US1489546A - Process for the washing and degumming of fibers - Google Patents

Description

April 8 1924. 1,489,546

R. L. PRITCHARD PROCESS FOR THE-WASHING AND DEGUMMING OF FIBERS Inlren'lt'av Patented Apr. 8, 1924.

f UNiTEo STATES REUBEN LEVI PBITCHARD, F LONDON, ENGLAND.

PROCESS FOR THE WASHNG AND DEGUMINING OIF."v FIBERS.

Application led October 20, 1920. Serial No. 418,2-61.

To all whom t may concern.' Be it known that I, REUBEN LEVI PRITCH- ARD, a subject of the King-'of Great Britain, residing in London, N. W., England, have invented certain new and useful Improvements in Processes for the Washing and Degumming of Fibers, f which the following` is a` specification.

This invention relates to the removal them after their growth. Whether it be a` degumming or washing of fibers the process is the same; the materials employed for the cleansing however, varying somewhat.

The invention herein described consists of an improved method and apparatus for applying cleansing solutions to large masses of liber for commercial purposes. Whilst the use of fluids for the cleansing ofsmall quantities of fiber has been more or less successful, it has hitherto been unsuccessful when employed upon large qauntities of fiber for commercial purposes. The failure is due to the fluid used being unable to either gain access to the fibers in the interior of a large mass; or from thel substances removed from the fibers in the interior of the mass being unable to escapelfrom within the mass outwards ando remaining with-l in the mass the-loosened substances re-adhere to the bers when they are dried. i

According to my invention thecleansing fiuid is given free access to 'the innermost' fiber of any quantity, however large, and this is effected by the establishment of currents of the particular fluid used, which flow between the individual fibers whilst the fibers are buoyant and fioat inthe fluid. 5@

without force suliicient to displace the fibers and float them towards and against each other, whereby each individual fiber .is

The currents are established throughout the whole area of the mass of fibers, and

bathed upon every side with the, cleansing fluid. The free currents between the\ individual fibers loosen the objectionable substance upon them and carry-it Yofi" in the currents to be dispersed throughout the4 whole fluid. Y These currents 'are preferably made to circulate from below upwards and 'Y are maintained until all of the objectionable substance is loosened from' the fibers.

The fluid employed must possess a solvent action upon the substance without having any injurious action upon the structure fiax and hemp and the washing of wool, a non-corrosive alkaline solution may be employed such as a solution of soap, which will suliice to effect their cleansing from the gum and resin or oleaginous substance if the fibers in the exterior of the mass do not prevent the solution of soap reaching the fibers in the interior. rlhe substance loosened' from the individual fibers by the currents of fluid being mingled throughout the fluid, some of it, held by the solvent solution, remainsl between'thevfibers after the mass 4of fibers is taken out of the fluid or 4the fluid is drained from the fibers. The,

residuum of loosened supstance `remaining between the fibers is due to the fact that wet fibers on the instant -they no longer float in a fluid cling to each other, which prevents the further escape/ of such substance still remaining' between them which is held in solution. This residuum is removed in my invention b transferring the entire mass of fibers, a terl the substance is loosened from the individual fibers, int0 a clean neutral iuid Alike water in which the fibers again float; andwhilst floating in the water the latterzis made to flow between the fibers, which carries OH.. the residuum of substance lying loose between the said fibers. ers is continued untilpure water completely replaces the former solvent solution be- 'tween the fibers. The mass of fi'bers is then taken ou-t'of the w-ater and dried, with no objectionable substance remaining between them, and they are then dried clean and do not adhere to, each other.

The whole process of cleansing is edectf ed by first placing theyfibers in rece tacles having solid lateral walls and per or-ated floors, and thedepth of each receptacle prefof the fibers; andl for the degumming of The flow of Water between the fibthe outer 'expanse erably being 3 -to 6 inchesA (7 to 15 cm). A number ofthe receptacles are fastened together with their solid lateral walls forming continuous solid sides extending to any suitable depth, with the perforated floor of each acting as a cover for the receptacle immediately below, the uppermost receptacle alone having a perforated cover.

For the loosenin stance from the individual fibers, the receptacles laden with them are immersed, ina suitable solvent fluid and placed upon an open support which may be 4 to 6 inches (10 to 15 cm.) from the bottom of the solvent fluid, and the same distance laterally from of the solvent fluid, and on which support the receptacles remain stationary. The solid lateral walls of the receptacles are continued upwards through the solvent fluid in which they are immersed and from 6 to 12 inches above, constituting an upper chamber containing the solvent fluid above'the said receptacles. 'The solvent i f by the pumping, in the di lfluid inside and outside the receptacles is 25E only permitted to communicate below the opn support. The solvent fluid which is a ve the immersed receptacles is then pumped into the outer expansetof the ysaine solvent fluid surrounding' the upper extension of the solid lateral walls'.- The pum ing of the fluid from the interior into tEe partitioned exterior ofV the same body of fluid produces a greater ressure in the fluid in the outer space, whi st diminishing the pressure in the fluid within the interior where the receptacles were immersed; and as a result of the unequal pressure, produced erent parts of the communicatingliquid,` currents of that liquid are set up circulating from the greater pressure onL the outside of the solvent fluid' towards its centret within the receptacles. The solid lateral walls of the receptacles and their extension upwards do not allow the circulation of the currents 'through ethein; and the currents towards the interior can-only find a way below the open support, and then upwards through the perforated floors and between the fibers into the upper chamber, which/currents continue until the pressure in the solventfluid within and without. the receptacles becomes equal. The pumping of Ithe fluid, however, continuingias it rises into the upper chamber until all Vthe objectionable substance is loosened 'from the individual fibers, an equilibrium of pressure, within and without the recepcannot be re-established so long as the pumping continues. The duration of the pumping and circulation of currents lvaries with the particular substance to be loosened from the fibers; and for the degumming of flax with a saponaceous fluid at 38 C. will effect it in from one half to two hours.

of objectionable subthe upper chamber,

' receptacles containing incase@ After the fibers have been sufficiently bathed by the current of a solvent fluid they are individually free from' the substance; but throughout the mass of fibers some of the solvent fluid containing loosened substance *remains in Athe sp-ace between the fibers. In this invention the latter is expelled from the mass of fibers by transfer-` v the fastened receptacles into pure water y and moving the said receptacles in the water,

which is warmed to say 300 C., in such a manner that the water displaced by the moving receptacles can esca e nowhere except through the perforated floors of the receptacles and between the individual fibers into which should be sufiiciently high to prevent the fluid expelled into it overflowing and mingling with the water in which the said receptacles are moved. The `the fibers may be moved in any direction, but it is mo-refeasible when made downwards. In whatever direction the receptacles are moved it must be in one direction onlyas a movement and fro, or downwards and upwards, will constantly returnwitliin the mass of fibers the liquid expelledfrom it bythe movement made in the opposite direction. The movement of the receptacles is effected slowly andsteadily through the water, producing a flow of the water in to that in which the receptacles are moved, which passes through the perforated floors of the receptacles and between the fibers. The force of the opposite flow of the water is reduced to a minimum by the slow movement of the' receptacles through the water but' some of the fibers may be carried towards and against each other. The open condition of the fibers, should they crowd together, is restored by the movement of the receptacles being frequent-ly and regularly suspended to permit the fibers to refioat apart. movement of the receptacles must at least bev equal to theV total height of the fastened receptacles. f i

The opposite flow of water, when thereceptacles containing the fibers are mov in the manner described, passes through the mass between the individual fibers at the same time carrying vent fluid existing between the individual fibers into the upper chamber. All the fluid escaping into the upper chamber is pumpe from it outside and not permitted to mingle with the water in which the receptacles are moved.

The upper chamber should be sufficiently high to prevent the water loverflowing from or into it. The intermittent movement of the receptacles in the water is continued until the liquid pumped from the upper chamber contains neither solvent fluid nor substance loosened from the fibers. Before The'extent of the downward.

the receptacles are moved in an opposite direction the receiving chamber, which is the upper chamber when the movement is made downwards, must be pumped clear of the liquid which had entered into it, to prevent its return within the mass of fibers when the receptacles areraised or moved in the opposite direction. The movement downwards of the receptacles is facilitated by a second chamber below, the sides of which are continuous with the lateral wall of the receptacles.

The whole treatment is completed when the liquid passing from the mass of fibers into the upper chamber contains nothing in addition to pure water. The receptacles are then 'raised and the fibers areI removed for drying.

Drawings illustrating a form of apparatus designed to accomplish this process of degumming and washing of fibers are appended in which:-

F igpl is a longitudinal section showing more or less diagrammatically apparatus for effecting the treatment of the fibers.

Fig. 2 is a perspective View of one of the .cages for retaining the receptacles in which the material is placed.

Figure 3 is a perspective view of a tray for holding the material being treated.

Referring to the accompanying drawings, a Fig. l indicates a vat havingwithin it a false vat b, the vat a being open at the upper end, the false vat b being open at both ends.

The false vat may conveniently be supported 1 in vat a by means of an open support indicated by a1, and provided with legs a2 resting upon the bottom of vat a. The dimensions of the false vat b are such as to leave a space on all sides between it and the vat a, which space is indicated by c. c1 indicates receptacles for the material, which receptacles are of box like form, the bottom of each being perforated or formed of wire netting or other open material to permit the ready passage of the solvent fluid. The receptacles are placed one upon the other, in a suitable cage or holder 02, as shown, the cage resting upon or near support a1 in vat a. The walls of the false vat b are made of sufficient height to form an upper chamber c3 designed to prevent the liquid flowing from the false vat b into the space c or from said space into the false vat b. d indicates a second vat provided with an inner sliding false vat d1 adapted to receive the cage c2 which fits snugly within d1. vThe false vat d1 is also provided with an upper chamber indicated by d2, and in addition with a lower chamber da. The depth of the liquid below the rece tacles should be at least equal to the tota height of the receptacles within cage c2. -e indicates a pump so arranged as tol be common to both vats a and d to pump the solvent liquid above the immersed receptacles into the space c between the vat a and false vat b. When dealing with vat d the pump, or the inlet and outlet pipes and discharged to a point outside the vat d.

f indicates a crane by means of which, and

chains, or other means attached to the cage,

the cage may be raised from one vat and placed in the other. The false vat d1 in which the cage holding the receptacles is fastened, is moved in the water with an intermittent downward motion by its own weight or suitable nmeans.

.1. A process for washing and degumming fibers which comprises immersing a quantity of fibers in a liquid, maintaining the fibers floating in al segregated condition in said liquid, circulating vertical currents of the liquid between the fibers, and preventing the li uid from flowing laterally.

2. process for washing and degumming fibers which comprises imme'rsing a quantity of fibers in a liquid, causing the fibers to float in a segregated condition in the liquid and causing vertical currents to circulate throughout the entire area of the liquid and between the fibers, said currents being prevented from flowing laterally, and being of sufficiently low velocity to prevent carrying the fibers against each other.

3. A process for washing and degumming fibers which comprises immersing a quantity of fibers in a liquid, maintaining the fibers floating in a segregated condition in said liquid, circulating continuously vertical currents of the liquid between the fibers, and preventing the liquid from flowing laterally.

4f. A. process for washing and degumming fibers comprising floating the fibers in a solvent liquid, holding the fibers practically stationary and in a segregated condition, circulating currents of the liquid upwardly throughout the entire area of the liquid and between the fibers, reventing the currents from flowing latera y, removing the fibers from the solvent liquid and replacing the residuum of solvent liquid remaming in the spaces between the fibers by immersing and floating the fibers in a neutral liquid and moving the fibers in one direction in said neutral liquid while floating.

5. A process for washing and degumming fibers which comprises floating the fibers in a solvent liquid, holding the fibers practically stationary and in a segregated condition, circulating currents of the liquid upward between the fibers, preventing the currents from flowing laterally, removing the fibers from the solvent liquid and washing the fibers by immersing and floating the fibers in a neutral liquid, moving the fibers in one direction in the neutral liquid, and

interrupting said movementperiodically to permit the individual fibers to float free of L each other.

6. Alprocess for washing and degumming fibers which comprises circulating uni-directional Currents between individual fibers whilst they float in a segregated condition in the liquid, the currents being of sufficiently low velocity to maintainsuch se egated condition; these currents being first produced by immersing the fibers in a solvent liquid in which they are maintained stationary at some distance from the bottom of the solvent liquid which is in free communication with the entire under surface of the fibers treated. and laterally the fibers are some distance from the outer confines of the solvent liquid in which they are partitioned by a solid vertical partition, the liquid outside the partitions being continuous with the liquid below the fibers, and said partition being extended upwards for some distance above the upper surface of the solvent liquid; `transferringr the solvent liquid above the immersed fibers into the liquid outside the partition; and then removing the fibers from the solvent liquid and reiinmersing them in a neutral liquid like pure water, and the water being made to fiow between the individual fibers by moving the fibers in the water.

' 7. A process for washing and degumming fibers which comprises causing the fibers to float in a segregated condition in a solvent liquid, circulating in the solvent liquid and between the fibers uni-directional currents of sufficiently low velocity to maintain the fibers in such segregated condition, then circulating a neutral liquid between the individual fibers by floating the fibers therein moving them in the neutral liquid in one direction, and periodically interrupting such movements, the movements of the fibers inl the neutral liquid being made with the mass of fibers closely confined by the wallscon- Laagste taining said neutral liquid; and finally rey moving the liquid which has, flowed between the fibers.

8. The process for washing and degumming fibers by immersing them in liquid and causing'theliquid to circulate in unidirectional currents between the individual fibers whilst the fibers float in a segregated condition in the liquid; these currents being first produced in a solvent liquid and afterwards'in a neutral liquid, the first currents of solvent liquid being produced by immersing the fibers in it and maintaining them stationary above the bottom vof `the liquid which is in free communication with the fibers, and laterally the fibers are parti tioned fromthe lateral confines of 'the solvent liquid, the liquid outside the partition being continuous with the liquid below the fibers, the partition separating the fibers laterally from the main body of solvent liquid being continued upwards above the upper surface of the solvent liquid; transferring the solvent liquid above the immersed fibers intoA the space between the upper extension of the solid vertical partition and the vessel containing the solvent liquid; and the `currents of the neutral liquid being produced by transferring the fibers from the solvent liquid into a neutral liquid in whichv REUBEN Lnvr Perrier-Lann.

lVitnesses: Y

EDMUND HARBERD, EDMUND H.'

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