DE19507664C2 - Shaped, assembled, insulating material and process for its manufacture - Google Patents

Description

The invention relates to a light, preformed, thermal insulation material with excellent physical properties and very high temperature resistance, as well as a process for the production of this material.

Blankets or mats made of inorganic fibers are used as a thermal insulation widespread, and a variety of organic binders, typically phenolic materials have been used to make the Maintain fiber cohesion. Give organic binders however, it adversely affects harmful gases when it does be warmed. Organic binders also lose after their Heating their structural integrity.

It is also known to be an aqueous dispersion of vermiculite onto a flat cloth or fabric of yarn that are not fire resistant, as disclosed in U.S. Patent 4,543,287 bart, the content of which is hereby incorporated by reference becomes. After removing the water, vermiculite flakes remain len as a coating on the fibers and give them more Resistance to fire.  

A silica dispersion is under the trade name Ludox® available. This product is heat resistant, but it contains organic material, which in the releases heated gases. Insulating materials made of Kera micro mats are rigid like a board and resist any movement supply. Ludox® tends to powder formation when it is is rubbed off or handled.

Other heat-resistant silicates such as sodium or potassium silicate result in very rigid products. The silicates are alkaline and can destroy ceramic fibers over time, and they too Reduce dust.

The present invention is based on the object better insulating material with excellent physi properties and very high temperature resistance as well specify a process for its manufacture.

This object is achieved by the features of the sayings 1 and 7 solved.

Advantageous developments of the invention are in the dependent marked against claims.

The molded, composite, insulating material is there by that first a water dispersion of Ver miculit is made that is free from organic materials is. The dispersion is then woven or non-woven te ceiling or substrate made of ceramic fibers, glass fibers or other fibers applied in an amount sufficient to To make the ceiling flexible and malleable. The substrate or section some of them are brought into the desired final shape. The water is removed by drying and the remaining vermiculite forms a solid binder and serves the substrate or the Keep blankets or mats in the desired shape.  

The resulting molded, insulating material withstands temperatures up to 1205 ° C (2200 ° F) without releasing any volatile components. Organic binders typically lose their structural integrity at temperatures between 121 ° C and 260 ° C (250 ° F and 500 ° F). The material of the invention maintains its structural integrity at higher temperatures, ie, temperatures of 260 ° C (500 ° F) or more. The molded material is good soundproofing and has a certain flexibility, which makes it easier to install. The vermiculite binder also serves to enclose all loose fibers, which improves handling and prevents safety risks, breathing in or swallowing loose fibers and the possibility of skin irritation is avoided. The advantages of the composite insulating material of the present invention are: it is compliant and flexible, its rigidity is determined by the manufacture;
it is easy to use and heat resistant;
it has improved acoustic properties;
there is no gas formation at any temperature;
Vermiculite results in a film that engages the fibers.

The following is a preferred embodiment of the invention described. The vermiculite dispersions used here are made by a variety of known methods. The Disper ions are caused by chemical exfoliation of vermiculite, a naturally occurring magnesium aluminum silicate material, too Papers or lamellas made with a high aspect ratio Ratio or aspect ratio and a particle size in the range of 50 microns. While both organic and inorganic Compounds were used to exfoliate vermiculite or slate, that is according to the present invention preferred material free of organic materials. Paver exfoliated vermiculite is commercially available Lich and can be dispersed or distributed directly in water.  

A commercially available vermiculite is under the Trade name MicroLite® offered.

The term "ceramic fiber" as used here means polycrystalline metal oxide fibers with a high Melting temperature typically above 1649 ° C (3000 ° F) lies. Ceramic fibers generally contain alumina or Calcium oxide and silica as well as smaller amounts of other oxides like those of iron, titanium and magnesium. A typical one For example, ceramic fiber contains more than 30% aluminum or Calcium oxide, more than 45% silica, with a remainder like other metal oxides. The above definition therefore includes others inorganic fibers such as those made of glass and asbestos. As A non-equivalent alternative can raise glass fibers Lich lower temperature conditions can be used.

The ceramic fibers become essentially flat Substrate or blanket or mat by several known methods shaped. For example, the fibers can be on a flat Surface arranged and sewn with barbed needles to intertwine the fibers and form a cohesive blanket. The Substrate or blanket can also be made by a paper maker development process.

The ceramic substrates or ceilings come in different Density generated, typically 48-192 kg / m³ (3 to 12 pounds per cubic foot). Typically have lower density ceilings better insulation properties, but they are more fragile than those of higher density. The desired thickness and density is required by the properties that the finished Piece. Blankets with a thick cross-section and less Density has the best insulation properties.  

This turns an aqueous inorganic disperson of vermiculite made that exfoliated vermiculite mixed with water becomes. The mixture typically has about 2 to 30% solids.

The aqueous dispersion is then on the ceramic fiber blanket through any suitable coating technology such as spraying, rolling coating, dipping or the like applied. It will enough dispersion applied that this at least partially penetrates the surface of the ceiling and part of the interior moistened. When applying the aqueous dispersion Thick flexible or malleable.

The amount of vermiculite solids in the dispersion and the The amount of application to the ceramic ceiling varies in Depending on the process conditions, the thickness of the ceiling and the desired stiffness of the end product. The ceiling can be one Thickness on the order of 1.6-152.4 mm (0.062 to 6 inches). For most purposes, the blanket has one Thickness in the range of 6.35-25.4 mm (0.25 to 1.0 inches). The The amount of dispersion applied is of the order of magnitude from about 2 to 50% vermiculite solids per 929.2 cm² (square foot), based on the weight of the ceramic ceiling.

After the dispersion is applied, the blanket is formed or brought into the desired shape. The damp or wet blanket can be molded by hand or with the help of a mandrel or a mold surface or it can be easily compressed between opposite faces of a shape. Preferably the total thickness of the original blanket is not significantly reduced changes to the maximum thermal performance characteristics maintain. Of course, the ceiling can be used in any ge desired shape can be cut, both before and after application of the binder dispersion.  

After applying the dispersion and molding, the molded blanket, either by air drying or by exposure to heat. When drying, the vermiculite is in converted a solid body, the shaped ceramic fa The ceiling remains in its shaped form.

In addition to the molding methods described above, the damp or wet blanket around the corresponding part of a mold molded to be protected and dry, thereby providing the part or shape with thermal protection layer is provided.

When applying the vermiculite, the molding and drying follows, the mixture or composite retains its shaped shape in a permanent way, adding the outer layer of vermiculite serves to embrace the fibers of the ceramic ceiling close and keep immobile. Thus, the generated one Form used and handled, without any significant replacement of fibers, and the composite is typically somewhat elastic.

Below is an example of the molded, assembled, insulating material described. A 101.6 cm (40 inch) wide, 1.27 cm (1/2 inch) thick ceramic blanket of 128 kg / m³ (8 pounds per cubic foot) density is determined by a press guided with stop jaws. The cheeks cut the size for the desired shape for the preform. These preforms can too be generated by a calender with die is equipped.

The preforms are impregnated by putting them in a 15% aqueous dispersion of vermiculite can be immersed. The kera Mix blanket is highly absorbent and immersion time is about 5 s. In some cases the dispersion is pigmen to create a more attractive product.  

The ceramic blanket with the impregnating agent is on the floor a multiple hollow shape. The shape will be in a hot one Press placed where the top of the form slightly preformed presses together to form the desired shape. The pressure is low and the shape determines the thickness and shape of the finished part. The temperature of the press is so high that Water evaporates from the ceiling, leaving only the solid vermicu residual particles remain. The dwell time in the press depends on the weight of the wet ceramic preform and is ty typically 0.5 to 10 min. The molded parts are made from the Form is removed and protruding burrs are removed with a knife away. The parts are examined and packed for dispatch.

Claims (9)

1. A process for producing a molded, composite, insulating material, characterized by the following steps:
Applying an aqueous dispersion of vermiculite flakes to a ceramic fiber substrate in an amount sufficient to make the substrate resilient,
Forming the substrate into a three-dimensional shape and then drying the substrate so that the substrate remains in this shape at elevated temperatures. 2. The method according to claim 1, characterized in that the molding and drying of the sub strats in a heated form. 3. The method according to claim 1 or 2, characterized in that the aqueous dispersion of Vermicu lit particles essentially free of organic materials is. 4. The method according to any one of claims 1 to 3, characterized in that the substrate is woven and not contains woven blankets. 5. The method according to claim 4, characterized in that the ceiling has a thickness that 1.6 to 152.4 mm. 6. The method according to claim 4 or 5, characterized in that the ceiling has a density which is about Is 48-192 kg / m³.   7. Composite insulating material, with a substrate made of ceramic fibers in three-dimensional form, which in the Shape is held by a truss characterized in that the binder the outer layers of the Enveloped substrate and essentially from vermiculite flakes exists that are free of organic materials. 8. A composite insulating material according to claim 7, characterized in that the material has the ability its structural integrity at temperatures above 260 ° C maintain. 9. A composite insulating material according to claim 7. characterized in that the inorganic fibers are ceramic Fibers with a melting temperature above 1649 ° C are.