METHOD AND INSTALLATION FOR THE PRODUCTION OF VISCOSE RAYON DIRECTLY DYED IN MASS IN TWO COLOURS SIMULTANEOUSLY

Abstract

According to the invention, in order to obtain viscose rayon directly dyed in two colours simultaneously, a second line for spinning is introduced to the existing one, as the first (38.1) and the second (38.2) pipe collectors, parts of these spinning lines, filled up with differently dyed viscose solution, supply respectively dosing pumps (22.1 and 22.2) at the first and second working positions of the spinning machine, which are powered by one and the same electromotor and work synchronously. The cellulose solution filled up in the added second pipe collector (38.2) is coloured in mass by the additionally mounted and operating independently second individual dyeing installation (10-1), so that differently dyed viscose fibers are being spun at the neighbour working positions. Then the spun at these neighbour working positions single-colour dyed rayon fibers are brought together, according to the innovative spinning design of the invention and are gathered in a common centrifuge to obtain a viscose rayon cake, directly and simultaneously dyed in two contrasting or gradating colours or colour mixtures.

Claims

1. A method for direct production of bicolour viscose filament rayon dyed in mass in two different colours simultaneously, including the following stages: mercerization of the initial cellulose with sodium hydroxide to obtain alkali cellulose, which afterwards is subjected to a process of destruction to decrease the degree of polymerization; reduction of temperature; treatment of the alkali cellulose with carbon-disulphide until it is transformed into cellulose xanthate; mixing of the cellulose of one batch to the one from the previous and the following batch; homogenization, deaeration and filtering to remove the impurities; then the viscose solution is mixed with preliminarily prepared suspension of one or a couple of pigments, the mixture is homogenized so that the pigment particles are distributed uniformly throughout the entire volume of this solution, which under pressure is passed for spinning; treatment of the freshly-spun viscose rayon with different solutions to remove the residues from the spin bath and the chemical reactions during spinning, then the obtained semi-finished product is dried, conditioned, rewound and sent for quality control inspection and packing as a finished product, with the main characteristic that the spinning is performed by means of dyeing installation consisting from two individual dying lines joined to the spinning machine, additionally adjusted to the formed complex of two dying linesspinning machine a new second viscose pipe collector, as the viscose solution dosing pumps arranged to be fed with cellulose solution from to the second pipe collector are actuated by the same electromotor powering the dosing pumps connected to the existing first pipe collector and operating synchronously with it, as the cellulose solution from the second pipe collector is dyed in mass in added new second independently operating individual dyeing installation, thus causing the spinning to be performed using complex of two dyeing lines, as each couple of neighbour working positions are supplied with differently coloured cellulose solutions by two independent pipe collectors, as in the neighbour spinning positions differently coloured viscose rayon fibers is being dyed, characterized also by the fact that the spun at the neighbour working positions differently coloured rayon fibers are joined in one immediately after spin bath leaving and through the spinning devices only at the first working position are collected in a common centrifuge until obtaining a rayon cake of bicolour viscose filament rayon dyed in two contrast or gradating colours.

2. Installation for the direct production of bicolour dyed-in-mass viscose filament rayon, including serially connected units: unit (1) for mercerization, unit (2) for aging, unit (3) for temperature reduction, unit (4) for dosing of the amount of alkali cellulose for the production of one batch of viscose, unit (5) for carbon-disulphide treatment, unit (6 and 7) for mixing and homogenization of the cellulose solution from the previous and the following batch and deacration, unit (8) for removal of the impurities, spinning machine (10), equipped with the first individual dyeing installation (10-1) for dyeing in mass, including a storage tank for a preliminarily prepared pigment suspension (30), a dosing pump (31) for pigment suspension and homogenizer (32), connected with the existing pipe collector (38) of the spinning machine to which a number of working positions are added each one equipped with a first and second spinning devices (27,28) and the relevant centrifuge (29) for obtaining of dyed-in-mass rayon cake, as well as a unit for washing (12), unit for treatment of the freshly-spun dyed-in-mass viscose rayon with various solutions for removal of the residues from the spin bath resulted from the chemical reactions during spinning, a unit for centrifugation of the obtained semi-finished product (14), a drying unit (15), a conditioning unit (16), a rewinding unit (17), a quality control unit (18) and a storage unit (19), with the main characteristic that to the first pipe collector (38.1) a second viscose pipe collector (38.2) is added, as the viscose solution dosing pumps, joined to the added second pipe collector are actuated by the same electromotor powering the dosing pumps of the first pipe collector and operating synchronously with it, as the second pipe collector (38.2) is connected to a second independently operating dyeing installation (10-2); the dosing pumps (22.1, 22.2) supplying the spinnerets (26) with viscose for spinning, for each couple of working positions are fed with viscose by the separate pipe collectors as follows: the dosing pump at working position (22.1) is supplied with viscose by the first pipe collector (38.1), and the neighbouring to it (22.2) dosing pump at second working position is fed with viscose by the added second pipe collector (38.2); as the freshly spun dyed-in-mass differently coloured filament rayon by the neighbour working positions (27.1, 27.2) is gathered immediately after spin bath leaving in the first spinning device only (27.1) and through the second spinning device at the same working position (28.1) is transferred into the centrifuge only of the first working position (29.1) in order to obtain directly a bicolour viscose filament rayon cake.

3. A fancy bicolour viscose filament rayon product produced directly after spinning in accordance with claims 1 and 2.

Description

SHORT DESCRIPTION OF THE FIGURES ENCLOSED

[0029] FIG. 1 illustrates the sequence of the processes in the classical production of dyed in mass viscose filament rayon.

[0030] FIG. 2 presents an individual dyeing installation used for viscose dyeing in mass.

[0031] FIG. 3 presents a part of the installation for the production of dyed in mass viscose rayon, illustrating the classical technology for spinning of coloured in mass viscose rayon.

[0032] FIG. 4 presents a part of a unit for spinning of bicolour viscose rayon according to the invention.

[0033] FIG. 5 presents a part of the installation for production of bicolour viscose rayon, according to the invention, showing an innovative way of spinning at two neighbour working positions of the spinning machine resulting into the production of bicolour viscose fiber directly dyed in mass.

MODEL PERFORMANCE OF THE INVENTION

[0034] According to FIG. 1, the installation for the production of dyed in mass viscose rayon includes the following units, where the processes for obtaining coloured viscose rayon are realized: unit 1 for mercerizationtreatment of the initial pulp (cellulose) with a concentrated solution of sodium hydroxide, unit 2for aging where as a result of the process of destruction alkali cellulose is obtained, i.e. the degree of polymerization is decreased, unit 3temperature reduction, unit 4dosing of the alkali cellulose amount for the production of one batch of viscose, unit 5for carbon-disulphide treatment of the alkali cellulose to obtain cellulose xanthate, units 6 and 7for mixing of the cellulose solution of one batch to the one from the previous and the following batch and deaeration, unit 8filtering to remove the impurities.

[0035] Unit 9, for the preparation of a dyeing suspension, is connected to spinning machine 10. After the spinning, the freshly-spun viscose rayon is treated in unit 12 with various solutions, prepared in unit 13 to remove the residues from the spin bath 11 after the spinning.

[0036] Further, following the process for obtaining coloured viscose rayon, serially connected are units 14, 15, 16, 17 and 18 for centrifugation, drying, conditioning, rewinding, quality control inspection and packing as finished production to be stored in unit 19.

[0037] In order to obtain coloured rayon, to the spinning machine 10 an individual dyeing installation 10-1 is connected for individual or group dyeing in mass. As shown in FIG. 2, it includes a pigment suspension storage tank 30, pigment suspension dosing pump 31, a control unit 34 for the dosing pump 31, a homogenizer 32, where the pigment(s) particles are mixed and distributed uniformly throughout the entire volume of the viscose solution and geared electromotors 35 to the homogenizer 32 and the suspension tank. From the main pipe collector 36 the cellulose solution passes into the homogenizer 32 through a local pipe line 37. The already dyed after the homogenization solution fills up under pressure a pipe collector 38, which supplies the working positions of the spinning machine 10.

[0038] Then a part of the installation for dyed-in-mass viscose rayon production according to the classical technology for spinning is presented on FIG. 3. Dozing pumps 22.1 and 22.2 doze the coloured viscose solution respectively to the first and the second working positions. The freshly-spun through spinnrets 26 viscose rayon at the presented two working positions passes through the first 27.1 and 27.2 and the second 28.1 and 28.2 spinning devices to the first and second centrifuges 29.1 and 29.2 where the freshly-spun coloured rayon is collected.

[0039] According to the invention, a part of the unit for spinning of bicolour viscose rayon is presented on FIG. 4, where a new pipe collector is added. The first and the additional second pipe collector 38.1 and 38.2 with differently dyed viscose solution, supply respectively dosing pumps 22.1 and 22.2 at the first and second working positions. According to the invention, dosing pump 22.1 is fed by the first pipe collector 38.1, and dosing pump 22.2by the second pipe collector 38.2.

[0040] A part of the installation for production of bicolour viscose rayon and the innovative procedure for spinning of bicolour viscose rayon according to the invention, showing two working positions for bicolour rayon spinning is presented in /FIG. 5/. According to the invention dosing pump 22.1 is fed with viscose for spinning by the first pipe collector 38.1, and dosing pump 22.2by the added second pipe collector 38.2. The dyed in mass viscose fibers from both working positions are joined in the first spinning device 27.1 at the first working position and by means of the second spinning device 28.1 at the same working position are passed to the centrifuge 29.1 of the first working position in order to obtain a rayon cake composed of two differently dyed viscose fibers.

[0041] The processes running in the suggested installation and method for production of bicolour viscose rayon, dyed in mass according to the invention, are as follows:

[0042] The preliminarily prepared pigment suspension, which during the production cycle is stored in tank 30 (FIG. 2), is dosed using pump 31 to the viscose and the mixture is passed into homogenizer 32 (FIG. 2), where the particles of the pigment(s) are distributed uniformly throughout the entire volume of the viscose solution. The already dyed after the homogenization cellulose solution is fed under pressure to pipe collector 38 (FIG. 2) of the spinning machine, to which a specific number of working positions are added. Through individual for each working position dosing pumps, the viscose solution is fed under pressure to the spinnerets.

[0043] According to the invention, to the already existing pipe collector 38.1 is introduced a second one 38.2, combined with a second installation for individual dyeing in mass, actuated in the same mode as the first pipe collector, FIG. 4. The cellulose solution from pipe collector 37 under pressure is passed simultaneously to two installations for individual dyeing. The dyed in one colour viscose solution is passed to the first pipe collector 38.1, and the dyed in the other colourto the second pipe collector 38.2, FIG. 4. According to the invention, dosing pumps 22.1 and 22.2, supplying viscose for spinning to the spinnerets, are fed with viscose for spinning by the different pipe collectors in the following way: dosing pump 22.1 is supplied with viscose by the first pipe collector 38.1, and the neighbouring to it pump 22.2 which corresponds to working position 2, is fed with viscose by the second pipe collector 38.2. The same is repeated for working positions 3 and 4 and for each successive pair of working positions. The realization of this innovative scheme enables to half of the working positions of the spinning machine to be supplied with undyed or dyed in one colour viscose, and to the rest of every other positionviscose dyed in another colour. In practice this means that in the neighbour spinning positions a differently dyed viscose fibers is being spun.

[0044] Passed through the spinnerets 26, the cellulose solution is led into a spin bath 11, where as a result of the chemical reactions in course the cellulose from cellulose solution is transformed into rayon fibers. Then the freshly-spun cellulose is transferred and arranged in a centrifuge 29.1. When it is filled up to a specific level, the filament between spinning devices 27.1 and 28.1 is interrupted and wound only on the first spinning device 27.1. Meanwhile, the first centrifuge 29.1 is stopped, the formed in it rayon cake is taken out, and the centrifuge is again put into operation. When the same enters in operating mode, the filament from spinning device 27.1 is again transferred to spinning device 28.1 from where it is led to centrifuge 29.1, giving start to the production of the next rayon cake.

[0045] The adjustment of the suspension dosing pumps takes place after both pipe collectors are filled up with the cellulose solution and deaerated. The dosing pumps in the positions with odd numbers are connected and are supplied with viscose by the first pipe collector 38.1. The dosing pumps at the even-numbered positions are connected to the second pipe collector 38.2 and fed with viscose, dyed in a colour different from the one of the viscose in the first pipe collector 38.1. The working positions are consecutively spun observing the fresh-spun rayon fibers spinning mode as shown in FIG. 5. The fibers in working positions 1 and 2, dyed in different colours, are joined at the first spinning device 27.1 to the first working position, they are transferred together to the second spinning device 28.1 of the same working position, and transported to the centrifuge 29.1 at the same first working positions. Centrifuge 29.2 at the second working position is not operating. When 29.1 is filled up to a specific volume, the bicolour rayon fiber between spinning devices 27.1 and 28.1 is interrupted, the rayon cake is taken out, and then again through spinning device 28.1 is transferred in the already emptied centrifuge of the same working position 1. These actions are periodically repeated until the production of the planned quantities of bicolour rayon is finished. Spinning device 28.2 and centrifuge 29.2 are not in operation.

[0046] Then this is followed by washing procedures where in unit 12 the freshly-spun viscose rayon is treated with various solutions, prepared in unit 13 to clear the residues of the spin bath, the sodium sulfate and sulfur resulted from the chemical reactions during spinning.

[0047] The obtained semi-finished product is then centrifuged, dried, conditioned, rewound and sent for quality control inspection and subsequently packed as a finished productunits 14, 15, 16, 17 and 18, and stored in unit 19.

[0048] The obtained bicolour rayon cakes are rewound on bobbins with the usual weight and size in the same way and parameters as the rayon cakes produced using the classical dying in mass technology. The quality control of bicolour rayon shade uniformity is carried out in the same way as with the single-colour dyed viscose rayon according to the approved colour standard.

[0049] After a careful selection of colours and recipes, including white, contrast and gradating colour mixtures are obtained, which enhances the possibilities for production of fancy yarns and textiles.