RU2467103C2 - Method of formation and preparing twist-free flax roving for spinning and device for its implementation - Google Patents

Abstract

FIELD: textiles, paper.

SUBSTANCE: invention relates to the textile industry, in particular to flax spinning production, where, at the last manufacturing step, to produce flax yarn the semi-finished in the form of roving is used. The method of formation and preparing flax roving for spinning, according to which, broken thread exiting drafting device is soaked in electrochemically activated water solution with an oxidation-reduction potential from minus 1000 mV to plus 1000 mV and the acidity of 2-12 pH at the temperature of 16-40°C. And the wetting is carried out directly to the cavity of the chemical reactor designed for obtaining electrochemically activated water solution.

EFFECT: invention enables to reduce the time, to reduce energy and water consumption for chemical treatment of roving, refuse chemicals which can lead to lowering disposal costs resulting from chemical processing of roving, solutions.

2 cl, 2 dwg

Description

The invention relates to the textile industry, in particular to flax spinning production, where, at the last technological transition, a semi-finished product in the form of rovings is used to produce linen yarn.

The sequence of processes for obtaining flax yarn consists of the formation of a fibrous product in the form of a tape having a constant weight (linear density), with its thinning - a decrease in linear density, at subsequent technological transitions. The technology for preparing the fiber for spinning by the formation of rovings, a product with a linear density of 0.25-2.0 kteks, is ending. To wrap it on a package that is convenient for use in further technological transitions, the roving must have a certain strength. Along with the method of hardening rovings used in industry, twisting them, there is a known method for producing flax rovings (RU No. 2208070 C, 07/01/2001), in which to increase its strength during formation a thin fiber bundle - the sliver coming out of the fume hood is moistened with water. In this case, gluing of technical flax fibers with pectin substances that are part of the flax fiber occurs.

To ensure the process of yarn formation and the stability of its course, the roving is subjected to chemical treatment (Lazareva S.E. et al. Spinning of flax with cooking rovings. - M.: Light Industry, 1966).

The purpose of this process is to weaken the bonds between elementary fibers in the complexes of technical fibers. As a result of chemical processing of rovings, it becomes possible to produce yarn that meets the requirements of the standard in a wide range of linear densities with a stable technological process.

The chemical treatment process has several disadvantages, which include - high energy costs (4200 kJ per 1 kg of roving), the use of chemicals, high water consumption, disruption of the process flow, the mandatory presence of treatment facilities.

A known method of preparing bast-fiber material (RU No. 2139374 C1, 12/11/98), in which, to break the bonds between the complexes and elementary fibers, an electrochemically activated (ECA) aqueous solution with a redox potential from minus 1000 mV to plus 1000 mV is used, with an acidity of 2-11 pH, at a temperature of 16-40 ° C. The high activity of ECA is explained by the presence of unstable ions in its composition, which are absent in solutions that have reached thermodynamic equilibrium. ECA activity depends on the relaxation time, which is about several days. Moreover, the decrease in activity occurs exponentially, i.e. in the first few minutes, the most active ions decompose or react in the solution, an intensive decrease in the activity of the solution occurs, and then its rate slows down, but the most active ions are absent in such a solution. According to the known method (RU No. 2139374 C1, 12/11/98), a short flax fiber or linen tow is processed, intended for the production of cotonin and subsequent processing by cotton technology. Using the resulting product as a roving is not possible.

The prototype of the invention in terms of the method is the invention (RU No. 2227824 C1, 02.25.2003), in which a sliver of flaxseeds upon exiting the fume hood is wetted with a solution of soda ash Na ₂ CO ₃ with a concentration of from 10 to 35 g / l, and such a way to form a grooveless roving. The use of soda ash allows the process of chemical processing of roving, starting from the moment of its formation on the roving machine. But it is not possible to complete the full cycle of chemical treatment on a roving machine with this method, because this requires high temperatures and a long contact time of the sliver with the solution, which cannot be ensured, mainly due to the high speed of release of the formed roving.

The prototype of the invention in terms of the device is the invention (RU 2078737 C1, 1994.05.26), in which the reactor for the electrochemical treatment of water comprises an electrochemical cell made of vertical coaxially arranged rod and cylindrical electrodes, a ceramic diaphragm coaxially placed between the electrodes and separating the interelectrode space to the electrode chambers, as well as a current source connected to the electrodes through a switching unit. The rod electrode has a variable cross section and the diameter of its end parts is 0.75 of the diameter of its middle part, while its middle part with a large diameter is located at a level bounded by channels in the upper and lower dielectric heads. The disadvantage of the prototype is the lack of a central channel for passing through the processed textile product, as well as the vertical orientation of the electrodes, limiting the position of the filling line on the roving machine.

The technical task of the invention is to reduce time, reduce energy and water consumption for the chemical treatment of rovings, the rejection of chemicals, which will reduce the cost of disposal resulting from the chemical treatment of rovings, solutions.

This goal is achieved by the fact that the roving is formed by moistening the sliver with an electrochemically activated solution, and the processes of electrochemical activation of the solution and the formation of the roving are combined and carried out in one device.

Figure 1 shows the technological diagram of a device for implementing the inventive method for producing and preparing rovings for spinning.

Figure 2 shows a structural diagram of a reactor for producing an electrochemically activated solution and processing flax rove therein.

The proposed method of forming a roving and preparing it for spinning is as follows. The sliver formed in the exhaust device of the roving machine, with a linear density of 0.25 to 2.0 ktex, leaves the exhaust pair 1 (Fig. 1) of the exhaust device, passes through the hole in the central electrode of the electrochemical reactor 2, where it is subjected to electrochemically activated processing a solution (anolyte or catholyte), which is obtained by decomposition of weakly mineralized water supplied to the reactor through fittings 3. In this case, lignin is destroyed in the middle plates of technical fibers and the bonds between eleme Tarn fibers, which provides a further stable flow drawing process resulting in a roving drafting system of a spinning machine. The catholyte or anolyte solution not used for processing is respectively discharged through the nozzle 4. Product movement through the reactor is ensured by feeding it to the treatment zone by exhaust pair 1 and withdrawing pulling pair 5 from the treatment zone. To reinforce the sliver, a reel 6 rotating around its axis. He clamps the sliver with spring-loaded jaws 7 and tells her a false twist. As a result of the action of the electrochemically activated solution on the linen sliver and its hardening in the false twist treatment area, a roving is formed that is suitable for processing into yarn on wet flax spinning machines without additional processing.

To implement the proposed method of forming and preparing for spinning flax rovings, a chemical reactor is used (figure 2). It consists of two coaxially arranged electrodes, inner 1 and outer 2. The electrodes are located obliquely, so that their axis coincides with the axis of the processed roving. The inner electrode is a tube with a central channel 3. In the middle part, the electrode 1 has a perforation 4 connecting the central channel with the interelectrode space. Between the electrodes 1 and 2 there is a diaphragm 5, which divides the interelectrode space into two chambers - the anode and cathode. The cavity of the chambers is sealed with bushings 6, 7 and 8 made of insulating material. Fittings 9 and 10 are designed to feed into the reactor a stock solution of NaCl. The fitting 11 is designed to drain the solution, not used for processing rovings.

The device operates as follows. A direct current is supplied to electrodes 1 and 2, the polarity of which is selected depending on which solution the roving should be processed. When a negative pole is connected to the internal electrode, anolyte will be used for processing, and when a positive pole is connected, catholyte will be used. Through fittings 9 and 10, a NaCl solution is supplied into the reactor cavity, which, under the influence of electric current, decomposes into anolyte and catholyte. The solution used for processing the roving flows from the interelectrode space into the channel 3, through which the fibrous sliver moves. In this channel, it is impregnated with an appropriate solution and the destruction of the lignin contained in the fiber begins. The solution, not used for processing roving, drains through the nozzle 11.

The solution wets the sliver, while due to the forces of the surface tension of the liquid, forces arise that press the fibers to each other. This leads to the fact that the product thus formed - the roving, has a strength sufficient to wind it onto a reel. Simultaneously with the formation of the roving, the splitting of the complexes contained in the technical fiber into elementary fibers begins, and the breaking of bonds between the fibers continues in the roving wound on the spool. The choice of the range of the indicated parameters of the electrochemically activated solution is determined by the requirements for the treated roving and depends on the properties of the initial fiber prepared for the production of yarn. It was experimentally established that with the right choice of the activity of the solution, the bond between the elementary fibers in the complexes of the technical fiber breaks within 30 minutes, after which the roving is ready to form yarn on a spinning machine.

An electrochemically activated solution loses its properties within three days, turning into water, which does not need special treatment for its disposal.

The implementation of the proposed method is illustrated by the following examples.

The determination of the charge parameter of an electrochemically activated solution to achieve the level of readiness (breaking bonds between elementary fibers) of the roving to the process of yarn formation depends on the type of fiber used.

To achieve this goal - to obtain a semi-finished product suitable for processing into yarn that meets the requirements of the standard, it is necessary to observe the processing modes listed in the table. The last column of the table shows the qualitative characteristics of the process of pulling rovings obtained according to the proposed method in the exhaust device of a spinning machine, depending on the processing time. These data allow you to set the minimum time required to obtain a positive effect - 30 minutes.

ECA charge of the solution, mV Acidity of ECA solution, pH Fiber type Flexibility mm The content of incrusts,% The content of fibers associated with lignification,% Processing time
ki min Characterization of the drawing process +1000 2.0 Very rude 45-50 above 3,50 thirty fifteen Unstable thirty Stable 60 Stable +700 4.0 Rude 50-55 3.25-3.5 16-25 fifteen Unstable thirty Stable 60 Stable -1000 11.0 Medium soft 55-60 3.00-3.25 14-16 fifteen Unstable thirty Stable 60 Stable -700 9.0 Soft 50-60 2.75-3.00 12-14 fifteen Unstable thirty Stable 60 Stable -500 8.0 Very soft More than 60 up to 2.75 10-12 fifteen Unstable thirty Stable 60 Stable

The useful effect of the present invention is to accelerate the process of forming and preparing rovings for spinning and eliminating bulky and expensive equipment intended for chemical processing of rovings, reducing energy consumption from 4200 kJ per 1 kg of rovings to 5 J / kg, ensuring environmental safety of the process for due to the fact that it does not use chemically hazardous components.

Claims (2)

1. The method of forming and preparing flax rovings for spinning, according to which the sliver coming out of the fume hood is moistened with an electrochemically activated aqueous solution with a redox potential of minus 1000 mV to plus 1000 mV and an acidity of 2-12 pH at a temperature of 16-40 ° C, characterized in that the wetting is carried out directly in the cavity of a chemical reactor designed to obtain an electrochemically activated aqueous solution. 2. The device for implementing the method according to claim 1, consisting of two coaxially arranged electrodes and a ceramic diaphragm installed between them, characterized in that the electrodes are inclined so that their axis coincides with the axis of the processed roving, the central electrode has a tubular shape and perforation in its middle part.

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