US2321775A - Dry carroting fur - Google Patents

Description

Patented June 15, 1943 oar cnnno'rme FUR Mensa-taken, Douglaston. Long Island, N. Y., assignor to No-Mercury Felt Corporation, a cor.- poratlon of New York lichrawlng. Application June 2, 1942,

' Serial N0. 445,454

8 Claims.

This invention relates to the treatment of fur in its preparation for the manufacture of felt hats and is particularly directed to thatstep which has to do with the carrotingof the fur to render it feltable. This application is a continuation-in-part of parent application, Serial No. 405,645, filed August 6, 1941. 1

- In order that the invention may be clearly understood, it is desirable to explain the manner in which furs have heretofore been treated to prepare them for carroting and the subsequent carroting thereof.

It has been the universal practice to deliver pelts to the carroting establishment in the condition in which they are stripped from the carcass, i. (3., with the flesh side out. To prepare them for carroting, these pelts, which are generally quite dry, are first placed in a tumbling barrel containing sawdust wet with water. They are tumbled in this barrel with the sawdust for a suflicient period to clean the dirt and flesh from the pelts and incidentally soften the pelts so that they become sufficiently pliable to be readily handled. This tumbling operation with sawdust in the presence of water is purely a cleaning operation. It forms no part of the carroting operation.

At the conclusion of this cleaning operation, the pelts are slit and opened and they are thereupon trimmed to out off ears, paws, tails, and other undesirable parts, and they may be then clipped or pulled to remove the hard, horny ends of the individual long hairs which are sometimes called the water hairs.

Thereafter it is the practice to stack the pelts fiat, generally skin to skin and fur to fur, and place them in storage, where they are permitted to lose most of the cleaning water. In this condition, the pelts are very flexible and remain, so until they are withdrawn from the stack for the 'carroting operation.

variety of carroting solutions have been em-' ployed. By far the most common is the so-cailed mercury nitrate carrot which has been used sometimes alone and sometimes with other included constituents, such as oxidizing agents.

Nitric and sulphuric acid carrots have also been employed, as well as solutions embodying the permanganates, -chloric acid, etc. It is not necessary here to specify all of these carroting solutions for they are well known in the art. Suffice it here to point out that, when a carrot is applied by a brush, as stated, the carroting solution has alwaysbeen of a dilute character. Those skilled in the art have avoided the use of strong active carrots for it has been universally recognized that overcarroting, such as results from brush application of too strong a carrot, is highly detrimental to the fur. Furthermore strong solutions are dangerous to the user, and brushes, rubber gloves and other application equipment will withstand only relatively weak dilute carrots. Consequently the carrots which have been used since the beginning of the art have invariably been dilute aqueous solutions.

' When attempt is made to brush furs with such solutions, it is recognized that appreciable amounts of such solution of the carrot must be applied to the fur, for, as the brush passes over the fur, it tends to flatten down the fur fibers and, unless the fur is practically soaked, only a relatively small. portion of the length of the fibers are wet with the carrot, leaving the base portion ofthe fibers substantially untreated. Brush application, under ordinary working conditions, cannot produce uniform treatment throughout the length of the fur fibers and some fibers invariably will be overcarroted while others will be deficient in the carroting solution. Brush carroted fur leaves the brushing operation in wet matted condition.

These wet carroted pelts are sometimes piled for a day or more to permit the carrot to react. They are thereafterspread for drying, which is sometimescarried out at atmospheric temperature for about one or twodays. Otherwise artificial drying is employed, in which case the pelts may be heated to temperatures varying from to 220 F., for a period of between one and two hours. After they are dried, the flesh side is moistened (i. e. wet down) and they are then'piled underfburlap until such time. as it is desired to cut the fur from the skin.

The fur side of the pelt is then thoroughly brushed, so as to free the fur fibers from the matting which is invariably present to some'degree.=. This brushing tends to separate the individual fur fibers, but very often is accompanied by material waste of the fur which-it is necessary to brush or tear out in order to. eliminate the matting. After the pelts have been brushed,

they are sorted and counted and bundled for cutting and they thereupon go to the cutting operation where the fur fibers are removed from the skin. The fur is subsequently blown and subjected to other operations preparatory to actually felting it into hat bodies. I

The foregoing carroting practice, which has been common in this art for decades, may be summarized as embodying the following steps:

These steps are the steps from carroting to cutting. Several of them must be carried out by III. IV. V. VI. VII.

' highly skilled operatives and all of them require repeated handling of the pelts,. witlp incident time consuming operations extending over protracted periods. These operations are expensive and any step or steps which it is possible to eliminate, will cheapen 'the cost of preparing furs for felting. These facts have been recognized for many years, but, although many have tried to evolve simpler and cheaper methods, no

satisfactory commercial way of solving the problem has been discovered by anyone. Consequently, the practice which I have above enumerated continues to be, aside from the present invention, practically the only method in use to this day.

One of the most pronounced drawbacks in the accepted method of carroting pelts is th fact that the carroting operation wets the pelt with a carrot which must be relatively dilute for the reasons given. This sometimes requires piling so that the carrot may be given sufllcient time to react. In all cases it requires prolonged drying so that the fur may be brushed and it requires brushing, for after a pelt has been wet according to brush carroting practice, the matting is frequently so severe that it can only be removed in this manner.

From prolonged study of the problem, I concluded that, if it were possible to eliminate this wetting of the pelt by a carroting solution, many of the steps heretofore necessary would be eliminated and I therefore sought some appropriate method of carroting without this wetting of the pelts.

I am aware that attempts have been madeto carrot by the use of appropriate gases, but these attempts have not proven practical. 'I am also aware of United States Patent No. 339,349, issued April 6, 1886, to Edmund Tweedy, Henry L. Brevoort and Isaiah L. Roberts on the process of preparing fur for felting. According to that patent, pelts are placed in a tumbling barrel with such dusty substances as powdered silica and powdered air slaked lime, chalk, fullers earth or potters clay, together with a relatively small quantity of marbles, pebbles or iron balls and are tumbled for a period of say eight hours. Although this patent has been known to the art for over half a century, the process described in this patent has never gone into practical use so far as I am aware and it has not solved the problem which, during the long intervening period, continued to vex this industry.

According tothe Tweedy et al patent, the purpose of the powdered silica is to abrade off the coating of the. fur fibers, while the slaked lime,

fullers earth, powdered chalk or potters clay,

serve to absorb the grease which coats the individual fur fibers. The marbles, pebbles or iron balls are used in a quantity of one-fourth of the bulk of the mass and their purpose is to beat thepowdered material against the coating on the fibers. The patent states that a rapid movement of the tumbling receptacle will produce the required effect quicker than a slow one provided that the movement is not so rapid that the particles will be held against the sides of the receptacle by centrifugal force.

I have carried out a very large number ofexperiments and tests utilizing a tumbling drum and these tests have very conclusively shown the reason why the process set forth in the Tweedy et al. patent did not and could not possibly solve the problem confronting the art prior to the advent of the present invention.

For example, a number of tests were carried out wherein English rack pelts (sometimes referred to as Scotch cony) were placed in a tumbling drum in dry condition with crushed abrasive material, such as powdered silica, of less bulk than the pelts. The drum was-rotated to tumble the pelts and silica together atvarious speeds for various periods ranging up to several hours. These tests conclusively showed that where such abrasive material was tumbled with the pelts for even a period of an hour or two, the pelts were badly cut and damaged and appreciable quantities of the fur fibers were abraded away and-made unfit for use. The loss of fur was so great as to render the operation wholly -uncommercial. Since powdered abrasive alone so destroys the pelts as to render the operation uncommercial, it is manifest that the addition of iron balls or pebbles to beat the abrasive against the fibers would produce an even worse condition and if this operation were carried out for eight hours, the results would be disastrous from a commercial aspect. Moreover, the powdered materials present are substantially chemically inert and are obviously intended by the patentees merely to soak up the grease. They exertno carroting action.

.I have also carried out tests wherein pelts were tumbled in a drum with crushed abrasive and relatively small quantities of well known dilute commercial carrots. These tests demonstrated that, unless a, sufllcient amount of these commercial carrots were used as to provide a very considerable free flowing liquid in the drum, no satisfactory commercial felt could be obtained. Unless there were en ugh liquid present to practically soak the fur, the tumbling had to be so protracted that the loss or waste of fur, due to abrasion, rendered the operation wholly uncom'mercial.

As a result of the very large number of tests carried out under the most careful and painstaking control, I have discovered that it is possible to effectually and commercially carrot pelts without undue waste of fur and in substantially dry condition by tumbling such pelts in a tum-- bling drum with pieces of an appropriate attrition material or materials, in the presence of a carroting solution of appreciably greater strength than could possibly be used for brush application and in such quantities that, in cooperation with carroted within an astonishingly short period of through the foramina in the cage.

time and will be substantially dry at the conclusion of the operation.

' I have discovered that through the conjoint use of an attrition material and such a strong, highly active carroting solution, I am able to obtain the necessary carroting action, when using such small uantities of the carrot that it may be carried upo' pieces of attrition material without leaving free liquid in the drum. The highly active carroting solution appears tobe adsorbed in an imperceptible highly active layer on the surface of the attrition material, ready to act on'the fur. Thorough tests, substantiated by actual commercial production of hats, have demonstrated that the pelts so treated do not require protracted drying and that in lieu of the eight steps which I have hereinbefore enumerated as common to general present day practice, I am able to produce a superior product with less waste roting agent, is evenly distributed, instead of.

tending to segregate in various areas as more or less scattered and separated pools, which leave insuflicient carroting agent in other areas.

Suflicient attrition material is present to en-' sure that it rubs, in tumbling, freely and repeatedly over every part of the fur on the skins present. For this purpose it usually seems best to tumble with somewhere nearly equal bulks of skins and attrition material, that is, somewhere nearly equal weights if the skins and materialhave about the same specific gravity.

In practically carrying out this invention, I place in a tumbling drum pieces of an attrition material, hereinafter more specifically described, together with the pelts to be carroted and a relatively small quantity of a strong, active carroting solution. The drum is rotated to drum tumble the contents for a relatively short period (fifteen or thirty minutes will generally sumce) Thereafter I discharge the contents of the drum into a, suitableiforaminous cage which is rotated foia sumcient period to cage tumble the pelts and thus separate out the attrition material While the pelts are being caged, they are preferably subjected to moving heated air, so that, during the few minutes which it is necessary to separate out the attrition material, the pelts are ventilated and aired. The pelts are taken from the cage in carroted condition with the fur in fine, open, fluffy condition and they may be passed directly to the cutting knives and the fur thus cut from the skins. I do not have to pile for a period to permit the carrotto react. I do not have to dry over protracted periods. I do not ,have to brush. I save at least half a dozen handlings of the pelts and- I obtain good felts.

Emmple 1 5600 grams of. powdered flint, 80 mesh were Into the-drum was then introduced 25 English racks weighing 1400 grams and the drum was thereupon rotated for 60 minutes. The skins were then removed, thefur was cut and blown. From this fur thoroughly satisfactory commercial felts were made. It was "found however that too much fur had been abraded away and lost to'render this procedure practical, particularly because of prevailing high prices of the raw fur.

Example 2 4.000 grams of the same 80 mesh powdered flint were introduced into the drum with 100 cc. of concentrated nitric acid and 50 cc. of concentrated sulphuric acid. This made a strong acid carrot. The drum was rotated until the acid and abrasive were thoroughly mixed, at which time it was found that, to all appearances, the abrasive was substantially dry.

Into the drum was then introduced 25 English racksweighing 1300 grams and the drum was rotated -for"65 minutes. The'treated skins were cut and tested and showed satisfactory shrinkage -and good felts. The fur used in this test exhibited the phenomenon of yellow carroting.

Here again there was considerable loss of fur ,due to abrasion.

In carrying out tests of the invention wherein the fur-was subjected to attrition, in the presence of an acid, various acids in various amounts before the fur wasremoved from the drum. I

accomplished this result in various tests by introducing into the drum appropriate quantities soda, 'or the like, and then rotating th drum for a while, until the acid character of the fur'had been lessened to the point'desired. I found this method of treatment very convenient and satisfactory for the control of acidity.

Example 3 4000 grams of mesh abrasive, wet with cc. of water, were introduced into the drum with 100 cc. concentrated nitric acid and 50 cc. concentrated sulphuric acid, making a strong acid carrot, and the drum was rotated untilthe contents were thoroughly mixed. There was then introduced into the drum 25 English racks weighing 1300 grams and the drum was then rotated for 60 minutes.

There were then introduced into the drum 1000 additional grams of abrasive with which had been thoroughly admixed 50 grams of pulverized potassium permanganate. The drum was then closed and rotation was continued of the whole mass for 30 minutes longer. The fur thus treated was subsequently tested and found to be entirely satisfactory and the resulting felt commercial.

The potassium permanganate which was introduced functioned as an oxidizer. In lieu of the potassium permanganate thus employed, I have found that other per salts, such as ammonium persulfate (NH4) aSrOa or potassium persulfate, or any other appropriate oxidizer, such as hydrogen peroxide are useful.

I have also substituted a strong solution of sulfamic acid (NHzSOaH) for the other acids and have found that it gives good results.

In all of the tests, wherein I used silica or some other abrasive material as a carrier for the carrot in the drum, I found that the abrasive action on the fur caused a considerable waste of fur fiber. In practice I may use such an abrasive as flint, pumice, carborundum or some other similar abrasive and while satisfactory felts may be obtained by combining this type of material and a strong highly active 'carrot, I have found it better and more economical to employ an attrition material which is not generally classed as an abrasive,

For example: I tried comminuted rubber as a carrier and found that the waste of fur was negligible but difllculty was experienced in separating the rubber particles from the fur after the carroting operation. I then tried shredded rubber which was obtained by shredding tire inner tubes into strips about 1 inch long and ra-A: of an inch wide. Several tests, as well as commercial production, were carried out with this latter material. Note the following:

' Example 4 24 lbsiof shredded rubber were placed in the factory drum and to this was added a mixture of 800 cc. nitric acid mixed with 640 cc. of the peroxide to produce a strong carrot. Then there were placed in the drum 200 skins of English racks, approximating 26 lbs. and tumbled for '15.,

minutes, and the rubber separated from the skins.

Very satisfactory commercial felts resulted from fur carroted by this procedure and the waste was negligible.

Example 5 In the drum, 1500 grams of shredded rubber were charged with 300 cc. of a 15 B. mixture of chloric and sulphuric acids to form a strong carrot. 24 flat English racks weighing 1320 grams were introduced and tumbled for 30 minutes and then removed from the drum and the rubber and the skins separated. Very satisfactory felts were made from this fur.

Up to about the time when I conducted the tests which used rubber as the carrier, I had employed an unlined wooden tumbling drum. I found that this drum-soaked up considerable acid so that accurate computation of the acid for controlled carroting was difficult. Moreover the wood deteriorated under the action of the strong carroting solutions. I therefore lined the'drum with glass and was thereafter better able to compute the amounts of carrot used. The drumstructure employed was a twelve sided drum 'of approximately 42" diameter with fiat ends and mounted to rotate with its axis horizontal and it was driven at approximately 17 R. P. M. It had one interior baflle extendinglongitudinally and projecting inwardly several; inches from a removable charging and discharging door in its periphery. It was originally unlined but later lined with glas's.

In addition to rubber, I tried many other nonabrasive materials as carrying agents for the carroting solution. Sawdust did not prove satisfactory for it withheld too much of the solution and with a strong nitric acid carrot there was too much danger of fire. Wooden chips, suitably pretreated to render them non-absorbent and practically inert, were used to produce satisfactory results. Note the following:

Example 6 1020' grams of wooden chips in the form of match sticks which had been boiled in paraflin wax and cooled, were introduced into the drum and then there was added 100 cc. of nitric acid and cc. of hydrogen peroxide (concentrated) to produce a strong carrot. 24 English racks weighing 1580 grams were introduced and tumbled for approximately 20 minutes. Tested subsequently in the laboratory they yielded very satisfactory felts.

Here also the waste of fur was negligible.

This and further tests showed that it was highly desirable for the best commercial results to use as the carrier an attrition material which would be substantially inert to the strong carrots used in connection therewith. This is not strictly chemically true of rubber which reacts slowly and in due time will deteriorate. Thus .while it is possible to use rubber or similar attrition materials which are for practical purposes substantially inert, I prefer, as'the best practice, to use a more inert material, so that it can be used over and over again without being changed and with substantially constant results which are conducive to controlled carroting, i. e., carroting which can be-carried out in successive batches with uniform and computable results.

I have found that certain natural or synthetic resins and plastics are very well adapted for this use. For example, highly satisfactory ends have been obtained through the employment of natural and synthetic resins and plastics, such as solidified vinyl resins, Lucite, Polystyrene," bituminous materials, asphalt, etc., which are water-resistant, acid-resistant, and causticresistant to a high degree. Materials possessing these characteristics are well adapted for employment with all the ingredients used in present-day carrots, even when such carrots .are employed in very strong active condition. Note the following:

Example 7 32 pounds of, the synthetic resin Polystyrene,".

in pieces of a size to pass a mesh screen and free from dust, were used in the glass lined drum with a prepared mixture of 600 cc. nitric acid (39-40 B.) and 512 cc. of volume hydrogen peroxide. This is a strong highly active carrot. The drum was rotated until the solution had been distributed over the resin particles and there 'on the floor for about one hour and then bundled until the next day when they were out. Very good felts resulted from this procedure and there was a negligible waste of fur.

Example 8 In Example 7, above given, the synthetic resin carrier was fresh material which had not been used before. It was found that, after use, some of the acid constituents of the carroting solution was found, by titration, that approximately 14% of the acid was retained onthe synthetic resin. Consequently in repeating this example under identical conditions adhered to in Example 7, it was only necessary to add 86% as much acid as in Example 7. With subsequent batches of fur, re-using the same synthetic resin, it was found that the adhesion of the acid remained substantially constant at approximately 14% and this was taken in account in the adding of the carroting solution to be used in conjunction therewith.

From my investigations it would appear that I may employ other forms of 'res'ins or other mate'- rials which are relatively hard and suitably nonreactive to the carroting solutions employed, Tests have indicated that I may use particles of hard paraflin wax as a carrying medium for the carrot and that I may also employ relatively hard asphalt particles, either in natural state or after hardening them with sulphur. The advantage of these materials, as well as resinous materials is that they do not tend to stick to the carroted fur and can be readily disassociated therefrom before cutting the fur from the skin. Moreover, they are substantially inert and non-reactive with the strong carrots employed. I have obtained the best results from pieces which pass the mesh screen but eliminating the smallest sizes and dust.

In Example '7 I have referred to cage tumbling of the pelts at atmospheric temperature and of subsequently laying them on the floor for an hour. In the carroting of furs according to this invention an appreciable portion of the carrot is rubbed off of the carrier material on to the fur fibers as the carrier rubs over the fur. Consequently at the conclusion of the carroting operation of tumbling, the fur fibers maybe slightly damp, although the fur is never actually wet. It

is because of this phenomenon that my process has become known in the trade as dry carroting. However, some moisture may be present at the conclusion of the drum tumbling operation and it was to permit the loss of some of this moisture that the fur was laid on the floor to ventilate for an hour before bundling.

According to the present invention, however, even this short period of ventilation and this accompanying handlingof the pelts may be omitted by circulating through the cage, during the cage tumbling thereof, a current of heated air. When this is done, it is found that the pelts come out of the caging operation dry enough to be immediately stacked, with the fur in a flne fluffy condition and entirely free from any matting tendency, so that they can go to the cutting machine immediately if desired. I

Another discovery which I have made and which is of great importance from a practical standpoint has to do with the preparation of the pelts for the carroting operation. For example I found by experimentation that, when the pelts were introduced into the drum with the flesh side of the pelt uncovered, it required much morecarro ting solution to properly carrot them, than is the case if the flesh side of the pelt were covered or otherwise protected against contact with the carrot or with the attrition material. This I have found, is due to the fact that, when the flesh side of the pelt is exposed, a considerable portion of the carroting solution is wasted by acting upon this side of the pelt where it does no good. In fact it does harm for, in conjunction with the attrition material, particularly where an abrasive is used, the thinner portions of the skin may be so tenderized that subsequent cutting of the skin involves considerable loss of fur. I made the discovery that, if the flesh side of the skin were protected against the action of the strong carrot and the attrition material, I

not only materially economize in the amount of.

carrot required, but I also leave the skin in perfect condition for subsequent cutting. v

When the flesh side of the skin is protected from the action of the carroting solution, I have found that the amount of carroting solution needed is almost directly proportional to the weight of fur 0n the skin, thus making it possible to predict in advance the amount of solution needed and eliminating any need for depending on the judgment of the carroting workman in treating the skins of different lots.

This protection of the skin can be accomplished by covering the flesh side of the pelt in various ways. For instance I may coat the flesh side of the skin prior to carroting with an appropriate coating material, e. g., a nitrocellulose lacquer, or I may secure skins in pairs to one another flesh side to flesh side. However, I have found the most convenient practice is to fold the individual skins longitudinally so that the two lateral halves of each pelt mutually cover each other in substantially face abutting relation, flesh side to flesh side. This leaves only the fur side exposed to the carroting action during tum-.

bling and brings about remarkable economy'and the advantages to which I have referred. This folding of the pelts does not add any appreciable labor. It simply means that, after the skins have come out of the cleaning operation in moist pliable condition, they are folded transversely as they are stacked to await the carroting operation. The folded condition of the skin is natural to the skin wherein the fur grows on the outside and consequently the pelt will readily retain this condition if it is stacked in this shape at the conclusion of the appropriate cleaning operation.

An example of highly satisfactory commercial procedure in this connection is as follows:

English racks weighing 6 pounds.

resin (dust free) were introduced into the drum with cc. of nitric acid, 38'B., 125 cc. hydrogen peroxide 13 B. (100 volume), 6 grams zinc sulphate, and 3 grams of chromium potassium alum. This is strong carrot. The drum was revolved for a timeto thoroughly admix the carroting solution and to deposit it in a thin, substantially imperceptible, layer over the pieces of resin. There were then placed in the drum 50 folded The drum was then rotated to drum tumble the pelts for 15 minutes. At the conclusion of this operation, the skins were dumped from the drum into the foraminous cage which was contained within a housing through which air heated to approximately F. was moving. They were cage tumbled for 15 minutes, during which time all of the resin was freed from the pelts. The cage was then opened and the pelts removed. They were found to be to all appearances perfectly dry.

The fur was particularly fiufi'y. There was not the slighest sign of matting and these skins were ready to be cut. The waste from this operation was so meagre that there was not enough waste fur to cover the palm of the hand. When out and felted, they produced highly satisfactory felts and it is to be noted that in this entire operation the skins were not touched by the human hand from the time they started the carroting operation until the time that they were removed to be sent to the cutting machine. Such a procedure is revolutionary in the carroting art. Nothing before has even distantly approached its ei= ficiency or economy.

It will be noted that in the last example, there is included, zinc sulphate and chromium potassium alum in very small quantities. These appear to act like catalysts while the latter in particular appears to react with the keratin of the pelt, so as to have a slight tanning action thereon which makes the handling of the pelt easier during the cutting operation.

I have not attempted by any means to enumerate all of the tests which have been made with respect to the present invention. They have conclusively shown that, through the employment of this invention, furs may be carroted without un- Example 350 cc. of potassium permanganate (6.2% solution) and 50 cc. of commercial concentrated sulphuric acid were placed in a drum with 9 pounds of pieces of synthetic resin and after being thoroughly distributed, 50-folded English racks weighing 6 pounds 4 ounces were introduced. The drum was rotated for minutes thereafter and the carroted pelts were caged for 15 minutes at room temperature. Very satisfactory felts were obtained.

I have found that I can satisfactorily use practically every carroting chemical or chemicals that have been employed for brush application, but with this difference, namely, that, whereas the brush application employs'a very dilute solution or weak carrot, I can employ acarroting solution so strong that it could not possibly be used for brush carroting and I find such a strong, highly active carrot is conducive to the highest efiiciency in dry carroting according to this invention. For example, I have found it useful to employ solutions two or three times as strong as could possibly be employed for brush application. Thus, if a particular solution for brush application would run about 10 B., the corresponding solution which I have used, ran at. least twice, or better three times, that Baum, e. g., 33- B. In other cases, where the solutions which I employed ran between 30 and 40 B., corresponding brush solutions never in practice run higher than 12 or 15 B.

As to the attrition material employed, I can obtain good felts by utilizing concentrated carrots with abrasive materials, but because of the waste incident to the use of these abrasives, as translated into cost per pound of the raw fur, I do not consider this the best practice. It is much more commercially satisfactory to employ an attrition material which is non-abrasive, such as rubber, plastic or resinous materials to which I have referred and of these latter materials the best results have been obtained by using an attrition material, the specific gravity of which runs under 2 and may, to advantage, approximate the specific gravity of the pelts. The advantage of this isthat the attrition material tends to more evenly distribute itself throughout the fur during the tumbling operation and with this low specific gravity, a better distribution of relatively light material is obtained with consequent wider distribution of a larger superficial area for the carrying of the carrotin'g solution, without the superimposition upon the fur of too heavy a mass of carrier material. This latter consideration minimizes damage to the fur fibers and consequently renders the loss of fur negligible.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of carroting fur on the pelt, which comprises: admixing a highly active concentrated chemical carroting solution, in sufficient amount to carrot the fur when rubbed against the fur fibers, with a suflicient amount of pieces of substantially acid-proof and substantially non-absorbent solid attrition material,

to carry the chemical carroting solution to the exclusion of free flowing liquid, thereafter tumbling the thus treated pieces of attrition material with the pelts to rub the carroting solution against the fur fibers thereof, and thereafter separating the attrition material from \the pelts.

2. The process of carroting fur on the pelt, which comprises: admixing a highly active concentrated chemical carroting solution, in sufficient amount to carrot the fur when rubbed againstthe fur fibers, with a sufflcient amount of pieces of substantially acid-proof and substancient amount to carrot the fur when rubbed I against the fur fibers, with a suflicient amount of pieces of substantially acid-proof and substantially non-absorbent solid attrition material of a specific gravity less than 2 to carry the chemical carroting solution to the exclusion of free flowing liquid, thereafter tumbling the thus treated pieces of attrition material with the pelts to rub the carroting solution against the fur fibers thereof, and thereafter separating the attrition material from the pelts.

4. The processof carroting fur on the pelt, which comprises? admixing a highly active concentrated chemical carroting solution, in suflicient amount to carrot the fur when rubbed against the fur fibers, with a sufficient amount of pieces of non-abrasive substantially acid-proof and substantially non-absorbent solid attrition material of a specific gravity less than 2 to carry the chemical carroting solution to the exclusion of free flowing liquid, thereafter tumbling the thus treated pieces of attrition material with the pelts torub the carroting solution against the sides of the pelts prior to carroting the fur, thereafter tumbling the thus treated pieces of attrition material with the pelts, while the flesh sides thereof are covered, to rub the carroting solution against the fur fibers thereof, and thereafter separating the attrition material from the pelts.

6. The process of carroting fur on the' pelt, which comprises: admixing a highly active concentrated chemical carroting solution, in willcient amount to carrot the fur when rubbed against the fur fibers, with a sufllcient amount of pieces of substantially acid-proof and substantially non-absorbent solid attritionmaterial to carry the chemical carroting solution to the exclusion of free flowing-liquid, folding the pelts prior to carroting the fur so that the lateral halves of each pelt mutually overlie and cover the flesh sides of on another, thereafter tumbling the thus treated pieces of attrition material with the folded pelts to rub the. carroting solution against the fur fibers thereof, and thereafter separating the' attrition material from the p lts.

7. The process of carroting fur on the pelt which comprises: tumbling the pelts with a relatively large bulk of pieces of substantially acid proof attrition material substantially free'from abrasive properties and dust and carrying a substantially imperceptible coating of adsorbed highly active concentrated carroting solution, and thereafter separating the attrition material from the pelts. I

8. The process of carroting fur on the pelt, which comprises: admixing a highly active concentrated chemical carroting solution containing at least one acid selected from'the group consisting of nitric and sulphuric acid together with hydrogen peroxide, in sufllcient amount to carrot the fur when rubbed against the fur flbers, with a sumcient amount of pieces of substantially acidproof and substantially non-absorbent solid attrition material to carry the chemical carroting solution to the exclusion of free flowing liquid, thereafter tumbling the thustreated pieces of attrition material with the pelts to rub the'carroting solution against the fur flbers thereof, and thereafter separating the attrition material from the pelts.

JACK D. SARTAKOFF.