BE1021033B1 - MIXTURE FOR THE MANUFACTURE OF GLASS. - Google Patents

Abstract

Mixture for the manufacture of glass The invention relates to a mixture for the manufacture of glass fibers which comprises the following materials, according to the percentages by weight thus defined: soda ash 8 to 10% dolomite 2 to 8% borax pentahydrate 6 to 11% cullet 40 to 65% sand 15 to 30% limestone 2 to 6% nepheline 0 to 1.5%

Description

Mix for glass production

The present invention relates to a mixture for the manufacture of glass, in particular a composition suitable for the manufacture of glass fibers, as well as to a process for the production of glass fibers.

The glass fibers are known, among others, for their insulation qualities. For this particular application, the fibers are generally bonded with a synthetic resin and the finished product will have the form of rigid panels or soft mattresses to protect walls and ceilings, or the shape of shells to insulate the pipes.

Compositions of raw material mixtures for the manufacture of glass fibers generally result from a compromise between the properties desired for these fibers and the constraints imposed by the industrial manufacturing processes. Generally, the molten glass is fed into a hollow body which rotates at high speed (centrifuge). This body has a peripheral wall perforated with many orifices through which the glass is sprayed under the action of the centrifugal force, so that so-called primary fibers are formed which are then stretched, for example by the action of flames or a gaseous stream .

In one aspect, the present invention provides a blend for the manufacture of glass fibers according to claim 1, the dependent claims having preferred embodiments. The invention relates to a mixture for the production of glass fibers, comprising the following materials, according to the weight percentages thus defined: sodium carbonate 8 to 10% dolomite 2 to 8% borax pentahydrate 6 to 11%, preferably 8 to 10% by weight at 10% calcine 40 to 65%, preferably 40 to 50% sand 15 to 30%, preferably 20 to 30% limestone 2 to 6% nepheline 0 to 1.5%

This composition has the advantage of being able to present several of the following interesting properties: the resulting fibers offer good insulating properties; the mixture melts at a temperature suitable for fiberizing in the centrifuges, reducing the risk of obstruction of the projection orifices of the centrifuges; the melted mixture homogenizes correctly in the oven, reducing the defects appearing during the fiberizing step; the cost of raw materials is advantageous; - the use of a large proportion of cullet (recycled glass) is beneficial for the environment.

The cullet (also called cullet) used in the mixture according to the invention can come from two sources: flat glass and hollow glass (bottles). Preferably, the mixture according to the invention comprises between 0 and 30% by weight of flat glass cullet and between 10 and 50% by weight of hollow glass cullet.

According to another aspect, the subject of the present invention is a method for manufacturing glass fibers according to claim 3. The invention relates to a process for manufacturing glass fibers from a mixture of raw materials, comprising the steps following: - loading of raw materials into the melting zone of an oven, the mixture of raw materials comprising the following materials, according to the weight percentages thus defined: sodium carbonate 8 to 10% dolomite 2 to 8% borax pentahydrate 6 at 11% calcine 40 to 65% sand 15 to 30% limestone 2 to 6% nepheline 0 to 1.5% - heating the mixture to a temperature above the liquidus temperature of the resulting glass, to form a molten glass capable of forming fibers ; - Fiberization of molten glass, that is to say, transformation of molten glass into fibers, for example by means of centrifuges.

Two particular embodiments of the invention will now be described, as examples.

Here are two examples (Ex.1 and Ex.2) of mixture composition according to the invention. The contents of different ingredients are given in percentages by weight.

These mixtures made it possible to manufacture glass fibers according to the centrifugation process previously described. After sizing with an organic binder, they formed insulating glass wool.

Claims (4)

1. Mixture for the manufacture of glass fibers, characterized in that it comprises the following materials, according to the weight percentages thus defined: sodium carbonate 8 to 10% dolomite 2 to 8% borax pentahydrate 6 to 11% cullet 40 at 65% sand 15 to 30% limestone 2 to 6% nepheline 0 to 1.5% 2. Mixture according to claim 1, characterized in that it comprises: sodium carbonate 8 to 10% dolomite 2 to 8% borax pentahydrate 8 to 10% cullet 40 to 50% sand 20 to 30% limestone 2 to 6% nepheline 0 to 1.5% 3. Mixture according to claim 1 or claim 2, characterized in that it comprises between 0 and 30% weight of flat glass cullet and between 10 and 50% by weight of hollow glass cullet. 4. A method of manufacturing glass fibers from a mixture of raw materials, characterized in that it comprises the following steps: - loading of raw materials into the melting zone of an oven, the mixture of raw materials including the following materials, according to the weight percentages thus defined: sodium carbonate 8 to 10% dolomite 2 to 8% borax pentahydrate 6 to 11% caldn 40 to 65% sand 15 to 30% limestone 2 to 6% nepheline 0 to 1.5 - heating the mixture to a temperature above the liquidus temperature of the resulting glass, to form a molten glass capable of forming fibers; - Fiberization of molten glass by centrifugation.