention is obtained by coating with a polyurethane dispersion in a solvent phase.

Polyurethanes include rigid parts (isocyanates) and flexible parts (polyols). The ratio between these two components makes it possible to obtain a somewhat rigid polymer. Polyether or polycarbonate polyols are hydrolytically stable and therefore durable.

The coating composition comprises a crosslinking agent, in particular an isocyanate or melamine, or a mixture of the two.

Isocyanates refer to both isocyanates and polyisocyanates and may be alone or in combination with one or more other isocyanates and / or polyisocyanates. The term "isocyanate" is to be understood herein to include the terms "isocyanate" and "polyisocyanate".

According to one embodiment, the content of the dry crosslinker is 5% by weight or more than 5% by weight, in particular 10-30% by weight relative to the dry polyurethane.

According to a preferred embodiment, the polyurethane is polyether based.

In one embodiment, the polyether based polyurethane is linear or branched and includes polyether polyol moieties and isocyanate moieties. In one particular embodiment, the isocyanate moiety is preferably aliphatic; Aromatic isocyanates have the disadvantage of yellowing over time.

According to another embodiment, the polyurethane is polycarbonate-based.

In one embodiment, the polycarbonate-based polyurethane is linear or branched and includes polycarbonate-type polyol moieties and isocyanate moieties. In one particular embodiment, the isocyanate moiety is preferably aliphatic; Aromatic isocyanates have the disadvantage of yellowing over time.

In one embodiment, the isocyanate crosslinker used is blocked, as originally known, to have a longer pot life product (particularly isocyanate functional groups are masked). In general, those skilled in the art are familiar with the polyurethane art and can propose coating compositions according to the invention and in particular produce a coating having a suitable tensile stress.

The coating step is carried out using techniques conventionally used for coating textiles, such as direct coating.

Direct coating is a coating by direct deposition using a scraper or cylinder or an air knife and refers to a pad coating, a Meyer bar coating (or a Champion method).

In one embodiment, the method comprises one or more aftertreatment step (s) to impart antifouling and / or water repellency to the fabric after step c).

Antifouling treatments refer to treatments using antistatic and / or anti-tack agents. Water repellent treatment refers to treatment using fluorinated resins with or without isocyanate extenders. The water repellent treatment is followed by a drying / crosslinking step.

In one embodiment, the aftertreatment is applied, in particular by padding, coating, spraying, or plasma treatment, using any method known to those skilled in the art.

According to one embodiment, the polyurethane used is flexible and durable against mechanical stress. In particular, the following specifications are met: 1 to 5 MPa in accordance with standard DIN 53504.

In an aqueous phase embodiment, the polymer is finely dispersed in the form of micrometric beads in water. This dispersion is stable due to the addition of surfactants. In the course of this method, the coating is deposited on the surface of the dry fabric by the heat of the furnace (evaporation of moisture) and the beads coalesce. In this way, a microporous film is obtained. As the temperature of the furnace increases, the beads melt to form a continuous film.

Aqueous phase polyurethanes have the inherent properties of the polymer and the physicochemical properties associated with its shaping. Thus, in one embodiment of the present invention, the aqueous phase polyurethane is characterized by 100% elongation tensile stress of less than 5 MPa. The aqueous phase polyurethanes are also characterized by dispersion concentrations of 30 to 60%. Finally, the aqueous phase polyurethanes of the present invention may be characterized by a viscosity (standard DIN EN ISO / A3) of less than 10,000 Pa.s at 23 ° C.

In solvent phase embodiments, the polymer is dissolved in the medium to prevent coalescence phase. The film naturally forms during the evaporation of the solvent.

In one embodiment of the invention, the solvent is selected from the group consisting of aromatic solvents, alcohols, ketones, esters, dimethylformamide, and n-methylpyrrolidone.

In one particular embodiment, the solvent is toluene, xylene, isopropanol, butanol, 1-methoxypropan-2-ol, methyl ethyl ketone, acetone, butanone, ethyl acetate, dimethylformamide, and n-methylpyrroli It is chosen from a group of money.

In one embodiment, the solvent-based polyurethane may be characterized by a concentration of 20 to 50%.

In one embodiment, the solvent-based polyurethane can be characterized by a viscosity of less than 100,000 Pa.s (standard DIN EN ISO / A3) at 23 ° C.

The aqueous polymer dispersion, which is a coating composition for textiles of the present invention, may also include additives.

The additive may be any additive commonly used in textile coating compositions. These are especially selected from the group consisting of viscosity modifiers, UV stabilizers, pigments, dispersants, surfactants. According to one embodiment, the coating comprises an anti-UV agent.

The fabric of the present invention can be any fabric known to those skilled in the art for which a coating is required. In particular, the fabrics of the invention can be made from yarns of synthetic or artificial materials. This may in particular be polyamide, polyester or viscose.

The present invention has the advantage of using fine yarns comprising a plurality of filament components. In addition to imparting lightness to the fabric, this can substantially reduce the porosity of the fabric prior to coating, especially if the step of unfolding the fiber by calendering precedes the coating step, thereby reducing the amount of polymer impregnation and thus The relative weight of the coating can be reduced, and ultimately the final weight of the fabric can be reduced while making the fabric more porous and durable.

In one embodiment of the invention, the fabric is formed of warp and weft yarns having different mechanical properties.

The invention also relates to a lightweight fabric which can be obtained by implementing the method according to the invention.

Fabrics of this type can be advantageously used for flying sails, in particular paragliders, which require significant mechanical strength, resistance to weather conditions, and strength over time.

The fabric according to the invention advantageously has high durability, in particular high moisture stability. This stability can be assessed by the different accelerated aging methods described in the Examples section:

Porosity after washing: preferably maintained at 70 L / m 2 / min or less at 2000 kPa;

Porosity after mechanical stress: preferably maintained at less than 40, preferably 20 L / m 2 / min at 2000 kPa;

Porosity after hydrolysis and mechanical stress: Preferably it should be kept below 70 L / m 2 / min at 2000 kPa.

The fabric according to the invention can be applied in all fields where the increase in weight, durability, in particular moisture stability, and porosity is advantageous.

The invention therefore relates to an item such as a paraglider sail comprising or made from the fabric according to the invention.

The present invention is described using embodiments corresponding to preferred embodiments, which are provided for non-limiting information.

Example  One:

Tilt: 22 dtex, 1.7 DPF

Weft: 33 dtex, 1.1 DPF

Seal material: polyamide, polyester or viscose

Weaving: 43.7 warp / cm and 47.6 weft / cm

Coverage 2.8

Calendering is carried out at a temperature of 180 to 210 ° C., at a pressure of 180 to 230 kg, at a speed of 10 to 20 m / min.

Coating composition:

Aliphatic polyether-based PU with 100% elongation tensile stress of 2 MPa: 70% (dry: 31.5%)

Isocyanate Curing Agent: 15% (Drying: 6.8%)

Additive: 10%

Thickener: 5%

(Unless otherwise indicated,% is by weight)

Coating was carried out with a scraper followed by a drying step (90-120 ° C. temperature) and a crosslinking step (140-210 ° C. temperature). The speed was 10 to 30 m / min.

The resulting fabric was subjected to a water repellent post treatment:

Composition: 10% fluorinated resin

      89% of water

      Wetting Agent 1%

The post treatment was padded, dried (90-120 ° C. temperature) followed by crosslinking (140-210 ° C. temperature) at a rate of 10-30 m / min.

Example  2:

Tilt: 22 dtex, 1.7 DPF

Weft: 33 dtex, 1.1 DPF

Thread Material: Polyamide

Weaving: 43.7 warp / cm and 47.6 weft / cm

Fabric weight: 27.7g / ㎡

Coverage 2.8

Calendering is carried out at a temperature of 180 to 210 ° C., at a pressure of 180 to 230 kg, at a speed of 10 to 20 m / min.

Coating Composition: (5.8g / ㎡)

Evotop U80ES (aliphatic polyether PU with 100% elongation tensile stress of 2 MPa): 70%

Rottal 444: 15% (isocyanate curing agent)

Additive: 10% (UV inhibitor, wetting agent, biocide)

Rotta 1227: 5% (Binder)

Coating was carried out with a scraper, drying step (90-120 ° C. temperature), crosslinking step (140-210 ° C. temperature). The speed was 10 to 30 m / min.

The obtained fabric was subjected to a water repellent post treatment (0.5 g / m 2):

Composition: Thobotex SLF 10% (Fluorinated Resin)

      89% of water

      Wetting Agent 1%

The post-treatment applied padding, followed by drying (90-120 ° C. temperature) / crosslinking (140-210 ° C. temperature) at a rate of 10-30 m / min.

The resulting fabric had a weight of 34 g / m 2 (coated fabric weight 27.7 g / m 2, contribution of the water repellent to the final weight of the fabric was about 0.5 g / m 2).

Elongation was measured in% under a force of 3 pounds (lbs.) Applied in the bias direction. This elongation characterizes the fabric stiffness in the bias direction. The standard used is NF EN ISO 13934-1. Test pieces were made 50 mm wide and 300 mm long. The jaw of the dynamometer was moved 200 mm apart and measured at a speed of 100 mm / min.

Elongation to Slope Bias Under 3 lbs .: 6.0%

Elongation to weft bias under 3 lbs .: 6.3%

Aging of the fabric was also measured using different methods.

The porosity of the fabric was measured after four 1 hour wash cycles in 30 ° C. water. Ideally, the porosity after treatment should be less than 70 L / m 2 / min.

Porosity after mechanical stress was also measured. In order to perform porosity measurements, the fabric was allowed to float while fixed in a mill-type assembly (assembly of 4 blades, the fabric is bound to the ends of each blade). Ideally, the porosity after 1.5 hours of treatment should be less than 4 L / m 2 / min, preferably less than 20 L / m 2 / min.

Porosity was also measured after hydrolysis. For this purpose, the fabric was placed in a pressure cooker with heated water and working pressure for 4 hours. Floating as described above was applied for 1 hour treatment and the porosity of the fabric was measured, the porosity after treatment should be less than 70 L / ㎡ / min.

Results: New porosity 1 L / m 2 / min.

      Porosity after 4 washes at 30 ° C .: 52 L / m 2 / min at 2000 kPa.

      Porosity after hydrolysis and suspension: 9 L / m 2 / min at 2000 kPa.

      Porosity after 90 minutes flotation: 10 to 14 L / m 2 / min at 2000 kPa.

Claims (17)

Lightweight fabrics formed of continuous warp and weft yarns, coated on one or both surfaces with polyurethane and characterized by a combination of the following properties:
The bare fabric has a coverage rate TC of 1.8 to 4, preferably 2.6 to 3.2, the TC being calculated as follows:
TC = (number of filaments / ㎝ × one diameter of the filament) + _slope (filament diameter × 1 number of one filament) _wefts,
The polyurethane has a polyether or polycarbonate base having a 100% elongation tensile stress (measured according to standard DIN 53504) of 5 MPa or less, with a dry impregnation rate of at least 10% by weight, preferably 12 To 30% by weight, more preferably 15 to 25% by weight,
The fabric has a weight of from 25 to 40 g / m 2 including the coating. The lightweight fabric according to claim 1, wherein the polyurethane has an elongation tensile stress of 4 MPa or less, preferably 3 MPa or less. The lightweight fabric according to claim 1 or 2, having an air permeability of 20 L / m 2 / min or less at 2000 kPa when measured according to standard NFG 07111 for a measuring surface area of 100 cm 2. The lightweight fabric as claimed in claim 1, having an elongation of less than 10% in the warp and weft direction bias under 3 lbs. According to NF EN ISO 13934-1. The method according to any one of claims 1 to 4, having an elongation of 1 to 10%, preferably 3 to 10%, more preferably 5 to 10%, in the warp and weft direction bias under 3 lbs. Lightweight fabric characterized. 6. The lightweight fabric of claim 1 wherein the warp and / or weft yarns have a dtex of 11 to 44 dtex and a DPF (decex per filament) of 1 to 4. 6. The lightweight fabric as claimed in claim 1, wherein the bare fabric has a weight of 20 to 33 g / m 2, preferably 24 to 28 g / m 2. 8. The lightweight fabric according to claim 1, wherein the weight of the coated fabric is 25 to 40 g / m 2, preferably 31 to 36 g / m 2. 9. The lightweight fabric as claimed in claim 1, wherein the fabric comprises 30 to 50 warp / cm and 30 to 50 weft / cm. 10. 10. The method according to any one of the preceding claims, wherein the polyurethane coating comprises isocyanates and / or melamine crosslinkers, wherein the dry crosslinker content is greater than 5% or more than 5% by weight, in particular 10, relative to the dry polyurethane. Light weight fabric, characterized in that from 30% by weight. The lightweight fabric according to claim 1, comprising an antifouling and / or water repellent treatment agent. Process for producing a coated lightweight fabric, in particular a fabric according to any one of the preceding claims,
(a) A fabric having a coverage TC of 1.8 to 4, preferably 2.6 to 3.2, is used and the TC is calculated as follows:
TC = (number of filaments / cm × 1 filament) _warp + (number of filaments / cm × 1 filament) _weft ,
(b) one or both surfaces of the fabric are coated with a polyether-based or polycarbonate-based polyurethane having a 100% elongation tensile stress (measured according to standard DIN 53504) of 5 MPa or less, and the dry impregnation rate At least 10% by weight, preferably 12-30% by weight, more preferably 15-25% by weight,
(c) the fabric is heated until the coating is dry / crosslinked,
(d) the fabric is recovered to have a weight of 25 to 40 g / m 2 including coating
Method of making coated lightweight fabrics. 13. A method according to claim 12, wherein the fabric is calendered before being coated in step (b). The method of claim 13, wherein said coating is performed on said calendering surface. 14. A method according to claim 13, wherein a finishing treatment is applied on the surface of the fabric prior to coating of the surface, wherein the finishing treatment increases the catching of the fabric coating. 16. A method according to any one of claims 13 to 15, comprising a coating on the opposite surface of the calendered surface. 17. The method according to any one of claims 13 to 16, comprising post-treatment step (s) to impart antifouling and / or water repellent properties to the fabric.