US1856475A - Metal impregnated fiber article and process of making same - Google Patents

Description

Patented May 3, 1932 UNITED STATES PATENT OFFICE I MEYRL FROST, OF CAPAC, MICHIGAN, ASSIGNOR TO DUROWOOD INDUSTRIES IN- CORPORATE-D 0F DETROIT, 0F DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN METAL IMPREGNATED FIBER ARTICLE AND PROCESS OF MAKING SAME No Drawing.

This invention relates to metal impregnated fiber articles and to processes for manufacturing fiber articles impregnated with a metallic substance or metal-like substance.

An object of this invention is a fiber article of any form or shape, impregnated with a metallic material, whereby the article, tho made of fiber, has certain of the characteristics of similar articles made of metal or covered with sheets of metal, etc.

Another object is a novel process formaking fiber articles having certain metallic properties, the process including as one of its'steps, the step of impregnating the articles with a metallic material.

Still further objects will readily occur to those skilled in the art upon reference to the followin description of the invention.

The article embodying the invention is a shaped fibrous article impregnated with a metallic substance.

The fibrous article, per se, may be composed of any suitable fibrous organic material, such as wood pulp, paper pulp, rag pulp, etc., mixed with a suitable adhesive or binder, and is in the nature of a dehydrated, form-retaining mass, of any desired shape.

The metallic substance used for impregnating the article may be copper, bronze, brass, metallic lead, metallic tin, etc. 'It'may also be one or more of the so-called low melting point alloys involving lead, tin, bismuth, cadmium, etc. It may also be of glass, which, tho not a metal, will be considered as a metallic material, since, as far as the invention is concerned, glass has the protecting properties of the metals above described. Other substances, not specifically named above, may also be used as the metallic substance of the invention.

When the metallic substance selected as the impregnating substance possesses a comparatively high melting point, that is to say a melting point much higher than the charring point of the fibrous material, the latter may be so treated as to include as a constituent, a fire resistin orfire proofing material whose presence raises the charring point of the fibrous material, giving to the article to be impregnated, the property of not charring tho Application filed March 16, 1931.

Serial No. 523,199.

it is immersed in the molten metal, then at a comparatively high temperature.

The article embodying the invention, tho constituted of fibrous organic material is found to possess certain desirable properties, due to its metallic impregnation, one of them being its exposure resisting characteristic.

The processes of manufacturing articles such as those above described, in general, include two major steps: (a) shaping the fibrous article and (b) impregnating the latter with a metallic substance. Various refinements of the simple process have been discovered and these, together with the simple process will now be described.

In shaping the fibrous article, a plastic, Wet, mass of the fibrous pulp is used, and the latter is then shaped, in molds, rolls, presses, or the like, under a pressure which may be in the neighborhood of from one hundred to several hundred pounds per square inch, this pressure being sufiicient to squeeze the water out of the mass and to dehydrate it. The resultant article is a fibrous, shaped and partially dried article and when completely dried is ready for the next step, impregnation.

1n impregnating the article, the latter is subjected to the influence of a partial vacuum which serves to draw air from the article itself. Then while the article is still in the exhausted condition, it is immersed in a bath of molten metallic substance, the latter having a melting point not a great deal above, the charring point of the article.

.While the article is so immersed, the partial vacuum is relieved, and the article is then placed under a pressure of one or more atmospheres, as desired. The pressure thus applied forces the substance into the outer portion of the article, and when the latter is re moved from its bath, it will be found to be impregnated with an amount of the substance.

The degree of impregnation may be controlled readily, since it is known to depend upon the nature of the materials used, upon the degree of exhaustion prior to immersion, upon the duration of the period of immersion, and upon the degree of pressure subsequent to immersion.

fibrous material, that the latter will char when immersed in the molten metallic substance. Under these conditions, it becomes desirable to prepare the article, before inimersion, in such a Way that its charring point will be raised, and the following has been found to be an effective mode of accom dishing this result.

Into the pulpy, plastic mass of fibrous ma terial, is introduced, by beating, stirring, etc, an amount of a fire resistant material, such as asbestos, calcium carbonate, calcium chloride, alum, limestone, etc., these being of the mineral fire resistlng group. The plastic mixture, now including the fibrous material and the fire resistant material, is then shaped and dehydrated, just as was shaped and dehydrated the plastic mass of fibrous material, in the manner above described. The selection of the proper mineral fire resistant material, and the amount used, depends upon the nature of the fibrous material, the metallic substance, etc. and the particulars of this step may befound upon suitable trial.

Now having described the invention and the preferred embodiment thereof, it is to be understood that the said invention is to be limited, not to the specific details herein set forth, but only by the scope of the claims which follow:

lVhat I claim is:

1. The method of producing an'article in predetermined shape or form and having exposure resistant characteristics which comprises shaping or forming the said article under pressure from a pulp of fibrous material, drying the shaped article, and then superficially impregnating said article with a metal-like material.

2. The method of producing an article in predetermined shape or form and having exposure resistant characteristics which comprises shaping or forming the said article under pressure, drying the shaped article, andthen superficially impregnating said article with a metal-like material by evacuating the air from said irticle and immersing in a prises shaping or forming said articles from.

organic fibrous materials and superficially impregnating said articles with metal-like material of a melting point not substantially M greater than the char point of the articles.

4. The process Which comprises producing a fluent pulp of fibrous material and water containing adhesive, forming said pulp into a suitable shape and expressing the water therefrom under moderate pressure, drying the shape, and superficially impregnating said article with a metallic substance.

a. fluent pulp of fibrous material and water containing adhesive, forming said pulp into a suitable shape and expressing the water therefrom under moderate pressure, drying.

the. shape, and providing said shape witha coating and superficially impregnating layer of a metallic substance. 7

In testimony whereof I sign this specification.

MEYRL M. raos'r.