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.

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 lines—spinning 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 .