US2161354A - Method for lubrication of artificial silk - Google Patents

Description

June 6, 1939. H H. lMRAY, JR., ET AL 2,161,354

METHOD FOR LUBRICATION OF ARTIFICIAL SILK Filed June 26, 1936 mvzsmoas Howard H. ImrayJr Edwin A. Robinson patented June 6, 1939 UNITED STATES PATENT OFFICE METHOD FOR LUBRICATION F ARTIFICIAL SILK New Jersey Y Application June 26, 1936, Serial No. 87,442

1 Claim.

This invention relates to the manufacture of artificial filaments such as those composed of cellulose organic derivatives, and more particularly to a method of and apparatus for the lubrication and other treatment of such filaments.

In the manufacture of yarns from cellulose organic derivatives and similar materials, it is customary to extrude a solution of the cellulose derivative through minute openings in a spinneroette, thereby forming filaments which are set by evaporation of solvent therefrom as they pass downwardly through a spinning cabinet countercurrently to a current of heated air. Heretofore,

it has been the practice to conduct the filaments 15 about a thread guide or equivalent device located, either inside thelower part of the cabinet, or directly underneath the same, and thence to a godet or draw roll from which they pass to an appropriate twisting and winding device. It has also been customary to apply various lubricating or other dressings to the filaments after they leave the godet roll, but before they reach the cap or ring spinner or whatever deviceis empioyed for imparting the twist. With the use of 2 thread guides there has always been considerable breakage of the filaments, since, as will be readily understood, any flexing of the filaments as they pass around the guide tends to place'a rather severe strain upon them. This tendency is accentuated where a positive pull is exerted on the 'material, as by the godet rollor other mechanism. This invention. has as its principal objectfto provide an improved method forthe production.

of artificial filaments in which the filaments are subjected to a minimum of mechanical wear and tearduring the course of their progress from the spinnerette to the godet roll. A further object is to provide an improved type of spinning apparatus in which the method'may be successfully carried out. A still further object is to provide an improved method and apparatus for the lubrication of artificial filamentsat an early stage in their formation. Another object is' to provide a method" and means for reducing almost com- 45 pletely' the frictional influences ordinarily met' with by the filaments in the course of their passage from the spinnerette to the drawing and/or winding and twisting devicesl I These objects are accompanied by 50 ing invention which, in its broader aspects, comprises conducting the filaments vertically from the spinnerette in'a substantially straight line to the godetroll, guide roll or other drawing or guiding mechanism, and lubricating the filaments 55 either Within or without the cabinet, before they the followreach such roll or guide. The invention also contemplates the provision of an improved type of spinning apparatus in which this method of handling the filaments and lubricating them may be successfully carried out, this apparatus consisting of a vertically disposed spinning cabinet having a spinnerette mounted in the top and provided with an outlet for the filaments at the bottom, an appropriate lubricating device located directly below or above this outlet, and a godet roll so positioned that the filaments pass vertically from the spinnerette to the godet.

Theapparatus is particularly characterized by the fact that no thread guide is employed inside the cabinet and that provision is made for lubrication of the filaments as soon as they emerge from the cabinet and even before they reach the godet roll or other mechanism.

In the following example and description we have set forth several of the preferred embodiments of our invention, but they are included merely for the purpose of illustration and not as a limitation thereof.

Our invention will be more clearly understood by reference to the single figure of the accompanying drawing, which is a diagrammatic sectional elevation of one form of device for carrying it into practice.

Referring to the drawing, the numeral I designates a vertically disposed spinning cabinet of a more or less conventional design, provided with a spinnerette 2, also of usual design, to which a spinning solution is supplied by means of manifold 3, conduit 4, valve 5, pump 6 and candle filter l. The candle filter is enclosed by a chamber 8 so as to segregate this portion of the spinning apparatus from the balance of the cabinet in order that a zone of elevated temperature may be maintained at this point in the dope stream independently of the temperatures of the other parts of the apparatus. The walls of the chamber 8 may be constructed of any suitable heatinsulating material. As shown, a heating coil 9 is provided in the chamber 8 for supplying heat to the candle filter. Hot water, hot oil, or other suitable liquid may be circulated through the coil in order to maintain the candle filter at any desired degree of temperature.

The cabinet I is supplied with a current of heated air which enters by means of conduit l0, controlled by valve II, and leaves the device by means of conduit l2. This current of air passing through the cabinet serves to facilitate evaporation of solvents from the filaments as they pass downwardly from the spinnerette.

The cabinet is closed at its lower end except for an opening closed by means of a hinged door I3. The door I 3 is also provided with a small circular opening [4 of sufiicient diameter to permit the filaments to emerge from the cabinet without making frictional contact therewith. The bottom of the cabinet is also provided with a valve controlled conduit l5 for supplying water, steam or other fluid for a purpose which will be described hereinafter. The spinning; cabinet may be conveniently supported or suspended by means of bracket 5 attached to the lower part thereof.

Located below the spinning cabinet at a distance which may range anywhere froma few inches to several feet, is the godet roll 11, so positioned that a line from the center of the spinnerette 2 will be approximately tangent to its outside circumference. Also located directly below the spinning cabinet and above the godet roll is a lubricating device comprising reservoir I8 containing lubricant which is carried up therefrom by means of conveyer roll [9, thence to an applicator roll 20 and finally into contact with the filaments immediately upon emerging from the cabinet, but before they make contact with the godet roll or any other mechanism.

Our improved method of lubrication will be readily understood by reference to the drawing;

The filaments F emerge from the spinnerette 2 and pass downwardly through the spinning cabinet in a substantially vertical line to the godet roll and thence to a suitable twisting and winding device such as a cap or ring spinner, (not shown). During the course of their passage through the cabinet, solvents are evaporated from the filaments by means of a current of heated air which passes through the cabinet in the direction indicated by the arrows. By the time they reach the bottom of the cabinet, practically all of the solvent has left the filaments and they are in a condition to be twistedand wound. If desired, a certain amount of stretch may be imparted to the filaments by operating the godet roll at a peripheral speed in excess of the linear speed of emergence of the spinning solution from the spinnerette, in known manner.

It is to be particularly noted that in accordance with our invention no thread guides of any kind are employed in the cabinet, and that the filaments pass directly downward to the godet roll.

This entirely does away with the frictional influences above referred to which tend to break" the filaments or distort them in any way. Not only are thread guides eliminated, but in accordance with our method, provision is made for entirely eliminating friction between the individual filaments by supplying lubricant thereto immediately upon emergence of the filaments from the spinning cabinet and before they make contact with any other parts of the spinning mechanism.

In accordance with the invention, the filaments are lubricated substantially simultaneously with their formation. and pass to the godet roll or'other' mechanism and thence to the winding and twisting mechanism in practically perfect condition for further mechanical treatment. This is of great importance in the proper handling of the filaments in subsequent operations, since, not only" do unlubricated filaments suffer from excessive breakageand the phenomenon knownasfluffing or hairing, but also, due to the peculiar electrical properties of cellulosic materials, and the fact that a large number of fine threads or filaments are constantly moving one over the other, a very considerable amount of static electricity is developed. 13y lubricating the threads as herein described immediately upon emerging from the spinning cabinet and before they make contact with rolls, guides or other mechanism, the tendency toward breakage is reduced to a minimum and the accumulation of charges of static electricity is prevented.

The lubricant employed for the purposes of our invention is preferably an aqueous emulsion of a soluble oil in: which the alkalinity-acidity ratio has been so adjusted that an extremely stable aqueous emulsion may be prepared therefrom. Satisfactory emulsions may contain from 5-2'0% of the oil, the balance being water. In some cases we may employ aqueous emulsions containing as much. as 50% or even more of the soluble oil. Generally it is desirable to place such an amount ofemul'sionon the yarn as will leave a deposit of oil representing about 1.5 to 2%, based .on the weight of the untreated yarn, after evaporation of the aqueous part-of the emulsion. For example, in order to" place such an amount of oil on the yarn, one may app1y'15 -20%, based on the weight of theyarn, of a 10% aqueous emulsion of the character described, or- 30-40% of a 5% emulsion. By applying larger quantities of" the emulsions to the-yarn, the entire surface of each filament tends to be covered and to about the same extent. In otherword's; the application of 20%- of a liquid materiat will more evenly cover the filaments than the application of 2 For example, when applying 20% of a: 10% aqueous emulsion to yarns by contact a roller, 18% of the 20% applied is wa-ter and the remaining 2 is oil. After evaporation of the water from the yarn, the oil content will be found to be about 2 As exampleso'f suitable oils which may be used inour' process may bementioned sulfonated olive or unsulfonated olive oil, neats-foot oil, mineral oil andthe like. Examples ofsuitable emulsions are the following:

Parts A; Sulfbnated'oll-veoih 15 Water B. Olive oil 9 Triethanolamine (ol'eate) 1 Water C. Mineraloit '7 Olive oil. s 1 Sulfonated: olive oil 2 Water 8 Di Neat's-foot' oil; 10 Benzene; 90

Although. we prefer aqueous emulsions of the general character alludedto, the broad scope of our invention includes other aqueous or nonaqueous lubricatingv materials. Instead of aqueous emulsions, the straight oil, such as sulfonated or unsulfonated olive oil, neats-foot oil, mineral oil and. the like, or a dilution of] the straight oil with. a compatible solvent may be employed with entirely satisfactory results. In fact, any liquid which has no deleterious action on the yarn and has the power of lubricating. the material and reducing static may be employed in accordance with the practice herein described and with the desirable results referred to.

Notwithstanding. that a large number of methods of and apparatus for the manufacture and treatment of artificial filaments have been devised, so far as we are aware, until the advent of the present invention it has never been thought practical-or desirable to. eliminate friction at such an early stage'i'n the filament-forming process 75 by lubricating the filaments in the manner set forth herein. The advantages which flow from the practice of such a method are highly important. The reduction of static at an early stage in the handling of the filaments is of the utmost importance. The lubrication of the filaments at the earliest possible stage in their manufacture reduces breakage defects in the thread formed therefrom to a practically negligible minimum.

Although we have described our invention by reference to a method in which lubrication of the filaments is carried out outside of the spinning cabinet, it is within the scope of our invention to lubricate the threads inside the spinning cabinet by locating the lubricating device inside the cabinet, preferably close'to the bottom thereof. or course, in this case the device will be of the proper size and design to fit within the cabinet without interfering with the passage of the filaments therethrough. I

If desired, and as an adjunct to the treatmen of the filaments as described herein, provision may be made for local humidification of the filaments by introducing a spray of water or steam through the pipe l5.

Instead of applying the lubricant by means of a roll applicator, it may be sprayed onto the filaments, either through the pipe l (provided with an appropriate atomizing device) or by a separate atomizing or spraying device similarly located. Lubrication of the filaments in the manner just described, that is, by applying the lubricating material inside the cabinet, is rendered practical in accordance with our invention, due to the fact that the air inlet I0 is positioned sufficiently above the bottom of the cabinet as to provide a dead-end space or quiet zone which is unaffected by the relatively rapid current of air which passes through the upper regions of the cabinet.

What we claim is:

In the manufacture of synthetic threads or yarn by extruding a solution composed of a cellulose organic acid ester dissolved in an appropriate solvent in the form of filaments through a spinnerette mounted at the top and inside of a spinning cabinet, setting the filaments by evaporation of solvent therefrom and passing the filaments in a substantially cured condition to a godet roll positioned below the spinning cabinet, the step of passing the filaments from the spinnerette to the godet roll in a downward vertical direction without contact with thread guides or any other parts of the yarn-making machinery and applying a lubricant to the filaments outside the cabinet while they are moving vertically downward to, but before they come in contact with, the godet roll.

HOWARD H. IMRAY, JR. EDWIN A. ROBINSON.

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