EP0958416B1 - Coating with textile appearance for covering shaped panels - Google Patents

Abstract

The covering of the invention for covering shaped panels is constituted by a knit (2) obtained on a four-bar Raschel or warp loom having two ground threads feeding the first guide needle (I) (Raschel notation) and two appearance threads feeding the second and third guide needles (II and III) in the following arrangement:where x is preferably equal to 2; the outside face (2a) of the knit (2) has a transparent coating (3) of an anti-adhesive material, e.g. a highly deformable transparent and lightweight membrane (3) made of an anti-adhesive material.

Description

The present invention relates to the covering of shaped panels, that is to say panels not necessarily flat and for which the covering must be produced by deforming the covering covering, for example by uses a hot forming technique. It concerns more particularly a coating of this type, having an external appearance textile and good cleanability.

The purpose of the covering is to aesthetically cover a element that we want to hide. For example, as an aircraft cabin, the cabin walls are lined with panels with a material which has all the required qualities of sound absorption, for example melamine-formaldehyde foam. These panels marry the interior shape of the cabin and are therefore not planar. During the application of the covering coating on the shaped panel, it is necessary to be able to locally deform said coating so as to make it match the external configuration of the panel. It is therefore important that the cladding can be extended in sufficient proportions to adapt to the external forms of the panel. Of course what has just been said about the panels for airplane cabins also for any type of shaped panel.

It is more sought after for covering coatings on the one hand sufficient aesthetic appearance and on the other hand good cleanability. On the from an aesthetic point of view we often look for a cladding which has a textile appearance, which has sufficient opacity to hide the panel to be dressed and which gives it a comfortable and warm visual appearance, compared to a smooth plastic coating. However the textile aspect is generally incompatible with good cleanability to the extent where the fibers or filaments making up the textile covering can easily absorb stains, dust etc.

The goal set by the applicant is to offer a coating for covering shaped panels, which have a good textile appearance and good cleanability.

This object is perfectly achieved by the coating of the invention which, in a characteristic way, consists of a knitted fabric obtained on a chain or Rachel loom with four bars with two bottom threads feeding the first pass (I) (Rachel notation) and two appearance son supplying the second and third passettes (II and III) according to the following assembly: I II III × × × ○ × × - - - × × × × 2 × 2 × - - - × × × 2 × × × - - - × × × × ○ ○ - - -

In addition, the outer face of the knitted fabric has a coating transparent in a non-stick material.

The particular structure of the knitted fabric gives it a textile look, the opacity and deformability sought; the coating in a material non-stick prevents stains from being absorbed or encrusted on the outer face of the knitted fabric; the transparent nature of the coating allows it has to visually keep its textile appearance.

Preferably, the value x in the assembly of the chain loom or Rachel is two. The Applicant has found that this method of knitting provides particularly effective results in concerns deformability.

Preferably knitting, obtained on chain or Rachel loom, is with a gauge of the order of 12. This density of wires is capable of bringing knitting very good opacity, allowing to mask as much as to do may be the panel on which is applied the covering coating.

In a first embodiment, the outer face of the knitted fabric is coated with a light, transparent and large membrane deformability, carried out in a non-stick material. The deformability of the membrane must be at least equivalent to that of knitting so as to that there is no alteration of the coating during the application thereof on the shaped panels to be dressed. The membrane should be light to do not recklessly increase the weight of the cladding and modify the visual appearance and possibly the touch thereof.

Preferably, the membrane in question is a membrane with polyurethane base which is applied by transfer and bonded to the surface knitting with an adhesive also based on polyurethane.

This type of membrane gives the covering coating its easy-care qualities since the knitting itself is no longer apparent but is protected by the membrane which on the one hand stains difficult and on the other hand is easily cleaned using the products routine maintenance.

In a second variant embodiment, each wire constituting the knit is sheathed by a transparent outer covering and in a material anti-adherent. In this second variant, it is the sheathing of each yarn which constitutes the covering which protects the outer face of the knitted fabric.

Compared to the first variant, this cladding presents disadvantages and advantages. To achieve an effect equivalent to the outer membrane, it is necessary to sheath each thread which is sufficient and which overall increases much more important the weight of the covering coating. In addition there is not a total barrier preventing the penetration of dirt into the knitted fabric so that there may remain incrustations between the stitches of said knitted fabric, difficult to clean. However, this alternative embodiment presents an undeniable advantage compared to the membrane when looking for a cladding that is acoustically transparent and not reflecting so as not to decrease the absorption efficiency of the shaped panel that he dresses. This is particularly true in the case of covering of noise correction walls, especially for cabin airline. Certainly the polyurethane membrane, which was presented above as the preferred embodiment, also exhibits some acoustic transparency, due to its micro-porosity; however it does remains no less true that the presence of this membrane is a factor to reduce the absorption efficiency of the sound correction panel comprising its covering coating.

The present invention will be better understood on reading the description which will be given of a preferred embodiment of a covering for covering shaped panels, comprising a knitted fabric chain or Rachel, coated on its outside with a light membrane and transparent polyurethane.

The coating of the invention is intended to cover all shaped panel, i.e. any panel with an outer surface is not necessarily flat, the application of the covering coating on the panel being produced in particular by the implementation of a technique of the forming type, in which the covering coating is hot formed to make it match the external shape of the panel to be dressed. From applications targeted by the applicant, we find in particular dressing sound correction panels lining the interior of the cabins airline. This application is of course not exclusive.

The applicant sought to combine in the same coating on the one hand, very high deformability, up to almost 100% in the weft direction and 85% in the warp direction, on the other hand a marked textile appearance, with good opacity and an apparent relief and finally a very good cleanability. The coating proposed by the applicant, in its first preferred embodiment, includes a knit obtained on chain or Rachel loom and a membrane which is arranged on the outer face of the knit and which is made of a material non-stick and transparent.

More precisely, the knitting is obtained on a four-bar loom with two bottom threads feeding the first pass (I) (Rachel notation) and two appearance threads feeding the second and third pass (II and III) according to the following arrangement: I II III × × × ○ × × - - - × × × × 2 × 2 × - - - × × × 2 × × × - - - × × × × ○ ○ - - -

Such a knit, meeting the definition above, has an appearance textile exterior, sufficiently opaque to hide surface defects of the panel to be dressed; moreover it has good deformability. Finally if necessary, it has good acoustic transparency, in particular for its application as part of a covering coating for aircraft cabin.

It should be noted that knitting is obtained on a four bar loom of which only three bars are supplied, while two bottom wires feed the same first pass together. It is the presence of two threads on the same pass which gives knitting its aspect of relief particular. Of course in practice the needles of the chain or Rachel loom, two wires on the same pass, must be equipped beaks larger than those of a conventional loom.

In order to obtain a knitted fabric having this structure which is balanced, according to the applicant it is necessary to respect a certain value of the length of absorbed yarn, hereinafter called LFA, as a function of the titration of the yarns constituting the knitted fabric. Table 1 below gives the values of the minimum LFA and the maximum LFA for a given wire titration, it being understood that this is the resultant titration for double-ended wires. Titration (dtex) LFA minimum cm / 100 mesh Maximum LFA cm / 100 mesh 667 28 37 500 27 35 400 22 32

In the case of a cladding covering which is sought also that it meets the standards required in terms of fire regulations, we use yarns based on polyvinyl chloride, obtained either by the so-called fiber spinning circuit short or cotton either by the long fiber spinning circuit or wool. In the first case, in a specific example, we used fibers having a cut of 6cm and a titration of 2.8dtex, for a twist between 500 and 570t / m. In the second case, we used fibers having a cut between 70 and 110mm, and a titration of 3.9dtex for a twist between 380 and 440t / m.

The knitting obtained with threads of 500 dtex and an LFA of 32 cm per 100 stitches was of the order of 250 to 400 g / m ² , depending on the gauge. In a preferred embodiment, the selected gauge was 12 and the value of the parameter x in the assembly was 2.

The membrane, placed against the outside of the knitted fabric, that is to say the face which is not intended to be applied against the shaped panel to be dressed, is a transparent, light and in a non-stick material. Due to its transparency, the coating retains its textile exterior appearance; due to its lightness it does not weigh down not prohibitively the weight of the coating, which is a factor important especially when it comes to a cabin trim coating aircraft; because of its composition, it constitutes a screen for dirt, which does not adhere to its surface and which can therefore be easily eliminated.

The applicant's preferred membrane is a membrane based polyurethane, which is slightly microporous. This membrane meets the aforementioned three criteria and moreover has a capacity elongation in all directions which allows it to follow, without limitation, the deformation of the knit when applying the coating against the shaped panel to be dressed.

The aforementioned structure of knitting with polychloride yarns vinyl and a microporous polyurethane membrane is particularly suitable for producing a front cladding comply with the fire resistance standards imposed for the covering of panels for commercial aircraft (aeronautical standard FAR 25).

The deposition of the membrane on the knitted fabric is obtained by transfer technique, using a transfer paper on which the coated membrane has been previously deposited on its outer face, not in contact with transfer paper, adhesive. Being a polyurethane membrane, the adhesive is itself an adhesive of the polyurethane type. The membrane is applied to the knitted fabric by feeding the transfer paper / membrane / adhesive assembly to a cylinder heating, the knitted fabric being fed between this assembly and said cylinder heating. The temperature used, at the level of the heating cylinder is of the order of 100 ° C., which enables the adhesive to be activated and the bonding of it and therefore of the membrane on the face of the knitted fabric, freeing up the transfer paper. This transfer technique, with adhesive, is preferred especially when the knitting is composed of fibers of the type polyvinyl chloride. We could of course implement other attachment techniques between the membrane and the knit, for example the direct coating technique.

It is certain that the presence of the membrane which extends over the entire outer surface of the knitted fabric forms a total screen for stains or dirt that cannot penetrate inside the mesh of the knitting. So in this version we have the best cleanability of the cladding.

However the presence of this membrane, for slight it can be, attenuates the acoustic transparency of the covering coating, transparency that can be sought.

This is why in the second variant of embodiment of the invention, it is no longer a continuous membrane which is applied to the outer face of knitting, but it is each yarn that makes up knitting that is itself coated with a transparent, light coating and in a material anti-adherent. So we have a kind of sheathing of each wire, by a coating or extrusion, which may for example be of the polychloride type vinyl.

This particular structure preserves the textile appearance and the particular relief of knitting. Acoustic transparency is certainly improved insofar as the sheathing of each sealing wire does not between the knit stitches. On the other hand, there can therefore be penetration soiling inside the knitting structure and therefore a reduction ease of cleaning.

Whether in the form of a membrane or a sheathing of the wires knitting, it is possible to add to the non-stick material constituting the coating on the outside of the knitted fabric with other additives intended for improve the desired characteristics, for example additives flame retardants for fire resistance, fluoride additives for ease of cleaning, anti-UV additives for light fastness.

It should be noted that the membrane is generally waterproof liquids and also, because of its micro porosity, permeable to air. The covering covering can, under these conditions, be qualified as breathable. This property can also open the coating of the invention to other applications.

Claims (6)

1. A covering for covering shaped panels, the covering being characterised in that it is constituted by a knit obtained from a four-bar Rachel or warp loom having two ground threads feeding the first guide needle (I) (Rachel notation) and two appearance threads feeding the second and third guide needles (II and III) in the following arrangement: I II III x x x 0 x x - - - x x x x 2x 2x - - - x x x 2x x x - - - x x x x 0 0 - - - and in that the outside face of the knit includes a transparent covering of anti-adhesive material.
2. A covering according to claim 1, characterised in that the value x in the arrangement of the Rachel or warp loom is two (Rachel notation).
3. A covering according to claim 1 or 2, characterised in that the knit obtained on the Rachel or warp loom has a gauge of about 12.
4. A covering according to one of claims 1 to 3, characterised in that the outside face of the knit is coated in a membrane that is lightweight, transparent, and highly deformable, being made out of an anti-adhesive material.
5. A covering according to claim 4, characterized in that the membrane is a microporous membrane based on polyurethane and applied by transfer and stuck to the surface of the knit by an adhesive that is also based on polyurethane.
6. A covering according to one of claims 1 to 3, characterised in that each thread constituting the knit is sheathed in a transparent outer coating of anti-adhesive material.