DE1659006A1 - Acoustic panels - Google Patents

Description

PATENT LAWYERS

DR. F. ZUMSTEIN - DR. E. ASSMANN 1659006 DR. R. KOENIQSBEReER - DIPL.-PHYS. R. HOLZBAUER

TELEPHONE: 2234 76 and 821911 CHECK ACCOUNT: MÖNCHEN 91139

BANK ACCOUNT: BANK H. AUFHKUSER

(2/2/1)
7 / Gd.

WOOD CONVERSION COMPANY

Acoustic panels «

The present invention relates to acoustic panels that have a porous, sound absorbing material
Own body part that is devoid of any organic
Content is and consists essentially of ceramic bonded or attached fiber felt, and in particular ceramic material, such as clay or loam, which is in the
Felt is spread out. The porous body part has a plurality of acoustic openings which are arranged to receive the sound and which extend into the body part from a surface of the plate.

For this purpose, coated porous plates, which have acoustic openings, which are either drilled or

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BATH ORIGINAL

* 359006

punched in or "poked" if the holes are smaller as drilled holes, in a wide range as acoustic panels, especially for ceiling cladding, related. Such plates, in felted fiber form, the mineral fibers, or vegetable fiber, or a mixture made from such fibers have been widely used as Insert panels, e.g. in the form of panels 60 χ 12o cm (2 ft. Χ 4 ft) in size, related to those of underlying Edge support bars or edges were worn. In such sheets, the fibers are usually made by adhesives Strength, bound. The fibers, in the case of vegetable fibers, and the adhesive, in the case of starch or such adhesives, however, are adversely affected by moist air and tend to be in high humidity they tend to soften, causing the plate to lower or, pushes through.

According to the present invention, when adequate porosity is desired, the particulate or granulated material is used in an amount not greater than the amount of fibrous material. Such Panels are characterized by a porous fibrous network, which is created by burning a mineral fiber felt in the presence of a granulated material is produced, which is ceramically bonded to the network during firing, originally being substantially uniform in the unfired Mineralfasex'filz, hereinafter to be referred to as a "preform" prior to firing.

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It has previously been suggested the preform of the Mineral fiber felt carrying the granular material by forming a slurry from the Fibers and the granular material, with or without a binder, preferably starch, to make the pulp flaky and to dewater the suspension of the flakes in order to create a wet or damp mat or Form ceiling. Depending on the dewatering method, the damp mat has suction through the mat may or may not be a variable density. Such a formation density can be achieved by pressing increase. The higher the density, the less porous the mat is when dry, but the strength is larger to handle the wet or dry mat.

The firmness of the dry mat is increased by adding a binder to the slurry to keep the contents to join the mat while drying «As preferred Starch is used as the binder. In contrast, clay as a granular or granular material has a low binding effect, however, an increased content of clay leads to a greater formation density and this reduces the porosity, Although starch can be used in solution form, starch granules are preferred for convenience. In each In the form of the starch, the starch is flocculated so that it is not freely suspended in the withdrawn water is. A small amount of a surfactant is used as described Flocculants, such as polyacrylamide flocculants,

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BATH ORIGINAL

preferably related to a small amount of a polyvalent metal salt as explained below.

When it comes to burning, the first effect is the organic one Burning out or carbonizing or charring material. In the case of a starch, a carbon residue becomes first formed, which can be oxidized with prolonged exposure or process if desired, but is its presence in the remaining small amount with no effect on the acoustic value, and on the appearance, if a surface coating is applied. Since the fired product has acoustic openings, it is preferred to form these in the dried mat before firing, so that an access for the air and the heat into the interior of the body is created to accelerate the combustion of the organic matter and any residual carbon. After the organic binder and any other organic compositions in the dry mat have been destroyed, the firing temperature is adjusted so that the mineral content, including that, the forms the openings, is ceramically connected. It can

Joining and setting temperatures up to 1 o93 ° C (2,000 ° F) can be used to obtain the porous skeletal network described. Higher temperatures can too lead to melting and thus reduce the porosity.

It was found that when firing such a drilled

ii by
or punched) (starch-bound, dry mat the porosity and sound absorption capacity on the properties of the

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dry mat can also be increased. Because the

is burned, mat, and thus the strength switched off or eliminated prevents the mat from becoming damp lowers or sags.

The invention is illustrated by the examples given below explained, inkenen the amount and type of granular Material and the firing temperature can be changed.

To a pulp containing loo parts of mineral fiber and particulate or granular material with or without a binder, a solution of:

Polyacrylamide o, o4 parts Calcium chloride 0.05 parts water 4o, ο parts

added.

The slurry is thus converted into flakes which are suspended in essentially clear water, which is quickly drawn off by pouring the pulp on a sieve, as is the case with a fiber entry in a Fourdrinier machine is made. The resulting wet mat is pressed to a suitable density and dried. When starch granules are used, the wet mat is heated in a humid atmosphere to protect the starch granules gelatinize and then dry to remove the contents or

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To connect deposits with the dried starch. Acoustic holes are then either drilled into the mat or stamped and then fired to create a ceramic bond.

The firing temperature can vary over a wide range, but it is chosen so that melting of the fibers is avoided in order to maintain the skeletal structure. This is strengthened or solidified by the ceramic bond while the firing temperature rises.

A dry matted mat without binding agents, made from 100 parts of mineral wool and 50 parts of Stratton (kaolin) clay was made into sections and these were kept at temperatures over a wide area The area was fired and the modulus of rupture or tear was determined. The tear module lies without a binding agent very low, so that large pieces require great care in handling. The following table shows how the tensile modulus is increased by the burning «

ü? _i £ °! äS3s £ Si-Ü! s) S5BBS £ 2 * SE-l2-IS-i: 2}

% -M

45}

7.7?

Ho

427 649 760 871 IO9;

(800] 1200

I600! 2ooo

12o4. (22oo; (begins to melt) -

Fired panels of the above composition made with different Densities were established were examined for the empty space contained therein, with the results

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were as follows:

ο, 48 ο, 64 ο, 8ο ο, 96 1.12 1.28

(3ο (4ο

\ ι °

-6ο

75.4 74, ο 75.5 72.1 63.2 4ο, ο

The less empty space there is, the lower the sound absorption. It has been found that when that Kaolin is increased in proportion, the dry mat and the fired plate become denser in a solid process. Thus, in the present invention, the amount of clay does not exceed the amount of fiber, and it is preferable that it is Amount of clay kept noticeably "below the amount of mineral wool, so that the voids in the fired skeletal network less to be filled.

The table above shows that above a density of 0.8 g / cnr (50 lbs./cu.ft.) The empty space is in the fired Plate begins to decrease. The following examples are provided for further explanation.

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Example_l

Glass wool is used.

Parts by weight

Glass wool loo

Kaolin clay loo

Starch grains Io

Polyacrylamide flocculant o, o4

Calcium chloride l, o

Water 6000

Thickness 2 »24o cm (0.882 inch)

Density 0.528 g / cnr (33 lbs./ou-.ft.)

Thickness 6.4 %

Area dimensions 0.4 %

density

Tear module 12.

0.524 g / cmg 02.7 lbs./cu.ft.

L2.45 kg / crn (178 lbs./sq.in.)

Example ^ g

Parts by weight

White slag wool loo

Kaolin clay loo

Calcium chloride 0.5

animal glue (dry solids) 5

Polyacrylamide flocculants ο, ο8

Water 37οο

Thickness 1.46 cm (o.575 inch)

g / cm ^p (49.7 .lbs. / cu. f t .;

Density o.795

Shrinkage £

Thickness 1.8

Density 1.5

Density 0.795 g / cm < (49.7 Ibs./cu.ft.)

Tensile modulus 19.85 kg / cm {282 lbs./sq. in.)

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Beisglel_3.

White slag wool loo Kaolin clay 5 ° ground feldspar 5o Tapioca starch grains Io water 3700 Polyacrylamide flocculant 0.08 Calcium chloride o, 5

Density o.77o g / cm- ⁵ (48 lbs./cm.ft «,)

a chrumgfung ^ __

Thickness o, 3 #

Area dimensions 0.8 %

Tensile modulus 11.75 kg / cm (167 lbs./sq.in.)

The low shrinkage indicates that it is essentially leash Reduction in density occurs when firing.

In Example 4 below, the dried mat was used random with bores of o.62 cm (l / 4-inch) and o.475 · c

ρ (3/16-inch) diameter of a total of j44o holes per m (319 holes per sq.ft.).

For example

Parts by weight

Rock wool loo Stratton tone 50

Tapioca starch grains 5

Polyacrylamide flocculant o, o4

Calcium chloride 2, ο

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- Io -

Density 0.550 g / cm- ⁵ (34.5 lbs./cu.ft.)

punched or punched

Shrinkage ^

Thickness 3.9 #

Area dimensions I * o5 %

Density 0.715 g / cm ⁵ (44.7 lbs./cu.ft.)

Tensile modulus 13 * 59 kg / cm (194 lbs./sq.in.) Deflection in the burning test zero

The acoustic property of the plate of Example 4, known as (Alpha Naught), was determined by the American Society of Testing Materials standard inpedance tube test, designation C 384-5ÖT. This is the mean value of a _Q for sound at 250, 500, looo and 2ooo Hz.

25Λ cm (lQ before firing 36.0 '39

after firing 44.7 63.7 The thickness of the plaque prior to firing was 1.59 cm (5/8 inch).

The test shows that the generally unacceptable oco of the punched or pierced unfired panel has only been increased to acceptable values by firing.

A selected ceramic material can be applied to the fired panel in order to obtain an acceptable surface appearance the surface of which is ceramically connected to the body part.

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This can be applied to a fired panel which is re-exposed to a firing temperature to create the bond to manufacture. Preferably this is applied to the mat prior to firing, such as a ceramic coated, fired Produce a panel in one firing process.

A coating may be formed on the main body part in one case by applying a selected material to the surface, which during firing becomes a non-homogeneous cover layer instead of sintered together to form a glass structure or glaze. Such a coating can form the entire exposed surface of the panel. The coating or the fired panel without the coating can partially or completely covered by a slurry of clay which is applied to form a glaze coating form. The coating or the coating composition is chosen so that it gives the exposed parts a color or a fibrous one Appearance so that it hides the color or appearance of the underlying burned body part. If the glaze is formed in a discontinuous coating, such as in punctiform areas, so can the coating or the coating composition and the glaze material have contrasting colors, so that the coating composition forms a substrate for the parts not covered with glaze.

When applying a coating compound or a grouted clay compound for a glaze, or both on a drilled or punched preform mat to be burned must be taken to ensure that

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that the acoustic holes are not filled or closed. Because of the low density of the body part that is Glaze preferably discontinuous.

A coating composition was prepared as follows

Kaolin clay 166 grams

Slag wool, pulverized J> y \ grams

Water 45o grams

Sodium tripolyphosphate 1 gram

Commercial ceramic frit + 5 ° gram

+ such as Ferro ^ 466 made by Ferro Corporation of Cleveland, Ohio.

Beisgiel_6

In order to form a glaze on firing, the following composition was made:

Parts by weight

Commercially available frit 596 grams

(Ferro 3466)

Chromium oxide pigment 4 grams

5 % Methocel 8o grams

Water 115 grams

A dried, unfired board, designed as described above, and acoustically perforated, made from 100 pieces Mineral wool and 50 parts of kaolin clay, with a density of O.64 g / cnr (40 lbs./cu.ft.) is coated with a coating composition, preferably by spraying the entire surface will. Using the base coating composition given in Example 5 5> 5 parts of zirconium oxide pigment are added to 2oo parts of this composition to obtain a

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white coating compound coating · This coating is dried.

The coating composition, in particular that of Example 6, is then applied by spraying at a pressure of 15 to 20 pounds per square inch (15 to 20 pounds per square inch) in order to form a discontinuous coating in brm of sprayed areas for to form the final glaze. This is then dried and the whole thing is ^{fired at lolo ° C (1850 0} P). The punctiform green glaze surfaces with the white background of the coating compound give the punched or drilled ceramic acoustic panel a decorative effect.

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Claims (2)

Claims Acoustic panel which has a porous sound-absorbing body part made of inorganic material and a ceramic-bonded porous body made of a mineral fiber felt and granular ceramic material, this mineral fiber being predominantly in synthetic mineral fiber, characterized in that the granular ceramic material is present in an amount that corresponds to the Amount of fiber does not exceed and that this body part has a plurality of acoustic openings which are exposed for the reception of sound and extend from an end face of the body part in, but not through; extend the body part, this end face having a coating of a glaze, which adheres to it ceramically on surfaces with the exception of these openings. 2. Acoustic panel according to claim 1, characterized in that improved acoustic properties by burning this Plate can be obtained, the amount of clay or granular material contained being significantly lower than the amount of Mineral fiber lies. 3 · Acoustic panel, characterized in that this panel is essentially produced in accordance with the method and the information in the example . 109852/0310