US1965455A - Method for reclaiming silk - Google Patents

Description

July 3, 1934.

l. DAVIS 1,965,455

METHOD FOR RECLAIMING SILK Filed 0012.8, 1952 Sheets-Shet 1 INVENTQR WITNESSES \a an Isaac- Haul/5 S4,? BY

W ATTORNEYJ July 3, 1934.

Filed Oct. 8, 1952 ITNESSES 2 Sheets-Sheet 2 INVENTOR Lsaac ,Z7avi5 ATTORNEYS Patented July 3, 1934 UNITED STATES PATENT OFFICE 7 Claims.

The invention relates to the recovery of .silk threads from old, worn silk hose or other silk garments and it has for an object the treatment of the silk threads to rejuvenate them so that they will have all the body strength and resiliency of new silk. The invention also relates to the treatment of old and "new silk threads to make the silk threads curly, kinky and flufiy.

An object of the invention is to provide an inexpensive method of reclaiming silk threads and yarns from old silk hose, old silk neckwear and factory knitwear waste.

Another object of the invention is to provide a method of treating old or new silk threads and yarns which will make the silk threads and yarns curly, kinky and fluffy and will increase their resiliency, the curly, kinky and fluffy character of the silk threads and yarns, as well as their resiliency, being maintained when the silk threads and yarns have been manufactured into cloth of various kinds, such as plain weaves, crepe silk, jacquard weaves, knitted weaves and diagonal or fancy weaves, pile fabrics, plushes, silk rugs, upholstery coverings, hangings and table covers, as well as knitted wearing apparel. Garments made either from the new or reclaimed treated silk will have the desired resiliency, as well as the curly, kinky and fiufiy properties, and the garments will not sag, bag, crease or cling to the body of the wearer and will resiliently give to the movements of the body of the wearer. The silk product may be made with a lustre, or may be made lustreless, as desired.

Another object of the invention is to provide a method of treating reclaimed silk in which the silk is free from weighting or foreign matter, the reclaimed silk being such that it will not be affected by perspiration.

Still another object of the invention is to provide a silk which is easy to dye because of its fiufiiness, as the fiufiy silk absorbs the dye readily. Still another object of the invention is to provide a reclaimed silk which has a long staple quality and which is not made fromspunshoddy silkof short staples.

The invention also comprehends a method. of treating silk threads or. yarns in which the yardage perpound for the sainegauge denier thickness is increased. When the treated-silk is used as a filler, it'gives the best results, as the filler gives the desired resiliency.

The invention further comprehends a method of carbonizing vegetable matter from the old silk which is to be, reclaimed and which leaves the silk undamaged.

The invention still further comprehends a method of treating an old silk fabric or garment which permits the rapid and convenient unraveling of the silk thread from the fabric or garment.

The invention also has for an object to provide a method of treating old silk thread or yarnto replace the matter which has been lost in the use of the silk fabric or garment and by washin and ironing.

In addition, the invention comprehends an 3P.- paratus for use in connection with the method.

Additional objects of the invention will appear in the following specification in. which the preferred form of the invention is described.

In the drawings similar reference characters refer to similar parts in the several views, of

which Figure 1 is a view showing the apparatus used in carbonizing vegetable matter from the old silk fabric or garment,

Figure 2 is a schematic view illustrating the apparatus for and the manner of unraveling, the thread from the fabric, together with the two tanks, in one of which there is boiling water, to remove the paraffin from the thread which, has been sprayed on the fabricor garment, the sece ond tank being providedv for reconditioning the silk thread, the view also showing. the eyelet through which the silk thread passes fromxthe second mentioned tank, and. 1 f

Figure 3 is a view illustrating the two tanks, one for heating the silk thread and the second tank for cooling the silk thread, and showing the means for transferring the silk thread from the first tank to the second tank.

In carrying out the method which is the suba ject matter of this application, old discarded silk hose or other silk garments or fabrics, as well as new discarded knittedsilk factorywaste, obtained and sorted with reference to color and all rayon and cotton portions, as well as foreign matter, are removed by scissors or a rotary knife and, if silk thread or yarn portions of the silk hose or othe'rsilk garmentslor .fabrics'ds pfa coarser grade than the leg. orbody portion, such as the top, this is removedand sorted separately with reference to colorf. The cottonito'ps of e silkhose areflaid'aside as? produc and the same may be 'rewound into cotton suitable for warp for. rag rugs or coarse cloth, fThe poriQ-L tions which are cut from thefeetof thje'silk'hose, and which consist mostlyofsilk and bleached and madev into afine shoddy."

In the manufacture of full-fashionedisil he the edges of the hose are customarilysewed as i io s

y no

' garments or fabrics.

gether with cotton. This cotton is removed by carbonizing in the following manner:-

A chamber 5 is provided having a stack 6, the chamber 5 being air-tight and the stack 6 being provided with a damper '7 which is pivoted in thestack 6 and is operable by a handle 8. In the chamber 5 there is disposed a drum 9 having openings therethrough and provided with an opening closed by a door 10, it being possible to dispose the old silk hose or other silk garments or fabrics in the drum 9 through the said opening closed by the door. The drum is mounted for rotating on bearings 11 and has a shaft 12 with a pulley 13 which is connected by a belt 14 with a motor 15, this means being provided for rotating the drum 9 in the chamber 5. Adjacent the chamber 5 there is a receptacle 16 with a hinged cover 17 which is held in closed position by a bolt and wing nut 18, the receptacle 16 being provided for receiving muriatic acid which is heated in the receptacle 16 by an electrical or other heater 19, the receptacle 16 having an outlet 20 which is connected with an inlet 21 in the chamber 5 by means of a conduit 22 in which there is a blower 23.

The silk hose or other silk garments or fabrics are moistened by steam and they are then disposed in the drum 9. The drum 9 is preferably of such a size as to receive approximately five hundred pounds of the silk hose or other silk garments or fabrics. The door 10 of the drum 9 is then closed, a door 24 in the chamber 5 is also closed and the damper 7 is closed. The drum is rotated for approximately thirty minutes and subjected during this time to the action of the gases or fumes from the muriatic acid, which have been generated in the receptacle 16, are transmitted by the blower 23 to the chamber 5. At the end of this period the rotation of the drum 9 is discontinued, the operation of the blower 23 also being discontinued, and the damper '7 in the stack 6 is opened. After a reasonable time, which may be fifteen minutes, the door 24 for the chamber 5 is opened and the silk hose or other silk garments or fabrics in the drum 9 are removed. The treatmentof the silk hose or other silk garments or fabrics with the hot muriatic acid gas fumes carbonizes the cotton and other vegetable matter which may have been used in the manufacture of the silk hose or other silk garments or fabrics without in any way damaging the silk hose or other silk In this operation it is important that the operator use a gas mask.

When the silk hose or other silk garments or fabrics have been removed from the drum 9 they are placed in a well-heated drying room in order to dry up the carbonized vegetable matter, after which this carbonized vegetable matter may be shaken as dust from the silk hose or other silk garments or fabrics. With this operation all the cotton and vegetable matter is removed.

With the cotton seam removed from the fullfashioned silk hose and the cotton and other vegetable matter removed from the silk hose or other silk garments or fabrics, the silk is decolorized and bleached. In this operation from one hundred and fifty to two hundred gallons of fresh water, free from salts or alkali, are used fo each one hundred pounds of unseamed silk hose or other silk garments or fabrics, and approximately four or five pounds of sodium hydrosulphite in powdered form are used to each one hundred pounds of the unseamed silk hose or other silk garments or fabrics, and this sodium hydrosulphite in powdered form is mixed with water in a separate vessel. When the same isdissolved, the solution is poured into a tank or vat with the one hundred and fifty to two hundred gallons of fresh water. One pound of liquid sulphuric acid is diluted with water in a separate vessel, which is used for 'each one hundred poundsof the unseamed silk hose or other silk garments or fabrics. This diluted sulphuric acid is then poured into the tank or vat containing the water and sodium hydrosulphite solution and the contents of the tank or vat are thoroughly mixed. This solution is then brought to a boiling point by steam, or by other means. Wire baskets containing the unseamed silk hose or other silk garments or fabrics are lowered into the tank or vat and the unseamed silk hose or other silk garments or fabrics are thoroughly stirred into the solution so that the solution will be absorbed by every part of the unseamed silk hose or other silk garments or fabrics. When the unseamed silk hose or other silk garments or fabrics indicate that the colors have been entirely stripped therefrom, the wire baskets are removed from the tank or vat and the solution is permitted to drain from the unseamed silk hose or other silk garments or fabrics. The silk hose or other sik garments or fabrics are then treated in a bath to neutralize the bleaching compound in the customary manner.

After the stripping of the colors has been completed inthe manner set forth, the unseamed silk hose or other silk garments or fabrics are washed to remove oil, grease, ointments or paints that the carbonizing and stripping operations may have failed to remove. In this step of the method five pounds of silkworm-oil soap or greenolive-oil soap are used in hot water and this washing operation may consume approximately thirty minutes. The unseamed silk hose or other silk garments or fabrics are thoroughly agitated and stirred during the washing. While it is advisable to use silkworm-oil soap, or greenolive-oil soap, in some cases palm-olive-oil soap heads may 'be employed. After this washing.

process has been carried on for approximately thirty minutes, the unseamed silk hose or other silk garments or fabrics are rinsed in fresh water to free the soap therefrom, whenthe water is drained from the unseamed silk hose or other silk garments or fabrics and they are subsequently dried, preferably in the sun. After the unseamed silk hose or other silk garments or fabrics have been thoroughly dried, they are sorted as to colors and shades and those which have not been entirely stripped of their colors, on account of having been dyed with basic colors, and any wild silk, are put aside and are dyed in logwood and iron black dye and unwound into black silk yarn.

After the unseamed silk hose or other silk garments or fabrics have been sorted as has been described, the ends of each of the silk threads or yarns are drawn out and are graded. This may be done by strong magnifying lenses, by weighing a portion of each thread or yarn, or by other means. With the unseamed silk hose or other silk garments or fabrics not only sorted as to color, but also graded as to the denier thickness oftlie silk thread or yarn, the unseamed silk hose or other silk garments or fabrics are treated prior to the unraveling or unwinding of the silk thread or-yarn therefrom. This is done by the use of white paraflin dissolved in carbon tetrachloride which makes a thin fluid, and this thin fluid is sprayed on the unseamed silk hose or other silk garments or fabrics, which saves labor in unwinding the silk thread or yarn. With the spraying of the parafiin, which is a waxy material, on the unseamed silk hose or other silk garments or fabrics, the silk thread or yarn is coated therewith and this retains the loose filaments of the silk thread-or yarn in place and prevents the silk thread or yarn in the unseamed silk hose or other silk garments or fabrics from catching, webbing, or becoming tangled during the unwinding operation. This is important, for the silk thread or yarn in the unseamed silk hose or other silk garments or fabrics has become felted from the washing, ironing and use of the unseamed silk hose or other silk garments or fabrics.

After the unseamed silk hose or other silk garments or fabrics have been coated with the parafiin or waxy material in the manner set forth, the unseamed silk hose or other silk garments or fabrics 25 are hung, as illustrated in Figure 2, by hooks 26 on a support 27 and the silk thread or yarn 28 is drawn therefrom. The silk thread or yarn 28 is preferably drawn from the bottom of the unseamed silk hose or other silk garments or fabrics and it is pulled through a porcelain tube 29 which is disposed in a tank 30 containing hot water, theweight of the tube 29 serving to draw, the silk thread or yarn under the hot water contained in the tank 30 and the hot water serving to release the paraflin. The silk thread or yarn 28 then passes over a roller 31 into a second tank 32 and passes through another porcelain tube 33 in the said tank 32. This tank 32 contains a material which will rejuvenate the silk thread oryarn and replace the albumen, silicon and other matters which the silk thread or yarn has lost in wearing, washing and other ways.

I Secretions from dead silkworms, that is, the mummies, are obtained, after the raw silk has been unwound therefrom, by pressing the dead silkworms or mummies. This secretion,'fiuid or oil obtained from the mummy of the silk worm contains silicon, albumen and a certain amount of celesin.

The material contained in the tank 32 consists of seventy-five percent of the secretions from the dead silkworms, one percent of diluted carbolic acid, five percent of citric acid crystals dissolved in formaldehyde mixed with water, and nineteen percent additional formaldehyde mixed with water. The one percent of the carbolic acid is poured on the-seventy-five percent of the secretions from the dead silkworms to purify the same, after which the five percent of citric acid crystals dissolved in formaldehyde and, subsequently the nineteen percent additional formaldehyde mixed with water, is added to the mixture. The solution is mixed thoroughly and allowed to stand for approximately three days in a cool place, after which it is ready for use and is disposed in the tank 32 for the purpose set forth.

The silk thread or yarn 28, after passing through the porcelain tube 33 in the tank 32, passes through a smooth eyelet 34 with a hole as fine as the silk thread or yarn and, as the silk thread or yarn passes through the eyelet 34, the eyelet 34 serves to press the loose filaments against .the long staple yarn and the material from the tank 32, with which the silk thread or yarn has become coated, is pressed into the silk thread or yarn in very much the same manner that a shoemaker waxes thread. The silk thread or yarn 28 which has now been treated to replace the matters lost in the wearing and washing of the silk hose, or other'silk garments or fabrics, and which is rejuvenated, is wound on winding frames ready to be made into standard size hanks and is hung up for drying purposes.

This rejuvenated silk thread or yarn may, of course, be used in various ways and for various purposes. In the ordinary manufacture, a number of the silk threads or yarns are thrown together in the customary manner. For instance, where three plys or pieces of the silk threads or yarns are thrown together, two silk threads or yarns are selected and each is thrown or twisted by any silk throwing machine five hundred and fifty times or turns, or more, to the left, when the other or third silk thread or yarn is thrown one hundred and seventy times or turns to the right, the three silk threads or yarns being then bunched together and thrown or twisted together one hundred and fifty times or turns to the right. ever, it will be understood that any number of these silk threads or yarns may be thrown together in any desired manner.

After the silk threads or yarns have been thrown together in the manner stated, and before the thrown silk threads or yarns have been made into hanks, the silk thread or yarn is passed through an albumen form of dressing. Albumen, either from the white of egg or other organic albumen matter, is used. The albumen is made into a very fine foam by passing the same through a beating machine such as an egg beater used by bakers. The foaming albumen is then placed in a tank or vessel and so arranged that the silk thread or yarn passes through this foaming albumen. The silk thread or yarn takes on the albumen dressing, which assists in rebuilding the silk thread or yarn and adding to its strength. The silk thread or yarn is then made into standard size hanks:

When the hanks of silk thread or yarn have been dried, after being coated with the albumen dressing, these hanks of silk thread or yarn are disposed in an open-work receptacle 35 which is supported by a cable 36, the cable passing over a pulley 37 on a carriage 38 which travels on a rail 39. This receptacle 35 is lowered into a tank 40 containing water 41 which is heated to the boiling point by passing steam through pipes 42 and the hanks of silk thread or yarn, which are contained in the receptacle 35, are lowered into the tank 40 containing the boiling water, three percent of olive-oil soap cut fine having been added to the water 41 in the tank 40. After the hanks of silk thread or yarn contained in the receptacle 35 have been disposed in the tank 40 for a period of thirty minutes, the receptacle 35 is drawn upwardly from the tank by means of the cable 36 and the carriage 38 is moved above a tank 43 which is cooled by passing a refrigerant through these pipes 44. The receptacle 35 containing the hanks of silk thread or yarn is lowered into the tank 43, the action of the cold water on the silk thread or yarn, which has been previously subjected to the boiling water in the tank 40, serving to shrink or shrivel the silk thread or yarn and this gives the silk thread or yarn a curly, kinky and fiuify property. The silk thread or yarn is permitted to remain in the tank 43 for a period of one hour.

The curly, kinky and fiufiy silk thread or yarn is then treated to preserve the shrinking and resiliency which has been acquired by the silk thread or yarn in its previous treatment, the silk thread or yarn being disposed in a tank containing approximately two and one-half to three pounds of granulated casein to each one hundred HOW- pounds of silk thread or yarn, the granulated casein having been dissolved with the aid of liquid ammonia in a .separate vessel, after which luke warm water is added. The dissolved casein is then poured through a fine wire strainer into the tank, after which from one-half to one percent of pure lactic acid is mixed with the other ingredients in the tank and the hanks of silk thread or yarn are disposed in this casein bath, in which they are permitted to remain for approximately fifteen minutes, after which the hanks of silk thread or yarn are removed from the tank and the casein solution is permitted to drain therefrom. The hanks of silk thread or yarn are then permitted to dry, preferably in the sun.

After the silk thread or yarn has been treated with the casein solution and is partially dry, it is given another cold bath to which is added from one percent to one and a half percent of formaldehyde in water, this bath being used for preserving purposes. The silk thread or yarn is permitted to remain in this bath for twenty minutes, when the silk thread or yarn is removed from the bath. The fluid is removed from the silk thread or yarn by a wringer or other means.

The last step in the method is "the immersion of the silk thread or yarn in a bath of cold water to which has been added approximately from eight to ten percent of formic acid. The silk thread or yarn is hung on poles and it is turned on these poles so that all parts of the silk thread or yarn will be thoroughly immersed in the bath. When the silk thread or yarn is removed from this bath, it is permitted to dry and, preferably, permitted to dry in the sun.

By following the steps which have been explained above, a resilient thread or yarn is obtained which is curly, kinky and fluffy.

In place of the means mentioned above for.

carbonizing the vegetable matter contained with the silk, the following means may be employed. Liquid muriatic acid is used and aluminum scrap is mixed with the liquid muriatic acid in a dark colored glass vessel and is permitted to remain in the open air in a cool place. The aluminum scrap dissolves and a sediment settles at the bottom of the vessel. When the sediment becomes thick, it is used to carbonize the vegetable matter. Approximately six to eight pounds of this sediment are dissolved in water at room temperature, one hundred and fifty gallons of water being used to each one hundred pounds of silk and vegetable material, and the said sediment is thoroughly mixed with the water. One pound of sulphuric acid is then mixed with ten times its volume in water in a separate vessel and this is mixed with the water in which the sediment has been dissolved. The silk and vegetable material is then treated in this bath by lowering a basket containing the silk and vegetable matter into the bath and is permitted to remain in the bath for from two to five hours until the vegetable matter has been eaten away by the bath without damage to the silk. The silk may be tested from time to time by taking a piece of the silk from the bath and heating the same. When the vegetable matter turns brown or black and becomes brittle, all the silk which is being treated should be removed from the bath and be heated and the silk should be shaken to remove the carbonized vegetable matter. The silk is then neutralized in another bath in which five pounds of soda ash are dissolved in one hundred gallons of wate'n or two pounds of liquid ammamas monia are dissolved in one hundred gallons of water. One hundred pounds. of the silk are then stirred in one of the said neutralizing baths for approximately fifteen minutes. The silk is then removed and drained.

The invention which is the subject matter of this application includes not only the process which has been described, but also the apparatus which has been described and whichis shown in the drawings.

What is claimed is:

l. A method of reclaiming silk thread from a silk fabric including the carbonization of vegetable matter mixed with the fabric, the treatment of the fabric with a waxy niaterial to prevent accidental unraveling, the unraveling of the silk thread from the fabric, and the removal of the waxy material from the unraveled silk thread.

2. The method of reclaiming silk yarn from old fabric having a certain vegetable contained therein, consisting in first wetting the fabric, then subjecting the wet fabric to a vapor of muriatic acid until the vegetable matter has been v carbonized, heating the fabric until the vegetable matter has become a powder, shaking out the powdered vegetable matter, decoloring and bleaching the silk yarn, washing the silk yarn in soapy water, rinsing the yarn in clear water, spraying the yarn with a waxy substance capable of being melted in hot water, unraveling the fabric and finally subjecting the unraveled fabric to water sufdciently hot to remove the waxy substance.

3. The method of recovering silk yarn from fabric containing silk consisting in wetting the fabric, subjecting the fabric to a carbonizing agent to carbonize the vegetable matter therein, heating the fabric until the vegetable matter has become a powder, removing said carbonized powdered vegetable matter, spraying the remaining part of the fabric with parafllne until a suflicient quantity has been added to provide an easily breakable connection for the respective threads, unraveling the fabric while the fabric is carrying the parafllne, and passing the unraveled yarn in a continuous strand through water sufficiently hot to melt the paraiiine therein. v

4. The method of reclaiming silk from fabric containing silk, consisting {in subjecting the fabric to a carbonizing agent sufficient to cause all the vegetable matter to be carbonized, removing said vegetable matter, subjecting the silk to a decoloring and bleaching agent, subjecting the fabric after it leaves the bleaching agent to a soapy solution until the decoloring and bleaching agents have been removed, rinsing the fabric in clear water, spraying the fabric with parafline powder, removing the powdered vegetable matter,

spraying the fabric with a waxy substance capable of being melted in hot water, unraveling the fabric while the waxy substance is thereon, and finally subjecting the unraveled fabric to water sufllciently hot to remove the waxy substance.

' carbonizing agent until all of the vegetable yarn.

' 6. The method of reclaiming silk yarn from fabric formed of silk yarn and vegetable yarn, consisting in subjecting the entire fabric to a has been carbonized, removing thecarbonized vegetable yarn; applying'a waxy substance to the remaining yarn, unraveling the remaining yarn while in a waxed condition, and finally subjecting the unraveled waxed yarn to heat until the waxy substance thereon has been removed.

7. The method of reclaiming silk yarn from paraflined yarn to heat until the parafline has,

been removed.

ISAAC DAVIS.

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