METHOD FOR THE MANUFACTURE OF ANTIBACTERIAL VISCOSE FILAMENT RAYON AND A PRODUCT OBTAINED USING THAT METHOD

Abstract

The antibacterial viscose rayon, according to the invention, is used for the manufacture of any type of textile articles, including items intended for medical use, ensuring a more lasting antibacterial and antifungal protection due to the uniform distribution of the antibacterial additive throughout the entire volume of the fibre. According to the invention, immediately before spinning, the viscose is mixed and homogenized with an antibacterial additive, and then spun following the classical procedure: the viscose solution, with required and strictly specified parameters is fed under pressure to the spinnerets of the spinning machine from which the cellulose solution enters a spin bath, where as a result of the chemical reactions in course is transformed into fibres subjected afterwards to a subsequent treatment. According to the invention, in the production of dope dyed antibacterial rayon, into the preliminarily prepared suspension composed of one or a couple of pigments, a specified amount of antibacterial additive is introduced, the obtained mix is homogenized and filtered, and then subjected to the classical stages of spinning and subsequent treatments.

Claims

1. Method for the manufacture of antibacterial viscose filament rayon based on following stages: Treatment of the raw cellulose with a concentrated solution of sodium hydroxide, resulting in alkali cellulose which after that is subjected to destruction to reduce its degree of polymerization; reduction of the temperature and dosing of the quantity of alkali cellulose for the production of one batch of viscose; treatment with carbon disulphide until it is transformed into cellulose xanthate which is soluble in diluted solutions of sodium hydroxide, mixing and then filtering for removal of the impurities, deaerating and filtering again after which the already cleared viscose with 8.8% cellulose and 6.4% sodium hydroxide content and ripeness index 18.5-19.5 is fed under pressure to the spinning machines. Wet spinning is performed by passing the cellulose solution, by means of a dosing pump, through the spinneret holes into the spin bath, where as a result of the chemical reactions the cellulose from the cellulose solution transforms into rayon filament yarn; next treatment with various solutions for removal of the residues from the spin bath, resulting from the chemical reactions during spinning; followed by drying, conditioning, rewinding and quality determination, with the main characteristic that antibacterial additive for raw white bright antibacterial viscose filament rayon production is added into ready for spinning viscose, mixed and homogenized with it immediately before its spinning on the spinning machine, after which the rest of the described stages are carried out.

2. A method for the manufacture of antibacterial viscose filament rayon dyed in mass, based on following stages: Treatment of the raw cellulose with a concentrated solution of sodium hydroxide, resulting in alkali cellulose which after that is subjected to destruction to reduce the degree of polymerization; reduction of the temperature and dosing of the quantity of alkali cellulose for the production of one batch of viscose; treatment with carbon disulphide until it is transformed into cellulose xanthate which is soluble in a diluted solution of sodium hydroxide, mixing and then filtering for removal of the impurities, deaerating and filtering again after which the already cleared viscose 8.8% cellulose and 6.4% sodium hydroxide content and ripeness index 18.5-19.5 is fed under pressure to the spinning machines. Wet spinning is performed by passing the dyed in mass cellulose solution, by means of a dosing pump, through the spinneret holes into the spin bath, where as a result of the chemical reactions the cellulose from the cellulose solution transforms into dyed in mass rayon filament yarn; next treatment with various solutions for removal of the residues from the spin bath, the sodium sulphate and the basic sulphur, resulting from the chemical reactions during spinning; followed by drying, conditioning, rewinding and quality determination, with the main characteristic that antibacterial additive and pigment suspension as antibacterial dyed complex for antibacterial and dyed in mass viscose filament rayon production are added together into ready for spinning viscose, mixed and homogenized with it immediately before its spinning on the spinning machine, after which the rest of the abovedescribed operations follows.

3. A method according to claim 1, with the main characteristic that the quantity of the antibacterial additive added Into ready for spinning viscose, mixed and homogenized with it immediately before its spinning on the spinning machine is from 0.01% to 5% in relation to the amount of the cellulose in the viscose solution, respectively in ready made antibacterial rayon filament yarn

4. A method according to claim 1 with the main characteristic that as antibacterial additive ZINC PYRITHIONE is used.

5. A method according to claim 1, with the main characteristic that when antibacterial additive Zinc Pyrithione is added into ready for spinning viscose, mixed and homogenized with it immediately before its spinning on the spinning machine, its amount is between 0.5 and 3.5% in relation to the cellulose content in the viscose solution.

6. Antibacterial viscose filament rayon products row white bright and dyed in mass obtained using the method according to claim 1.

7. Method for the manufacture of antibacterial artificial cellulose fibers with the main characteristic that as antibacterial additive ZINC PYRITHIONE could be used.

Description

SHORT DESCRIPTION OF THE FIGURES ENCLOSED

[0033] FIG. 1 illustrates the sequence of the processes of the manufacture of viscose rayon filament according classical technology of manufacturing

[0034] FIG. 2 presents dope dyed viscose rayon filament production (10-1) with and without the use of antibacterial additive.

[0035] FIG. 3 presents a detailed construction of an original centrifugal spinning machine.

[0036] In FIG. 4 a chart presents the recipe for the preparation of the suspension with antibacterial additive, introduced in the cellulose solution in the homogenizer.

[0037] In FIGS. 5a and 5b are given the results of external laboratory investigations of antibacterial rayon, manufactured using the method according to the invention.

MODEL PERFORMANCE OF THE METHOD FOR PRODUCTION OF ANTIBACTERIAL VISCOSE RAYON

[0038] With reference to FIGS. 1, 2 and 3 a model performance of the method according to the invention is demonstrated.

[0039] Firstly, the base cellulose is fed into unit 1 for mercerizationtreatment of the initial pulp with a concentrated solution of sodium hydroxide (NaOH), resulting in alkali cellulose, which afterwards in unit 2 is subjected to destruction, i.e. aging, where the degree of polymerization is decreased. In unit 3 temperature reduction takes place, and in unit 4dosing of the alkali cellulose amount for the production of one batch of viscose. In unit 5 is introduced the next stagecarbon disulphide treatment of the alkali cellulose until obtaining cellulose xanthate, whose most important property is that it is soluble in sodium hydroxide diluted solutions. In units 6 and 7 the solution of cellulose from one batch is mixed and homogenized with the one from the previous and the following batch, deaerated, and then filtered in unit 8 for removal of the impurities.

[0040] Then, in case that there is no production of coloured rayon, the viscose solution with requires and strictly defined parameters is fed under pressure to the spinning machines 10 in a pipe collector 38 which is permanently full of cellulose solution under pressure for the prevention of incidence of a gas phase. This collector 38 provides the necessary quantity of cellulose solution to the spinneret for each working position of the rayon spinning machine 10 through the respective dosing pump 22 (FIG. 3). Passed through the spinneret 26 (FIG. 3), the cellulose gets into a spin bath 11 where, as a result of the chemical reactions in course, the cellulose from the cellulose solution is transformed into rayon fibres. Leaving the bath the freshly-spun sour rayon is transported to the centrifuge 29 (FIG. 3). When it is filled up to a specific volume, the fibre between spinning devices 27 and 28 (FIG. 3) is interrupted manually and wound on spinning device 27 only. During that period the centrifuge 29 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 rayon fibre from spinning device 27 is again transferred to spinning device 28 from where it is led to the centrifuge 29, giving start to the production of the next rayon cake.

[0041] Then this is followed by washing procedures in unit 12, where the freshly-spun sour rayon is treated with different solutions, prepared in unit 13, for removal of residues from the spin bath, the sodium sulfate and basic sulfur resulted from the chemical reactions during spinning.

[0042] The obtained semi-finished product is then dried, conditioned, rewound and sent for quality control inspection and packaging as a finished productunits 14, 15, 16, 17, 18 and after quality control inspection it is stored in unit 19.

[0043] In the production of dope dyed viscose rayon the spinning machine 10 is additionally equipped with an individual or multifunctional system for mass dyeing 10-1 (FIG. 2). In order for such production to be realized, a preliminarily prepared pigment suspension, made of one or a couple of pigments, for one production cycle is transferred and stored in container 30 (FIG. 2).

[0044] By means of pump 31 the required amount of the suspension is dosed into the viscose, so the viscose and the pigments are mixed and homogenized in unit 32 (FIG. 2), and as a result the pigment particles are uniformly distributed throughout the entire volume of the already coloured solution. The dyed and homogenized cellulose solution is then fed into a viscose pipe line 38 (FIG. 2) of the spinning machine and passed through the spinnerets into the spin bath in the already described mode.

[0045] In the demonstrated performance of the invention for the production of antibacterial viscose rayon by recipe (FIG. 4) the suspension of the antibacterial additive is prepared, i.e. 1.0% in relation to the amount of cellulose to be spun for 24 hours. The calculated quantity of additive is scaled and quantitatively transferred in the suspension preparation container where the required amount of water and other components of the recipe have already been weighted. The prepared suspension is transported to the container 30 of the individual installation for mass dyeing (FIG. 2), after which the feed of the suspension to the homogenizer 32 from the suspension dosing pump 31 is set. This important setting is performed when the viscose pipe collector 38 is filled with the cellulose solution/viscose/ and deaerated. Further follows the spinning as above-described.

[0046] After the viscose is mixed with the suspension, whatever it is, as a result of the dilution its parameters are modified:

TABLE-US-00001 Prior to After mixing with mixing with the suspension the suspension viscosity Sec. 39.0 30.0 ripening ml. NH.sub.4CL 19.25 17.40 temperature C. 17.0 19.0

[0047] The spinning of the viscose solutionantibacterial component complex is performed in the same spin bath, used for spinning of the same viscose solution without such an additive or of the same solution, dyed in mass.

[0048] After spinning, the freshly-spun sour antibacterial rayon passes through the processing to which rayon is subjected, spun through all the spinning machines, i.e. these operations are performed in accordance with the approved technological requirements and practice. These treatments include washings with softened water, neutralization with sodium carbonate, desulphoration and again washing with softened water.

[0049] The drying and rewinding of the rayon cakes to bobbins with standard weight and size is carried out in the same way and parameters like the rest of rayon yarn manufactured in the classical mode. The only difference is that the rewinding of the antibacterial rayon is performed on separate rewinding machines in order not to mix it with the rest, and it sent to the quality control immediately, after which each bobbin of antibacterial rayon is wrapped in sterile packaging.

[0050] The quality control inspection is performed in the same way as with the traditionally manufactured types of viscose rayon.

[0051] In FIG. 5b are shown the results from the antibacterial tests of antibacterial rayon, manufactured using the method according to the invention, and in FIG. 5athe methodology used to determine antibacterial activities, which is not subject of the invention.

[0052] The introduction of any type of additives to the viscose solution changes its parameters and especially its ripening speed. That is why, the introduction of the additive in the viscose immediately before its spinning, which is the innovative solution of the suggested method, is one of its essential advantages as compared to the ones already known, because the changes in the parameters of the cellulose solution/viscose/ happen minutes before its direct spinning, which guarantees its stable trouble-free spinning, with no need whatever changes to be made in the rest of the parameters of the spinning process.