WO2010097550A1

WO2010097550A1 - Light and/or high compactness fabric, in particular for parachutes

Info

Publication number: WO2010097550A1
Application number: PCT/FR2010/050321
Authority: WO
Inventors: Philippe Guimbard
Original assignee: Porcher Industries
Priority date: 2009-02-24
Filing date: 2010-02-24
Publication date: 2010-09-02
Also published as: FR2942481B1; US20120085456A1; KR20110128891A; FR2942481A1; EP2401427A1

Abstract

The invention relates to a fabric made of continuous warp yarns and weft yarns, comprising 30 to 63 warp yarns and 30 to 63 weft yarns per centimetre, and in which the yarns are spread so as to lie in a same plane, the yarns having a dtex of between 11 and 78 dtex and a DPF (decitex per filament) defined in the following manner on the basis of the number of warp and weft yarns: (I) the fabric has a weight of between 27 and 40 g/m2 and a perviousness to air lower than or equal to 120 l/m2/s at 127 Pa, as measured according to the ASTM-D-737 standard (1 hour) on a measuring surface of 20 cm2.

Description

LIGHTWEIGHT AND / OR HIGH-COMPACTED FABRIC, IN PARTICULAR FOR

PARACHUTE

The present invention relates to fabrics having properties, especially of lightness and / or compactness, improved, being of great interest for the manufacture of articles such as parachutes. The invention also relates to a method of manufacturing such a fabric as well as articles such as parachutes, made from this fabric.

Traditionally, the parachute consists of a harness bag that contains a main jump sail and a rescue sail.

The parachute fabric must meet a number of technical criteria such as tear resistance, service life, porosity. The manufacturers of parachutes have technical knowledge allowing them to meet the specifications for the main sail and the rescue sail. Traditionally, manufacturing involves the use of synthetic or natural yarns composed of a multitude of continuous filaments. These threads are intertwined according to traditional weaving techniques. The so-called "ecru" fabric thus obtained is then cleaned to remove the protective and lubricating products of the yarns, especially the size, and then various steps are taken in order to make the properties of the fabric more homogeneous over its entire surface. One of the main functional properties of fabrics is the air permeability. It is this property that will slow down the fall, the main function of the parachute.

Parachutes are often constructed using ripstop nylon fabric. Rip-stop nylon is a square-mesh fabric with warp and weft threads positioned at 90 degrees to each other, some threads being doubled, tripled or more generally in a regular manner.

Depending on the level of air permeability required, the fabric may be heat set (heat treatment for stabilizing properties), primed (deposit of a chemical primer conferring particular properties), calender (pressurized tissue between heated rolls) ), coated (depositing a layer of polymer).

For coated fabrics, the material is typically calendered and then coated with a silicone-based material or the like. The silicone or other material makes it possible to fill the pores of the fabric in order to adjust the porosity and thus to control the permeability and the behavior of the sail. The principle is always the same, the larger the apparent surface of the wires, the more they will disturb and therefore slow down the flow of the air flow. Treatments, coatings and primers increase this apparent surface.

Two properties are now very popular in the world of skydiving. The first of these properties is the compactness of the fabric to obtain a folded volume as small as possible so as to limit the size of the harness bag containing the jump sail and the rescue sail. The other of these properties is lightness for obvious reasons.

On the same surface, a low compactness is generally easier to obtain for the emergency sail which is generally a sail made from an uncoated fabric having a low porosity. These properties are more difficult to obtain for the main skiff sail which is generally made of a fabric coated so as to have a very low porosity, so-called zero porosity. The major difficulty to increase the lightness and / or compactness is to keep the fabric properties allowing it to be always suitable for its use in the manufacture of parachute sails. The same problem exists in other applications such as paragliding sails, kite-surfing sails, sailing sails, including spinnaker or gennaker.

The present invention aims to improve the level of compactness and / or the lightness of these fabrics, particularly those used for the manufacture of parachute sails.

The subject of the present invention is therefore a fabric formed of warp yarns and continuous weft yarns, comprising from 30 to 63 warp yarns and from 30 to 63 weft yarns, per centimeter, and in which the filaments are spread out for present in the same plane, the threads have a title between 1 1 and 78 dtex and a DPF (decitex filament) defined in the following manner, according to the number of warp and weft son:

The spreading of the filaments in the same plane is an important feature of the invention. Spreading makes it possible to place the warp filaments, respectively of frame, so that they are parallel to each other or substantially parallel. Due in particular to the mesh and therefore the crossing and the superposition of the son at the son crossings, the spreading of the filaments in the same plane may not be perfect, however, the use of very fine filaments makes it possible to obtain optimized spreading. By spreading in the same plane, the invention thus also covers a spread substantially in the same plane.

The fabrics according to the invention are therefore characterized by the use of son having a high and optimized number of constituent filaments. The spreading of these filaments is facilitated. In addition, for the same weight of fabric, the surface then covered is greater than what is traditionally obtained with son having a smaller number of filaments of larger diameter. The weight / area ratio is also optimized, in particular because the thickness of the fabric is reduced by spreading finer filaments. The invention defines an optimum between the weight of the fabric, the number of threads per cm and filamentary spreading. It also optimizes the compactness of the tissue, whether in the center or the fold, thanks to the synergistic combination of the use of finer filaments and the spreading of the filaments. The fabrics according to the invention can be used as such, for example for the manufacture of the emergency sail of a parachute, or after coating, for example for the main sail of the parachute. The invention then brings another advantage. The optimum spreading of the filaments means that for a given weight of fabric and a number of threads in the given cm, the spaces between the constituent threads of the fabric are reduced to the maximum and the wear rate of the coating is thereby reduced. which reduces the amount of coating and therefore the weight of the coated fabric. This also allows to maintain optimal compactness after coating. The constituent yarns of the fabric according to the invention are preferably parallel filament yarns.

The fabric according to the invention is advantageously a square mesh fabric, with warp and weft threads crossed at about 90 °. According to a preferred embodiment, it is a rip-stop fabric. The constituent material of the filaments is preferably a synthetic or artificial material. It may especially be polyamide, polyester or viscose.

In a preferred embodiment, it is polyamide, in particular polyamide 6.6 (PA 6.6, nylon 6.6). In one embodiment, the yarns have a titer of between 22 and 44 dtex, preferably between 33 and 44 dtex.

According to an advantageous characteristic, the yarns have a tenacity greater than or equal to 5.8 cN / dtex, preferably greater than or equal to 6 cN / dtex, for example between 5.8 or 6 and 7 cN / dtex.

In a particular embodiment, the number of warp son and weft son is between 30 and 62, especially between 30 and 60.

In two other embodiments, the fabric has the following characteristics:

According to one embodiment, this fabric is also coated, in particular to obtain a very low porosity. For the purposes of the invention, the term "very low porosity" means a porosity or permeability to air of less than or equal to 1 l / m ² / s at 1000 Pa, as measured according to ASTM-D-737 (1). hour) on a measuring surface of 20 cm ² . Such a fabric can be advantageously used for a main jump sail.

In another embodiment, the fabric has the following characteristics:

The fabric corresponding to this definition can be used as it is with a low porosity. By low porosity is meant in the sense of the invention a porosity or air permeability less than or equal to 15 l / m ² / s at 127 Pa, as measured according to ASTM-D-737 (1 hour) on a measurement surface of 20 cm ² . Such uncoated fabric can be advantageously used for an emergency sail. In another embodiment, the fabric has the following characteristics:

The fabric that meets this definition can be used as is or coated. Uncoated, its porosity or permeability to air may be less than or equal to 120 l / m ² / s at 127 Pa, as measured according to ASTM-D-737 (1 hour) on a measuring surface of 20 cm ² . Such uncoated fabric can be advantageously used for an emergency sail. The compactness of a fabric can be measured at the overlap of several layers of tissue (called center measurement) and at the fold. The measurement in the center gives information on the compactness obtained by stacking several layers of fabric. It is not enough in itself. The measurement at the fold is more informative because it gives access to the foldability of the fabric, and the overall compactness of a folded fabric several times on itself, as in the case of a parachute sail folded in the bag -harness. In accordance with the invention, the center measurement is a thickness measurement of 12 superimposed fabric layers. The pleat measurement is the maximum thickness value at the "flattened" fold joining 12 layers of fabric. The tissue sample to be characterized is deposited around two fingers carried by a support plate. The controlled rotation of this plate makes it possible to superimpose 12 layers of fabric in a reproducible manner. A finger is then retracted, which releases the folded fabric from any tension and is deposited on a marble or platinum measurement. A third finger is connected to means for measuring the thickness of material located between the finger and the measuring plate or marble, these means make it possible to obtain variations in thickness throughout the measurement zone. For measurements, it is preferably the fabric that is moved with the plate under the finger, the latter being parallel to the fold. The fold value is the maximum thickness value recorded in the crease area when the finger is touched on this area. According to one embodiment, the fabric has a compactness of the fold less than or equal to 0.65 mm, in particular less than or equal to 0.58 mm, preferably less than or equal to 0.52 mm. According to this embodiment, the fabric has in particular a center compactness less than or equal to 0.55 mm, in particular less than or equal to 0.52 mm, preferably less than or equal to 0.45 mm.

According to other characteristics, this fabric may have one, several or all of the following characteristics: weight between 27 and 40, preferably between 27 and 35 g / m ² ; center thickness between 36 and 45 μm; - air permeability less than or equal to 120, preferably less than or equal to 15 l / m ² / s at 127 Pa, as measured according to standard ASTM-D-737 (1 hour) on a measuring surface of 20 cm ² . According to one embodiment of the invention, the fabric is coated. It is coated on one side or on both sides. It is preferably coated on both sides, for example for parachute applications.

Preferably, this fabric comprises a number of threads (for warp and weft) of between 37 and 47 and a DPF such that 1.0 <DPF <1, 35.

Advantageously, the coated fabric has a compactness of the fold less than 0.85 mm, in particular less than 0.75 mm, preferably less than 0.65 mm. Its compactness in the center may especially be less than or equal to 0.75 mm, preferably less than or equal to 0.55 mm.

Its weight is advantageously between 30 and 50, preferably between 30 and 40 g / m ² .

Advantageously, the coated fabric has a thickness of between 60 and 85 μm.

The coated fabric preferably has an air permeability less than or equal to 2, preferably 1 l / m ² / s at 1000 Pa, as measured according to ASTM-D-737 (1 hour) on a surface. measuring 20 cm ² .

The coating may be carried out using materials commonly used for coating fabrics used in parachute, paraglider, spinnaker, kite surfing, etc. applications. These once polymerized or crosslinked materials have the properties of hanging on the fabric and elasticity suitable for these applications. Among the preferred materials, mention will be made of silicone materials. Advantageously, the supply of coating material is optimized and may in particular be such that the weight of coating is reduced by about 25% compared to the standard for a similar porosity, this result being obtained as explained above by means of the spreading of the filaments. For example, a coating weight of between 4 and 7 g / m ² , in particular between 5 and 6 g / m ² .

According to one characteristic of the invention, the filaments constituting the threads have a diameter of between 10 and 22 μm, preferably between 10 and 19.5 μm.

Spreading of the filaments can be achieved by any means. In the case where a coating is provided, the spreading precedes the coating. Spreading is preferably performed on a fabric without sizing and advantageously thermofixed in the usual manner.

According to one embodiment, the fabric is cleaned to remove the size, it is then heat set, and then spreading.

Preferably, the spreading is carried out by calendering. The effectiveness of calendering, or any other spreading procedure, can easily be controlled by optical, digital or electronic microscopy, with suitable magnification. This allows the skilled person to adjust the spreading parameters according to the tissue, in order to obtain optimum spreading, resulting in the fact that the filaments are substantially in the same plane. For an uncoated fabric, the calendering can be carried out in the presence of a slip agent. For a coated fabric, it is not necessary.

According to a particular embodiment, the fabric, in particular PA, preferably PA 6.6, is of the type 46 ± 1 warp / cm, 46 ± 1 weft / cm, 26 ± 1 filaments per yarn, 33 ± 2 dtex, that is a DPF of 1, 27 dtex approximately, thermofixed, primed and calender. Fabric weight 33 ± 1 g / m ² . See properties in example 2.

According to another particular embodiment, the fabric, in particular of PA, preferably PA 6.6, is of the type 45 ± 1 warp / cm, 45 ± 1 weft / cm, 26 ±

1 filament yarn, 33 ± 2 dtex yarns, ie a DPF of approximately 1.27 dtex, heat-set, calender and coating (silicone coating weight approx. 6-7 g / m ² ). Fabric weight coated approximately 39-40 ± 1 g / m ² . See properties in example 2.

According to an advantageous characteristic, the fabrics of the invention have a tear strength greater than or equal to 1.5 daN according to the ISO 4674 test standard, or greater than or equal to 1.8 daN according to the ISO 13937-2 standard. In one embodiment, an anti-slip agent is applied to at least a portion of the surface of the yarns or fabric. This agent is especially applied to the assembly areas between two pieces of fabric, for example on the seam assembly areas. This anti-slip agent may be formed of particles of a mineral nature, especially of silica, for example of colloidal silica, smoke or diatomaceous earth. The particles preferably have a cross section or a mean diameter of between 5 and 100 nm. This anti-slip agent may also be of an organic nature, for example based on acrylic. The anti-slip agent may be present between 0.01 and 0.5%, preferably between 0.01 and 0.1% by weight relative to the total weight of the fabric.

The fabrics according to the invention can find application in all applications where the compactness gain has an advantage. As a first area, we may mention the applications for which reduced space is a decisive advantage, which is particularly the case of large surface parachutes and / or parachutes embedded or used under conditions where the place that can be attributed to them is limited. As another area, there may be mentioned applications for which it is advantageous to be able to increase the surface area of the fabric with identical dimensions, for example making it possible to increase safety or to reduce the rate of fall. The fabrics according to the invention find application in the field of skydiving, whether for skydiving people or skydiving equipment, for example material drop, civil or military field, or parachute relief or slowing down for light aircraft for example (ULM, drone, light aircraft, etc.). They may find employment more generally in the various disciplines related to wind or air. Thus, the invention also relates to a parachute sail, a paraglider sail, a kite-surf sail, a sail sail, including spinnaker or gennaker, or any other article comprising or formed of a fabric according to the invention. invention.

The invention also relates to a skydiving bag, or a skydiving harness bag, comprising at least one sail comprising or consisting of a fabric according to the invention, the sail being the rescue sail, preferably uncoated, or the main sail, preferably coated. Preferably, this article contains the two webs comprising or consisting of a fabric according to the invention. The subject of the invention is also a process for producing such a fabric, in which, after weaving the warp and weft threads, preferably at 90 °, in particular in the rip-stop format, the filaments are spread out so that they present themselves substantially in the same plane. The spreading may be carried out as described above, in particular by calendering, under the conditions defined in particular above.

For an uncoated fabric, the fabric may be heat set and / or primed, according to the methods and with the products usually employed, before spreading.

For a coated fabric, spreading is advantageously preceded by heat-setting. Spreading precedes coating. The coating can be on one side or both sides.

Thermofixation is a conventional step, in particular being able to be conducted at a temperature of between 150 and 170 ° C.

The calendering is carried out at a temperature which may be between 190 and 210 ° C for the uncoated fabric and between 140 and 160 ° C for the coated fabric.

The stages of spreading, preferably calendering, and any other stages such as heat setting and application of a primer, and coating, are preferably carried out after cleaning the fabric called "ecru", that is to say the fabric from weaving. This cleaning aims to eliminate in particular the size. The invention will now be described in more detail using embodiments taken as non-limiting examples.

EXAMPLES

Example 1 Two polyamide 6.6 fabrics A and B were made having the following specifications. Fabric C (comparative) is a PA 6.6 standard fabric coated with silicone for parachute. The weight of the fabric is measured according to BSEN 12127 and expressed in g / m ² .

Fabric A is primed and heat-set, then calendered. The fabric B is heat-set, then calendered, then coated with a silicone coating identical to that of fabric C.

The compactness measurements of 12 layers of fabric are carried out as described above and the results obtained are as follows:

The permeability to air was measured as described above, under 127 Pa for A and under 1000 Pa for B:

Example 2

Two D and E fabrics of polyamide 6.6 are made with the following specifications. The comparative fabric C is the same as in example 1.

Fabric C is primed and heat set, then calendered. The fabric E is heat-set, then calendered, then coated with a silicone coating identical to that of fabric C.

The permeability to air was measured as described above, under 127 Pa for D and under 1000 Pa for E:

Claims

claims

1. Fabric for parachute, paraglider or sail sail, consisting of continuous warp and weft yarns, having 30 to 63 warp yarns and 30 to 63 weft yarns, per centimeter, and in which the filaments are spread out to be in the same plane, the yarns have a dtex between 11 and 78 dtex and a DPF (decitex per filament) is defined in the following manner, according to the number of warp and weft yarns:

the fabric has a weight of between 27 and 40 g / m ² and an air permeability less than or equal to 120 l / m ² / s at 127 Pa, as measured according to ASTM-D-737 (1 hour ) on a measurement surface of 20 cm ² .

Fabric according to claim 1, characterized by the following features:

Fabric according to claim 1, characterized by the following features:

4. Fabric according to any one of the preceding claims, characterized in that the fabric has a compactness of the ply less than or equal to 0.65 mm, in particular less than or equal to 0.58 mm, preferably less than or equal to 0 , 52 mm.

5. Fabric according to any one of the preceding claims, characterized in that the fabric has a compactness in the center less than or equal to 0.55 mm, in particular less than or equal to 0.52 mm, preferably less than or equal to 0 , 45 mm.

6. Fabric according to any one of the preceding claims, characterized in that the fabric has a weight of between 27 and 35 g / m ² .

7. Fabric according to any one of the preceding claims, characterized in that the fabric has a thickness between 36 and 45 microns.

8. Fabric according to any one of the preceding claims, characterized in that the fabric has an air permeability less than or equal to 15 l / m ² / s at 127 Pa, as measured according to ASTM-D- 737 (1 hour) on a measuring surface of 20 cm ² .

9. Fabric according to any one of claims 1 to 3, characterized in that the fabric is coated.

10. Fabric according to claim 9, characterized by a number of threads (for warp and weft) of between 37 and 47 and a DPF such that 1.0 <DPF <1, 35.

11. Fabric according to claim 9 or 10, characterized in that the fabric has a compactness of the ply less than 0.85 mm, in particular less than 0.75 mm, preferably less than 0.65 mm.

12. Fabric according to any one of claims 9 to 1 1, characterized in that the fabric has a compactness in the center less than or equal to 0.75 mm, preferably less than or equal to 0.55 mm.

13. Fabric according to any one of claims 9 to 11, characterized in that the coated fabric has a weight of between 30 and 50, preferably between 30 and 40 g / m ² .

14. Fabric according to any one of claims 9 to 12, characterized in that the coated fabric has a thickness of between 60 and 85 microns.

15. Fabric according to any one of claims 9 to 13, characterized in that the coated fabric has an air permeability less than or equal to 2 l / m ² / s under 1000 Pa, as measured according to ASTM standard. D-737

(1 hour) on a measuring surface of 20 cm ² .

16. Fabric according to any one of claims 9 to 14, characterized in that the fabric is coated with a silicone material.

17. Fabric according to any one of the preceding claims, characterized in that the diameter of the filaments is between 10 and 22 microns, preferably between 10 and 19.5 microns.

18. Fabric according to any one of the preceding claims, characterized in that the son are crushed by calendering.

19. Fabric according to any one of the preceding claims, characterized in that the yarns have a tenacity greater than or equal to 5.8 cN / dtex.

20. Fabric according to any one of the preceding claims, characterized in that it has a tear strength greater than or equal to 1, 5 daN according to the ISO 4674 test standard, or greater than or equal to 1.8 daN according to ISO 13937-2.

21. Fabric according to any one of the preceding claims, characterized in that an anti-sliding agent is applied on at least a portion of the surface of the son or fabric.

22. A parachute, paraglider or sailboat sail, comprising or consisting of a fabric according to any one of the preceding claims.

23. A method of manufacturing a fabric according to any one of the preceding claims, wherein, after weaving the warp and weft son, the filaments are spread so that they are substantially in the same plane.