The method of manufacture of aramid paper

 

(57) Abstract:

The essence of the invention: paper weight further comprises a waste uncalendered aramid paper density of 0.10 to 0.40 g/cm and a thickness 0,050 2,50 mm Paper weight contains the following components, wt. fibrid of polymethacrylamide 5,0 87,5; cut synthetic fiber to 12.0 85.0 and waste nagalandiana aramid paper of 0.5 and 10.0. In the preparation of paper pulp waste nagalandiana paper is subjected to the primary first dissolved in the pulper with mass fraction of suspended solids 0,2 3,2 for 20 to 60 min, and then further dissolution and refining by successively passing the resulting suspension through antiper with a gap between the grinding elements 1.5 to 2.5 mm and through one or more of Antiparos with a gap between the grinding elements 0,2 0,5 mm or one or more conical or disc mills in the specific consumption of useful energy of 100 to 1500 kJ/kg 1 tab.

The invention relates to the technology of paper-based synthetic fibers, namely the manufacturing process aramid paper containing fibrous film binders (fibrid) from polymethacrylamide and cut synthetic fiber and pregnation.

A known method of manufacturing aramid paper by preparing paper pulp containing fibrid of polymethacrylamide and cut synthetic polyester fiber, low tide paintings of paper from pulp, pressing, drying and subsequent calendering of the paper [1]

There is also known a method of manufacture of aramid paper by preparing paper pulp containing fibrid and cut synthetic fiber, both components of polymethacrylamide, at a ratio, by weight. (15:85)-(90:10), low tide paintings of paper from pulp, pressing, drying (at a temperature of up to 185aboutC) and subsequent calendering of paper (240-320about(C) [2]

In these ways as raw material for the manufacture of paper used only the original fibrous components fibrid and cut the fiber. Meanwhile, in the paper production process aramid produce large amounts of dry her waste in the form of disruption of the canvas, filling ends, rests on the sleeves and so on, returning to the main production process would reduce the consumption of expensive and scarce source of fibrous components and, consequently, to reduce the cost of paper.

The aim of the invention CLASS="ptx2">

This objective is achieved in that in the method of manufacturing aramid paper by preparing paper pulp containing fibrid of polymethacrylamide and cut synthetic fiber, low tide paintings of paper from pulp, pressing, drying and subsequent calendering of the paper, the mass further comprises a waste uncalendered aramid paper density of 0.10-0.40 g/cm3and thickness 0,050-2.50 mm in the following ratio of components, weight, wt.

Fibrid from polymeta - phenylenedimaleimide 5,0-87,5

Cut synthetic fiber 12,0-85,0

Waste neilander - EN-aramid paper of 0.5-10,00

In preparing paper pulp waste uncalendered paper is subjected to the primary first dissolved in the pulper with mass fraction of suspended solids of 0.2-3.2% in techenie 20-60 min, and then further dissolution and refining by successively passing the resulting suspension through antiper with a gap between the grinding elements 1.5-2.5 mm and through one or more of Antiparos with a gap between the grinding elements of 0.2-0.5 or one or more conical or disc mills in the specific consumption of useful energy 100-1500 kJ/kg.

At the same time, although unity, but to reduce the degree of non-uniformity in thickness.

Predlagaemy method significantly differs from the known methods for the production of aramid paper, since it provides for the introduction of pulp waste uncalendered paper, not previously carried out in the manufacturing process of the aramid paper and considered possible (without compromising quality) for technology for aramid and many other types of paper-based synthetic fibrous components. In this case, the conventional wisdom was due to irreversible changes in the structure of hibrido during the drying of paper, as well as significantly less hydrophilic and, therefore, much weaker plasticizing effect of water on polymethylpentene compared to cellulose (edge bonoloto, cut off at the end of the paper machine wire section and having a humidity of about 90% of the so-called "wet waste" is returned in the paper production process after the dissolution of the couch-pool or gidrorazbivatele. (Gutman B. B. Yanchenko L. N. Gurevich, L. I. Paper from synthetic fibers. M. Forest industry, 1971, S. 104).

In addition, it was believed that the passage donnovan which led to the formation of fibrous aggregates (chapeaurouge), reducing the uniformity of the paper pulp, the formation and worsening of the properties of the final material, especially in the case when such long-fibre components are mixed with more flexible components of hibrido (Gutman, B. B. and others).

Manufacturer of aramid paper on the proposed method produces the following way. Fibrid of polymethacrylamide and cut synthetic fiber separately dispersed in hydromassages when the mass fraction of suspended solids 0,3-3,0%

Waste uncalendered aramid paper density of 0.10-0.40 g/cm3thickness of 0.05-2.5 mm dismiss in gidrorazbivatele when the mass fraction of suspended solids 0,2-3,2% within 20-60 minutes Specified limits changes in the density and thickness of the uncalendered paper cover the whole possible range of variation of the properties of the aramid paper, being formed by the continuous scheme at PM.

After the initial dissolution, without changing the mass fraction of suspended solids resulting suspension, take further dissolution of the waste by passing the suspension through intestines when the gap between the grinding elements 1.5 to 2.5 mm, Then the suspension of waste is passed either through intestines or system intestinew when the gap between the Mr. popular useful energy 100-1500 kJ/kg Depending on the specific conditions of the waste slurry passes through the grinding equipment once or is recirculated through the equipment during the time required for the dissolution of all major units voloknistych components.

Suspension hibrido cut synthetic fibers and flowing waste uncalendered paper are mixed in a given proportion in the composition of the pool, the pool is adjusted mass or in the machine pool.

The cooked pulp is served in the pressure line stock pump, feed inlet device machine. And the tide (the speed of 9-12 m/min), pressing (linear pressure of 15-40 kg/cm), drying (temperature 70-190aboutC) and subsequent calendering (temperature 200-290aboutWith a linear pressure of 400 to 600 kgf/cm) are made of aramid paper.

The main parameters of the stage of dissolution of the waste and the parameters of the final paper are summarized in table.

P R I m e R 1. In the pulper "Bruderhaus-Grubbers", type 0,5 R useful volume of 0.5 m3load 16 kg of dry waste uncalendered aramid paper density of 0.40 g/cm3and a thickness of 0.10 mm, containing fibrid and the 6 mm polyester fiber polyester with a linear density of 0.17 Tex (TC 6-06-C-87) at the ratio of these components (wt.) 87,9:12,1.

After the initial dissolution within 20 min (mass fraction of suspended solids 3,2%) carry out further dissolution by successively passing the resulting suspension (recirculation when the pump capacity of 2.5 DM3/s) through antiper (which is used as a conical mill refiner "Bruderhaus-Grubbers" with the truncated cone type 510, at a fixed gap between the rotor blades and stator) in the following mode: when the gap between the grinding elements 2.0 mm 20 min, with a gap of 0.5 mm to 30 minutes

The result is a suspension flowing waste uncalendered aramid paper that does not contain large aggregates of fibrous components, in which the fiber Dacron retained its original length (6 mm).

After that, the suspension flowing waste is pumped into the machine pool, where it is mixed with a suspension of hibrido of polymethacrylamide (the degree of grinding 40aboutSHR, the indicator of average length on device Ivanov sheer mesh 91 DG) and the suspension cut ripe for 6 mm fiber polyester with the formation of paper pulp in the following ratio, wt. fibrid 87,5; cut fiber 12, 0mm; waste paper 0,5.

Then the mass is Reena inlet 500 mm, double cloth pressure drying cylinder Yankees and gas infraventures drying. As a result of low tide (speed 12 m/min, the mass fraction of sediment in the inlet device 0,03%), pressing (linear pressure of 40 kgf/cm), drying (temperature of the drying cylinder 120aboutWith, infrasauna drying is not involved) and subsequent calendering on a 4-shaft calandre "ramish (temperature 200aboutWith a linear pressure of 400 kgf/cm) are made of aramid paper, parameters of which are given in the table.

P R I m m e R 2. Analogously to example 1) conduct initial dissolution of waste uncalendered aramid paper in the pulper and the further dissolution by recycling the resulting suspension through antiper when the gap between the grinding elements 2.0 mm for 20 min recirculation when the pump capacity of 2.5 DM3/cm and through the refiner-conical mill "Bruderhaus-Grubbers", type 510, when the specific consumption of useful energy of 100 kJ/kg.

The result is a suspension flowing waste uncalendered aramid paper that does not contain large aggregates of fibrous components, in which the average fiber length polyester is 2.1 mm

Then, analogichnoi the following ratio of components, wt. fibrid 87,5; cut fiber 12, 0mm; waste paper 0,5.

In the low tide, pressing, drying and subsequent calendering (all as in example 1) are made of aramid paper, parameters of which are given in the table.

P R I m e R 3. In the pulper "Bruderhaus-Grubbers", type 8R, useful volume of 8 m3load 30 kg of dry waste uncalendered aramid paper density of 0.29 g/cm3and a thickness of 0.22 mm, containing fibrid of polymethacrylamide and cut fiber phenylon " cutting length of 6 mm and a linear density of 0.22 dtex (fiber, polyaramid threads with improved characteristics for technical papers, THE 6-13-0209562-51-90) when the ratio of these components (wt.) 50:50.

After the initial dissolution within 50 min (mass fraction of suspended solids 0,38%) carry out further dissolution by successively passing the resulting suspension when the pump capacity of 8.3 DM3/s through the labyrinth antiper "Bruderhaus-Grubbers", type AB-2 with a gap between the grinding elements 2.5 mm and two Antiparos (which use the conical refiners mill "Bruderhaus-Grubbers", type I, with a fixed gap between the rotor blades and a hundred is C waste in a specified grinding equipment receive a suspension, does not contain large aggregates of fibrous components, in which the fiber phenylon " retained its original length (6 mm).

After that, the suspension flowing waste uncalendered aramid paper is served in the pool adjusted mass, where it is mixed with a suspension containing the source fibrid (the degree of grinding 51aboutSHR, the indicator of average length 105 DG) and cut the fiber phenylon " with the formation of the paper pulp with the following ratio of components, wt. fibrid 47,5; fiber 47,5; waste paper 5,0.

Then the weight of the machine through the pool and serves on the paper machine "Bruderhaus" with the forming device "But The Former" the width of the overlap 2250 mm, double cloth pressure 16 and the drying cylinders.

As a result of low tide (speed 10 m/min, the mass fraction of sediment in the inlet device 0,04% ), pressing (linear pressure of 30 kgf/cm), drying temperature drying cylinders 70-110aboutC) and subsequent calandrinia 4 shaft calandre "ramish (temperature 290aboutWith a linear pressure of 600 kgf/cm) are made of aramid paper, parameters of which are given in the table.

P R I m e R 4. Analogously to example 3 perform prohozhdenie the resulting suspension through antiper "Bruderhaus-Grubbers", type AB-2, with a gap between the grinding elements 2.5 mm Then make final dissolution and refining of waste through their suspension (recirculation for 25 min at a pump capacity of 8.3 DM3/C) via two conical refiner mill "Bruderhaus-Grubbers", type I and disk mill MD-00 at specific consumption of useful energy 1100 kJ/kg.

The result is a suspension of crushed waste uncalendered aramid paper that does not contain large aggregates of fibrous components, in which the average fiber length phenylon " is 1.7 mm

Then, similarly to example 3, the waste slurry is mixed with a suspension of hibrido and cut fiber phenylon " with the formation of the paper pulp with the following ratio of components, wt. fibrid 47,5; fiber 47,5; waste paper 5,0.

In the low tide, pressing, drying and subsequent genandrialine (all as in example 3) are made of aramid paper, parameters of which are given in the table.

P R I m e R 5. In the pulper "Bruderhaus-Grubbers", type 0,5 R zagruzayu 1 kg of dry waste uncalendered aramid paper density of 0.10 g/cm3and thickness of 2.50 mm, containing fibrecement M M and other New heat-resistant and fire-protected, hygienic textile fibers and yarn Tegelen. In kN. Chemical fiber, fibrous and composite materials for technical purposes. M NITAI, 1990, S. 114-116) when the ratio of these components (wt.) 5,6:94,4.

After the initial dissolution within 60 min (mass fraction of suspended solids 0,20%) carry out further dissolution by passing the resulting suspension through antiper (which is used as the conical refiner mill "Bruderhaus-Grubbers", type 510, with a fixed gap between the rotor blades and stator) in the following mode: when the gap between the grinding elements 1.5 mm and 20 minutes of recirculation when the pump capacity of 2.5 DM3/s, with a gap of 0.3 mm in a single pass of the suspension.

The result is a suspension flowing waste uncalendered aramid paper that does not contain large aggregates of fibrous components, in which the fiber Tegelen retained its original length (5 mm).

After that, the suspension flowing waste is pumped into the machine pool, where it is mixed with a suspension of hibrido of polymethacrylamide (the degree of grinding 49aboutSHR, the rate of srednevekov, wt. fibrid 5,0; cut fiber 85,0; waste paper 10,0.

Then the mass is fed to a paper machine described in example 1. As a result of low tide (speed 9 m/min, the mass fraction of sediment in the inlet device 0,06%), pressing (linear pressure of 15 kgf/cm), drying (temperature of the drying cylinder 120aboutWith the temperature infraventures drying chamber 190aboutC) and subsequent calendering on a 4-roll calender "Ramesh" (temperature 250aboutWith a linear pressure of 450 kgf/cm) are made of aramid paper, parameters of which are given in the table.

P R I m e R 6. In the pulper "Bruderhaus-Grubbers", type 0,5 R load 1 kg of dry waste uncalendered aramid paper density of 0.21 g/cm3and a thickness of 0.24 mm, containing fibrid of polymethacrylamide and cut fiber phenylon " cutting length of 6 mm and a linear density of 0.22 Tex when the ratio of these components (wt.) 60:40.

After the initial dissolution within 30 min (mass fraction of suspended solids 0,20%) carry out further dissolution by passing the resulting suspension through antiper when the gap between the grinding elements 1.5 mm (as in example 5), and further, the dissolution and refining by od the efficiency of the pump 2,5 DM3/s and the specific consumption of useful energy 1500 kJ/kg.

The result is a suspension flowing waste uncalendered aramid paper that does not contain large aggregates of fibrous components, in which the average fiber length phenylon " is 2.4 mm

After that, the suspension flowing waste is pumped into the machine pool, where it is mixed with a suspension of hibrido of polymethacrylamide (the degree of grinding 55aboutSHR, the indicator of average length of 80 DG) and cut fiber phenylon " with the formation of paper pulp in the following ratio, wt. fibrid 58,2; cut fiber 38,8; waste paper 3,0.

Then the mass is served on paper musinu described in example 1. As a result of low tide (speed 10 m/min, the mass fraction of sediment in the inlet device 0,04%), pressing (linear pressure 22 kg/cm), drying (temperature of the drying cylinder 130aboutWith, infrasauna drying is not involved) and then calandrinia 4 roll calender "ramish (temperature 230aboutWith a linear pressure of 500 kgf/cm) are made of aramid paper, parameters of which are given in the table.

P R I m e R 7 (prototype). Make Arie hibrido and cut fiber (at a ratio of these components (wt.) 87,9:12,1 without adding suspension flowing waste uncalendered paper. Indicators of the paper is given in the table.

P R I m e R 8 (prototype). Made of aramid paper as in example 3, but with the difference that during the formation of paper pulp mixed suspension hibrido and cut fiber (at a ratio of these components (wt.) 50:50 without adding suspension flowing waste uncalendered paper. Indicators of the paper is given in the table.

P R I m e R 9 (prototype). Made of aramid paper as in example 5, but with the difference that during the formation of paper pulp mixed suspension hibrido and cut fibers at a ratio of these components (wt.) 5,6:94,4 without adding suspension flowing waste uncalendered paper. Indicators of the paper is given in the table.

P R I m e R 10 (prototype). Made of aramid paper as in example 6, but with the difference that during the formation of paper pulp mixed suspension hibrido and cut fibers at a ratio of these components (wt.) 60:40 without adding suspension flowing waste uncalendered paper. Indicators of the paper is given in the table.

P R I m e R 11. Made of aramid paper as in example 4, but with the difference that when Sanogo fiber in the following ratio of components, wt. fibrid 44,0; cut fiber 44,0; waste paper 12,0. Indicators of the paper is given in the table.

P R I m e R 12. Cook pulp as in example 3, but with the difference that after the initial dissolution of the waste uncalendered paper in the pulper and passing the resulting suspension through antiper with a gap between the grinding elements 2.5 mm, the suspension passes through antiper with a gap between the grinding elements 0,1 mm

The result is a suspension flowing waste neelakurunji aramid paper containing a significant number of large aggregates of fibrous components.

After preparation of the final paper pulp, shimmer paper, pressing and drying (all as in example 3) get the uncalendered aramid paper containing a significant number of petals and are therefore not suitable for subsequent genandrialine.

P R I m e p 13. Cook pulp as in example 3, but with the difference that after the initial dissolution and passing the resulting suspension through antiper with a gap between the grinding elements 2.5 mm, the suspension passes through antiper with a gap between grind the amide of paper, containing a significant number of large aggregates of fibrous components.

After preparation of the final paper pulp, shimmer paper, pressing and drying receive uncalendered aramid paper containing a significant number of petals and are therefore not suitable for subsequent calendering.

P R I m e R 14. Conduct initial dissolution of the waste uncalendered aramid paper as in example 1, but with the difference that in the pulper download 17.5 kg of dry waste paper, which corresponds to the mass fraction of suspended solids, 3.5% of Mixing is difficult, the dissolution of the waste is uneven and it has to stop.

As follows from the table, the proposed method for the manufacture of aramid paper significantly reduces the flow of the original fibrous components, and hence the cost of paper, while maintaining its operating characteristics at the same level, because it allows us to use as an additional source of raw materials waste uncalendered paper.

From a comparison of the conditions of the manufacture and properties of aramid paper of examples 1, 2 and 7 (prototype), examples 3 the W uncalendered paper within 0.5 to 10.0% (examples 1 and 2 0.5% example 6 3.0% examples 3 and 4 5.0% example 5 10,0%) indicators of quality aramid paper do not differ from those for paper in the manufacture of which paper pulp contained only source of fibrous components fibrid and cut the fiber and does not contain waste. So for paper produced according to examples 5 and 9 (prototype) destructive force in the machine direction is 4.6 and 4.5 kgf, in cross-2.3 and 2.2 kg, respectively, elongation and tensile strength in the machine direction is 3.4 and 3.3% in the transverse direction of 3.4 and 3.4%, respectively, resistance to tear in the machine direction is 6.4 and 6.3 kgf, transverse to 3.6 and 3.6 kg, respectively, dielectric strength 7 and 7 kV/mm, respectively.

When the contents of the waste paper pulp more than 10% of the quality indicators aramid paper are reduced. This is evident when comparing the properties of paper made according to example 11 (the content of the waste in the mass of 12.0%) indicators paper examples 5 and 9 (prototype) above. So destructive force decreases in the machine direction from 4.5 to 4.6 to 4.2 kgf, in a cross from 2.2 to 2.3 to 1.9 kgf; elongation at elongation decreases from 3.4 to 3.2% resistance to strain is reduced in the machine direction with 6,3-6,4 kg to 5.9 kgf, in a cross from 3.6 to 3.3 kgf.

Introduction to paper weighing less than 0.5% of the waste is impractical from an economic point of view, since it requires all additional operations on the dissolution of the waste, and the floor is about to 87.5 (examples 1 and 2) wt. When smaller proportion of hibrido in the composition forming the paper web on a paper making machine is unstable due to frequent breakages. When the mass fraction of hibrido over 87.5% molding paper is difficult due to the very high resistance of the mass filter.

These limits content in the mass of hibrido and waste uncalendered paper determine the limits of the content in the mass cut synthetic fibers: from 12.0 wt. (examples 1,2) to 85.0 wt. (example 5).

In the examples shown the initial dissolution of the waste uncalendered aramid paper in the pulper for 20 (examples 1 and 2), 30 (example 6), 50 (example 3 and 4) and 60 (example 5) minutes When dissolution within less time resulting suspension contains large areas of aramid paper, which can cause clogging of pumps and subsequent grinding equipment, 60 min are sufficient duration of initial dissolution of the waste uncalendered paper in the entire range of thicknesses and densities.

In the examples, the method is mass fraction of suspended solids in the dissolution of the waste is 0.20 (examples 5 and 6), 0,38 (examples 3 and 4), and 3.2 (examples 1 and 2)% Make the initial dissolution of the waste in wt and increases the energy cost. The excess mass fraction of suspended solids values of 3.2% (example 1.4 to 3.5%) leads to difficulties when mixing and uneven primary dissolution.

The following examples show the possibility of varying the gap between the grinding elements of the first antiper in the range of 1.5-2.5 mm (examples 5 and 6 1.5 mm; examples 1 and 2 2.0 mm; examples 3 and 4 2.5 mm). The reduction of the gap between the grinding elements of the first antiper below 1.5 mm is impractical due to the increasing danger of blockage of its mass, and the corresponding increase of the load on the motor. At the same time, the upper boundary of the specified gap (2.5 mm) is defined as the characteristics of standard equipment, and increase the probability (in the case of larger gap) driving mills and increasing the load on them.

When carrying out the last stage of dissolution of the waste through their suspension through antiper with a gap between the grinding elements 0.2-0.5 mm degree of non-uniformity of bitumen in thickness remains approximately at the same level as in the manufacture of paper without adding waste mass (examples 1, 3 and 5 on the one hand and examples of prototypes 7, 8 and 9 on the other). So the coefficient of variation in paper thickness saltstone.

When reducing the gap between the grinding elements to a value of less than 0.2 mm (example 12 0.1 mm) cut synthetic fiber Travemunde, in suspension form of additional units (flocculation), and after formirovaniya at PM paper contains a noticeable amount of petals and is not subject to calendering. If you increase the specified clearance in excess of 0.5 mm (example 13 0.7 mm) in the mass remains a significant number of primary units, and the paper has the same defects as in the previous case.

The final dissolution of the waste uncalendered aramid paper simultaneously with the grinding by passing the suspension of waste through one or more conical or disc mills (examples 2, 4 and 6) leads, in addition, to reduce the unevenness of the paper thickness. So the coefficients of variation in paper thickness are according to examples 2 and 7 (prototype) of 6.1 and 7.2%, respectively, in examples 4 and 8 (prototype) of 6.7 and 9.2%, respectively, as in examples 6 and 10 (prototype) of 7.2 and 8.5%, respectively.

Specific consumption of useful energy 100-1500 kJ/kg at the time of suspension of waste through the mill (example 2 100 example 4 1100, example 6 1500 kJ/kg) limits are the limits, beyond cataractogenesis work equipment (lower limit).

Conducted laboratory experiments, and made an experimental batch of paper in the experimental and industrial production.

The use of the proposed method of manufacture of aramid paper will reduce the flow of the original fibrous components and the cost of paper, while maintaining its performance.

The METHOD of manufacture of ARAMID PAPER, including the preparation of paper pulp containing fibrid of polymethacrylamide and cut synthetic fiber, low tide of the paper web, pressing him, drying and subsequent calendering, characterized in that the paper weight further comprises a waste uncalendered aramid paper density of 0.10 to 0.40 g/cm3and thickness of 2.50 mm 0,050 in the following ratio, wt.

Fibrid of polymethacrylamide 5,0 87,5

Cut synthetic fiber 12,0 85,0

Waste uncalendered aramid paper 0,5 10,0

in preparing paper pulp waste neelankarai paper previously subjected to primary dissolution in gidrorazbivatele when the mass fraction of suspended solids of 0.2 to 3.2% for 20 to 60 min, and then further dissolution and refining by posledovati through one or more of Antiparos with a gap between the grinding elements 0,2 0,5 mm or one or more conical or disc mills in the specific consumption of useful energy of 100 to 1500 kJ/kg

 

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