RU2810291C1 - Unit for producing sorption-filtering materials from polymer solutions by aerodynamic moulding with increased sorption activity - Google Patents

Abstract

FIELD: nonwoven materials.

SUBSTANCE: unit for producing sorption-filtering nonwoven materials from polymer solutions by aerodynamic moulding is equipped with a system for controlling solution pressure pulsation and fixing a given stretch ratio, contains a unit for preparing the spinning solution, a spinning machine with spinning blocks, a conveyor belt, a washing unit, a dryer and a winding unit for the finished nonwoven material, additionally includes a rotary-plate dispenser for supplying coarse coal filler, productivity of which is synchronized with the amount of spinning solution supplied to the spinning blocks of the forming machine. The total number of nozzles is at least 20, sequentially arranged in a row in the direction of formation of the nonwoven material, forming an underlying bottom layer and a top coating layer of polyurethane, 70% of the nozzles of the total number form an intermediate middle layer of a sorption-active nonwoven material containing coarse activated carbon as a filler, which is fed into the middle of the outflowing spinning jet formed from each unit nozzle using rigid curved tubes fixed in the spinning unit parallel to the unit nozzle at an angle ranging from 25° up to 35° from the vertical direction of movement of the spinning solution for uniform distribution of coarse activated carbon filler across the width of the forming nonwoven material.

EFFECT: improved efficiency of the materials produced.

1 cl, 4 dwg, 2 tbl

Description

The invention relates to the field of producing non-woven materials, namely to a device for producing non-woven sorption-filtering materials from polymer solutions and compositions by aerodynamic molding.

Modern sorption-filtering materials have a sufficient thickness of the working layer, made in the form of fabrics or non-woven materials containing various solid fillers, being elastic sorbents. A special place among the various methods for producing nonwoven materials is occupied by the process of aerodynamic (spunbonding) spinning from polymer solutions, which makes it possible to carry out composite modification of a nonwoven material by introducing a filler into a spinning solution of a synthetic polymer.

There is a known installation for producing nonwoven materials from polymer solutions (US Pat. No. 3320479, 317-2, published May 16, 1967), in which the polymer solution from the collector comes out in the form of a jet, hits a special reflective screen equipped with a guide tray, performing a reciprocating movement along a horizontal axis and carrying out the layout of the forming threads. Additional stretching of the threads before they enter the receiving conveyor is carried out in an electric field.

However, such an installation is characterized by the presence of high stretching gradients, which are provided in high voltage electric fields. The installation is very energy-intensive, economically ineffective, and does not allow the production of multilayer nonwoven materials capable of purifying liquids and gases from dissolved and gaseous impurities.

There is a known installation for producing sorption-filtering fibrous materials from polymer solutions by aerodynamic molding (RF patent No. 62931, D04N 3/16, published May 10, 2007), which makes it possible to obtain multilayer materials with a wide range of filtering and sorbing properties. The installation contains a system for preparing spinning solutions and suspensions based on them, a molding machine with moving spinning blocks that form a fibrous web on a conveyor, a washing machine, a dryer for drying the material and a winding unit for the finished material. The presence in this installation of 3-5 lines for the preparation of spinning solutions, connected by a main line to the corresponding spinning blocks, makes it possible to obtain multilayer sorption-filtering materials consisting of homogeneous or heterogeneous layers.

However, the proposed technological scheme does not provide the possibility of obtaining composite layers that are homogeneous in structure and surface density, included in multilayer composite nonwoven materials (MCNM). As a result, in order to maintain the protective properties, MCNM are produced with an increased surface density of 400-600 g/ ^m2 .

A known installation (RF patent No. 2668446, D04H 3/16, B01J 20/30, published 10/01/2018 BI No. 28) for producing sorption-filtering nonwoven materials with improved properties from polymer solutions by aerodynamic molding, including a system for preventing pressure pulsation spinning solution and maintaining the specified number of spinning hoods, high-speed laying device, specialized systems for washing the solvent and drying the molded material. The specified installation was chosen as a prototype.

However, the proposed technological scheme of this installation and the design solutions of the component units make it possible to obtain a filled fibrous material with a predominantly located filler inside the fibers that form a fibrous (non-woven) canvas in the process of solution (wet) molding and simultaneous aerodynamic stretching. The installation forms a non-woven canvas based on moldable suspensions of fine filler in a solution of a fiber-forming polymer.

In this case, the filler, for example, activated carbon, is located inside the polymer matrix (fibers forming a canvas based on polyacrylonitrile or polyurethane). In this case, the entire surface of the filler particles is surrounded (screened) by polymer (Genis A.V., Kuznetsov A.V., Nekrasov Yu.P., Plastics, 2021, No. 1-2, pp. 38-43). The installation according to the specified prototype makes it possible to obtain filled nonwoven materials with low sorption activity.

The technical problem to be solved by the present invention is the development of an installation for the production of sorption-filtering nonwoven materials for personal respiratory protection equipment (RPPE) and skin protection equipment (PPE), which have an increased protective action time, while maintaining high values of air permeability, which makes wearing comfortable products.

The posed technical problem is solved due to the fact that an installation for producing sorption-filtering nonwoven materials from polymer solutions by aerodynamic molding, equipped with a system for controlling solution pressure pulsation and fixing a given stretch ratio, containing a unit for preparing a spinning solution, a spinning machine with spinning blocks, and a conveyor belt , a washing unit, a dryer and a winding unit for the finished nonwoven material, additionally includes a rotary disc dispenser for supplying coarse activated carbon filler (CAUN), the productivity of which is synchronized with the amount of spinning solution supplied to the spinning blocks of the molding machine, ensuring the formation of carbon-filled three-layer fibrous nonwoven material with interfiber and interlayer distribution of coarse activated carbon filler with its content in the volume of material from 70 to 82%, and the ratio of the speed of outflow of the spinning solution from a single nozzle of the spinning unit to the rotation speed of the rotor of the disc dispenser is in the range from 0.51 to 2.38, wherein the spinning blocks are made conjugate and located in the direction of movement of the conveyor belt, performing a reciprocating movement in the direction perpendicular to the movement of the conveyor belt when the ratio of the total speed of the two spinning blocks to the conveyor speed changes from 30 to 160, having a total number of forming nozzles of at least 20 sequentially located in a row in the direction of formation of the nonwoven material, of which in the first spinning block 15% of the nozzles placed at the beginning of the row of the total number and in the second spinning block 15% of the nozzles placed at the end of the row of the total number form the actual polyurethane layers, forming respectively, the underlying bottom layer and the top covering layer are made of polyurethane, 70% of the nozzles from the total number form an intermediate middle layer of sorption-active nonwoven material containing coarse activated carbon as a filler, and its supply to the middle of the outflowing spinning jet formed from each unit nozzle is carried out at using rigid curved tubes fixed in the spinning unit parallel to a single nozzle at an angle ranging from 25° to 35° from the vertical direction of movement of the spinning solution to uniformly distribute the coarse activated carbon filler across the width of the forming nonwoven material.

The proposed design of the installation combines two independent molding processes: coarse activated carbon filler (CAF) and a polyurethane solution of polymer and fiber, and subsequent aerodynamic stretching and deposition of the latter leads to the simultaneous formation of a carbon-filled fibrous layer with an interfiber and interlayer arrangement of carbon filler, in particular coal with coarse dispersion in the range of 200-500 microns and its complete absence inside the fibers forming the polymer layer.

The use of coarse activated carbon is not accidental, but is due to the fact that this filler is a universal sorbent for organic substances, having a developed surface and a large number of micro- and mesopores, it has a high absorption capacity, determining the mechanism of physical sorption, the share of which in the sorption of NH ₃ , SO ₂ simultaneously with the sorption of organic compounds can reach 50-70%.

This becomes especially noticeable with this method of introducing filler, the particles of which are coarse. In this case, the protective action time (PAT) does not depend on the structure of the matrix as a whole (including the diameter of the fibers), but is determined by the amount of introduced coarse activated carbon filler and the surface density of the composite material.

The invention is illustrated by the following graphics.

In fig. Figure 1 shows a diagram of dosing a polymer solution onto a spinning unit with simultaneous supply of coarse activated carbon filler (CAUN).

In fig. Figure 2 shows a detailed diagram of the operation of a rotary-disc dispenser with a synchronized supply of granular sorbent into two mating spinning units simultaneously with the spinning polymer solution.

In fig. Figure 3 shows the sequence of formation of the underlying layer (layer I), the intermediate middle sorption-filtering layer (layer II) and the covering layer (layer III) of a three-layer nonwoven material.

In fig. Figure 4 shows the lateral arrangement of the sedimentation bath supply systems, the aerodynamic drawing of a jet of polyurethane (PU) solution in dimethylformamide (DMF) in the capillary dies (syringe nozzles) of the spinning unit, the angular supply of granular sorbent by rigid tubes into the middle of the outflowing spinning jet formed from a single nozzle.

The installation consists of a supply line for the spinning solution of the polymer 1, a consumable unit for the spinning solution of the polymer 2, a filter 3, a PID controller 4, a servo pressure control system 5, a gear motor 6 combined with a frequency converter 7, 8, a pump 9 that supplies the spinning solution to the filter, pump 10, supplying the purified spinning solution to the spinning unit 12, rotary disc dispenser 11, spinning unit 12, conveyor belt 13.

The installation combines two independent circuits (Fig. 1). In the first independent circuit, a spinning solution of polyurethane polymer 1 is formed. The circuit is equipped with a tracking system aimed at preventing pressure pulsation when supplying the spinning solution from the spinning solution supply unit 2 to the spinning unit 12, which includes ten capillary dies that perform the functions of a nozzle as part of a blowing device in the spinning unit. block 12.

The tracking pressure control system 5 includes a PID controller 4, a frequency converter 7 combined with a gear motor 6, which reduces the performance of the NSh-20 pump 9, which supplies the spinning solution through a filter 3 to the molding line manifold. Next, the PID controller maintains equality in the performance of the NSh-20 9 pump and the NSh-10 10 pump, depending on the number of spinning positions (nozzles) involved. In this case, the fixed speed of the drawing air ensures the exact flow rate of the spinning solution of the polymer from the capillary dies (nozzles) of the spinning unit 12 due to the presence of a tracking system 8, 10, which reduces fluctuations in the multiplicity of the spin drawing. The jets of polymer solution emerging from the nozzles of the spinning unit 12 under the influence of the air flow form a fibrous web of nonwoven material.

Simultaneously with the compressed air, a precipitation bath representing an aqueous solution of DMF, indicated in the spinning unit 12 in FIG. 1 dotted line.

The precipitation bath is supplied parallel to the spinning jets being formed, emerging from individual nozzles. As a result, the process of stretching the spinning solution jet is accompanied by the process of polymer deposition. In this case, simultaneously with the drawing of the fibers, their orderly laying occurs.

The second circuit is intended for dosing coarse activated carbon filler (Fig. 2), which contains a frequency converter 11.1, a gear motor 11.2, and a rotary disc dispenser hopper 11.3. In general, this block is designated 11 (Fig. 1).

Combining the rotary-plate dispenser 11 with the spinning unit 12 makes it possible to create a unit for producing carbon-filled nonwoven material with an interlayer arrangement of carbon filler. In this case, the spinning unit 12 is equipped with adjacent rigid curved tubes 12.2 for supplying coarse activated carbon filler (CAUN) to the web formation zone of the nonwoven material (Fig. 2, Fig. 4).

A detailed diagram of its operation is presented in Fig. 2. In the rotary disc dispenser 11.3, the working rotating element is a horizontally mounted disk (rotor) with holes of equal diameter, which are filled with granulated coal from the hopper under its own weight. The rotating disk is located between the upper and lower fixed plates (stator) with holes of equal diameter. Filling of the cells in the movable disk occurs when the holes of the upper plate and the disk coincide; spillage of bulk material occurs when the holes of the bottom plate and the disk coincide. The distribution block 11.5 (Fig. 2) is a device for dividing the carbon filler into 14 equal shares with the subsequent transportation of granular carbon filler along flexible guide silicone hoses using compressed air 11.6 coming out of the ejectors 11.7, with the further flow of coarse activated carbon filler into rigid curved dosing tubes 12.2 mounted on spinning blocks 12. On each of the two spinning blocks, seven curved rigid tubes 12.2 are mounted opposite each nozzle 12.1, except for the first, second, third nozzles of the first spinning block I and the eighth, ninth, tenth nozzles of the second spinning block II ( Fig. 2), where pure polyurethane is supplied in the form of a 20% solution in DMF.

The supply of jets of polymer solution from the six indicated nozzles of the I and II block and jets of polymer solution 12.3 simultaneously with granular filler from fourteen metering tubes 12.2 into the middle of the formed outflowing spinning jet from each single nozzle 12.1 at an optimal angle is completed in the main process of web formation of a three-layer carbon-filled nonwoven material at conveyor belt 13 (Fig. 2) with interlayer arrangement of filler.

The speed of flow of the spinning solution from the nozzle is υ _u in m/min. calculated from the continuity equation (1) (Genis A.V., Filbert D.V., Sindeev A.A., Chemical fibers, 1978, No. 3, pp. 27-29):

where Q is the weight feed of the spinning solution, kg/min;

ρ _solution - density of the spinning solution, kg/m ³ ;

d _nozzle - nozzle diameter, m.

In accordance with the parameters of the created equipment, the values of the peripheral speed of the dispenser rotor υ _o.p.d. were measured. , and also recorded the productivity of the dispenser rotor in g/min and the weight productivity of the spinning solution on twenty nozzles of two spinning units.

Table 1 presents the obtained values of the peripheral speed of the rotor, the supply of coal by the rotor, the speed of flow of the spinning solution from the nozzle and the weight supply of the spinning solution to 20 nozzles.

Based on the data obtained, the maximum content of activated carbon in dry polymer (PU) was calculated.

The maximum content of activated carbon in dry polymer is calculated using formula (2):

where W _AC is the maximum content of activated carbon in the sorption-active material;

m _ay - weight supply of activated carbon by the rotor, g/min.;

m _PR - weight feed of the spinning solution, g/min.;

C _PR - concentration of the spinning solution, %.

Taking into account the fact that per unit time of coal flows from 70 to 145 g/min, and a 20% polyurethane solution from (80 to 150 g/min.) x 0.2 contains from 16 to 30 g/min of dry polymer, the percentage the content of coarse activated carbon filler in the fibrous host is from 70/(70+30)⋅100% to 145/(145+30)⋅100%, otherwise from 70 to 82%.

To ensure such a content of activated carbon in the nonwoven fabric, the ratio of the flow rate of the spinning solution from the nozzle to the rotor rotation speed is from 0.51 to 2.38.

When the ratio of these speeds is less than 0.51, unstable formation of jets of spinning solution from the nozzle is observed, and when the ratio is greater than 2.38, insufficient coal content in the canvas is observed.

When forming a fibrous web from a polymer solution with two conjugate spinning blocks I and II located in the direction of movement of the conveyor belt 13 (Fig. 2), performing a reciprocating movement along its width, having a total number of forming nozzles of at least twenty sequentially located in a row in the direction Formation of the non-woven material web, the process of formation of the fibrous non-woven material is completed. When obtaining it, the principle of adding, first of all, sorption (protective) properties (Fig. 3), as well as improving the physical and mechanical properties of the composite three-layer non-woven sorption-filter material as a whole (Table 2) is implemented. From Table 2 it follows that the arrangement of filler particles in the interfiber space increases the elongation at break by more than 3 times (in Table 2, examples 2, 3, 4, 5), due to which the sorption-filtering protective material will have significantly higher elasticity and crease resistance , abrasion resistance compared to a material with filler particles located inside the elementary fibers (Table 2, example 1).

Another advantage of this installation is that the proposed sequence for producing carbon-filled nonwoven material with an interlayer arrangement of coarse activated carbon filler makes it possible to obtain nonwoven materials with increased air permeability (Table 2, examples 2-5). This increases the comfort of wearing the products.

The presence of outer layers of pure PU: underlying layer I and top layer III (Fig. 3) makes such a material suitable for hermetic ultrasonic welding (Table 2, examples 2-4). This is achieved by having in the first spinning unit 15% of the nozzles placed at the beginning of the row of the total number and 15% of the nozzles placed at the end of the row of the total number in the second spinning unit forming pure polyurethane layers, respectively forming the underlying bottom layer I and the top coating layer III (Fig. 3) on the conveyor belt 13 (Fig. 2), 70% of the nozzles of the total number in two blocks form the intermediate (middle) layer II of sorption-filtering nonwoven material.

The specified ratio is ensured under the conditions of realizing uniform web formation of nonwoven material when changing the ratio of the total speed of two spinning blocks 12 to the speed of movement of the conveyor belt 13 in the range from 30 to 160. When the ratio is less than 30, it is not possible to ensure a low surface density (120±20 g/ ^m2 ) while maintaining the required uniformity of web formation of the nonwoven material. Ratios greater than 160 are limited by the technical capabilities of the folding device.

In addition to the uniform distribution of fiber in the volume of the nonwoven material, it is necessary to uniformly distribute the coarse activated carbon filler throughout the volume of the latter. This is achieved at the final stage of molding through the interaction of the previously described contours presented in Fig. 4. Conveyor belt 13 and spinning blocks 12 move in mutually perpendicular directions (12.7 and 12.8). Moreover, blocks 12.1 perform a reciprocating motion. Using twenty nozzles of two spinning units, the spinning solution PU 12.4 is supplied, which is drawn out in the form of jets by compressed air. Fixing the structure of the nonwoven fabric on the conveyor belt 13 is carried out by feeding the precipitation bath 12.5 through special frames 12.6. Fourteen 12.2 dosing tubes, bent to the inside of the spinning block housings and attached to them, serve to supply filler - coal - into the middle of the outflowing spinning jet formed from each individual 12.1 nozzle. In this case, in the process of reciprocating movement of the spinning blocks and individual nozzles 12.1 across the conveyor belt, a uniform distribution of the filler throughout the volume of the fibrous web of nonwoven material is ensured. At angles a from the vertical direction from 25° to 35° (Fig. 4), there is no increased concentration of coarse activated carbon filler at the edges of the nonwoven material web in the extreme right and left positions of the spinning unit.

The resulting nonwoven sorption-filtering material enters a washing machine, where it is washed from the solvent with wash water using simultaneously two principles of washing nonwoven material: using circulation circuits and countercurrent.

The non-woven fabric, washed from the solvent, is fed for drying into a three-section convection-type dryer with continuously adjustable steam supply to heat the air in each section, ensuring that the actual temperature of the heated air is as close as possible to the set temperature, maintaining the temperature with an accuracy of 1°C, as well as implementing a certain the temperature relationship between the dryer zones, eliminating undesirable processes of under-drying and over-drying, ensuring the consistent removal of free, sorbed and hydration moisture. The dried finished nonwoven material is wound into a roll of a given size in the winding unit of the installation.

The installation works as follows.

In the first circuit, a spinning solution is first formed, which is prepared on the basis of a polyurethane polymer (PU) in the solvent dimethylformamide (DMF). The main indicators characterizing the technological properties of the spinning solution are the concentration of the polymer in the solution, viscosity, and stability of the spinning system during storage. Before feeding the spinning solution to the spinning machine, it undergoes additional operations of mixing, deairing, and filtration.

The installation is equipped with a monitoring system that prevents pressure pulsation when supplying the spinning solution from the supply tank to the spinning unit, which includes ten capillary dies with nozzle functions in the system of blowing devices of the spinning unit. Using the NSh-20 pump connected to the specified system, the spinning solution is supplied through a filter to the manifold of the spinning line. Next, the PID controller maintains equality in the performance of the NSh-20 pump and the NSh-10 pump, depending on the number of spinning stations (nozzles) involved. In this case, the fixed speed of the drawing air ensures the exact flow rate of the spinning solution of the polymer from the capillary dies (nozzles) of the spinning unit due to the presence of a tracking system that reduces fluctuations in the multiplicity of the spin drawing. Jets of polymer solution emerging from the nozzles of the spinning unit under the influence of the air flow form a fibrous web of nonwoven material.

The processes of fiber formation and the formation of a nonwoven material web occur almost simultaneously and are combined by one molding stage. The formation of a fibrous web of nonwoven material is carried out as follows: jets of polymer solution emerging from the nozzles are drawn out by compressed air from the built-in blowing devices of the spinning unit. A sprayed precipitation bath is simultaneously supplied to the molding zone. Thus, the process of stretching jets of polymer solution is accompanied by the process of polymer deposition and the formation of thin (40-50 μm) polymer threads. Simultaneously with the drawing, their ordered laying occurs to form the structure of a fibrous web of non-woven material on the surface of the conveyor belt.

In parallel with the first circuit, a second circuit operates, intended for dosing coarse filler. In the second circuit, coarse activated carbon filler (KAUN) is supplied by a drum-plate dispenser using flexible silicone guide hoses and compressed air coming out of the ejectors, with the further flow of carbon filler into rigid curved dosing tubes 12.2 (Fig. 2), mounted on the spinning blocks 12 (Fig. 2).

On both spinning blocks, seven rigid curved tubes 12.2 are fixed opposite each of the nozzles 12.1, except for the first, second and third nozzles of the first spinning block I (Fig. 2) and the eighth, ninth and tenth nozzles of the second spinning block II (Fig. 2), where a pure 20% polymer solution of polyurethane in DMF is supplied.

Supply of jets of “clean” polymer solution from the six indicated nozzles I and II of the spinning unit and jets of polymer solution 12.3 (Fig. 2) simultaneously with granulated carbon filler from fourteen dosing tubes into the middle of the formed outflowing spinning jet from each individual nozzle at the selected optimal angle a together they provide the process of formation of a three-layer carbon-filled nonwoven material on a conveyor belt 13 with an interfiber and interlayer arrangement of coarse activated carbon filler (CAUN).

Orderly laying of fiber with the formation of a uniform structure of the fibrous web of nonwoven material is realized due to the reciprocating movement of two conjugate spinning blocks in the direction perpendicular to the movement of the conveyor belt when the ratio of the total speed of the two spinning blocks to the speed of movement of the conveyor belt changes from 30 to 160.

The simultaneous supply of carbon filler through curved tubes fixed to the spinning blocks, directed to the inside of their bodies during the reciprocating movement of the latter, additionally ensures uniform distribution of the filler throughout the volume of the fibrous web of nonwoven material.

A homogeneous three-layer web of nonwoven material formed in this way with an interfiber and interlayer arrangement of KAUN is supplied to a washing machine using simultaneously two principles of washing nonwoven material. Using circulation circuits and countercurrent, the nonwoven fabric, washed from solvent, is fed for drying into a three-section convection-type dryer with continuously adjustable steam supply to heat the air in each section.

Maintaining the temperature with an accuracy of 1°C, as well as implementing a certain temperature ratio between the dryer zones, eliminating undesirable processes of under-drying and over-drying, ensure the consistent removal of free, sorbed and hydration moisture. The dried finished nonwoven material is wound into a roll of a given size in the winding unit of the installation.

The invention is illustrated by the following examples:

Example 1.

The installation operates in a technological mode that makes it possible to obtain carbon-filled material corresponding to clause 2 (Table 2). The spinning solution is prepared on the basis of PU in DMF. After deairing and filtration operations, the spinning solution from the supply tank 2 of FIG. 1 is fed into the first circuit to two spinning blocks 12 containing twenty syringe dies (nozzles), ten in each spinning block. The mass flow rate for each die-nozzle is 7.5 g/min, corresponding to a solution flow rate of 3.73 m/min. The total amount of solution supplied to 20 spinning nozzles is 150 g/min, which in terms of “dry” polymer corresponds to 30 g/min, taking into account the 20% concentration of the spinning solution.

In addition to the spinning solution, compressed air at a speed of 180 m/s and a precipitation bath in the form of a 20% solution of DMF in water are simultaneously supplied to the spinning unit through reinforced hoses.

The second circuit is designed for dosing coarse activated carbon filler (KAUN). The combination of a rotary-disc coal dispenser 11 with a spinning unit 12 makes it possible to create a unit for producing coal-filled material with an interlayer arrangement of coal. In this case, the spinning unit is equipped with adjacent curved tubes for supplying activated coarse carbon into the web formation zone of the nonwoven material. Coal is supplied by a rotating horizontal disk-rotor through holes of equal diameter.

Filling of the cells in the movable disk occurs when the holes of the upper plate (stator) and the movable disk coincide; spillage of activated carbon is observed when the holes of the lower plate (stator) and the specified disk coincide. Next, through a distribution device with the help of compressed air coming out of the ejectors, granular coal is transported through flexible guide silicone hoses. Then the carbon filler (KAUN) enters rigid curved metering tubes mounted on the spinning blocks, seven rigid tubes opposite each nozzle, except for the first, second, third nozzles of the first spinning block; the eighth, ninth, tenth nozzle of the second spinning unit, where pure PU is supplied in the form of a 20% solution of the polymer in DMF.

Thus, fixing the spinning solution feed speed at 3.73 m/min. designated as υ _p.r. =3.73 m/min corresponding to the weight flow rate of the spinning solution of 7.5 g/min entering one nozzle and the rotor peripheral speed of 1.57 m/min, designated d _o.p .=1.57 m/min. provides a coal content in the canvas of 70% (70/(70+150x0.2)=70%), as well as the ratio υ _p.r. /υ _o.r. =2.38.

With the established ratio of the total speed of two spinning blocks (30 m/min) to the speed of the conveyor belt (0.4 m/min) equal to 75, conditions are provided for obtaining a uniform structure of a carbon-filled fibrous web of nonwoven material with a surface density of 300-350 g/ ^m2 , which has a good air permeability in the range of 230-250 dm ³ / m ² ⋅s, measured on a FF-12 device from Metrimtex according to GOST 12088-77.

The indicators of sorption capacity and time of protective action (PTA) indicated in line 2 (table 2), column 9 and 10, are equal to 170-190 mg/g and 15-22 minutes, respectively, determined on the DP-3 device according to GOST 12.4.158 -90; GOST 12.4.159-90. The latest PDM indicator is close to the Gost standard (GOST R 59959-2021).

Example 2.

The installation operates in a technological mode that makes it possible to obtain carbon-filled nonwoven material corresponding to clause 3 (Table 2). The preparation and supply of the spinning solution is carried out similarly to example 1. The mass flow rate for each die-nozzle is 7.5 g/min, which corresponds to the flow rate of the spinning solution 3.73 m/min.

The total amount of solution supplied to 20 nozzle dies is also 150 g/min, which in terms of dry polymer corresponds to 30 g/min. At the installation, as in example 1, compressed air and a precipitation bath are supplied in parallel. The quantitative supply of activated carbon is 120 g/min, which corresponds to a rotor peripheral speed of 3.08 m/min. As a result, the coal content of the canvas is 80% (120/(120+150x0.2)=80%), as indicated in row 3, column 4 (Table 2). In this case, the ratio of the spinning solution feed rate υ _p.r. =3.73 m/min to the value of the rotor peripheral speed υ _o.r. =3.08 m/min is equal to υ _p.r. /υ _o.r. =1.21.

With the established ratio of the total speed of two spinning blocks (30 m/min) to the speed of the conveyor belt (0.4 m/min) equal to 75, the conditions for obtaining a uniform structure of carbon-filled fibrous canvas with a surface density of 300-350 g/m ² are provided. Good air permeability of the carbon-filled material is maintained (column 7, table 2).

Due to the increased content of filler up to 80%, the values of sorption capacity indicators increase to 190-210 mg/g and the time of protective action (PAA) increases by more than 2 times (columns 9 and 10, table 2), relative to the 15 min indicator specified in GOST R 59959-2021.

Example 3.

The installation has the same configuration as in examples 1 and 2, it operates in a technological mode that makes it possible to obtain carbon-filled material corresponding to clause 4 of table 2. The preparation and supply of the spinning solution is carried out similarly to examples 1 and 2. The mass flow rate of the spinning solution for each die-nozzle at 7.5 g/min and a total of 20 die-nozzles at 150 g/min, which, in combination with the established quantitative supply of activated carbon at 120 g/min, ensures its content in the canvas in an amount of 80%.

Increased coal content is not the only source of increased PVD, as in example 2 (column 10, table 2). An increase in the surface density of the fibrous canvas to 450-550 g/m ² (column 7, table 2) further increases the value of the ESD to 50-62 min. This is achieved by reducing the conveyor belt speed (υ _t ) to 0.25 m/min. At the same time, the ratio of the total speed of two spinning blocks υ _pr.bl increases to 120. =30 m/min and conveyor belt speed υ _pr.bl. / υ _t =30/0.25=120.

Thus, the installation for producing sorption-filtering nonwoven materials from polymer solutions using the aerodynamic molding method of the present invention makes it possible to obtain sorption-filtering nonwoven materials for personal respiratory protection equipment (RPPE) and skin (PIPE), which have an increased protective action time, while maintaining high values an indicator of breathability, which determines the wearing comfort of products.

Claims (1)

Installation for producing sorption-filtering nonwoven materials from polymer solutions by aerodynamic molding, equipped with a system for controlling solution pressure pulsation and fixing a given stretch ratio, containing a unit for preparing a spinning solution, a spinning machine with spinning blocks, a conveyor belt, a washing unit, a dryer and a winding unit for the finished product. nonwoven material, characterized in that it additionally includes a rotary disc dispenser for supplying coarse activated carbon filler, the performance of which is synchronized with the amount of spinning solution supplied to the spinning blocks of the molding machine, ensuring the formation of a carbon-filled three-layer fibrous nonwoven material with interfiber and interlayer distribution of coarse activated carbon filler with its content in the volume of material from 70 to 82%, and the ratio of the speed of outflow of the spinning solution from a single nozzle of the spinning block to the rotation speed of the rotor of the disc dispenser is in the range from 0.51 to 2.38, while the spinning blocks are made conjugate and located in the direction of movement of the conveyor belt, performing a reciprocating movement in the direction perpendicular to the movement of the conveyor belt when the ratio of the total speed of two spinning blocks to the speed of movement of the conveyor changes from 30 to 160, having a total number of forming nozzles of at least 20, sequentially located in a row in the direction forming a non-woven material, from which in the first spinning unit 15% of the nozzles placed at the beginning of the row of the total number and in the second spinning unit 15% of the nozzles placed at the end of the row of the total number form polyurethane layers, respectively forming the underlying bottom layer and the covering top layer made of polyurethane, 70% of the total number of nozzles form an intermediate middle layer of sorption-active nonwoven material containing coarse activated carbon as a filler, and its supply to the middle of the outflowing spinning jet formed from each individual nozzle is carried out using fixed in the spinning block parallel to the individual nozzle rigid curved tubes at an angle ranging from 25° to 35° from the vertical direction of movement of the spinning solution for uniform distribution of coarse activated carbon filler across the width of the forming nonwoven material.