Enhancing the strength, moisture resistance of wood, timber, lumber, similar plant-derived construction and building materials, and other cellulosic material

Abstract

Materials variously treated with sodium silicate were studied until enough information was obtained to find a way to solve the problems that have prevented sodium silicate from being the used as a fire retardant. These problems are: 1) water solubility (miscible with water), which results in extensive leaching when exposed to water, 2) cracking, chipping and peeling of treated surfaces, and 3) surface granulation. During flame tests it was discovered that sodium silicate formed a foam-like material, and this material was found to have become water insoluble, yet its elemental composition had remained virtually identical to that of the unmodified sodium silicate. This investigator proposes that under the influence of heat and dehydration, sodium silicate undergoes a polymerization process resulting in particles sizes too large to dissolve in water, and then developed a mechanism to explain how the process could occur. The temperature and moisture conditions in treated samples were then manipulated to cause the polymerization process to occur while protecting the wood from damage. Thus samples were prepared that were both water insoluble, and possessed effective fire retardant properties. These samples also proved to be stronger than untreated wood, thus providing an improved product that was fire retardant and moisture resistant. Since aqueous sodium silicate can be combined with other inorganic fire retardants, this technique is a potential method for making any inorganic fire retardants moisture resistant. This represents a potential breakthrough in fire retardants that has been sought for approximately 100 years. In addition, sodium silicate treated samples were made moisture resistant by the application of a micro-thin layer of silicon monoxide to the surface of samples. This technique, also never tried before, represents a second method for providing moisture resistant, fire retardant substances.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001]This application claims domestic priority of U.S. Provisional Application Ser. No. 60 / 040,709, filed Mar. 14, 1997; and is a continuation-in-part of U.S. application Ser. No. 08 / 818,195, filed Mar. 14, 1997, now U.S. Pat. No. 6,303,234, which, in turn, claims benefit of U.S. Provisional Application Ser. No. 60 / 013,452, filed Mar. 15, 1996 and U.S. Provisional Application Ser. No. 60 / 040,709, filed Mar. 14, 1997.<?insert-end id="INS-S-00001" ?>BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The purpose of this invention is to provide 1) impregnated wood materials introducing a fire retardant property to wood products, 2) impregnation of other cellulosic materials, such as paper and cloth, and other organic compounds in such a way as to allow their intended functions while reducing the risk of flammability, 3) impregnated wood materials introducing increased strength to wood products, and 4) impregnated wood materials...

AI Technical Summary

Benefits of technology

[0015]The purpose of this invention is to provide 1) impregnated wood materials introducing a fire retardant property to wood products, 2) impregnation of other cellulosic materials, such as paper and cloth, and other organic compounds in such a way as to allow their intended functions while reducing the risk of flammability, 3) impregnated wood materials introducing increased strength to wood products, and 4) impregnated wood materials introducing decreased solubility of the constituents of the final product thereby providing moisture and leachate and weather resistant products.

[0016]Alkali metal silicates, applied to various products can be used to impart fire retardant properties, and this fire retardant property can be maintained and enhanced by simultaneous or subsequent treatment to cause the alkali metal silicates to become water insoluble, thus greatly increasing the applicability and utility of products treated with alkali metal silicates, and also providing a product with improved strength and durability.DETAILED DESCRIPTION OF THE INVENTION

[0017]The purpose of this invention is to provide 1) impregnated wood materials introducing a fire retardant property to wood products, 2) impregnation of other cellulosic materials, such as paper and cloth, and other organic compounds in such a way as to allow their intended functions while reducing the risk of flammability, 3) impregnated wood materials introducing increased strength to wood products, and 4) impregnated wood materials introducing decreased solubility of the constituents of the final product thereby providing moisture and leachate and weather resistant products.

Problems solved by technology

Both of these techniques are expensive and produce toxic fumes.

A simple trip to the local lumberyard showed however, that there are apparently very few fire retardants for wood in widespread consumer use.

Sodium silicate is only of historical interest in the literature and is not studied at present due to the following facts: 1) sodium silicate is highly water soluble and leaches readily, 2) if you apply it to wood, within a few months it will have completely peeled and chipped away, 3) with air exposure it will form a granular powder that is very irritating to the eyes and hands.

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