US1412968A - Process of treating shark skins and the like - Google Patents

Description

UNITED STATES PATENT OFFlCE.

ALLEN ROGERS, OE BROOKLYN, NEW YORK, .ASSIGNOR TO OCEAN BOND CO. INC., 0]

NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF TREATING SHARK SKINS AND THE LIKE.

Specification of Letters Patent. Patented A r. 18, 1922.

Ho Drawing. Original application filed July 19. 1919, Serial No. 311,921. Patent No. 1,395,773, dated November 1, 1921. Divided and this application filed June 10, 1921. Serial No. 476,626.

To all whom it may concern:

Be it known that I, ALLEN Rooms, citizen of the United States, residing at Brooklyn, New. York, have invented certain new and useful Improvements in Processes of Treatin Shark Skins and the like, of which t efollo'wing is a specification.

This invention relates to the treatment of skins of sharks and the like, to remove the hard or horny coating known as dermal armor. Many attempts have been made to remove this coating by chemical and mechanical means, but outside of the process described in my application Serial No. 295,549, filed May 8, 1919, in which I describe the. treatment of the skin with hot I water while still on the animal, the efforts have been unsuccessful and satisfactory results have not been attained.

The resent process overcomes the difiiculties eretofore experienced in. this art, and is applicable to skins that have been removed, and which may be 'in'a dry, fresh or salty condition. I

The present invention has for its ob e cts among'others to enable one to accomplish the desired results in much less time and with less labor, and with a cost that is comparatively small inasmuch as the bath, when once prepared, may be used over and over and over again almost indefinitely before losing its efficiency.

This ap lication is a division of my ap-.

plication erial No. 311,921, filed July 19, 1919. i

In carrying out my invention, the skins are first soaked in water to bring them to a soft and natural condition. They are then placed in a saturated salt solution to which has been added one-half its volume of commercial hydrochloric acid, and as many pounds of salt as there. are gallons of acid.

used. In making up this bath, I have found that the following proportions give the most satisfactory, and, possibly, the best, results attainable l Water 2 gallons Hydrochloric acid 1 gallon Salt 3 pounds The addition of, more salt; I find in no wayinterferes with the results, but if less with salt, gives most satisfactory results, I

have found that other acids, such as sulphuric, nitric, acetic, lactic, and formic, will produce nearly equally satisfactory results.

In the practice of my process, the dermal armor becomes loosened in about one and one-half hours, and may then beeasily removed over the beam, as is the customar practice for unhairing the pelts of land anlmals.

Although the dermal armor may be readily removed when the skin is taken from the acid, I find it preferable to transfer the stock for a short time to a 10 Baum salt solution. The object of this second bath is to remove the excess acid and thus obviate the necessity of protecting the hands of the workman by rubber gloves.

While at first thought it may seem that this process would be too expensive for practical purposes on account of the large amount of acid required, it is a' fact that only a small quantity of acid is actually consumed. A bath once prepared may be run almost indefinitely before losin its efiit ciency or becoming unfit for use. y a simle chemical test, the exhausted acid may e determined and the strength cheaply and quickly restored.

The salt solution used as a second bath gradually becomes acid on account of the liquid carried over from the first treatment. This excess of acid may be readily neutralized from time to time by adding sufiicient sodium carbonate to bring it back to its normalcondition.

I have also found that in removing the shagreen, strong solutions of nitre-cake, salt cake, sodium acid sulphate, will also give very satisfactory results. The best-strength to use, however, is 10 Baum.

The skins having been de armored are in a pickled condition, and may then be handled in the same manner as are pickled skins from land animals.

If sulphuric acid is employed in lieu of the hydrochloric acid I use only one-half gallon to each two gallons of water likewise the same amount of nitric or formic acid should be employed. If either acetic or lactic acid is used, I employ one gallon of each to each two gallons of water.

Modifications within the scope of the appended claims may be resorted to without departing from the spirit of the invention or sacrificing any of its advantages.

What is claimed as new is 1. A step in the method of removing the