RU2238378C2 - Flexible sheet material for stretched structure, method of its production and sheet material for stretched suspended ceiling - Google Patents

Abstract

FIELD: building structures, particularly stretched ceilings.

SUBSTANCE: flexible sheet material with thickness of less than 0.5 mm has microscopic relief formed by embossing sheet material and provides increase in sound-absorbing coefficient in comparison with sheet material having no relief.

EFFECT: enhanced sound-absorbing properties.

23 cl, 19 dwg, 9 tbl

Description

The invention relates to building materials, namely sheet materials of relatively small thickness (mainly up to 0.5 mm), used to make suspended ceilings, false ceilings, false walls, wall coverings by tensioning such materials and more specifically relates to sheet material for tension structures, the method of its manufacture and suspended false ceilings from such a material.

The prior art includes a large number of methods for the manufacture of such materials and their use in suspended false ceilings.

When describing the prior art, reference can be made to patent applications in France published under the following numbers: 2767851, 2751682, 2734296, 2712006, 2707708, 2703711, 2699211, 2699209, 2696670, 2691193, 2685036, 2645135, 2630476, 2627207, 2624167, 2624167, 2624167, 2624167, 2624167, 2624167, 2624167, 2619531, 2611779, 2597906, 2592416, 2587447, 2587392, 2561690, 2552473, 2537112, 2531012, 2524922, 2523622, 2486127, 2475093, 2310450, 2270407, 2202997, 2175854, 2145147, 26630, 13070, 14707, 12707, 12307, 0236. as an example, the following documents: US-A-5058340, US-A-4083157, EP-A-643180, EP-A-652339, EP-A-588748, EP-A-504530, EP-A-338925, EP-A-281468, EP-A-215715, EP-A-089905, EP-A-043466, WO-A-94/12741, WO-A-92/18722. You can also refer to the following patent applications in France, filed by the Applicant: 2736615, 2756600, 2727711, 2712325, 2699613, 2695670, 2692302, 2658849.

Known materials of the prior art for suspended ceilings or suspended ceilings, for example, according to US Pat. No. 3,782,495, are most often polymeric materials having various properties, in particular, such as resistance to fire, impermeability to air, dust or humidity, ease of maintenance.

In false ceilings made of such materials, thermal insulation, various lighting devices, including directional actions, as well as holes for ventilation or aeration or sprinklers can be integrated. Simplicity in dismantling false ceilings allows, if necessary, easy access to embedded devices.

Polymeric materials for suspended ceilings are known from the prior art, having the following properties: translucent or opaque, painted in bulk or not, matte, shiny, marbled, leather or various fabrics. These materials can be used both in industry and for equipping utilities, laboratories or residential premises.

The final polishing finish creates a mirror effect, which is often used in shopping centers. The matte finish is pretty close in appearance to the stucco and more familiar with traditional decor.

Despite its many advantages, which have led to their increasing use in various interiors, the false ceilings and false walls made of stretch polymer paintings known from the prior art have a significant drawback due to poor acoustic properties, in particular, the reverberation of sound on such stretch ceilings is increased.

The technical problem of reducing sound reverberation on walls and ceilings has long been known.

Several technical solutions to this problem are known from the prior art.

According to the first embodiment of the technical solution, the soundproofing panels include perforated panels made of metal or plastic mounted on a special basis such as slag wool or polyurethane foam. For the first version of the technical solution by passive sound absorption by fibrous or porous materials, one can refer to the following documents from the prior art: EP-A-013513, EP-A-023618, EP-A-246464, EP-A-524566, EP-A- 605784, EP-A-652331, FR-A-2405818, FR-A-2536444, FR-A-2544358, FR-A-2549112, FR-A-2611776, FR-A-2611777, FR-A-2732381, US-A-4,441,580; US-A-3,948,347. These technical solutions consist in using an assembly in which the sound-absorbing inner layer is rigidly bonded to the perforated front with a visible side. Perforation is designed to reduce vibrations of sound-absorbing material, in addition, the latter cannot be left visible either because of its fragility, or its dirty surface or rough unaesthetic appearance.

According to the second embodiment of the prior art technical solution, panels forming partitions are used, such as, for example, suspended ceilings, provided with cavities whose volume is calculated in order to correspond to a certain frequency range, while the cavities are protected by a porous finish. For this second embodiment of a technical solution using a Helmholtz resonator, reference may be made, for example, to documents DE-PS-3643481, FR-A-2463235.

According to the third embodiment of the technical solution known from the prior art, in the manufacture of suspended ceilings, panels are used whose diffusing surface is corrugated or provided with slots or deep depressions. When describing such a solution, reference can be made, for example, to documents FR-A-2381142, FR-A-2523621, FR-A-2573798, WO-A-80/01, WO-A-94/24382.

According to the fourth embodiment of the technical solution, absorption membranes forming honeycomb surfaces are used for sound absorption purposes. This expensive technique is sometimes used in recording studios.

None of the known levels of technical solutions for improving the sound properties of walls or false ceilings is adapted for the specific technique of suspended ceilings or walls.

The basis of the present invention is to create a soft, sheet material suitable for use in tension structures (decorating or masking), in particular in false ceilings or false walls, having significantly improved acoustic properties and the appearance of which would be well suited for use in industry, trade and the residential sector for the equipment of modern or historic buildings, as well as to develop a method of manufacturing such a material and suspended false ceilings from such material.

The problem is solved due to the fact that in the soft sheet material with a thickness of less than half a millimeter intended for the manufacture of tension structures, in particular false ceilings, microreliefs are made according to the invention by extruding its basic material with an increased acoustic absorption coefficient compared to the same material without microreliefs.

According to various embodiments of the invention, these materials are preferably made having the following characteristics, optionally combined:

- the height of the microreliefs in the direction perpendicular to the plane of the sheet of material is less than the triple thickness of the sheet;

- microreliefs are made with the formation of protrusions on only one side of the sheet;

- each of the microreliefs is located at the nodes of the regular motive;

- all microreliefs are located at the nodes of only one motive, for example, square cells;

- microreliefs are made with the formation of protrusions on two sides of the sheet, with each of the microreliefs located at the nodes of the regular motive, and more specifically, located at the nodes of only one motive, for example square cells;

- microreliefs are made in the form of channels with a substantially flat bottom connected to the hole by a strip of material whose thickness is less than or equal to the thickness of the part of the sheet separating the microreliefs;

- the channels are made with axial symmetry about an axis substantially perpendicular to the bottom wall;

- a strip of material connecting the wall of the bottom of the channels and the holes is made intermittent;

- the material is equipped with microperforations with holes with a diameter of less than 0.4 mm, and at least part of the microreliefs is equipped with microperforations, and a part of the microperforations is located between the microreliefs;

- microperforations are located at the nodes of a certain motive;

- microperforations are located at the nodes of a certain motif identical to the microrelief motif and offset relative to it;

- microperforations are made by piercing with needles or any other equivalent method;

- microperforations obtained without removing material;

- the material is selected from the group consisting of polyvinyl chloride, vinylidene chloride and copolymers of vinyl chloride / vinylidene chloride or any other equivalent material;

- the surface occupied by microreliefs is from 0.5% to 10% of the surface of the sheet;

- the density of microreliefs and / or microperforations is from 2 to 60 units per square centimeter, preferably from 15 to 35 units per square centimeter, and even more preferably from 20 to 30 units per square centimeter.

The problem is also solved due to the fact that the proposed method of manufacturing a sheet material, which according to the invention includes the step of piercing with needles to expel at the puncture site of the base material of the sheet with the formation of microperforation according to a predetermined motive. Preferably, the needle piercing step is carried out without removing the sheet material. When piercing, needles having an outer diameter of less than a tenth of a millimeter, for example about four hundredths of a millimeter, are used. In one embodiment, the needle piercing step is carried out when the sheet of material is tensioned in the same order as the tension when it is finally used in the tension structure.

The problem is also solved by creating a false ceiling made of a sheet of material according to the present invention, subjected to tension on the supporting means.

Other features and advantages of the present invention will be apparent from the following description of non-limiting specific embodiments, which is carried out with reference to the drawings, in which:

- figa, 1b and 1C depicts various options for the manufacture of material for a stretch ceiling according to the invention,

- figure 2 is a graph representing the dependence of the value of the acoustic absorption coefficient on the average frequency of a third of an octave in four experimental conditions 1b, 2b, 3 and 4, as well as for a sample of the reference frequency;

- figure 3 is a graph similar to the graph of figure 2, for experimental conditions 5, 6 and 7;

- figure 4 is a graph similar to the graph of figure 3, for experimental conditions 8, 8b and 9, the results obtained for conditions 1b, 2b are plotted on the graph of figure 4 for comparison;

- figure 5 is a graph similar to the graph of figure 2, for experimental conditions 10, the results obtained for conditions 3, 6 are plotted on the graph of figure 5 for comparison;

- Fig.6 is a graph similar to the graph of Fig.2, for experimental condition 11, the results obtained for conditions 4, 5 are plotted on the graph of Fig.6 for comparison;

- Fig.7 is a graph similar to the graph of Fig.2, for experimental conditions 12, 13 and 14;

- Fig. 8 is a histogram of the values of the acoustic absorption coefficient, measured depending on the frequency value of a third of an octave for experimental condition A;

- Fig.9 is a histogram similar to the histogram of Fig.8, for experimental conditions In;

- figure 10 is a histogram similar to the histogram of Fig.8, for experimental conditions C.

We turn first to figure 1.

Figure 1 - depicts a front view of the material 1 with a thickness of the order of one tenth of a millimeter, equipped with exactly the same microreliefs 2, regularly located on the nodes of square cells. On fig.1b presents on an enlarged scale the relief 2 in cross section by a plane perpendicular to the plane of the material of figure 1. The dimensions of the microreliefs are such that they appear almost pointlike in FIG. Reliefs 2 represent, in the considered embodiment, channels that are strictly symmetrical about axis 3, perpendicular to the plane of the sheet of material 1. These reliefs project to a small height h (from several microns to several tens of microns) and are visible holes with a diameter of about two tenths of a millimeter.

In the presented embodiment, the microreliefs 2 have a bottom 4. These through holes are obtained by piercing the material 1 with needles, which in one particular embodiment have a tip diameter of the order of several hundredths of a millimeter, for example, 0.04 millimeters.

In one embodiment, piercing with needles is carried out when the sheet of material 1 is tensioned. This tension, in a particular embodiment, has the same order as when applying the sheet in stretch ceilings.

Through holes 19 with a diameter of several hundredths of a millimeter are obtained without removing material.

The bottom walls 4 of the microreliefs 2 are connected to the edge of the holes by an annular wall 5, which is a surface of revolution with the axis 3. If necessary, this wall 5 can be made with a thickness e5, smaller than the thickness e1 of the sheet material 1. This difference in thickness is all the more noticeable, the greater the height h microreliefs 2, for a given thickness e1.

In some, not represented, particular cases of manufacturing, for at least part of the reliefs 2, the annular wall 5 is made intermittent.

In one embodiment, the bottom wall 4 of at least a portion of the microreliefs may be solid, i.e. without through hole.

As a non-limiting example, a device with the following dimensions may be used:

- pitch p between microreliefs 1 mm;

- the density of microreliefs per square centimeter 25;

- the height of the reliefs from a few microns to 100 microns.

Consider other embodiments of the invention.

According to the first embodiment, not all microreliefs are identical, two or more two groups of reliefs can be distinguished, moreover, these reliefs have different shapes.

According to a second embodiment of the invention (optionally combinable with the first embodiment described above), the microreliefs are not strictly pointwise, but are located in at least one direction, forming micro-grooves and micro-ring grooves.

According to the third option (if desired combined with one of the two options described above), all the microreliefs do not have axial symmetry with respect to the axis strictly perpendicular to the middle plane of the sheet 1 of the material.

The bottom of the micro-grooves when viewed from above can be, for example, square, rectangular, oval, in the form of a regular or irregular polygon. The microrelief grid cell in the embodiment of the invention depicted in FIG. 1 is square. In other manufacturing options, it is not square, but rectangular.

In some embodiments, at least two microrelief grids with different linear cell sizes (p1, p2, p'2) are located on sheet 1 of material 1 as shown in FIG. 1c.

Depending on the density of the microreliefs, their height and application motive, they can be more or less noticeable on sheet 1. In this case, a significant improvement in the acoustic properties of the sheet 1 of the material can be obtained without a noticeable change in appearance. Thus, the use of microreliefs is both effective in terms of acoustics and appearance. The application of the present invention allows you to maintain the classic appearance of suspended ceilings and achieve acoustic properties similar to the acoustic properties of anti-noise suspended ceilings.

In some of the embodiments described above, the sheet is provided with a microrelief but is not perforated or microperforated. Performing a microrelief without perforation improves the acoustic properties of the material without compromising its ability to retain moisture. Compared to perforated sheets, such material does not have dark marks formed from the air passage, as well as holes with irregular edges obtained when using a worn tool for perforation. In addition, material without perforations is easy to wash.

The performance of microperforations 19 on the sheet 1 of the material shown in FIG. 1b does not substantially change its appearance when viewed along arrow F. The performance of microperforations 19, such as those shown in FIG. 1b, makes them almost indistinguishable if the visible front side 20 of the sheet 1 of material made matte. Improved acoustic properties of the material when using the present invention can abandon the use of fibrous insulation, which leads to dust and microfibers and adversely affecting health.

The improved acoustic properties of the sheets of material achieved by creating micro-perforated microreliefs will be illustrated using experimental results. Before presenting these results, it is necessary to recall some concepts of acoustics since these concepts are not included in the field of knowledge of specialists in ceilings and walls from stretched paintings.

Sound waves propagate in elastic media in the form of wave fronts of pressure change with a speed depending on the modulus of elasticity and density of a solid (about 500 m / s in a traffic jam and 3100 m / s in ordinary concrete, for example). The sound heard by the human ear is formed by the frequencies of sound vibrations enclosed between 16 Hz and 20,000 Hz when these sounds are emitted above a certain acoustic pressure (the auditory threshold is four backgrounds). The area of conversational frequencies lies between 10 Hz and 10 kHz, and, understood speech is conducted at frequencies between 300 Hz and 3 kHz. The range of musical frequencies lies between approximately 16 Hz and 16 kHz, with one octave corresponding to a doubling of the frequency (Table A).

Sound absorption can be obtained either by converting acoustic energy into the potential energy of deformation of the material, or by loss of internal friction in a porous absorbing material with low acoustic impedance, or by using a resonator due to internal friction, which dissipates the acoustic energy of sound in the form of heat whose frequency is close to the natural frequency of the resonator. Accordingly, four types of acoustic insulating materials are distinguished:

- porous “hard” materials, such as porous concrete and rigid foams, in which capillary networks form acoustic resistance;

- "elastic" porous materials, such as mineral wool, felt, polystyrene, in which acoustic energy is dissipated due to solid friction;

- materials with acoustic resonance, acting on the principle of Helmholtz resonators, such as perforated panels;

- materials with mechanical resonance, acting on the basis of oscillation damping generators.

The sound absorption coefficient is denoted by a (dimensionless quantity). This coefficient is the normalized difference between the incident acoustic energy and the reflected. This coefficient is a function of the frequency of incident sound vibrations. Since sound scattering in air is a function of temperature, pressure, and relative humidity, measurements of the absorption coefficient must be carried out at known values of temperature, pressure and humidity (see French standards NF S 30 009). Regarding the norms for measuring this coefficient, one can refer, for example, to the following documents: international standards ISO 354, French standards NF EN 20354, NF S 31 065, US standards ASTM C423. Table B below gives some values of this sound absorption coefficient α.

In addition, the sound reflection coefficient ρ, sound scattering δ and the sound transmission coefficient τ are introduced.

At the interface between two media, the principle of conservation of acoustic energy requires that ρ + τ + δ = 1, ρ + α = 1.

The more acoustic energy dissipated by acoustic insulation, the less acoustic energy will be reflected, reducing the echo effect.

An echo or reverberation resulting from the reflection of sound from obstacles causes interference, which can significantly increase the noise level in the room and make ordinary speech difficult to perceive.

The reverberation time T is determined by the Sabin formula

T = 0.163 V / αA,

where V is the amount of free space; A is the area of the absorbing surface; α is the absorption coefficient defined above.

Sabin's formula is derived from the assumption of a perfectly uniform distribution of the reverb field. The reverberation time is the time after which the acoustic energy decreases by 60 dB, i.e. up to one millionth of its original value.

After presenting data from the theory of acoustics, experimental results obtained under normal conditions are presented below.

In the first series, twelve bands of material were tested for acoustic absorption.

Canvases of material measuring 9 '× 8' (2743.2 × 2438.4 mm) were fixed to the box surface in the form of a parallelepiped made of fiberglass with a wall thickness of 3/4 "(19.05 mm) measuring 9 '× 8' × 4 ' (2743.2 × 2438.4 × 1219.2 mm), which was mounted on a corrugated steel plate.

A fiberglass box was installed in a reverberation (boom) chamber for measurements, called in an empty chamber. The measurement results are given in table 1.

The frequencies shown in Table 1 are the center frequencies of the normalized bands of a third of an octave.

The test results are presented in table 2.

Sheets marked "perforated NLM41" are of the same type as those sold by the Applicant under the name NewLine NLM41. These sheets are equipped with perforations of large sizes (round holes with a diameter of four millimeters) obtained by removing material, and the density of the holes is less than one per square centimeter. These round openings are intended for ventilation and possible smoke removal: this range of products NLM41 belongs to the class M1 / B1 / Fire 1.

Sheets marked "perforated NL601" are of the same type as those produced by the Applicant under the name NewLine NLM601. These sheets are also provided with large perforations (round holes with a diameter of about one millimeter), obtained by removing material. These round openings are intended, as with NLM41 sheets, to ventilate the room and possibly remove smoke. The range of products NL601 belongs to the class M1 / B1 / Fire 1.

The curves corresponding to the results are shown in figure 2-7:

- figure 2 depicts the results of experiments 1b, 2b, 3, 4 in relation to the five values obtained for the frequency standard;

- figure 3 - the results of experiments 5, 6, 7 with respect to the aforementioned frequency standard;

- figure 4 - the results of experiments 8, 8b and 9 in comparison with the results obtained for experiments 1b, 2b and 7;

- figure 5 - the results of experiment 10, in comparison with the results obtained for experiments 3 and 6;

- Fig.6 - the results obtained for experiment 11, in comparison with the results obtained for experiments 4 and 5.

A comparison of curves 1b and 2b shows the effect of the installation of classical fiber sound insulation, as this can be done in the plenum.

A comparison of curves 3 and 4, on the one hand, with the curves lb and 2b, on the other hand, shows that the use of perforations on a stretched sheet can increase the acoustic absorption properties, in particular at high frequencies, i.e. areas in which the use of fiber insulation is ineffective. Applying calculations from the theory of acoustics, it can be shown that a rigid perforated panel of thickness h located at a distance e from the partition and containing n cylindrical perforations of radius a, being supported by four orthogonal supports, is a resonator with a resonant frequency determined by the formula:

ω = c (mπ / a ² e (h + 8a / 3π)) ^0.5 ,

i.e., this panel behaves like an ensemble of Helmholtz resonators, and its maximum value of acoustic absorption depends on the attenuation coefficient and the degree of perforation. This type of acoustic absorption mechanism is used in perforated ceilings.

In the case of stretched canvases considered here, the sheets of stretched material are able to vibrate and, therefore, are not rigid and not deformable, in addition, the thickness h is very small compared to the thickness of the soundproof panel, so the mathematical model described above cannot be used. Other models known in acoustics describe the behavior of perforated diaphragm panels, taking into account the intrinsic rigidity of the panel and the air pressure behind the panel, as well as the outflow of air through perforations, which can play a dissipative role.

These very complex models could be used, if necessary, to explain the results obtained in experiments 3, 4, 5, 6, 10, 11.

Curves 5, 6, and 7 illustrate the effect of applying an acoustic coating by spraying onto stretched sheets. The effect of this coating is especially noticeable at higher frequencies. On the contrary, as shown in Fig. 4, for a smooth stretched sheet, the use of fibrous insulation (experiments 2, 8, 8b) or the use of acoustic coating by spraying (experiments 7 and 9) for frequencies exceeding 400 Hz gives results lower than those obtained for perforated sheets with or without acoustic spray coating. For all cases of experiments 1b, 2b, 3, 4, 5, 6, 7, 8, 8b, 9, 10, and 11 shown in the figures, the acoustic absorption properties are very different between low and high frequencies.

The use of the present invention, in particular the implementation of microreliefs and microperforations, allows to obtain no less favorable results than perforation of large sizes. The sound absorption effect obtained with microperforation is even better in the high frequency region than the results obtained for large perforations.

Tests 12, 13, and 14 illustrate reference results. The test conditions were as follows: temperature 70 ° F (approximately 21.2 ° C), humidity 84%, pressure - atmospheric. A sheet of microperforated material measuring 9 '× 8' (2743.2 × 2438.4 mm) was tested in a type E 1219 installation. By “microperforated sheet” is meant here, with reference to tests 12, 13 and 14, a sheet of PVC material, a thickness of 0.17 mm, with microperforation applied, obtained by piercing with needles without removing material, and the used needles had a tip diameter of the order of 0.04 mm, while the density of the obtained microperforations was 23 pieces per square centimeter and the perforations were arranged according to the grid, 1a. The sheet was pulled onto the top of the box in the form of a parallelepiped, not painted, made of 3/4 "(19.05 mm) fiberglass with a volume of 10,154.72 cubic feet (287.55 m ³ ). For these tests, in an" empty chamber ", the T690 value of the reverberation time of which corresponds to the average reverberation times. The acoustic absorption coefficient CAA and refinements were obtained according to US standards ASTM C423-90a. The NRC and AAC values were obtained according to ASTM C423 standards. For test 12, a layer of fiberglass R19 was 6 "thick (152.8 mm) manufactured by Owens Coming was dvesa in the box at a distance of 3.75 "(95.75 mm) of the stretched sheet of material. For the test glass layer 13

Owens Coming's 1 ”(25.4 mm) RA24 was suspended in a drawer 8.75” (222.75 mm) from a stretched sheet of material. For experiment 14, no material was placed in a box.

The obtained AAC and NRC values are given below in table 4.

The values of the acoustic absorption coefficient obtained during tests 12, 13 and 14 are plotted on the graphs of Fig. 7, while only frequencies included in the range from 125 Hz to 4000 Hz are taken into account, with the aim of the uniform presentation of the graphs of Figures 2-6.

The combination of microperforated membranes with fiber insulation placed at a certain distance from the rigid wall makes it possible to obtain uniform acoustic absorption over the entire range of frequencies under consideration.

In the tests of the first and second series, described below, they used an acoustic chamber with fiberglass walls, which does not correspond to the real situation of the use of suspended ceilings.

In order to identify the effect of the support of the stretched sheet on the acoustic absorption properties of the entire assembly, a third series of tests was carried out under the following conditions.

Tests A.

8 '× 9' 9 '× 8' (2743.2 × 2438.4 mm) panels of fiberglass with a total weight of 0.25 psf, (93.3 g), 1 "thick (25.4 mm), 3 lb density per cubic inch (16 kg / m ³ ), surrounded by a tubular metal frame 4 "(101.6 mm) high with a nominal thickness of 1-1 / 2" (38.1 mm), were mounted directly on the base of the reverb chamber (installation A by ASTM E 795.) These frames were used as the base for placing strips of smooth stretched PVC material on them.

Tests B.

Smooth PVC 8 '× 9' panels (5 mil) were mounted using a bracket / rail mounting at a distance of 4 "(101.6 mm) from the bottom wall of the reverberation chamber (EO installation according to ASTM E 795).

The supporting frame for smooth PVC panels is made of metal pipes 4 "(101.6 mm) high and 1-1 / 2" nominal thickness (38.1 mm).

The support frame is fixed externally to the bottom wall of the reverb chamber.

A fiberglass panel 2 "(50.8 mm) thick with a density of 3 pounds per cubic inch (48 kg / m ³ ) is fixed directly to the base of this chamber.

The total weight of this fiberglass panel is 0.49 psf (182.9 g), while the weight of the PVC panel is 0.05 psf (18.7 g).

Test C.

Smooth PVC 8 '× 9' panels (5 mil) were mounted using a bracket / rail type at a distance of 4 "(101.6 mm) from the bottom wall of the reverberation chamber (EO installation according to ASTM E 795).

The supporting frame for smooth PVC panels is made of metal pipes 4 "(101.6 mm) high and 1-1 / 2" nominal thickness (38.1 mm).

The support frame is fixed externally to the bottom wall of the reverb chamber.

A fiberglass panel 1 "(25.4 mm) thick with a density of 3 pounds per cubic inch (48 kg / m ³ ) is fixed directly to the base of this chamber.

The total weight of the fiberglass panel is 0.25 psf (93.3 g), while the weight of the panel is PVC-0.05 psf (18.7 g).

The results are shown below in table 5.

The average NRC values obtained for tests A, B and C are shown below in table 6.

Acoustic absorption coefficients were obtained in accordance with ASTM C 423-90a requirements with a 2133 Bruel Kjar analyzer.

The histograms in FIGS. 8, 9 and 10 represent changes in acoustic absorption coefficients for frequencies between 100 Hz and 5000 Hz for tests A, B and C.

The described polymeric sheet material with improved acoustic properties is intended for use in decorative or mosaic tensile structures, such as, in particular, false ceilings or false walls.

This material can also be used in poster panels (stationary or mobile), while reducing reverberation while reducing the inconvenience arising from the reflection of sound by these panels.

Since the appearance of the material does not change significantly when performing microreliefs, it remains well suitable for use in the industrial sector and in the environment, both for the equipment of collective and individual residential premises, modern or historical.

The acoustic properties of the materials of the present invention are fully comparable with those of the corresponding noise-absorbing suspended ceilings, as shown in Table 7 below, as an illustration.

Claims (23)

1. Soft sheet material with a thickness of less than 0.5 mm, intended for the manufacture of tension structures, in particular false ceilings, characterized in that it is made of microreliefs (2) by extruding it with a higher acoustic absorption coefficient compared to the same material without microreliefs . 2. The material according to claim 1, characterized in that the height (h) of the microreliefs (2) in the direction perpendicular to the plane of the sheet of material is less than the triple thickness of the sheet. 3. The material according to claim 1 or 2, characterized in that the microreliefs (2) form protrusions on only one side of the aforementioned sheet. 4. The material according to claim 1 or 2, characterized in that the microreliefs (2) are made with the formation of protrusions on two sides of the aforementioned sheet. 5. Material according to claim 3 or 4, characterized in that each of the microreliefs (2) is located at the nodes of a regular motive. 6. The material according to claim 5, characterized in that all the microreliefs (2) are located at the nodes of only one motive. 7. The material according to claim 6, characterized in that square cells are selected as the motive. 8. The material according to any one of claims 1 to 7, characterized in that the microreliefs are made in the form of channels with a substantially flat bottom connected to the hole by a strip of material whose thickness is less than or equal to the thickness of the part of the sheet separating the microreliefs (2). 9. The material according to claim 8, characterized in that the channels are made with axial symmetry about an axis (3) substantially perpendicular to the bottom (4). 10. The material according to claim 9, characterized in that the strip of material (5) connecting the wall (4) of the bottom of the channels and holes is made intermittent. 11. The material according to any one of claims 1 to 10, characterized in that it is equipped with microperforations with holes with a diameter of less than 0.4 mm. 12. The material according to claim 11, characterized in that at least part of the microreliefs (2) is equipped with microperforations. 13. The material according to claim 11, characterized in that the microperforations are located between the microreliefs. 14. The material according to item 13, wherein the microperforations are located at the nodes of the motive. 15. The material according to 14, characterized in that the microperforations are located at the nodes of the motif, identical to the motif of the microreliefs and offset relative to it. 16. The material according to any one of paragraphs.11-15, characterized in that the microperforations are made with a density of 2-60 pieces per square centimeter. 17. The material according to any one of claims 1 to 16, characterized in that the material is selected from the group consisting of polyvinyl chloride, vinylidene chloride and copolymers of vinyl chloride / vinylidene chloride or any other equivalent material. 18. The material according to any one of claims 1 to 17, characterized in that the surface occupied by the microreliefs is 0.5-10% of the surface of the aforementioned sheet. 19. A method of manufacturing a sheet of material according to any one of claims 1 to 18, characterized in that it includes the step of piercing with needles to ensure that the sheet material is punctured at the puncture site according to a predetermined motive. 20. The method according to claim 19, characterized in that the step of piercing with needles is carried out without removing the sheet material. 21. The method according to PP.19 or 20, characterized in that the needles used for piercing, have an outer diameter of less than 0.1 mm 22. The method according to any one of paragraphs.19-21, characterized in that the step of piercing with needles is carried out when the sheet of material is tensioned in the same order as the tension when it is used in the tension structure. 23. False ceiling, characterized in that it is made of sheet material according to any one of claims 1 to 18 and has been subjected to tension on supporting means.

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