FR2864564A1 - THREE-DIMENSIONAL TEXTILE TABLECLOTH FOR TEMPORARY CEILINGS - Google Patents

Abstract

Nappe textile fabric (NM) for the realization of temporary ceilings, laid horizontally stretched, formed of a ribbon structure provided with through-holes, contiguous, forming open tubular cavities.It is formed of a nonwoven web provided with perforations whose edges are constituted by fibers (F) discharged forming the sides of the cells.

Description

Field of the invention

  The invention relates to a masking fabric web for the realization of temporary ceilings, laid horizontally stretched, formed of a web structure provided with through holes, contiguous, forming open tubular cavities.

  STATE OF THE ART The techniques for producing temporary false ceilings in the exhibition halls are very important in order to solve several ephemeral architecture problems. Indeed, these halls are generally very high ceiling to be able to accommodate the presentations of the largest products, (the big parts of the industry). But the majority of exhibitions concern smaller objects (consumer goods). For the latter, it is useful to establish in the hall, a temporary intermediate false ceiling, which will reduce the visible height by masking the upper parts where annoying utilitarian elements are always present. This significantly improves the quality of the exhibition by creating volumes in harmony with the size and nature of the products to be showcased. In addition, the fixed lighting in the halls is dazzling and almost always inappropriate, the false ceilings will allow them to be attenuated or transformed, for example by creating luminescent white ceilings. We will have the opportunity to make custom lighting, much appreciated as a means of staging.

  But in addition to their aesthetic importance, these false ceilings must satisfy all the obligations of safety and economy, which is particularly complex.

  Most exhibition hall ceilings are currently equipped with a regular mesh of smoke detectors, automatic smoke extraction systems and / or a network of automatic fire extinguishers. However, for these installations to work, when the exposures are installed, it is essential that the column of hot gases which is established vertically from the initial hearth, reaches and triggers, by rising, the extinguisher head installed in the ceiling, the closest to the vertical of this fireplace. This is then extinguished by the jets of water, sprinklers from top to bottom. It is therefore necessary that the hot, ascending gases and the downward jets of water not be stopped or deflected by a horizontal obstacle, as would a conventional ceiling. The correct operation of the smoke detectors presents, for the same reasons, the same requirements. Along with the extinction of fires, the evacuation of fumes released by a fire is doubly important, because in addition to being harmful, these fumes can also hide the sight of emergency access access signposts. create panic.

  These technical requirements complicate the realization of false ceilings. In addition to having to be economical and fire-resistant, they must also, imperatively, be per- missible for gases and liquids, while masking the upper parts of the halls.

  Today, two types of techniques are used: to - the techniques of two-dimensional textile webs, using stretched fabrics more or less complex, flat, in flexible layers by juxtaposition of edges placed at edges, - techniques three-dimensional, honeycombed false ceilings forming horizontally open mesh, consisting of panels of lightweight materials forming screens suspended vertically.

  The techniques of planar velums to a two-dimensional sheet.

  1. The classic awnings. This simplest and oldest technique consists in stretching light fabrics, generally sheets of cotton cloth of about 80 gr / m2, fireproof, usually horizontally. The strips are joined by seams. This technique is easy, economical and aesthetic. It was used a lot, but being not permeable, it is only allowed for false ceilings of small dimensions.

  2. Flat awnings in openwork textiles. These fire-resistant awnings are stretched horizontally and their weave has sufficiently wide open cells, like a net, to allow the ascending passage of the hot gases and down the jets of water extinguishers, But as these fabrics must also beings sufficiently opaque to perform the function of masking, they must meet two contradictory conditions: if these awnings are sufficiently masking, they are not permeable enough and if they are sufficiently permeable, they are not enough masking. According to certain regulations in force, open meshes for flat textiles must be at least 3x3 or 4x2 mm apart.

  3. Flat, stretched canopies with fusible lines. This technique uses the principle of assembling thin, planar, opaque and fire-resistant textile panels joined by lines of fusible material at a relatively low temperature (# 70 C).

  The panels are generally made of mesh fabric mesh opacity and sufficient fire resistance, joined during their manufacture by mesh lines made with a fusible thread. These textile webs, once tensioned, realize false ceilings masking, aesthetic and a good degree of security. The textile, relatively elastic, allows implementation under tension in both directions of its plan. At the beginning of a fire, the fusible lines dissociate the live panels causing openings, by shrinkage, allowing both the evacuation of hot fumes to the extractors, the triggering of fire extinguishers and the extinction of the fireplaces. because this textile is very permeable to water. The temperature of 70 C is lower than that of the triggering of permanent extinguishers, (# 80 C). This technique is aesthetic, however it does not always provide sufficient evacuation of all fumes, especially when they have a temperature below 70 C, the minimum operating temperature of this technique. Because the opening temperature of 70 C, can not be lowered, without causing untimely openings that would hinder the operation of false ceiling.

  The techniques of false ceilings in three dimensions or 3D ceilings or in honeycombs.

  1. These false ceilings are not continuous. They operate on the principle of normal horizontal vision. They are composed of cells open in the horizontal plane, limited by panels arranged in vertical planes of thin materials, rigid or semisouples, and assembled in a regular network generally horizontal. These false ceilings are completely open and therefore perfectly permeable to vertical flows. Their masking capacity is a function of the horizontal dimensions of their voids and the vertical height of their screens. This technique is used in the traditional construction of buildings, in the form of rigid grids, usually square bases, made of lacquered aluminum sheet strips. In this form, the cells measure about 1 decimeter, horizontally and 5 centimeters vertically. This technique is effective but too expensive to be used in temporary exhibitions. However, the same principle is exploited by suspending screens of nonwoven or fabrics vertically in large formats, which also makes their use difficult and expensive in exhibitions.

  Figures 1 and 2 show the operating principle of the honeycomb technique. Figure 1 is a vertical sectional view, according to CD of the horizontal section, Figure 2. In these figures, a flat false ceiling ply is shown, horizontally, in front of and higher than the observer placed A. This false ceiling mesh consists of masking vertical bands, light and fire resistant.

  I o To describe, understand and define the operation of the 3D false ceiling, it is essential to refer to the analysis of the principle of the usual human vision. It is indeed recognized that the usual vision of a spectator on a horizontal surface, is exercised mainly horizontally. This usual vision is inscribed in a cone whose axis is horizontal and normal in the middle of the segment joining the two eyes of the spectator. This cone has an opening 30 vertically, (Figure 1) and 60 horizontally, (Figure 2). The underside of the false ceiling for the viewer located at A will be completely masking from point 1/1 and beyond. The point 1/1 represents the beginning of the usual view of the observer located at A (top of the cone of vision); if the observer unconsciously raises his head, the ceiling will no longer seem completely masking, between the point 1/1 and the portion of space above him. This case is of little importance, because experience shows that even in this case, the viewer will keep the impression of having visited an exhibition with a masking ceiling, continuous over the entire surface. This peculiarity of visual memory linked to human behavior is exploited in the design and production of three-dimensional false ceilings (false 3D ceilings). In exceptional situations the angle may be different from the usual angle of 15 depending on the need for an upward or downward view to observe large objects.

  For the observer placed at A, Figure 1 shows the usual horizontal plane of vision which is the locus of the axes of the cones delimiting the usual vision. Under this plane, the line AF represents the lower limit of the cone of vision (or solid angle) if the observer pivots around its vertical axis A'A '.

  Above the horizontal plane, line AG represents the upper limit of the usual cone of vision from point A. This line AG has already been described. Above this line AG is a partially masked zone corresponding, for a pivoting of the observer around its vertical axis A'A ', to a cone of non-perception, of an opening of 120. This cone of non-vision accompanies the visitor and defines, on the contrary, the upper limits of the usual vision.

  In Figures 1 and 2, the square meshes of the false ceiling are diagonally illustrated with respect to the viewer's axis of vision. This arrangement is the most unfavorable for masking.

  The half-angle of vision which according to the indications given above is an angle a = 15 above the horizontal plane, corresponds, for an observer to the upper limit of his usual vision; this angle defines the principle of optimum scrolling of a false 3D ceiling. OBJECT OF THE INVENTION The object of the present invention is to develop a sheet of light masking product for producing temporary false ceilings as well as false ceilings, offering vertical permeability to gases and water whatever their temperature. satisfactory masking power, an attractive aesthetic appearance allowing industrial production, a possibility of prefabrication of tablecloths, economy and ease of installation by suspension and tension, a variety of colors, sufficient crush resistance required during handling and storage tablecloths in rolls, an improvement in fire resistance.

  DISCLOSURE AND ADVANTAGES OF THE INVENTION For this purpose the present invention relates to a masking textile web for the production of temporary ceilings, laid horizontally stretched characterized in that it is formed of a nonwoven web provided with perforations whose edges are constituted by the repressed fibers forming the sides of the cells.

  The walls of the tubular cavities are made in the mass of the material constituting the web which is shaped by a perforating embossing thus giving a masking effect according to the principle of the three-dimensional ceiling.

  For the purposes of the present invention, the expression "integral open cells" having a prismatic section refers generally to a three-dimensional sheet-like structure provided with through-holes which are contiguous and form through cavities.

  The textile false ceilings according to the invention have not only the interest of masking the equipment located above the false ceiling but also to improve the stationary lighting hall, too often inappropriate to substitute more suitable lighting. Thus, the false ceilings according to the invention can attenuate the direct illumination of light sources located above the false ceiling if the false ceiling is a matte black material. It will then be possible to create special adapted lighting. It is also possible to use the false ceiling as a light diffuser that regulates the luminous flux and spreads it over a larger area. The false ceilings thus become luminescent ceilings if the light sources above illuminate white and translucent sheets by manufacture.

  The false ceiling according to the invention makes it possible to attenuate and transform the fixed lighting of the halls which are currently dazzling and often inappropriate. The false ceiling can be a luminescent white ceiling. In general, it allows to make custom lighting popular as a means of staging.

  The textile ply has open, integral cells, in particular of prismatic faith forming tubular cavities, passing through the ply, the height of the cavities being equal to or greater than the largest diagonal of the horizontal section of the cell multiplied by the tangent of the vertical viewing angle. Since the relationship between the height and the largest dimension of the horizontal section of the cells is a dimensionless relationship in the mathematical sense, the cells of the textile ply according to the invention are very small compared to the dimensions of the false ceiling elements masking 3D type, formed by panels of thin material assembled in a network.

  The masking layer and therefore the false ceiling made with such plies have an exceptional vertical permeability since in plane, horizontal projection, the only non-permeable surface occupied by the ply is that constituted by the sum of the slices or thicknesses of the walls of the cells. . This allows the rise of gases and in particular hot gases in case of fire. This rise is done vertically through the sheet and likewise the water or the extinguishing liquid emitted by the nozzles and in particular the automatic nozzles placed above the sheet may descend vertically, that is to say in the opposite direction to that of the rise of hot and smoked gases to directly reach the fire. This permeability also obviously favors the very rapid and direct evacuation of fumes upwards from the halls and possibly towards the extractors.

  The permeability is inversely proportional to the sum of the wall thicknesses calculated in the horizontal plane of the laid sheet. This sum is also a function of the necessary resistance of the ply to crushing, during storage and handling in the rolled state. In addition, some current safety regulations require that this sum be equal to or less than 50% of the total surface area of the aquifer. These obligations, in addition to those of efficient masking and economy of material, lead to the construction of cell walls whose vertical section is substantially rectangular with two small sides in the direction of the horizontal planes of the sheet and two long sides. in the vertical direction of the thickness.

  The tablecloth offers a masking power, equivalent to that of the best current masking honeycomb ceilings and this regardless of the orientation of the horizontal axis of vision relative to a vertical axis, with very significant savings improvements and security. The observer can look in one direction or turn his head around the vertical axis to look in another direction, his usual horizontal gaze will always be hidden under the normal viewing angle. Moreover, even if he raises the head with a direction of non-horizontal and even vertical vision, he will not see the space directly above the masking layer, the vision will be veiled or attenuated by the meshes, creating an effect of partial curtain.

  The regular false ceiling is industrializable, it has the advantage of offering a pleasant aesthetic appearance by its fine and regular structure and possibly translucent. The product webs can easily be assembled and prefabricated by seams or welds.

  The laying is particularly easy and economical given the lightness of the product and the reduced means necessary for the attachment of the strips or assemblies of les on the sides of the surface to be covered. The web can be manufactured with a wide variety of colors by dyeing the components or the produced textile product. The obtained surface may be decorative and / or constitute an advertising surface.

  Advantageously, the nonwoven web is provided with a strong integral reinforcement.

  It is also possible to improve the fire resistance by the choice of fibers, grids and plastic foams, or the treatment of the tablecloth after weaving.

  According to another advantageous characteristic, the meshes are of rectangular section, in particular square, of which two sides are parallel to the edge of the sheet. The angles of these squares may also advantageously be rounded to improve strength and masking.

  The rectangular and in particular square shape of the meshes with two sides parallel to the longitudinal direction of the lé is very interesting because the tension is exerted directly in the longitudinal direction of the walls of the meshes and in the transverse direction that is to say perpendicular, when the strips are assembled. The result is a perfectly stretched ceiling, meeting most of the requirements for the establishment of false ceilings on surfaces that are themselves rectangular. The square also has the advantage of presenting two equal, orthogonal medians which have a better efficiency for masking, unlike the rectangle.

  According to another advantageous characteristic, fusible lines are integrated in the sheet. This makes it possible, in case of exceeding the melting temperature of these fuse lines, an opening of large longitudinal slots in the layers substantially canceling the pressure drop with respect to the gases and liquids at the crossing of the layers in case of recovery of hot gases of high temperature.

  According to another advantageous characteristic, the invention relates to a method for manufacturing a masking textile web of the type defined above, characterized in that a non-woven textile web is used, the web is perforated by perforating according to a method described in US Pat. perforation distribution grid, and - the fibers are forced on the sides of the perforations to form the sides of the cells.

  This manufacturing method has the advantage of being very simple and economical because it makes it possible to start from a nonwoven textile web, whose fibers have the appropriate characteristics and in particular characteristics of non-flammability or fire resistance. and the nonwoven textile web may also have a strong, solidarized reinforcement integrated in the nonwoven web. 30

  Then, this textile web is shaped by the method of the invention, to provide a third dimension, characteristic of a 3D masking layer, by the backflow of the fibers initially distributed more or less regularly over the entire sheet to form the sides of the cells. The fibers thus discharged on the sides of the cells or sides of the perforations can be frozen naturally or by coating, gluing or heat sealing.

  These different operations are executed continuously. Puncture of the web is either mechanically or fluidly or by a combination of mechanical and fluidic means.

  In the case of a fluidic perforation, it is very advantageous to achieve this perforation by a jet of fluid, in particular a jet of liquid or gas.

  This embodiment has the advantage of the flexibility of use because the fluid jet performing the perforation can be constituted by a set of stationary jets, under which scrolls the nonwoven web to be embossed or by displacement of the or nozzles and their control for making pulse jets of defined duration and position depending on the perforation pattern or faith inc perforations or cells to achieve.

  Such fluidic techniques are currently highly developed, particularly as a fiber bonding means in the nonwovens industry.

  According to an advantageous characteristic, a nonwoven textile ply is used, the fibers of which are mainly distributed in two directions, in particular perpendicular directions or whose fibers have a preferential distribution according to strands in the ply, corresponding to the distribution of the walls to be made.

  The fibers distributed in two directions will have a preferred orientation as a function of rectangular or square perforations to be made, which facilitates this operation and allows it to be executed more quickly.

  The invention also relates to a machine for carrying out the method. Such a machine is a matrix comprising a distribution of projecting portions of frustoconical or pyramidal shape, bordered by forming channels in which the fibers of the web are pushed back. to

  These protruding parts of the machine have a pyramidal shape of square section, rectangular, diamond or hexagonal.

  According to the invention, the machine can cooperate with either a mold of complementary shape with cavities cooperating with the projecting parts or with fluidic means blowing and pushing the web and the fibers on the projecting parts to form progressively the perforations, open them, push back the fibers in the channels and end up in the shape of the masking textile web which will then be frozen.

  Finally and as already indicated, the invention also relates to false ceilings made up of plies as defined above and having means for fixing and tensioning the plies, for example the use of support cables placed in hems, welds or seams in the junctions of the webs.

  Drawings The present invention will be described hereinafter in more detail with the aid of the accompanying drawings in which: - Figure 1 is a vertical section of the usual vision diagram of a false ceiling 3-dimensional or honeycomb FIG. 2 is a plan view of the usual scheme of view of the false ceiling of FIG. 1; FIG. 3 is a schematic perspective view of a greatly enlarged scale of a sheet of hexagonal mesh textile product; FIG. 4 is a diagrammatic perspective view on a greatly enlarged scale of another embodiment of a layer of textile masking material with rectangular mesh, FIGS. 5 and 6 show two modes of FIG. 7 shows, in its parts 7A-7F, various steps for manufacturing a perforated web according to a first embodiment of the method of the invention; FIG. 8 shows, in FIG. his parts 8A-8C, three states of a nonwoven web before perforation, during and after perforation; FIG. 9 shows, in its parts 9A-9F, the various steps of another method of manufacturing a web FIG. 10 is a diagrammatic perspective view showing the shape of a matrix, the shape of a pre-perforation wicking sheet and the shape of the cellular sheet obtained after perforation and discharge of the fibers, FIG. 11 is a view similar to that of FIG. 10, but for a fleece of woven nonwoven reinforced with a textile grid and the result obtained, FIG. 12 shows an installation diagram of textile product webs. masking or masking tablecloths making a false ceiling. DESCRIPTION OF EMBODIMENTS According to FIGS. 1 and 2, the definition of the usual angle of vision, which is valid for the vast majority of exposures, commonly accepted in architecture, ergonomics or, more generally, in psychology, is an angle of 30 in a vertical plane about a horizontal axis and an angle of 60 in a horizontal plane.

  The only thing that is important for a hidden false ceiling is to take into account the usual viewing angle or normal vision of 30 in a vertical plane with respect to a horizontal axis. The half-angle directed downwards does not intervene and only intervenes the angle of 15 in the vertical half-plane above the horizontal axis of usual vision.

  But this angle currently accepted as usual viewing angle can be modified according to particular considerations, for example for the presentation of objects of great height, the angle of vision is taken with respect to an inclined direction that is to say to say that it is increased by this particular inclination angle, the masking layer being always horizontal.

  According to FIG. 3, the invention relates to a masking layer N intended in particular for producing false masking ceilings or temporary false ceilings, in particular for exhibition halls. The sheet N is laid stretched usually horizontally, corresponding to the horizontal plane P. This sheet N is formed of open cells, generally prismatic, of base section, polygonal or curvilinear forming open tubular cavities CT through the sheet N in the vertical direction V with respect to the horizontal direction P. The cavities or their cavities CT are contiguous and thus define an array of tubular cavities all of axis V, vertical.

  These CT cavities have dimensions defined by their larger horizontal diagonal DG corresponding for example to the diameter of the circle circumscribing the polygon formed by the mesh or more generally to the possibly mixtiligne curve formed by the section of the mesh.

  The height H of the tubular cavity CT is chosen as a function of the greatest horizontal diagonal DG of the section by the following relationship: H = tga.DG, a being the usual half-angle of vision, defined previously. The triangle formed by the diagonal DG and the height H has for vertex one of the vertices SO, S1, S2, S3, S4, S5 of the prismatic section of the mesh. Any line of usual vision boundary passing through this peak SO and meeting one side of the cell closer to SO than the top S3 opposite to the summit SO, will meet this side at a height less than the height H. The tubular cavity thus formed will be perfectly masking in the sense of the masking effect defined for false ceilings or structures of the same type.

  The value of the coefficient (tangent a) for an angle of 15 is (tg 15) 0, 267. The height H corresponds substantially to a quarter of the greatest

  diagonal DG which results in a layer of masking textile product of relatively small thickness if for the cell is chosen a dimension of the order of 3 to 4 mm, the thickness of the sheet then being of the order of 1 mm.

  The open cells with prismatic section forming the tubular cavities CT are delimited by substantially vertical faceted sides F0, F1, F2, F3, F4, F5. These facets, which are generally perfectly opaque, are opaque or translucent depending on the nature of the material constituting these facets and the illumination in the environment of the n-shaped layer. FIG. 3 shows, by way of example, a masking layer of which the cells have a hexagonal section to emphasize the possibilities of the invention. This section can be very variable form provided to respect the ratio between the largest horizontal diagonal and the height of each cell or prismatic through cavity. This section may also be rounded, circular or more generally prismatic or curvilinear.

  FIG. 4 shows another embodiment of a layer of masking textile product 20 formed by occultation wires constituting the walls of the tubular cavities passing through the masking layer.

  The principle of orientation (horizontal / vertical) is the one defined previously. The sheet is supposed to be horizontal and the through cavities open in the vertical direction.

  In this example, the sheet 2 is formed of cells 21 of rectangular section or more particularly square whose sides 22 are preferably directed parallel to the longitudinal direction of the web and the other sides 23 in the transverse direction and preferably perpendicular. The cells 21 are joined in both directions.

  FIG. 5 shows cells 51 formed by a struc- ture with strips 52, 53 of a certain height, obtained for example by fusion or coating at the junctions.

  FIG. 6 shows another embodiment of a sheet with cavities 61 formed of a reinforcing mesh composed of wires 62, 63 provided with a thickening 64, 65 in the two directions of the wire 62, 63.

  An example of a method of manufacturing a masking layer as shown in FIGS. 3, 4, 5 and 6 will be described using FIGS. 7A7F.

  According to this method, a nonwoven web NT is used, the fibers of which are oriented in any way or in two directions.

  These directions may be perpendicular but also inclined at an angle to the direction of the web. The fibers may also have a preferential distribution, for example be in the form of wicks aligned on preferential directions themselves perpendicular or intersecting at an angle.

  This sheet NT is then perforated with distributed perforations PR1 and then the fibers F are spread on the sides of the perforations, so as to enlarge the perforations and to form the sides C1, C2 in relief of the perforations which thus become cells. These cells may have a rectangular, square, diamond or polygonal section, for example hexagonal so that the neighboring cells have common sides constituting a common wall. The orientation of these walls may be directed in the longitudinal or transverse direction or may, in some cases, be an angle with respect to the longitudinal direction for example in the case of cavities denominated diamond.

  More particularly, a machine is used to perform the perforations and to force the fibers back to enlarge the perforations and to push back the fibers to form the sides of the cells.

  In a first step (Figure 7A), a ma-chine (100, 200) is used having a lower die 100 provided with projecting portions 101 of substantially triangular vertical section and rectangular or hexagonal car-rée base. The protruding parts are bordered by troughs 102 forming channels.

  This fixed matrix 100 cooperates with a matrix of complementary shape or counter-matrix 200, mobile, having cavities 201 in homologous positions of the protruding portions 101 of the fixed matrix 100. The notions of fixed and mobile are relative notions for facilitate the description. In fact, it is simply a matter of indicating that the matrix 100 and against matrix 200 are movable relative to each other and that they can move closer or apart to perform the operations corresponding to the method of the invention. The dies 100, 200 can perform approximation movements in a discontinuous manner, that is to say step by step, so as to treat each time a certain length of web NT. But it is also possible to make dies 100, 200 in the form of rolls which cooperate in the manner of a rolling mill to perforate the sheets NT and emboss them. In this case, the dies cooperate continuously and permanently instead of cooperating alternately, with progression step by step.

  In a first step (FIG. 7A), the counter-matrix 200 is moved away from the fixed matrix 100. FIG. 7B shows an NT nonwoven textile web that is introduced into the gap between the die 100 and the counter 200 (Figure 7C). Then, we bring the matrix of the contrematrice (Figure 7D) so as to perforate the nonwoven web NT (Figure 7E) by pushing the web with the counter-matrix. The fibers of the sheet slide on the protruding parts of the matrix to descend along the sides as and when the descent of the counter-matrix to final-ment, to regroup in the hollow-shaped channels 102 bordering the 3o projecting portions 101 of the matrix 100.

  The fibers are guided towards these channels 102 by the inclined, flat, straight or curved shape of the protruding portions 201 and the more or less flared or straight shape of the section of the channels. The fibers F thus grouped together constitute ribbons of rectangular section and of appropriate height, defined with respect to the base of the projecting parts to constitute the cells with a blackout effect giving the masking sheet.

  Then, the counter-matrix 200 is opened and the web is disengaged, which will thus have a structure such as that of FIG. 5. In other words, fibers are produced by pushing back into the channels, a kind of molding of the textile web. masking by replacing the initial distribution of fibers in two dimensions (length and width of the web) in three dimensions, that is to say a perpendicular dimension thus forming a three-dimensional textile structure.

  FIGS. 8A-8C show an example of evolution of the NT nonwoven textile web during the perforation steps.

  According to FIG. 8A, in this example initially the web has fibers F1, F3 apparently oriented in two perpendicular directions. This NT web is then perforated NT1 and there is a certain grouping of the fibers (FIG. 8B) to finally arrive at the grid grouping of the fibers (FIG. 8C) on the sides C 1, C2 giving a masking sheet NM, corresponding schematically to the shape of the web represented in FIG.

  A simultaneous or subsequent step consists in freezing the fibers thus grouped on the sides C1, C2, to give the shape-keeping shape of the cells. This freezing can be done by different processes connecting the fibers together, such as coating, gluing or heat-sealing, for example by heating the dies 100, 200.

  The method of perforation with the displacement of the fibers F, F1, F2 on the sides C1, C2 of the perforations PR1, represented in FIGS. 7A-7F, is a mechanical perforation method using a die 100 and a counterweight 200 of complementary shapes. But other processes, including a fluidic process, can also be considered. Thus, as represented in FIGS. 9A-9F, a matrix 100 with projecting portions 101 corresponding to the distribution of the perforations to be produced is used. These protruding parts are pyramidal shapes of square, rectangular, diamond or more generally, polygonal. As before, these protruding portions 101 are lined with a network of channels 102 to form the sides of the cells of the masking sheet.

  As before, an NT nonwoven textile web is used with fibers having a random orientation, or oriented orientation along two or more preferential directions or also a web whose fibers are already grouped into locks.

  This sheet NT is made to come on the die 100 (FIG. 9C) and then fluid jets emitted by nozzles 301 are made to act to push the sheet NT against the protruding parts (FIG. 9D) and perforate the sheet progressively (FIG. 9E). ) to finally push back the fibers F in the channels 102 surrounding the projecting portions 101 and also obtain a masking fabric mat with cavities NM, such as that of FIG.

  After deposition of the fibers F in the channels 102 which perform a kind of molding, the sheet is thus embossed, if necessary freeze by coating, gluing or heat bonding as in the example above. This fluidic method can be applied dis-continuously or continuously and in these two cases the matrix is a cylinder and the fluid is projected by a nozzle ramp 301 or by a single or a few nozzles which sweep one or more generatrices of the cylinder being rotated.

  The fluid used is air or a liquid such as water. The fluid, like the matrix, can be heated to create at the same time a slight fusion of fibers to set them by heat sealing.

  Fig. 10 is a schematic perspective view of the perforation process with fiber delivery and shaping.

  Thus, and as shown, starting from an NT nonwoven textile web whose fibers F are already organized mainly in CF-letters distributed in two directions, for example perpendicular, this web is placed on the matrix 100 formed of projecting parts. 101 of pyramidal structure with rectangular or square base, bordered by channels 102. The sheet is perforated completely by pushing it against the protruding parts 101 so as to push the intermediate fibers F and the fibers of the locks CF into the channels 102 using either a counter-matrix not shown or a method of perforation or fluid discharge or a combination of both. Finally, a molded sheet is obtained, molded like that NM shown schematically and which corresponds to the shape of the channels of the matrix.

  FIG. 11 shows another example of the method according to which an NT nonwoven textile web is used, the fibers F of which are grouped into CF locks provided with a reinforcing grid G. This results in a honeycomb-containing fabric sheet NMR reinforcement whose walls are bordered by the reinforcing fibers or fibers FR of the grid G. FIG. 12 shows a very schematic plan view of the realization of a false ceiling masking with 400 strips assembled or juxtaposed and fixed to both sides of the Hall by fastening means 401 such as hooks or nails on which are stretched the strips. The webs 400 may be assembled along their side 402, for example by stitching or welding with or without hem for the passage of support cables. They can also be left free. In the case where the strips are assembled, it is possible to also stretch the false ceiling in the direction perpendicular to the transverse direction by means of hooking means and tension 403. More simply, the stretched sheet can be also nailed to its periphery.

Claims (14)

  1) Three-dimensional textile sheet masking for the realization of temporary ceilings, laid horizontally stretched, formed of a sheet structure provided with through-holes, contiguous, forming open tubular cavities, characterized in that it is formed of a nonwoven web (N) provided with perforations, the edges of which consist of upstanding fibers forming the sides of the cells.   2) masking sheet according to claim 1, characterized in that the nonwoven textile web is provided with a solidarized reinforcing armature.   3) masking sheet according to claim 1, characterized in that the cells (210, 220) are of rectangular section, including square, two sides are parallel to the edge of the ply (200) or polygonal section, in particular hexagonal.   4) masking sheet according to claim 1, characterized in that fusible lines are integrated in the sheet.   5) A method of manufacturing a masking fabric web for producing temporary ceilings, according to claim 1, characterized in that - one uses a nonwoven textile web, - this web is perforated by perforating a grid distribution of the perforations, and the fibers are forced on the sides of the perforations to form the sides of the cells.   6) Process according to claim 5, characterized in that the frozen fibers are frozen according to the section of the sides of the perforations.   7) Method according to claim 6, characterized in that the fibers are frozen by gluing, coating, or heat sealing.   8) Process according to claim 5, characterized in that the sheet is perforated by a mechanical perforation, a fluidic perforation or a combined mechanical and fluidic perforation.   9) Process according to claim 8, characterized in that the fluidic perforation is carried out by a jet of fluid.   10) A method according to claim 5, characterized in that a nonwoven web is used whose fibers are mainly re-parties in two directions including perpendicular or whose fibers have a preferential distribution following wicks in the sheet, corresponding the distribution of walls to achieve.   11) Machine for producing masking sheets according to claims 1 to 4, with the aid of the method according to claims 5 to 10, characterized in that it comprises a matrix (100) having a distribution of projecting parts ( 101) of pyramidal shape, bordered by forming channels (102) in which the fibers (F) of the web (NT) are pushed back.   12) Machine according to claim 11, characterized in that 3o the protruding portions (101) of pyramidal shape have a square, rectangular, diamond or hexagonal.   13) Machine according to claim 11, characterized by a contrematrice (200) complementary shape of the matrix (100) with cavities (201) cooperating with the projecting portions (101).   14) False ceiling formed of masking layers according to claim 1, characterized by means for fixing and tensioning (401, 403) webs (400).