CN102228764A - Basalt fiber coating film filter material - Google Patents

Abstract

The invention relates to a basalt fiber film-coated filter material, which is formed by dewaxing the basalt fiber bulky yarn base cloth, impregnating the surface treatment solution, baking, and then laminating it with a PTFE film under high temperature and hot pressing; the aforementioned surface treatment solution It is a water-based mixed solution prepared according to the following weight ratio: PTFE emulsion 5%~40%, waterproofing agent 0.3%~5%, coupling agent 0.05%~5%, and the balance is water. The invention can be used for a long time at a high temperature of 300°C, and the filtration efficiency of dust below 1 μm can reach 99.995%.

Description

A kind of basalt fiber membrane filter material

technical field

The invention relates to an ultra-high temperature, corrosion-resistant high-performance film-coated filter material in the high-temperature flue gas filtration industry, in particular to a basalt fiber film-coated filter material.

Background technique

With the development of industry, the working conditions of the high-temperature flue gas filtration industry are becoming more and more complex and diverse. In the face of harsh working conditions, how to perform high-efficiency filtration while ensuring and prolonging the service life of filter bags, ensuring filtration efficiency, and achieving the purpose of environmental protection is a problem. A long-term project is required.

The base material of the existing high-temperature filter material is mainly glass fiber fabric or a mixed fabric of glass fiber and other fibers, and the maximum service temperature is 250°C. In addition, there are needle-punched felts made of chemical fibers such as aramid fiber and acrylic with low temperature. , the use temperature does not exceed 200 ℃.

Contents of the invention

The purpose of the present invention is to prepare a basalt fiber film-coated filter material with high temperature resistance and corrosion resistance, in order to solve the problems of excessive dust temperature, complex composition, short service life of filter material and low filtering effect in some high-temperature flue gas filtration industries .

After research, the applicant found that compared with carbon fiber, aramid fiber, ultra-high molecular weight polyethylene fiber and other fibers, in addition to the characteristics of high strength and high modulus, continuous basalt fiber also has good temperature resistance (-269 ~ 650 ℃), Anti-oxidation, anti-radiation, heat and sound insulation, good filterability, high compressive strength and shear strength, suitable for use in various environments and other excellent properties. The operating temperature range of continuous basalt fiber is -269~650°C (softening point is 960°C), while that of glass fiber is -60~450°C. When the continuous basalt fiber works at 400°C, its post-break strength can maintain 85%; when it works at 600°C, its post-break strength can still maintain 80% of its original strength; It can maintain 50% to 60% of its strength, and the glass wool is completely destroyed. The oxidation resistance of carbon fiber is poor, and CO and CO ₂ are produced at 300°C, and the maximum use temperature of meta-aramid fiber is only 250°C. The acid and alkali resistance and corrosion resistance of the fabric produced by basalt are also better than the currently commonly used glass fiber base cloth.

Based on the above research, the applicant proposes a base fabric made of basalt fiber, and then uses the surface filtration characteristics of PTFE membrane to laminate the two, so as to obtain a high-temperature-resistant, corrosion-resistant, high-filtration basalt fiber-coated fabric. Membrane filter material.

The basalt fiber film-coated filter material of the present invention is made of basalt fiber bulky yarn base cloth after dewaxing, surface treatment liquid impregnation treatment, baking, and then hot-pressed and laminated with PTFE film; the aforementioned surface treatment liquid is a A water-based mixed solution, prepared in the following weight ratio:

5% to 40% of PTFE emulsion, 0.3% to 5% of waterproofing agent, 0.05% to 5% of coupling agent, and the balance is water.

The above-mentioned coupling agent is a silane coupling agent, such as A151 (vinyltriethoxysilane, molecular formula CH ₂ =CH-Si(OCH ₂ CH ₃ ) ₃ ) or KH550 (γ-aminopropyltriethoxysilane , the molecular formula is NH ₂ (CH ₂ ) ₃ Si (OCH ₂ CH ₃ ) ₃ ). The above-mentioned waterproofing agent can be organic fluorine waterproofing agent, such as commercially available brand AG-E800, AG-415 or JCA-410 and other waterproofing agents.

The above-mentioned basalt fiber base cloth is woven from basalt fiber through conventional loom and conventional technology, and is also commercially available. The base fabric is a twill weave two-dimensional double-structure woven fabric, and the weft direction is bulked yarn, that is, the weft yarn has been expanded. The weft-expanded basalt base fabric can increase the efficiency of the fabric to capture dust.

Since the surface of the basalt fiber is covered with a layer of coating agent, this coating agent will hinder the combination of the surface treatment agent and the basalt base cloth. Therefore, high temperature dewaxing is required to remove the fiber surface coating when it is laminated with PTFE membrane at high temperature and hot pressure. thing. The dewaxing temperature is 400℃～480℃, and the dewaxing time is 30s-120s.

Although basalt fiber has good temperature resistance and corrosion resistance, it also has the fatal disadvantages of poor flexibility, inability to fold, and brittleness and breakage. Therefore, the basalt fiber bulked yarn base cloth should be surface treated after dewaxing. After surface treatment of the basalt fiber bulked yarn base cloth with the above surface treatment liquid, its mechanical properties are enhanced, wherein the radial strength is increased by 30%, and the latitudinal strength is increased by 50%. At the same time, the surface treatment makes the surface of the basalt fiber bulked yarn base cloth covered with a layer of coating. This layer of coating does not lose the unique characteristics of basalt, but also endows the basalt fiber base cloth with better folding resistance. Corrosion resistance is also enhanced.

The surface treatment process of the above-mentioned basalt fiber bulked yarn base cloth after high temperature dewaxing is as follows:

Pre-bake the basalt fiber base cloth impregnated with the surface treatment solution at 150°C-200°C for 0.5-2min, then bake at 200°C-280°C for 2-5min to coat the surface of the basalt fiber with the treatment solution, and finally 150°C Bake at ℃～200℃ for 0.5-2min, wind up.

The above-mentioned PTFE membrane is an expanded microvoid polytetrafluoroethylene membrane produced by Sinoma Science and Technology Co., Ltd., with the brand name ePTFE-N. This PTFE membrane has a multi-layer microporous wire drawing structure, its maximum pore size is ≤1.5μm, and its air permeability is ≥4cm/s.

The lamination temperature of the surface-treated basalt fiber expanded yarn base cloth and the PTFE membrane is 300°C-380°C, and the lamination pressure is 0.1MPa-1MPa. After the above-mentioned high-temperature hot pressing, the chemical coating on the surface of the basalt fiber combines the basalt fiber-treated cloth and the PTFE membrane into a whole.

Principle of the present invention is:

The PTFE membrane on the surface endows the surface of the filter material with filtration characteristics, and the unique self-cleaning performance of PTFE makes the basalt fiber coated filter material non-stick and easy to clean. The melting point of PTFE is as high as 327 degrees, corrosion resistance, acid and alkali resistance, erecting the first line of defense for the filter bag, and basalt fiber's own high temperature resistance and corrosion resistance, erecting the second line of defense for the filter bag. Since the PTFE membrane is an expanded microporous, multi-node, and multi-layer brushed mesh structure, this multi-layer interlaced space mesh structure blocks most of the dust, and a small part of the fine dust that enters the basalt fiber base cloth, due to the basalt base cloth The weft-expanded structure greatly improves the efficiency of dust capture.

The invention has soft hand feeling, is easy to sew, and has excellent mechanical properties. The radial strength of the treated cloth can reach 3700N/25mm, the weft strength of the treated cloth can reach 3500N/25mm, and the air permeability of the treated cloth can reach as high as 40cm/s. Moreover, the present invention can be used for a long time at a high temperature of 300 degrees, and the filtration efficiency of dust below 1 μm can reach 99.995%, and can be widely used in high temperature and harsh smoke environments that cannot be achieved by ordinary filter materials.

Detailed ways

The manufacturing method of the present invention will be specifically described below in conjunction with examples.

Example 1

1. Weaving, the basalt base fabric has a warp and weft density of 18*16, the weft yarn has been puffed and blown, and the base fabric is a twill weave double-dimensional structure;

2. Lay the cloth, arrange the basalt fiber base on the unwinder, heat up, dewax at high temperature, the dewaxing temperature is 480°C, and the dewaxing time is 25s;

3. Put the surface treatment agent in the storage tank, unwind through the unwinding device, so that the treatment agent is impregnated on the basalt dewaxed cloth, and adjust the content of the treatment agent on the basalt base cloth through the pressure roller with adjustable gap and pressure . Among them, the coupling agent is silane coupling agent A151 (vinyl triethoxysilane, the molecular formula is CH ₂ =CH-Si(OCH ₂ CH ₃ ) ₃ ), which is commercially available, and the waterproof agent is AG-415 waterproof and oil-proof agent. , commercially available, the surface treatment solution formula is as follows:

Element Proportion (%) PTFE emulsion 5 waterproofing agent 0.3 Coupling agent 0.05 water 94.65

4. Oven baking, pre-baking section temperature 150°C, pre-baking time 2min, high-temperature baking section temperature 200°C, baking time 5min, annealing section temperature 200°C, baking time 0.5min, so that the treatment liquid is attached to the basalt fiber;

5. Rolling, use the winding device to wind the surface treatment cloth into a roll, and place it for use;

6. Film covering, place the prepared PTFE film on the top of the basalt treatment cloth, and laminate it under high temperature and hot pressing. The average pore size of the PTFE membrane is 0.5 μm, and the average air permeability is 4 cm/s.

Example 2

1. Weaving, the basalt base fabric has a warp and weft density of 18*16, the weft yarn has been puffed and blown, and the base fabric is a twill weave double-dimensional structure;

2. Lay the cloth, arrange the basalt fiber base on the unwinder, heat up, dewax at high temperature, the dewaxing temperature is 430°C, and the dewaxing time is 25s;

3. Put the surface treatment agent in the storage tank, unwind through the unwinding device, so that the treatment agent is impregnated on the basalt dewaxed cloth, and adjust the content of the treatment agent on the basalt base cloth through the pressure roller with adjustable gap and pressure . Among them, the coupling agent is KH550 (γ-aminopropyltriethoxysilane, the molecular formula is NH ₂ (CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ ), commercially available, and the waterproofing agent is organic fluorine waterproofing agent AG-E800 , commercially available, the surface treatment solution formula is as follows:

Element Proportion (%) PTFE emulsion 15 waterproofing agent 1.5 Coupling agent 0.8 water 82.7

4. Oven baking, pre-baking section temperature 200°C, pre-baking time 0.5min, high-temperature baking section temperature 280°C, baking time 2min, annealing section temperature 150°C, baking time 2min, to make the treatment liquid adhere to the basalt fiber.

5. Rolling, use the winding device to wind the surface treatment cloth into a roll, and place it for use;

6. Film covering, place the prepared PTFE film on the top of the basalt treatment cloth, and laminate it under high temperature and hot pressing. The average pore size of the PTFE membrane is 1 μm, and the average air permeability is 6 cm/s.

Example 3

1. Weaving, the basalt base fabric has a warp and weft density of 18*16, the weft yarn has been puffed and blown, and the base fabric is a twill weave double-dimensional structure;

2. Lay the cloth, arrange the basalt fiber base on the unwinder, heat up, dewax at high temperature, the dewaxing temperature is 450°C, and the dewaxing time is 25s;

3. Put the surface treatment agent in the storage tank, unwind through the unwinding device, so that the treatment agent is impregnated on the basalt dewaxed cloth, and adjust the content of the treatment agent on the basalt base cloth through the pressure roller with adjustable gap and pressure . The coupling agent is KH550 (γ-aminopropyltriethoxysilane, the molecular formula is NH ₂ (CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ ), commercially available, and the waterproofing agent is JCA-410, commercially available. For sale, the formula of the surface treatment liquid is as follows:

Element Proportion (%) PTFE emulsion 40 waterproofing agent 5 Coupling agent 2 water 53

4. Oven baking, pre-baking section temperature 190°C, pre-baking time 1min, high-temperature baking section temperature 260°C, baking time 3min, annealing section temperature 190°C, baking time 1min, to make the treatment liquid adhere to the basalt fiber.

5. Rolling, use the winding device to wind the surface treatment cloth into a roll, and place it for use;

6. Film covering, place the prepared PTFE film on the top of the basalt treatment cloth, and laminate it under high temperature and hot pressing. The average pore size of the PTFE membrane is 1.5 μm, and the average air permeability is 8 cm/s.

The invention combines the high temperature resistance and corrosion resistance of basalt fiber with the advantages of easy dust removal, high dust removal efficiency and long service life of the film-coated filter material. It provides corrosion resistance, high temperature resistance and excellent mechanical performance support. The PTFE membrane on the surface realizes super filtering performance for fine dust due to its unique multi-layer space network structure. PTFE itself has unique non-stick and corrosion resistance characteristics. It ensures the reduction of dust removal times of the dust collector system and the extension of the service life of the filter material. The combination of PTFE membrane and basalt fiber further expands the use range of the film-coated filter material. For ordinary film-coated filter materials, it can withstand up to 260°C Compared with high temperature, basalt fiber-coated filter material can work stably at 300°C for a long time, with radial strength ≥ 3500N/25cm and latitudinal strength ≥ 3200N/25cm. The acid and alkali resistance of basalt fiber-coated filter material is better than The glass fiber coated filter material can filter dust below 1μm up to 99.995%, and can be popularized and used in special working conditions with high corrosiveness and high temperature to meet the national environmental protection requirements.

Claims (5)

1. A basalt fiber film-coated filter material is characterized in that the basalt fiber bulked yarn base cloth is formed by laminating with PTFE film high temperature hot pressing after dewaxing, surface treatment liquid immersion treatment and baking; The treatment solution is a water-based mixed solution prepared according to the following weight ratio: PTFE emulsion 5%~40%, waterproofing agent 0.3%~5%, coupling agent 0.05%~5%, and the balance is water. 2. The basalt fiber film-coated filter material as claimed in claim 1, characterized in that the basalt fiber bulked yarn base cloth is a twill weave-dimensional double structure, and the weft direction is bulked yarn. 3. The basalt fiber-coated filter material according to claim 1 or 2, characterized in that the dewaxing temperature is 400°C to 480°C. 4. basalt fiber film-coated filter material as claimed in claim 1 or 2, is characterized in that the concrete process of described baking is: Pre-bake at 150°C~200°C for 0.5-2min, bake at 200°C-280°C for 2-5min, and bake at 150°C~200°C for 0.5-2min. 5. The basalt fiber film-coated filter material according to claim 1 or 2, characterized in that the lamination temperature is 300°C~380°C, and the lamination pressure is 0.1MPa-1MPa.