US1901658A - Process of treating spinnerets - Google Patents

Description

Patented Mar. 14, 1933 I ED STATES PATENT JEAN mmmrrn; or PEAGE DE nOUssILLoN, FRANCE, AssIGNoR To nuv ronr RAYON COMPANY, OF NEW YORK, n. Y., A CORPORATION, or DELA A 1 rnociiss or rnm'rmesrmimnnrs" No Drawing.

This invention relates to'the art of produc-- ing artificial thread by the dry spinning process. More particularly, it relates to a method of treating thespinnerets so that the spinning solution is such that the filaments or thread may be conveniently'formed upon extrusion and during arelati-vely short travel in an evaporative medium,'such as is present in the spinning cell or otherdevice, whereby the volatile ingredientsare wholly or partly dissipated. v

The easy volatility of the liquid components of the spinning solution is, however, a liability to the extent that the spinning solution frequently deposits the solute in the orifices of the spinnerets or on'the surfaces thereof. As a result, non-uniform thread, occasioned by the interrupted and non-continuous production of filaments, is produced. For example, in starting a spinning position in operation, the spinning solution issuing from the orifices of the spinneret, even though it be clean and clear, has a tendency to spread over the face of the spinning die instead of issuing therefrom as a column 40f liquid or a partially formed thread or filament. Frequently, during operation of a spinning position one or more of the orifices in the spinneret become wholly or partly closed and the same phenomenon of the spinning solution crawling along the surface of the spinneret and/or building-up around the orifices occurs. Usually this phenomenon proceeds to a point where other orifices of the same spinneret are involved. In any case, there results a situation which must be corrected in order to have successful spinning.

Applicatiori filed March 19, 1931. Serial No. 523,937.

Prior to this invention, an 'atternptf'was-j made to overcome the above-mentioned difficulty-by 'either' dipping the spinneret, and I particularly the face thereof, in a solvent for the material constituting the mass of thread or by wiping the face of the spinneret with a cloth which'has beenwetted with th'e' SOIj vent. This practice is not' very satisfactory','

Not only does it require ;considerable time and labor in'getting the position into proper operation, but there results a large amount of waste in the-form of- -inferior-and unmarketable materials. i

The problem has been attempted to: be 7 solved by applying-a vacuum to the spinneret until the orifices are clean and clear. In actual practice, a-solvent was applied to the face of the spinneret prior to applying the vacuum. This procedure requiredadditional paratus. A I:

I have found that by applying a ,nonsolvent ofthe solute of the solution which constitutesthe mass of the thread, and either subsequently orsimultaneously wiping the face of the spinneret, Ican easily,'qui cklyand effectively bring the spinneret in condi tion for proper and successful spinning. l

It'is therefore an object of this invention to provide a simple method, without the use of any auxiliary expensive apparatus, of treating spinnerets whereby they"may be. quickly" and efiectively brought into proper condition for successful-spinning; f

'A specific object of thisinventioii is to provide a method of bringing "the s'pinneret into the;.necessary condition for successful i spinning which comprises applying a nonsolvent of the material constitutingthe mass ofjthe thread and .either simultaneouslyor subsequently wiping the face of the spinneret.

Other objects will appear fromithe following description and appended claims.

As. is apparent: from the: foregoing ob;

comprises treating the spinneret, and .par-; ticularly the face thereof, preferably. while in spinning position'with a non-solvent for the material constituting the mass of the jects, the method constituting thisinvention i thread and either simultaneously or subsequently wiping the face of the spinneret.

Instead of diluting the spinning solution or re-dissolving a deposit of the solute to form a dilute solution which may again produce the bad condition, the non-solvent precipitates the solute in place and permits the precipitate to be subsequently removed.

In actual practice, for example, when a spinning position is begun in operation, the

face of the spinneret or a portion thereof may be wiped one or more times with a cloth Wetted with a non-solvent for the material constituting the mass of the thread. The non-solvent precipitates the solute and the mechanical action occasioned by wiping the cloth across the face of the spinneretremoves the precipitated mass. 'As a modification of the aboveprocedure, the face of the spinneret may be dipped or immersed in a small receptacle containing a non-solvent and'subsequently removing the precipitated mateas it issues from the spinneret.

rial from the spinneret in any suitable manner, such as by Wiping with acloth.

,I do not know the exact reason why the above-described procedures produce satisfac 'tory results.- It may be that in addition to removing the precipitated materials the face of the spinneret is coated with a thin film of the non-solvent which produces an interfacial tension between the spinning solution and the so -coated spinneret that the spinning solution tends to remain in the form of a column of liquid or partly formed thread .111 the production of artificial thread from cellulose acetate by the dry spinning process, I find that I can quickly bring the spinnerets in proper spinning conditions by employing, as above described, any one-of anumber the ethers, such as benzyl cellulose, butyl,

cellulose and the like. When these cellulose derivatives are spun, it is only necessary to select a material which is a non-solvent therefor as explained hereinabove.

Since it is obvious that various changes may be made in the specific details abovedescribed without departing from the nature or spirit of the invention, the invention is not restricted thereto except as defined in the appended claims. v

I claim:

1. A method of bringing a spinnereteme ployed in the dry spinning process into prop= er spinning condition, either substantially immediately prior to the beginning of spinning or at any necessary time during spinning, which comprises applying to the face of the spinneret in spinning position a nonsolvent for the solute in the. spinning solu tion and wiping the face of said spinneret.-

2. A method of bringing a spinneret emproper spinning condltion, either substantially immediately prior to the beginning of spinning or at any necessary time during spinning, which comprises simultaneously applying to the face of the spinneret in spin ning position a non-solvent for the solute in the spinning solution and wiping the face of, said spinneret. e 3. A method of bringing ployed in the dry spinning process into proper spinning condition,;either substantial- -ployed in the dryspinning process into a spinneret em-l ly immediately. prior to the beginning of sp nning or at any necessary time during spmnmg, which comprises applying to the face of the spinneret in splnnmg position a non-solvent for the solute in the spinning solution and then wiping the face of said spinneret. v v I 4. A method'of bringing a spinneret employed in the dry spinning process into prop-v er spinning condition, either substantially immediately prior to the beginning of spinning or, at any necessary time during spinning, which comprises wiping the face of the spinneret in spinning position with a cloth Wetted with a non sol-vent for the .solute'in the spinning solution.

In testimony whereof, I 'have aflixed my signature to this specification. V V 7 JEANLADRETTE.