US408838A - Henry w - Google Patents

Description

UNITED STATES PATENT OFFICE.

HENRY WV. JOHNS, OF NEWV YORK, N. Y.

PROCESS OF MANUFACTURING ASBESTUS SHEETS. V

SPECIFICATION forming part of Letters Patent No. 408,838, dated August 13, 1889.

Application filed November 16, 1886. Serial No. 219,071. (No specimens.)

To all whom it may concern.-

Be it known that I, HENRY W. JOHNS, a citizen of the United States,,and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Processes of Manufacturing Asbestus Sheets, of which th following is a specification.

My invention relates to a new process for the manufacture of asbestus sheathing, so called, or, in other words, sheets of asbestus or of asbestus and other fibrous material com bined having a flocked or nap-like surface. Such sheets are used for roofing and for boiler and pipe covering and other like purposes.

Sheets of pure asbestus and of asbestus combined with other fibrous materials having a fibrous, fiocky, or nap-like surface have been heretofore made, the same having been patented to me by the United States Letters Patent dated August 10, 1880, No. 230,945; but in the said prior invention the napped sheets are made by the employment of adhesive substances applied to the surface or surfaces of previously-completed sheets, by means of which the asbestus, pure or combined with other materials which form the nap or fibrous surface, is attached thereto, being held by the cementing properties of the adhesive materials.

By my present invention I produce sheets possessing all" the valuable qualities of my said prior products and which are more inexpensively and quickly produced, since I do away with one step in their manufacture namely, the application of the adhesive material to the completed sheet. They are also lighter in weight and more pliable, thus rendering them more desirable for certain uses than those heretofore patented to me.

In practicing 'my invention I proceed as follows: I first fibrate or finely divide the as bestus and other material, if other material be used, and remove from them all impurities, and then pulp them in any preferred manner, such as is now practiced in papermaking. I prefer to employ an apparatus for making my improved product and practicing my process the same as that now employed for paper-making, composed of pulping-vats, a traveling apron, compression-rolh ers, heating-cylinders, the. Such apparatus is now well known and does not require specific description here. After the pulp has been formed I make it into sheets upon the machine by drawing it from the pulping-vats in any manner now practiced in paper-making and depositing it upon the apron of the machine in a thin even layer, which is to be compressed-into the desired sheet. Then I sprinkle by sifting or in any other desired manner upon the surface of the pulp before it has been finally compressed by the pressure-rollers an even layer of fibrous asbestus or of asbestus fibers mixed with other fibrous or fiocky material, which, supported on the partly-compressed pulp, is carried by the apron which supports it in between the pressure-rollers, and is by them forced down upon and partly embedded in the surface of the soft pulp, so that when the sheet has been subjected to the final pressures and is dried it will be found that the upper side of the sheet has upon it a long nap of fibrous particles held to the surface of the sheet by the partial embedment of the fibers in the surface thereof. After the sheet is thus made I dry it in any preferred manner and by any suitable apparatus;- or it may beallowed to dry in the atmosphere.

The base-sheets may be of pure asbestus, or of asbestus mixed with other materials, or entirely of other fibrous material, and the nap may be produced on one side only or on both sides; but when it is desired to have the nap on both sidesthereof one layer of the fibers which are to compose the nap should be applied to the apron of the machine before the pulp is applied thereon and the other layer of fibers put on top of the pulp, or else the machine must be so constructed that the sheet can be turned over before it is completely compressed, and the second layer of fibers applied to the reverse side of the sheet.

I do not limit myself herein to any specific mechanical appliances for producing my products or practicing my process.

Having described my invention, I claim The process of manufacturing asbestus sheathing, or sheets containing asbestus and Signed at New York, in the county of New having a mapped surface, consisting in pulp- York and State of New York, this 15th day 10 ing the material and forming the same into a of November, A. D. 1886.

layer or sheet, and then applying fibrous 5 asbestus t0 the surface of the sheet while it is HENRY \V. JO] INS.

soft, and then pressing the superposed fibers \Vitnesses: into the pulp of the sheet, and then drying GEORGE 'W. (niLADWlN,

the sheet, substantially as set forth. CHARLES H. PATRICK.