US2179985A - After-treatment of yarn of artificial origin - Google Patents

Description

NOV. 14, 1939. STQECKLY r AL 2,179,985

AFTERTREATMENT OF YARN OF ARTIFICIAL ORIGIN Filed Oct. 1, 1936 2 Sheets-Sheet 1 gwucwtoo folmnfi ase 0A floeckly Kurt 'micllf JZWZW @HMM Nov. 14, 1939. J, s o c r L 2,179,985

AFTER-TREATMENT 0F YARN 0F ARTIFICIAL 03mm Filed Oct. 1, 1936 2 Sheets-Sheet 2 Patented Nov. 14, 1939 UNITED STAT AFTER-TREATMENT OF YARN OE ARTIFICIAL ORIGIN Johann Joseph Stoeckly, Teltow-Seehof, and Kurt Schmidt, Kassel-Bettenhausen, Germany, assignors to NortlLAmerican Rayon Corporation, New ware York, N. Y.,

a corporation of Dela- Application october 1, 1936. Serial No. 103,558 In GermanyOctober 5, 1935 6 Claims. 01. 8 158) The present invention relates to the manufacture of yarn of artificial origin, but primarily has to do with the after-treatment of artificial silk yarn or staple fibre made therefrom.

In the manufacture of yarn of artificial origin, it is necessary to subject the freshly spun yarn to a thorough after-treating process consisting of deacidification, desulphurization,-and/or decopping, bleaching, washing, reviving and the like. The after-treatment of the yarn in the undivided state, i. e., in a continuous skein or, bundle of threads, was heretofore carried out by leading .the bundle of thread in a continuous operation through the various after-treating baths which were contained in open vats or tanks and the like provided with spraying devices. The aftertreatment of staple fibre, i. e:, artificial silk cut up into small pieces of thread immediately after the spinning of the yarn, was generally carried out in apparatus provided with agitating devices similar to those used for the washing of wool.

Becausethese after-treatment processes necessitate the employment of a plurality of open vats or tanks, it is rather difficult and complicated to recover the chemicals used in preparing the after-treating baths, while the process itself was very complicated and expensive.

The present invention has therefore for its object to provide a method and means which facilitates the after-treatment of artificial silk in the form of continuous skeins or staple fibre.

Another object of the present invention is to provide a method and means which make it possible to carry out the after-treatment of artificial silk bundles or staple fibre with a minimum of chemicals.

Still another object is to provide a method and means which facilitate the recovery of the chemicals from the various discharged baths used for the after-treatment.

These and other objects will in part become obvious and will in part'be pointed out in the following specification and appended claims, taken in conjunction with the accompanying drawings, in which-- Fig. 1 is a diagrammatic cros -sectional view of the new device; and Fig. 2 is diagrammatic lay-out of an after-treating arrangement employing the new apparatus.

Referring now to the drawings and particularly to Fig. 1, the new device comprises a tank i divided into three compartments 3, 5 and 6 by means of two perforated horizontally positioned plates 2 and 4. The after-treating liquid is fed through pipe 7 and discharged through pipe 8, 5

is'the cover of the tank which can be opened by means of the lifting ring it.

The spun goods to be after-treated are inserted only in the compartment 5, and it is of importance that this compartment is filled up only to such an extent, that the increase in volume caused by the after-treating liquid subsequently introduced fills the compartment to capacity. It was found, that in the case of cellulose threads it is advisable to use about 6-12 kg. of filaments calculated on a treating space of 100 liters capacity. If "necessary, the aforementioned weight limits may be either somewhat decreased or increased.

Another factor which plays an important part in the satisfactory after-treatment is the speed at which the treating liquid is forced through the yarn body. If the speedof fiow is too fast, the treating liquid is not utilized sufficiently and too much-liquid is required. If, on the other hand, the speed of the liquid is too slow, the liquid tends to mix with the subsequently introduced liquid, and consequently the duration of treatment will be too long. Speeds of fiow of from 1 to 20 cm.

.per minute, preferably from 5 to 10 cm.. per

minute have given the best results. If the quantity of goods placed in the tank is'too small in volume a high speed of fiow of the treating liquid will cause the goods to gather in the upper portion of the tank, whereas if the speed of flow is low the goods will tend to remain in the bottom of the tank. In both cases the efficiency of the apparatus is impaired. Only by properly proportioning the volume of spun goods and the speed of flow of the after-treating liquid with respect to the capacity of the tank, is it 'possible to completely fill up the tank without leaving any open spaces therein, resulting in a uniform distribution of the goods in the tank.

In some cases it was found advantageous to assist in uniformly distributing the goods in the tank by blowing finely dispersed air or inert gases into the tank. The after-treating liquid may be either fed to the tank continuously or intermittently, and if more than one wash tank is employed it is preferable to carry out the aftertreatment by the counter-current principle.

' In the treatment of staple fibre the freshly spun thread is first cut into the desired length and then subjected to the after-treatment. Endless skeins or bundles of yarn are preferably placed in the tank in uniform layers. After the treatment is finished the skeln is reeled from the tank beginning with the previously marked end piece of the skeln.

In order to more uniformly disperse the aftertreating liquid supplied through the pipe 1, the holes in the plates 2 and 4 are varied in size. Those around the center of the plates are made smaller while those close to the edge of the plates are made larger in size.

For the more convenient insertion of the spun goods into the tank, perforated containers filled with the yarn may be used. The employment of these containers has the advantage that the yarn body as a whole can be moved from one tank into another. These perforated containers would eliminate the use of the two perforated plates 2 and 4; it is only necessary to provide supporting means for the container in the tank.

1 Reference is now made to Fig. 2 of the drawings, in which the tank I is connected with liquid containers I8, I9, 20, 2|, 22 and 23 by way of branch pipe lines l2, l3, l4, |5, i6 and "and a collective pipe line H. from the containers l8, I9, 20, 2|, 22 and 23 is controlled by the valves 39, 40, ll, 42, 43 and M. The collective pipe line H is also connected to a discharge pipe 2!. The upper end of the tank I is connected to another collective pipe line 25 which by means of a branch pipe line 26 leads to a de-aerating device (not shown). Another branch pipe line 21 leads to the discharge pipe, while a third branch pipe line 28 leads to the carbon bisulphide recovery plant 29. Three additional branch lines 30, 3| and 32 are connected to the regenerating plants 33, 34, and 35 for sodium sulphite, bleaching lye and soap, from where the recovered baths are returned to the pipe lines 36, 31 and 38.

Example of operation kg. of freshly spun artificial viscose threads cut up into staple fibre, calculated on the cellulose content, are inserted in the middle compartment of the tank, thus lying between the two perforated plates. The capacity of this compartment is 1000 liters, whereby the distance between the two perforated plates is one meter and the free cross-section of the tank is one square meter. After the upper perforated plate has been bolted and the cover of the tank closed, wash water is introduced into the tank from below. A total amount of 3600 liters of water is forced through the goods in a uniform stream within a period of 50 minutes, which is discharged at the upper end of the "tank. The water remaining in the tank after the supply thereof has ceased is discharged at the bottom of the tank and is subjected to an acidity test. If it is found necessary, the washingprocess is continued for a short period of time, preferably through refilling of the tank with 11:32 water which is discharged a few minutes The supply of liquid' a compartment of a tank with such spun goods,

passing uniformly distributed after-treating liquid from below through said spun goods, controlling the rate of fiow of the treating liquid through said spun goods so that a uniform distribution of the goods in the said tank takes place and discharging the after-treating liquid from the upper end of the tank.

2. In a process for the after-treatment of yarn of artificial origin, the steps of placing from 60 to kilograms of yarn in a tank having a capacity of 1000 liters, passing uniformly dist ibuted treating liquid from below through said yarn, controlling the rate of flow of the treating liquid so that a uniform distribution of the goods in said tank takes place, and discharging the treating liquid from' the upper end of the tank.

3. In a process for the'wet-treatment of yarn of artificial origin, the steps of placing from 60 to 120 kilograms of yarn in a compartment for each 1000 liters capacity of said compartment, forcing treating liquid through the yarn from below, and controlling the rate of liquid flow so that the liquid level in thecompartment is caused to rise from one to twenty centimeters per minute.

4. In a process of the class set forth, the steps of placing from 60 to 120 kilograms of yarn in a compartment for each 1000 liters capacity of said compartment, forcing uniformly distributed treating liquid upwardly through said yarn body, and

controlling the speed of liquid flow so that the liquid level in the compartment rises from five to ten centimeters per minute.

5. In a process for the wet-treatment of yarn of artificial origin, the steps of placing approximately 80 kilograms of yarn in a compartment having a height of one meter and a capacity of 1000 liters, and then passing at a uniform rate of flow approximately 3600 liters of treating liquid upwardly through said yarn during a period of approximately fifty minutes.

6. In a process for the wet treatment of viscose threads cut up into staple fiber, the steps of placing approximately 80 kilograms of said threads in a compartment having a height of one meter and a capacity of 1000 liters, and then passing at a uniform rate of flow approximately 3600 liters of treating liquid upwardly through said threads during a period of approximately fifty minutes, the weight of said viscose threads being calculated on the cellulose content thereof.

JOHANN JOSEPH STOECKLY. KURT SCHMIDT.

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