DE102004024249B4 - Shaped soundproofing material and method for its production - Google Patents

Abstract

The invention relates to a molded sound insulation material and a method for producing these sound insulation materials. DOLLAR A The invention has for its object to provide a mechanically stable, surface-workable, molded Schalldämmmaterial predominantly short and biopolymer fibers and biopolymer binders, which causes high density with low specific density. DOLLAR A The object is achieved with a molded sound insulation material comprising thermally treated, expanded cereal flour, vegetable fibers or partially mineralized vegetable fibers and fine-grained aggregates with both open-pore and interior porous structure, and a method for producing these sound insulation materials, comprising the following steps: DOLLAR A - Preparation of an aqueous suspension of cereal flours and fine-grained inorganic aggregates, DOLLAR A - Foaming of this suspension by mechanical introduction of air or other gas (page 7, above the established documents), DOLLAR A - mixing the foam with vegetable fibers, DOLLAR A - Forming of the mixture, DOLLAR A - Fixation of the molded structure by thermal treatment and DOLLAR A - Removal of the resulting surface crust by mechanical processing.

Description

The The invention relates to a molded acoustic insulation material containing thermally treated, foamed Cornmeal, vegetable fibers or partially mineralized plant fibers and fine-grained inorganic aggregates, and a method of preparation from these soundproofing materials.

Sound-absorbing materials serve for the acoustic separation of premises.

Noise is one the largest and at the same time the most underestimated Environmental pollution for the people. As a result of the increasing noise pollution of the population incur huge costs for the economy. It plays both the protection against noise from the outside as well as the sound insulation inside the house an important role. Due to the different type of sound propagation are also different Methods for soundproofing required. Airborne sound can be mainly through the use of heavy, massive constructions are insulated. For the house modernization are also suitable multilayer lightweight walls. structure-borne sound works best with a multi-layered wall or ceiling construction be insulated. Here, heavy layers alternate with light, elastic Layers off.

The Meaning of the raw materials used is in doors in addition to the basis weight determined by their bending stiffness.

It is decisive for the cutoff frequency. Small cut-off frequencies due to "flexible" materials, high modulus of elasticity ( _dyne in MN / m ² ) are the prerequisite for good sound insulation.

There The components are minimized in their weight more and more is it is necessary to protect the sound also on other technological measures to realize on materials with lower surface density based. soundproofing can with sound absorbing materials, structure-borne sound insulation materials or insulating materials be achieved.

One Way to dam sound with specifically relatively lightweight materials is the construction of layers of different materials or the same Materials, but with different structure in the relevant components as well as the avoidance of sound bridges.

specially for the soundproofing of doors, especially for Soundproof doors Materials were developed that are more based on sound Structure as by the basis weight dam can. The possibility this is given because the Schalldämmmaß a Component is determined by the structure of the construction. It will a sonic interaction of the different door layers achieved. Furthermore It is determined by the longitudinal sound insulation dimension of the adjacent Components influenced.

In JP 2003106066 and JP 11210341 For this purpose a special door construction is described.

In US 4924969 the construction of a metal-clad door is described. At the in EP 0513605 and DE 3531802 As well as sound insulation, special emphasis is placed on good stability and safety.

Furthermore, various synthetic (eg. EP 1321554 A1 . EP 1347107 A1 ) and biopolymeric materials such as. B. cotton ( CN 1143025 ), Hemp ( EP 1314705 A2 ) used for making soundproofing panels / materials.

In the DE 195 17 950 C2 is a method for producing a mixture of substances for shaping objects such as flower seed pots, planting plates, fermenting dishes, packaging tablets, insulation boards and Floristikmaterial described. The method is essentially characterized in that protein-containing raw materials are foamed with water, wherein in the foam fibrous plant parts, water glass and other fine-grained raw materials such as limestones, clays, clay and kieselguhr are added. The resulting mass is shaped and dried at a higher temperature. As a result, moldings with closed-pore, crust-like surface and a density between 0.4 to 0.5 g / ml. The molded materials thus prepared such. B. insulation boards are suitable for use as thermal insulation panels. For use as sound insulation materials, these panels are rather not suitable, which have resulted in sound insulation measurements.

In the DE 198 07 821 A1 is an insulation made of vegetable fibers for use as heat or Sound insulation described. This insulating material consists of a non-woven fabric made of vegetable fibers containing supporting fibers of a polyester plastic or of polypropylene or polyethylene. By thermal treatment in the order of magnitude of the melting temperature of the plastics plastic support fibers are welded together, so that a substantially dimensionally stable support matrix is formed, in which the plant fiber is embedded. These usually have a low structural stability, since they consist essentially of relatively long fibers which are mixed together so that a certain penetration of the fibers is formed. To counteract this disadvantage, the said plastic fibers are used here, which are to achieve stability after a fusion process. However, it has been shown that these fleece-like insulating materials are not particularly suitable as sound insulation materials, since their sound insulation properties are not suitable for many applications, especially under pressure due to the loose nature. Disadvantages arise in particular in the impact sound insulation, where a compression of this insulating material under load is obviously possible, although it is alleged that an elastic recovery should eliminate this disadvantage. Another disadvantage of this material is the low dimensional stability, with a higher dimensional stability is important for many applications, especially in vertical arrangement of the insulation boards. Another disadvantage of this insulating material is the processing of plastic fibers whose production is based on predominantly fossil raw materials.

In WO 93/04226 A is a fiber composite material based on Natural fiber fleeces described. The natural fibers used here have fibers having a diameter below 10 microns and a Fiber total length of more than 100 millimeters. These fiber dimensions are typical and necessary for the production of fiber webs. Shorter and thicker natural fibers do not find use. In this fiber composite material is also disadvantageously a binder used on fossil raw materials based. The manufacturing process additionally requires a pressing process, which leads to a compression of the material. This will worsen the sound insulation properties and the cost of the manufacturing process.

Of the Invention is based on the object, a mechanically stable, surface-workable, shaped soundproofing material from predominantly short and biopolymer fibers and biopolymer binders create a high sound insulation with low specific gravity.

According to the invention the solution the task with the features of claims 1 and 12th

advantageous Further developments of the invention are specified in the subclaims.

The molded according to the invention Sound Absorbing Materials contains thermally treated, foamed cereal flour, Plant fibers or partially mineralized vegetable fibers and fine-grained aggregates with both in the edge area and inside open-pored structure.

In An embodiment of the invention contains the sound insulation material polyvalent, water-miscible, having a boiling point of over 150 ° C. Alcohols, in particular, the content of glycerol advantageous for physical-mechanical Properties. This advantageously improves the flexural strength of the sound insulation materials according to the invention.

In One training is in the formed sound insulation materials coarse-grained synthetic or natural Aggregates containing the main amount of coarse-grained additives a Grain size of approx. 0.5 to 3 mm. As a main amount will be 60 to 90% of the total designated.

In Another embodiment of the invention are proteinaceous foamed Biopolymers Meal flours, such as rye flour with a grain size below 0.5 mm included.

A Another embodiment provides that as plant fibers fibers made of wood, hemp, linen, palm leaves, Reed, flax or xylitol as a partially mineralized plant fiber are.

According to one Another embodiment are as fine-grained inorganic additives Limestones, silicates, thermally activated clays, clay or kaolin with a grain size below 0.5 mm included.

A Another embodiment provides that as coarse-grained synthetic or natural aggregates Cork or elastomers, such as elastic biopolymers are included.

• a. 15 bis 70 Gew% proteinhaltige verschäumte Getreidemehle,
• b. 10 bis 50 Gew% Pflanzenfasern oder teilmineralisierte Pflanzenfasern,
• c. 1 bis 30 Gew% feinkörnige anorganische Zuschlagsstoffe,
• d. 1 bis 70 Gew% grobkörnige synthetische oder natürliche Zuschlagsstoffe

enthalten.In a further embodiment of the sound insulation material according to the invention

• a. 15 to 70% by weight of protein-containing expanded cereal flours,
• b. 10 to 50% by weight of vegetable fibers or partially mineralized plant fibers,
• c. 1 to 30% by weight of fine-grained inorganic additives,
• d. 1 to 70% by weight of coarse-grained synthetic or natural aggregates

contain.

In an advantageous embodiment contains the molded sound insulation material 10 to 60% by weight of polyhydric, water-miscible, one boiling point from above 150 ° C having Alcohols. In particular, the addition of 10 to 60% by weight of glycerol as for the flexural strength of the material advantageously proved.

The inventive method for the production of sound insulation materials is that watery Suspension consisting of protein-containing, foamed biopolymers and fine grained inorganic additives is produced, this suspension foamed and then plant fibers and coarse-grained synthetic or natural Aggregates are admixed. After that, this mass is shaped, dried and the normally forming surface crust is mechanically removed.

One Another production method relates to the admixture of coarse-grained synthetic or natural aggregates, such as elastomers and also a mechanical surface treatment to remove the surface crust the dried shaped body.

A Development of the invention provides, the aqueous suspension before foaming polyvalent, water-miscible, having a boiling point of over 150 ° C. Alcohols, such as glycerol. The after the drying process conducted mechanical surface treatment serves to produce an open-pored structure. You eliminated the surface crust that forms after the drying process.

The Sound Absorbing Materials is used as sound insulation board for installation in doors and walls, for impact sound insulation and for noise reduction Machinery.

The specific gravity of the materials according to the invention is in the range of 150 to 400 kg / m ³ . The fibers in the material are not in an ordered structure. The material is surface treated after its production. As a result, an open-pore structure of the surface is achieved. The plate is characterized by a length-specific flow resistance of ........... It is mechanically stable and characterized by a characteristic elasticity.

These However, it is designed so that when installing the material in a frame and a subsequent lamination of the surface (z. B. sticking with a foil and subsequent pressing) not a hindrance is.

It has been surprising shown that this material in a device, especially in a door built in, despite the low specific weight leads to a good sound insulation, the similar to conventional, specifically heavy materials. The incorporation of cork particles and / or elastomer particles elevated this sound insulation.

Of the Installation of the insulating material according to the invention in the door takes place as a single or multi-layered sandwich.

The base for the composite material is the suspension of the protein-containing biopolymer, such as B. Rye flour with water. This suspension can be mineral Additives such as hydroxides, silicates or thermally activated clays be mixed.

By mechanically introducing air or another gas, the specific gravity of the suspension is lowered to 150 to 350 kg / m ³ .

Of the Solids content in this suspension is 20 to 40% by weight. hydroxides such as B. lime support the loosening process, thereby further reducing the specific Density occurs.

In a subsequent process step, vegetable fibers, in particular wood fibers or teilmi Neralized wood fibers mixed into the light suspension. These plant fibers are characterized by lengths of up to 50 mm with a thickness of up to 2 mm. Particularly suitable are fibers which have a rough surface, since this causes a felting effect. To achieve a disordered structure and inhomogeneities of the material cork and / or elastomer granules can be mixed to continue.

The Mixture of substances becomes plates of defined dimension or one shaped continuous endless belt. The fixation of the structure done by thermal treatment.

These takes place in a first section in a saturated steam atmosphere (dew point about 100 ° C) or under saturated steam, at a temperature of 140 to 240 ° C a duration from approx. 60 to 120 min. In a second step is in a relative dry atmosphere (Dew point approx. 80 ° C) at a temperature of 80 to 200 ° C the composite up to a moisture content of 15 to 2% dried.

During this thermal treatment, the starch component of the protein-containing biopolymer changes from the crystalline to the amorphous state. The starch grains are destroyed and form an aqueous phase with the existing water, which lays around the other components of the composition. In the subsequent thermal treatment, the water is removed from the mixture. The substances contained therein solidify and form the structure in complex with the other particles of the substance mixture. The mineral constituents solidify this structure by z. For example, the formation of bonds with the biopolymeric constituents (eg, lime and protein via disulfide groups) or by incorporation into this structure. The solidification of the siliceous constituents is based on the formation of inorganic, three-dimensional networks of SiO ₄ tetrahedrons. They form a kind of solid structure.

To This process is a mechanically stable insulating material in the form of a defined Plate or an endless band. For producing the sound-absorbing Deposit for the soundproof door Calibrate the surfaces of the plate by grinding or milling and the blank according to the required dimensions.

The inventive method is also suitable for the manufacture of panels used in interior construction (house building) become. The porosity of the material is also possible, the material for the Use water retention as a moisture retaining material.

Based From microscopic images it is made clear what effect the mechanical surface treatment in terms of training a related to the overall plate has open-pored structure.

It demonstrate

1 a micrograph of the forming surface crust after the drying process,

2 the formation of an open-pored structure after mechanical surface treatment,

3 the cut surface of a sound absorbing panel with the compacted surface crust, which is removed according to the invention to achieve the surprising sound insulating properties and

4 in a sectional view of the stored coarse-grained aggregates, in this case rubber granules in the open-pored structure of the plate.

The microscopic enlargements of 1 to 4 is 6.5 times.

The The invention is based on exemplary embodiments explained in more detail.

example 1

A sound insulation panel consisting of 46% by weight rye flour, 35% by weight wood fibers, 0.7% by weight lime, 19% by weight chalk is cut to the side dimensions 1845 mm × 720 mm by means of a sliding table saw. By a wide belt sander a plate thickness of 11 mm or 17 mm is set. The surface The surface of the plate is ground or planed so that a smooth but open-pore surface is achieved. By means of conventional technology used in the door industry, 2 panels 17 mm thick or 3 panels 11 mm thick are placed in the prefabricated door frame.

Conventional will be the door by bonding with one hardboard at the top and underside and veneer finished.

The finished door leaf (1985 × 860 × 40 mm) has a weight less than 30 kg and a sound insulation greater than or equal to 38 dB.

Example 2

A from 26% by weight of rye flour, 17% by weight of wood fibers, 0.4% by weight of lime, 57% Wt.% Rubber or cork granules existing plate is on the side dimensions 1845th mm × 720 mm by means of sliding table saw cut. A wide belt sander becomes a plate thickness of 11 mm or 17 mm. The surfaces of the plate are ground or planed so that a smooth surface is achieved. By means of conventional in the door industry existing technique are 2 plates with a thickness of 17 mm or 3 Plates with a thickness of 11 mm in the prefabricated door frame inserted.

Conventional will be the door by bonding with one hardboard at the top and underside and veneer finished.

The finished door leaf (1985 × 860 × 40 mm) has a weight of less than 35 kg and a sound insulation equal to or greater than 39 dB.

Example 3

A suspension of 15% by weight of rye flour, 75% by weight of water, 1% by weight of lime and 9% by weight of thermally activated clay is produced. By means of conventional discontinuous or continuous technique, the suspension is exposed to air, so that at a solids content of about 25%, a specific density of 190 to 250 kg / m ^{3 is} achieved. 15% by weight of wood fibers are mixed into this light suspension. Partially mineralized wood fibers in the form of xylitol or a mixture of wood fibers and partially mineralized wood fibers may also be used instead of the wood fibers.

The resulting mixture is on sheets to plates or to a shaped endless band of defined dimension.

The Fixation of the structure is done by thermal treatment.

These takes place in a first section in a saturated steam atmosphere (dew point about 100 ° C) or under saturated steam, at a temperature of 140 to 240 ° C a duration from approx. 60 to 120 min. In a second step is in a relative dry atmosphere (Dew point approx. 80 ° C) at a temperature of 80 to 200 ° C the composite up to a moisture content of 15 to 2% dried. After cooling, be Plates on so cut, that a plate with the dimensions 1845 mm × 720 mm arises. By means of a wide belt sander, a plate thickness is achieved optionally set to 11mm, 17mm or other thickness.

With the processing of the surface crust creates an open-pore structure with good sound-insulating Properties.

Example 4

A further soundproofing panel according to Example 3 with a modified formulation is produced, which has very good flexural strength values: Glycerol / clay

Example 5

A further soundproofing panel according to Example 3 with a modified formulation is produced, which has very good sound insulation properties: rubber

Example 6

A further soundproofing panel according to Example 3 with a modified formulation is produced, the suspension having excellent foaming properties and the panel having in addition to the very good sound insulation excellent bending strength: glycerin / flour VC-1

Claims (19)

Shaped sound insulation material containing thermal treated, foamed Cornmeal, vegetable fibers or partially mineralized plant fibers and fine-grained Aggregates with both the edge area and inside open-pored Structure. Shaped soundproofing material according to claim 1, characterized in that polyvalent, with water miscible, a boiling point of over 150 ° C having Alcohols are included. Shaped soundproofing material according to claim 1 or 2, characterized in that glycerol is. Shaped soundproofing material according to claim 1 to 3, characterized in that coarse-grained synthetic or natural Aggregates are included, wherein the main amount of a grain size of about 0.5 to 3 mm. Shaped soundproofing material according to one of the claims 1 to 4, characterized in that as a protein-containing foamed biopolymer Meal flours such as rye flour with a grain size less than 0.5 mm included is. Shaped soundproofing material according to one of the claims 1 to 5, characterized in that as plant fibers fibers made of wood, hemp, linen, palm leaves, Reed, flax or xylitol as a partially mineralized plant fiber are. Shaped soundproofing material according to one of the claims 1 to 6, characterized in that as fine-grained inorganic additives with grain sizes less than 0.5 mm, such as limestones, silicates, thermally activated clays, brick dust or kaolin are included. Shaped soundproofing material according to one of the claims 1 to 7, characterized in that as coarse-grained synthetic or natural aggregates Cork or elastomers are included. Shaped soundproofing material according to one of the claims 1 to 8, characterized in that a. 15 to 70% by weight proteinaceous foamed biopolymers b. 10 to 50% by weight of vegetable fibers or partially mineralized Plant fibers, c. 1 to 30% by weight of fine-grained inorganic additives, d. 1 to 70 wt% coarse grained synthetic or natural aggregates are included. Shaped sound insulating material according to one of claims 1 to 9, characterized in that 10 to 60 wt% polyvalent, with Water-miscible, having a boiling point of about 150 ° C containing alcohols are. foamed Sound Absorbing Materials according to one of the claims 1 to 10, characterized in that 10 to 60 wt% glycerol is. Process for the production of sound insulation materials according to claim 1, comprising the following steps - Preparation of an aqueous Suspension of cereal flours and fine-grained inorganic aggregates, - Foaming of this Suspension by mechanical introduction of air or another Gases (page 7, at the top of the submitted documents), - mixing the foam with plant fibers, - shaping the mixture, - fixation the shaped structure by thermal treatment and - Distance the resulting surface crust by mechanical processing. Method according to claim 12, characterized in that that with the vegetable fibers coarse-grained, synthetic or natural aggregates be mixed. A method according to claim 12 or 13, characterized in that the aqueous suspension more valuable, water-miscible, a boiling point of about 150 ° C having alcohols are added. Method according to one of claims 12 to 14, characterized that the mechanical surface treatment performed after the drying process for producing an open-pore structure is performed. Method according to one of claims 12 to 15, characterized in that the surface crust forming after the drying process Will get removed. Use of the soundproofing material according to the claim 1 as Schalldämmplatte for installation in doors and Walls. Use of the soundproofing material according to the claim 1 as Schalldämmplatte for impact sound insulation. Use of the soundproofing material according to the claim 1 as Schalldämmplatte for machine insulation.