FI85387B - Process for manufacturing mineral wool products - Google Patents

Description

1 85387

Method for the production of mineral wool products -Förfarande för tillverkning av mineralullprodukter

The present invention relates to a process for the production of products formed from mineral-5 fibers treated with a dust-binding agent.

Mineral wools are commonly used as thermal insulators in various shapes, such as sheets, rolls, gutters 10, etc. The fibers of mineral wools are generally bonded together with phenolic resins which give the finished products sufficient processing strength but do not prevent the fibers from coming off the products. Loose fibers irritate the skin, eyes and respiratory tract to some extent. Users 15 find this naturally uncomfortable.

According to the currently commonly used method, the aim is to reduce the amount of loose fibers by adding a dust-binding oil emulsion to the product, which is sprayed into the fibers produced by centrifugation or other methods before the fiber web is formed or on the finished product. As an example of the use of an oil-containing emulsion, reference is made to Finnish patent application 872127. However, the disadvantage of this method is that the addition of oil 25 increases the fire load of the product. In addition, the surface of the product feels sticky.

Mineral wool products are also coated with a suitable material, e.g. a thin plastic film. The use of a separate coating 30 significantly increases costs.

Finnish patent application 875260 discloses a method for bonding the surface fibers of mineral wool products together with alkali silicate, which is applied to the surface of the product as an aqueous solution, after which the water is allowed to evaporate. The binder is used in an amount of 75 to 150 g dry matter / m2.

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East German patent publications 76421 disclose a method for improving the surface resistance of building elements formed of mineral fibers, in which method a polyvinyl acetate emulsion or a bitumen solution is applied to the surface of the element. According to the publication, an amount of 300 to 500 g / m 2 has proved to be advantageous.

U.S. Pat. No. 3,861,425 discloses a coating composition for fiberglass insulators containing 70 to 90% flame retardant filler, 5 to 20% binder and 1 to 10% water-soluble flame retardant borate, wherein the flame retardant filler consists of aluminum hydrate or magnesium hydrate or a mixture thereof. and a binder of vinyl acrylic latex or polyethylene vinyl acetate or a mixture thereof. According to one embodiment, the amount of coating dried was about 120 g / m 2. The coating composition is intended for use in glass wool insulation where a hard, yet flexible, smooth surface is required.

In known methods, the additive is sprayed into the fibrous stream before the stream enters the forming wire or is applied to the surface of the formed product by means of a nozzle, roller or brush. What all methods have in common is that they use larger amounts of binder than would be necessary to bond the intersecting fibers together. When using conventional spraying methods, the additive is present in large droplets.

The object of the invention is to provide a method for the production of mineral wool products, by means of which the release of fibrous dust can be reduced with a considerably smaller amount of additive than previously used. This is achieved according to the invention by adding a water-dispersing, dust-binding agent to the product or applying it to the surface of the product as a gaseous suspension with an average particle size of 5-10. The binder used is preferably polyvinyl acetate or vinyl acrylic or a mixture thereof. Fire performance requirements

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3 85387, it is often necessary to add flame retardants to the mixture. The composition may also contain a surfactant or hydrophobizing agent if necessary for the use of the product.

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A gaseous suspension in which the substances to be added to the product are finely dispersed in a carrier gas is provided in a manner known per se by means of atomizers, e.g. inert propellants.

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The gas suspension can be brought into contact with the fibers immediately after their formation or after the formation of the nonwoven, in which case the gas suspension can be made to flow through the nonwoven by suction. Alternatively, the finished product can be coated by blowing a gas suspension onto the surface of the product. Because the additive is in a finely divided form, it penetrates deep into the carpet. Due to the small size of the particles, a small amount of binder provides an effective dust-binding effect.

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The invention is further illustrated by the following examples.

Example 1 25

The following mixture was prepared: 50 parts by weight of a 50% aqueous dispersion of PVAcr (Hernia 7224 from Hernia-National AB) as a binder 30 10 parts by weight of aluminum trihydrate Al (OH) 3 (Martinal from Martinswerk AG) as a flame retardant 40 parts by weight of water

The prepared solution was sprayed onto the surface of the pipe insulation (about 10 35 g / m 2, calculated as dry matter), after which the surface of the product was dried at 150 °. The amount of fibers detached from the product was measured. According to the method used, 82% less fibers were detached from the treated product than from the 4 85387 untreated products. The product met the non-combustibility requirement when tested according to the ISO standard. The abrasion treatment of the product lasted better than the untreated.

5 Example 2

In the solution of Example 1, 7 parts by weight of water were replaced by a silicone oil emulsion containing 50% water (TH

Goldsmidth AG's Sitren 447) as a hydrophobizing agent. The product was 10 clearly water repellent.

Example 3 45 parts by weight of a 50% aqueous dispersion of PVAc (Kiilto 15 Oy's Kiilto VAK) 10 parts by weight of aluminum trihydrate 5 parts by weight of diquaternary polydimethylsiloxane (Goldsmidth AG's Tegopren 6224) as surfactant water 45 parts by weight 20

The prepared mixture was sprayed on the surface of a glass wool plate (density 20 kg / m 2). The plate was dried after spraying. The amount of fiber detached from the board was 86% lower than the amount of fiber detached from the untreated board. Subjects compared the feelings of the 25 treated and untreated plates in the blinded test and rated the treated plate as clearly more pleasant.

Although the invention has been illustrated by the above-mentioned Examples, it is clear that these are in no way limiting and that modifications may be made within the scope of the following claims.

Claims (9)

A process for the production of dust-treated products 5 made of bonded mineral fibers, characterized in that a water-dispersed dust-binding material is added to the product or applied to the surface of the product as a gaseous suspension with an average particle size of 5-10 μπι. Process according to Claim 1, characterized in that the dust-binding agent is polyvinyl acetate. Method according to Claim 1, characterized in that the dust-binding agent is vinyl acrylic. 15 Process according to one of Claims 1 to 3, characterized in that the aqueous dispersion contains a flame retardant. Process according to one of Claims 1 to 4, characterized in that the aqueous dispersion contains a surfactant. 5 85387 Process according to one of Claims 1 to 4, characterized in that the aqueous dispersion contains a hydrophobizing agent. Process according to one of Claims 1 to 6, characterized in that the aqueous dispersion contains at least 50% of a dust-binding agent. Method according to one of Claims 1 to 7, characterized in that the amount applied to the surface of the product is from 5 to 50 g of dry matter / m 2, preferably from 10 to 25 g / m 2. 35 Process according to one of Claims 1 to 7, characterized in that the amount added to the product is 0.5 to 10 g of dry matter / kg, preferably 2 to 5 g / kg. s 85387