A multi-layer aramid fiber high-temperature-resistant material and a preparation method and application thereof

Abstract

The application provides a multilayer aramid fiber high-temperature-resistant material and a preparation method and application thereof, and belongs to the technical field of multilayer fiber materials. The multilayer aramid fiber high-temperature-resistant material comprises a dust-encountering layer, an anti-static layer and a high-strength filtering layer, wherein the dust-encountering layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, and the fiber is entangled through water jet strengthening to form a covalent cross-linking crystal network structure; the anti-static layer is a woven fabric made of meta-aramid, para-aramid and conductive fiber in a plain weave structure or a basket weave structure, and the woven fabric is formed after low-pressure water needle water jetting, and has the characteristics of anti-static, stable structure and high-temperature resistance; and the high-strength filtering layer is a woven fabric made of polyimide filaments in a 2 over 2 under right twill weave structure or a honeycomb weave structure. The application relies on special fiber morphology and fabric organization to prepare a high-temperature-resistant material with high filtering efficiency and high strength.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber multilayer materials, and in particular to a multilayer aramid fiber high-temperature resistant material and a preparation method and application thereof. Background Art

[0002] With the acceleration of industrialization and urbanization, air pollution has become increasingly serious. Industrial high-temperature flue gas emissions have attracted much attention, and the demand for high-temperature polymer filter materials is increasing. Compared with metal and ceramic filter materials, high-temperature polymer filter materials have the advantages of being lightweight, corrosion-resistant, easy to process, and resistant to high temperatures. High-temperature polymer filter materials mainly include fiber materials such as polyimide, polyester, polypropylene, and aramid. However, polyester and polypropylene have poor temperature resistance, low mechanical strength, poor pressure resistance, and easy breakage, which limits their application areas. While aramid fiber has superior performance to polyester and other fibers, it is more difficult to process, has higher costs, and has poor product thickness and strength stability.

[0003] Aramid includes para-aramid and meta-aramid. The molecular chain orientation and crystallinity of para-aramid are high, which gives the fiber high strength and high modulus; the molecular chain of meta-aramid is curved and it is difficult to form a highly crystalline structure, so the fiber is softer and more elastic.

[0004] For example, patent CN107187126A discloses an environmentally friendly filter material for filtration, including a textile cloth blended from nano-polyphenylene sulfide fibers, nano-basalt fiber fibers, nano-carbon fiber fibers and nano-aramid fiber fibers, fluoromethanone needle-punched felt needle-punched on the upper and lower surfaces of the textile cloth, glass fiber water needle felt needle-punched on the surface of the fluoromethanone needle felt, a microporous film coated on the surface of the glass fiber water needle felt; silica aerogel bonded to the surface of the microporous film, and a HEPA high-efficiency filter mesh bonded to the surface of the silica aerogel.

[0005] CN103785225A discloses a preparation method for a multi-component flame-retardant and easy-to-decontamination filter material and a non-woven filter material. The preparation method comprises the following steps: unpacking and inspecting 30%-40% by mass of low-melting-point polyester staple fibers, 20%-30% by mass of three-dimensional hollow flame-retardant polyester staple fibers, 20%-30% by mass of flame-retardant polyester staple fibers, and 8%-15% by mass of aramid staple fibers, and then evenly mixing the fibers. The mixed fibers are then loosened and combed, and then laid out on a web. The laid raw materials enter a hot-melt forming area, and the hot-melt forming temperature is 190-215°C, and the vehicle speed is 5-10 m / min. At this time, the low-melting-point polyester staple fibers of the filter material are first melted at a high temperature of 190-215°C, and are hot-melted and bonded together with the evenly laid high-melting-point polyester staple fibers and aramid staple fibers to form a multi-component flame-retardant and easy-to-decontamination filter material.

[0006] However, needle-punched nonwovens have poor filtering stability and high initial filtration efficiency. However, after long-term use, the filtered material tends to generate static electricity, causing a large amount of filtered material to be adsorbed on the filter surface, thus affecting the filtering effect. It is also difficult to clean, which greatly reduces the service life of the filter material. Woven filter materials are prone to slippage between the warp and weft yarns, resulting in uneven porosity in high-temperature filters, which seriously affects the filtering effect.

[0007] To sum up, due to the special use environment of high-temperature filter materials, they need to adapt to high temperature, high humidity, high corrosive and other filtering environments. This makes the existing high-temperature filter materials have poor temperature resistance, low mechanical strength, large strength loss, poor product stability, easy clogging and easy breakage, etc., which are still problems that need to be solved urgently. Summary of the Invention

[0008] In response to the above problems, the present invention provides a multi-layer aramid fiber high-temperature resistant material, a preparation method and application thereof. By using different fibers and different preparation processes between different layers, as well as different stitching methods between layers, different layers play different roles, thereby improving the comprehensive performance of the filter material.

[0009] The present invention provides a multi-layer aramid fiber high-temperature resistant material. The multi-layer aramid fiber high-temperature resistant material is divided into three layers, which are respectively divided into a dust-receiving layer, an antistatic layer and a high-strength filter layer according to the material flow direction; the dust-receiving layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, the antistatic layer is a woven fabric made of meta-aramid, para-aramid and conductive fiber in a plain weave structure or a basket weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a 2-up 2-down right twill structure or a honeycomb weave structure. The dust-receiving layer, the antistatic layer and the high-strength filter layer are sewn together by means of a snap hook; the gram-to-weight ratio of the dust-receiving layer, the antistatic layer and the high-strength filter layer is (130-180): (180-220): (150-180);

[0010] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 99.5-100%, the breaking strength retention rate is 96.0-97.5%, the temperature resistance of the dust-facing layer is ≥200°C, and the temperature resistance of the antistatic layer and the high-strength filtration layer is ≥300°C.

[0011] Furthermore, the multi-layer aramid fiber high temperature resistant material has a service life of 2-4 years at 200°C.

[0012] Furthermore, the multi-layer aramid fiber high temperature resistant material has a dust emission in the flue gas of ≤10mg / m at a filtration wind speed of 1.0m / min. 3 .

[0013] The present invention also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0014] Step 1: The meta-aramid fiber is opened under an opening roller, and then enters a feeder to be transported to a carding machine to be carded into a single fiber web. After polyolefin elastic fiber is laid on the fiber web, it enters a web laying machine for reciprocating folding to form a dust-proof fiber web;

[0015] The dust-receiving fiber web is stretched by a stretching machine, and then hydroentangled by a low-pressure water needle, and then dried to obtain a dust-receiving layer;

[0016] Step 2, opening the meta-aramid fiber, the para-aramid fiber and the conductive fiber under an opening roller, then feeding the fibers into a feeder and conveying them to a carding machine for combing, then feeding the fibers into a drawing frame for drawing, and then drawing the fibers, and then continuing to process the coarse and fine yarns, and doffing the fibers to prepare an antistatic yarn; weaving the antistatic yarn into an antistatic mesh by a high-speed air-jet loom, and then hydroentangling the yarn with a low-pressure water needle, and then drying the yarn to obtain an antistatic layer;

[0017] Step 3, weaving the polyimide filaments in a rigid rapier loom to obtain a high-strength filter layer;

[0018] Step 4: sew the dust-receiving layer, the antistatic layer and the high-strength filter layer together, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread, to obtain the multi-layer aramid fiber high-temperature resistant material.

[0019] Furthermore, the length of the meta-aramid fiber in step 1 is 38-51 mm.

[0020] Furthermore, the rotation speed of the opening roller in step 1 is 2000-2500 rpm.

[0021] Furthermore, the feeding speed of the feeder in step 1 is 20-30 m / min.

[0022] Furthermore, the cylinder rotation speed of the carding machine in step 1 is 800-900 rpm.

[0023] Furthermore, the weight of the fiber web in step 1 is 20-25 g / m 2 .

[0024] Furthermore, in step 1, the total mass ratio of the polyolefin elastic fiber to the meta-aramid fiber is (0.5-1): (9-9.5).

[0025] Furthermore, the polyolefin elastic fiber in step 1 has a linear density of 44 dtex and a 90° cross structure.

[0026] Furthermore, the polyolefin elastic fiber in step 1 has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%.

[0027] Furthermore, the speed of the web laying machine in step 1 is 30-40 times / min.

[0028] Furthermore, the number of layers of the dust-proof fiber mesh in step 1 is 16-18 layers, and the gram weight is 280-300g / m 2 , uniformity (CV) ≤4.5%.

[0029] Furthermore, the stretching ratio in step 1 is 1.5-1.7 times.

[0030] Furthermore, the pressure of the low-pressure water needle in step 1 is (5.0-6.0)*10 6 Pa.

[0031] Furthermore, the drying temperature in step 1 is 100-120° C. and the drying time is 5-10 minutes.

[0032] Furthermore, the weight of the dust-facing layer in step 1 is 130-180 g / m 2 .

[0033] Furthermore, in step 2, the mass ratio of the meta-aramid fiber, the para-aramid fiber and the conductive fiber is (90-96): (6-8): (1-2).

[0034] Furthermore, in step 2, the lengths of the meta-aramid fiber, the para-aramid fiber, and the conductive fiber are 38-51 mm.

[0035] Furthermore, the rotation speed of the opening roller in step 2 is 2000-2500 rpm.

[0036] Furthermore, the feeding speed of the feeder in step 2 is 20-25 m / min.

[0037] Furthermore, the cylinder rotation speed of the carding machine in step 2 is 800-900 rpm.

[0038] Furthermore, the number of raw slivers combined by the drawing frame in step 2 is 6-8.

[0039] Furthermore, the stretching ratio in step 2 is 7.5-10.5 times.

[0040] Furthermore, the twist coefficient of the roving in step 2 is 85-100, and the stretching ratio is 1.2-1.5 times.

[0041] Furthermore, the twist coefficient of the spun yarn in step 2 is 320-360, and the stretching ratio is 32-35 times.

[0042] Furthermore, the antistatic yarn in step 2 has a yarn count of 32-40S / 2.

[0043] Furthermore, the high-speed air-jet loom in step 2 weaves in a plain weave structure or a basket weave structure.

[0044] Furthermore, the antistatic mesh in step 2 has a warp density of 250-260 threads / 10 cm and a weft density of 180-200 threads / 10 cm.

[0045] Furthermore, the pressure of the low-pressure water needle in step 2 is 3*10 6 -1*10 7 Pa.

[0046] Furthermore, the drying temperature in step 2 is 100-150° C. and the drying time is 5-15 minutes.

[0047] Furthermore, the antistatic layer in step 2 has a gram weight of 180-220 g / m 2 .

[0048] Furthermore, in step 2, the moisture regain of the meta-aramid fiber is 4-6%, the moisture regain of the para-aramid fiber is 3-5%, and the moisture regain of the conductive fiber is 0.5-4%.

[0049] Furthermore, the polyimide filaments in step 3 have a fineness of 400-500D and a multi-lobal structure.

[0050] Furthermore, the breaking strength of the polyimide filament in step 3 is 25.4 cN / dtex.

[0051] Furthermore, the rigid rapier loom in step 3 weaves in a 2-up 2-down right twill structure or a honeycomb structure.

[0052] Furthermore, the warp density of the weaving in step 3 is 150-170 strands / 10cm, and the weft density is 160-170 strands / 10cm.

[0053] Furthermore, the weight of the high-strength filter layer in step 3 is 150-180 g / m 2 .

[0054] Furthermore, the ply-twisted para-aramid yarn for the snap-button suture in step 4 is a ply-twisted yarn of 200D*2, 200D*3 or 200D*4.

[0055] Furthermore, in the process of suturing the snap fastener in step 4, a live thread opening is left.

[0056] The present invention provides a smoke filter screen, which is made of the multi-layer aramid fiber high-temperature resistant material.

[0057] Furthermore, when the smoke filter is in use, the smoke enters through the dust-receiving layer of the multi-layer aramid fiber high-temperature resistant material and flows out through the high-strength filter layer.

[0058] Furthermore, the smoke filter has a dust emission of ≤10mg / m at a filtering wind speed of 1.0m / min. 3 .

[0059] Beneficial effects of the present invention:

[0060] 1. The multi-layer aramid fiber high-temperature resistant material of the present invention is composited by three functional layers of snap stitching, wherein the dust-facing layer is made of meta-aramid fiber and polyolefin elastic fiber, which are pre-treated and then laid to prepare a non-woven material, and then the entanglement and cohesion between the fibers are strengthened by hydroentanglement, thereby strengthening the breaking strength of the dust-facing layer. At the same time, the meta-aramid fiber and polyolefin elastic fiber in the dust-facing layer form a covalently cross-linked crystalline network structure; during high-temperature filtration, the dust-facing layer first contacts the filter material, and the polyolefin elastic fiber in the layer gradually melts as the ambient temperature rises, and completely disappears at about 80°C. However, due to the covalently cross-linked structure, the entire molecular network can still maintain its integrity at a temperature of up to 220°C. Its crystals are reversible and can re-form a crystalline network when the temperature gradually drops. In this process, electrostatic impurities in the filter material will be captured by the melted crystals. After the filtration is completed, the crystalline structure is restored, the adsorption force on electrostatic impurities is reduced, and it is easy to clean, which avoids the problem of reduced filtration efficiency due to the adsorption of impurities during filtration, thereby improving the reusability of the material;

[0061] 2. The antistatic layer of the present invention is made by mixing meta-aramid, para-aramid and conductive fibers, and then hydroentangled by low-pressure water needles, which also increases the hairiness on the surface of the fabric, increases the thickness, and makes the warp and weft yarns more uniform and neat, thereby improving the cohesion between different fibers, making the layer antistatic and structurally stable. The addition of aramid fibers in this layer also improves the high temperature resistance of the material. The high-strength filter layer is a woven fabric made of multi-lobed polyimide filaments. The special shape of the fibers and the combination of the fabric structure make the fabric have a large The surface area is large, and it has the characteristics of high strength, high temperature resistance, good filtering effect and recycling. Finally, the three layers of materials are sewn together by a snap stitch method, and the sewing thread is a para-aramid twisted thread, which has the characteristics of high strength, high modulus and high temperature resistance. The dust-receiving layer and the anti-static layer are sewn with a single thread, and the anti-static layer and the high-strength filter layer are sewn with a double thread. Due to the structure of the non-woven fabric of the dust-receiving layer, it is more easily damaged than the other two layers. Therefore, this layer is sewn with a single thread to facilitate its replacement, and a snap stitch opening is left between each layer, which improves the replaceability between each layer and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a schematic diagram of the 2-up 2-down right twill weave structure described in the present invention;

[0063] Figure 2 Schematic diagram of the honeycomb tissue structure described in the present invention. DETAILED DESCRIPTION

[0064] The invention is described in detail below with reference to the embodiments:

[0065] The present invention provides a multi-layer aramid fiber high-temperature resistant material, a preparation method and application thereof. By preparing different layers and separating the functions of each layer, the overall comprehensive performance of the filter material is improved. Each layer is compounded by sewing with a snap fastener and can be replaced during use, which greatly improves its durability.

[0066] Example 1

[0067] This embodiment provides a multi-layer aramid fiber high-temperature resistant material, which is divided into three layers, which are respectively divided into a dust-receiving layer, an antistatic layer, and a high-strength filter layer according to the material flow direction; the dust-receiving layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, the antistatic layer is a woven fabric made of meta-aramid, para-aramid, and conductive fiber in a basket weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a 2-up, 2-down right twill weave structure. The dust-receiving layer, the antistatic layer, and the high-strength filter layer are sewn together with a snap hook; the weight ratio of the dust-receiving layer, the antistatic layer, and the high-strength filter layer is 150:180:150;

[0068] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 99.5%, the breaking strength retention rate is 96.5%, the temperature resistance of the dust-facing layer is 200°C, and the temperature resistance of the antistatic layer and the high-strength filtration layer is 300°C.

[0069] This embodiment also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0070] Step 1: Open the 38mm meta-aramid fiber on the opening roller at a speed of 2000rpm, then feed it into the carding machine at a speed of 20m / min, and card it into single fibers of 20g / m on the cylinder at a speed of 900rpm. 2 The fiber web is laid on which a polyolefin elastic fiber with a total mass ratio of 1:9 to the meta-aramid fiber, a linear density of 44 dtex, and a 90° cross is laid. The fiber web is then fed into a web laying machine and folded back and forth at a speed of 30 times / min to form 16 layers of 300 g / m 2 , dust-proof fiber web with uniformity (CV) ≤ 4.5%;

[0071] The dust-proof fiber web was stretched by a stretching machine at a ratio of 1.5 times and then passed through a 5.0*10 6 The low-pressure water needle of Pa was used for hydroentanglement, and after drying at 120℃ for 5min, the weight of the obtained 2 The dust layer;

[0072] The polyolefin elastic fiber has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%;

[0073] Step 2, the meta-aramid fiber, the para-aramid fiber and the conductive fiber, all of which are 38 mm in a mass ratio of 93:6:1, are opened at an opening roller speed of 2000 rpm, and then enter the feeder at a speed of 20 m / min to be conveyed to the carding machine at a cylinder speed of 800 rpm for carding, and then enter the drawing frame to combine 6 carded slivers and then draft them at 7.5 times, and continue to stretch them at a twist coefficient of 85 and a stretching multiple of 1.2 to produce roving, and at a twist coefficient of 360 and a stretching multiple of 32 to produce spun yarn, and then doff the bobbins to prepare an anti-static yarn with a yarn count of 32S / 2;

[0074] The antistatic yarn is woven into an antistatic mesh with a basket weave structure by a high-speed air-jet loom. The antistatic mesh has a warp density of 260 yarns / 10cm and a weft density of 200 yarns / 10cm. 6 After hydroentanglement with a low-pressure water needle of Pa, the weight of the obtained product was 180g / m 2 Antistatic layer;

[0075] The moisture regain of the meta-aramid fiber is 4%, the moisture regain of the para-aramid fiber is 3%, and the moisture regain of the conductive fiber is 0.5%;

[0076] Step 3: The multi-leaf structure polyimide filament with a fineness of 400D is woven in a rigid rapier loom with a 2-up 2-down right twill structure. The warp density is 170 strands / 10cm and the weft density is 160 strands / 10cm, and the weight is 150g / m 2 High-strength filter layer;

[0077] The breaking strength of the polyimide filament is 25.4 cN / dtex;

[0078] Step 4: The dust-receiving layer, the antistatic layer and the high-strength filter layer are sewed together with 200D*3 twisted para-aramid yarn, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread to obtain the multi-layer aramid fiber high-temperature resistant material.

[0079] Example 2

[0080] This embodiment provides a multi-layer aramid fiber high-temperature resistant material, which is divided into three layers, which are respectively divided into a dust-receiving layer, an antistatic layer, and a high-strength filter layer according to the material flow direction; the dust-receiving layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, the antistatic layer is a woven fabric made of meta-aramid, para-aramid, and conductive fiber in a plain weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a honeycomb weave structure. The dust-receiving layer, the antistatic layer, and the high-strength filter layer are sewn together by snap fasteners; the weight ratio of the dust-receiving layer, the antistatic layer, and the high-strength filter layer is 160:220:150;

[0081] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 99.6%, the breaking strength retention rate is 96.3%, the temperature resistance of the dust-facing layer is 200°C, and the temperature resistance of the antistatic layer and the high-strength filtration layer is 300°C.

[0082] This embodiment also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0083] Step 1: Open the 51mm meta-aramid fiber on the opening roller at a speed of 2000rpm, then feed it into the carding machine at a speed of 30m / min, and card it into single fibers of 25g / m on the cylinder at a speed of 800rpm. 2The fiber web is laid on which a polyolefin elastic fiber with a total mass ratio of 0.8:9.2, a linear density of 44dtex and a 90° cross is laid. The fiber web is then fed into a web laying machine and folded back and forth at a speed of 40 times / min to form 18 layers of 280g / m 2 , dust-proof fiber web with uniformity (CV) ≤ 4.5%;

[0084] The dust-proof fiber web was stretched by a stretching machine at a ratio of 1.7 times and then passed through a 6.0*10 6 The low-pressure water needle of Pa was used for hydroentanglement, and after drying at 100℃ for 10min, the weight of the obtained 2 The dust layer;

[0085] The polyolefin elastic fiber has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%;

[0086] Step 2, the meta-aramid fiber, the para-aramid fiber and the conductive fiber, all of which are 51 mm in a mass ratio of 92:6:2, are opened at an opening roller speed of 2500 rpm, and then enter the feeder at a speed of 25 m / min to be conveyed to the carding machine at a cylinder speed of 900 rpm for carding, and then enter the drawing frame to combine 8 carded slivers and then draft them at 10.5 times, and continue to stretch them at a twist factor of 100 and a stretching multiple of 1.5 to produce roving, and at a twist factor of 320 and a stretching multiple of 35 to produce spun yarn, and then doff the bobbins to prepare an anti-static yarn with a yarn count of 40S / 2;

[0087] The antistatic yarn is woven into an antistatic mesh with a plain weave structure by a high-speed air-jet loom. The antistatic mesh has a warp density of 250 yarns / 10cm and a weft density of 180 yarns / 10cm. 7 After hydroentanglement with a low-pressure water needle of Pa, the weight of the obtained product was 220g / m 2 Antistatic layer;

[0088] The moisture regain of the meta-aramid fiber is 5%, the moisture regain of the para-aramid fiber is 5%, and the moisture regain of the conductive fiber is 2%;

[0089] Step 3: The multi-leaf polyimide filament with a fineness of 500D is spun in a rigid rapier loom with a honeycomb structure. The warp density is 170 strands / 10cm and the weft density is 160 strands / 10cm, and the weight is 150g / m 2 High-strength filter layer;

[0090] The breaking strength of the polyimide filament is 25.4 cN / dtex;

[0091] Step 4: The dust-receiving layer, the antistatic layer and the high-strength filter layer are sewed together with 200D*2 twisted para-aramid yarn, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread to obtain the multi-layer aramid fiber high-temperature resistant material.

[0092] Example 3

[0093] This embodiment provides a multi-layer aramid fiber high-temperature resistant material, which is divided into three layers, which are respectively divided into a dust-receiving layer, an antistatic layer, and a high-strength filter layer according to the material flow direction; the dust-receiving layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, the antistatic layer is a woven fabric made of meta-aramid, para-aramid, and conductive fiber in a plain weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a 2-up, 2-down right twill structure. The dust-receiving layer, the antistatic layer, and the high-strength filter layer are sewn together with a snap fastener; the weight ratio of the dust-receiving layer, the antistatic layer, and the high-strength filter layer is 150:180:180;

[0094] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 99.8%, the breaking strength retention rate is 97.4%, the temperature resistance of the dust-facing layer is 200°C, and the temperature resistance of the antistatic layer and the high-strength filtration layer is 300°C.

[0095] This embodiment also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0096] Step 1: Open the 38mm meta-aramid fiber on the opening roller at a speed of 2500rpm, then feed it into the carding machine at a speed of 20m / min, and card it into single fibers of 20g / m on the cylinder at a speed of 900rpm. 2 The fiber web is laid on which a polyolefin elastic fiber with a total mass ratio of 0.5:9.5, a linear density of 44dtex and a 90° cross is laid. The fiber web is then fed into a web laying machine and folded back and forth at a speed of 30 times / min to form 16 layers of 300g / m 2 , dust-proof fiber web with uniformity (CV) ≤ 4.5%;

[0097] The dust-proof fiber web was stretched by a stretching machine at a ratio of 1.5 times and then passed through a 5.0*10 6 The low-pressure water needle of Pa was used for hydroentanglement, and after drying at 120℃ for 5min, the weight of the obtained 2 The dust layer;

[0098] The polyolefin elastic fiber has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%;

[0099] Step 2, the meta-aramid fiber, the para-aramid fiber and the conductive fiber, all of which are 38 mm in a mass ratio of 90:8:2, are opened at an opening roller speed of 2000 rpm, then enter the feeder at a speed of 20 m / min and conveyed to the carding machine at a cylinder speed of 800 rpm for carding, and then enter the drawing frame to combine 6 carded slivers and then draft them at 7.5 times, and continue to stretch them at a twist coefficient of 85 and a stretching multiple of 1.2 to produce roving, and at a twist coefficient of 360 and a stretching multiple of 32 to produce spun yarn, and then doff the bobbins to prepare an anti-static yarn with a yarn count of 32S / 2;

[0100] The antistatic yarn is woven into an antistatic mesh with a plain weave structure by a high-speed air-jet loom. The antistatic mesh has a warp density of 260 yarns / 10cm and a weft density of 190 yarns / 10cm. 6 The low-pressure water needle of Pa was used for hydroentanglement, and then dried at 100℃ for 15min to obtain a gram weight of 180g / m 2 Antistatic layer;

[0101] The moisture regain of the meta-aramid fiber is 6%, the moisture regain of the para-aramid fiber is 5%, and the moisture regain of the conductive fiber is 4%;

[0102] Step 3: The multi-leaf structure polyimide filament with a fineness of 400D is woven in a rigid rapier loom with a 2-up 2-down right twill structure. The warp density is 150 strands / 10cm and the weft density is 170 strands / 10cm, and the weight is 180g / m 2 High-strength filter layer;

[0103] The breaking strength of the polyimide filament is 25.4 cN / dtex;

[0104] Step 4: The dust-receiving layer, the antistatic layer and the high-strength filter layer are sewed together with 200D*4 twisted para-aramid yarn, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread to obtain the multi-layer aramid fiber high-temperature resistant material.

[0105] Comparative Example 1

[0106] This comparative example provides a multi-layer aramid fiber high-temperature resistant material, which is divided into three layers, which are respectively divided into a dust-receiving layer, an antistatic layer, and a high-strength filter layer according to the material flow direction; the dust-receiving layer is a non-woven fabric made of meta-aramid, the antistatic layer is a woven fabric made of meta-aramid, para-aramid, and conductive fibers in a basket weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a 2-up 2-down right twill weave structure. The dust-receiving layer, the antistatic layer, and the high-strength filter layer are sewn together by snap fasteners; the weight ratio of the dust-receiving layer, the antistatic layer, and the high-strength filter layer is 150:180:150;

[0107] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 90.2%, and the breaking strength retention rate is 97.1%.

[0108] This comparative example also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0109] Step 1: Open the 38mm meta-aramid fiber on the opening roller at a speed of 2000rpm, then feed it into the carding machine at a speed of 20m / min, and card it into single fibers of 20g / m on the cylinder at a speed of 900rpm. 2 After the fiber web is formed, it enters the web laying machine and is folded back and forth at a speed of 30 times / min to form 16 layers of 300g / m 2 , dust-proof fiber web with uniformity (CV) ≤ 4.5%;

[0110] The dust-proof fiber web was stretched by a stretching machine at a ratio of 1.5 times and then passed through a 5.0*10 6 The low-pressure water needle of Pa was used for hydroentanglement, and after drying at 120℃ for 5min, the weight of the obtained 2 The dust layer;

[0111] Step 2, the meta-aramid fiber, the para-aramid fiber and the conductive fiber, all of which are 38 mm in a mass ratio of 93:6:1, are opened at an opening roller speed of 2000 rpm, and then enter the feeder at a speed of 20 m / min to be conveyed to the carding machine at a cylinder speed of 800 rpm for carding, and then enter the drawing frame to combine 6 carded slivers and then draft them at 7.5 times, and continue to stretch them at a twist coefficient of 85 and a stretching multiple of 1.2 to produce roving, and at a twist coefficient of 360 and a stretching multiple of 32 to produce spun yarn, and then doff the bobbins to prepare an anti-static yarn with a yarn count of 32S / 2;

[0112] The antistatic yarn is woven into an antistatic mesh with a basket weave structure by a high-speed air-jet loom. The antistatic mesh has a warp density of 260 yarns / 10cm and a weft density of 200 yarns / 10cm. 6After hydroentanglement with a low-pressure water needle of Pa, the weight of the obtained product was 180g / m 2 Antistatic layer;

[0113] The moisture regain of the meta-aramid fiber is 4%, the moisture regain of the para-aramid fiber is 3%, and the moisture regain of the conductive fiber is 3%;

[0114] Step 3: The multi-leaf structure polyimide filament with a fineness of 400D is woven in a rigid rapier loom with a 2-up 2-down right twill structure. The warp density is 170 strands / 10cm and the weft density is 160 strands / 10cm, and the weight is 150g / m 2 High-strength filter layer;

[0115] The breaking strength of the polyimide filament is 25.4 cN / dtex;

[0116] Step 4: The dust-receiving layer, the antistatic layer and the high-strength filter layer are sewed together with 200D*3 twisted para-aramid yarn, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread to obtain the multi-layer aramid fiber high-temperature resistant material.

[0117] Comparative Example 2

[0118] The present comparative example provides a multi-layer aramid fiber high-temperature resistant material, which is divided into three layers, which are respectively divided into a dust-facing layer, an antistatic layer, and a high-strength filter layer according to the material flow direction; the dust-facing layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, the antistatic layer is a woven fabric made of meta-aramid, para-aramid, and conductive fiber in a basket weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a 2-up 2-down right twill weave structure, the dust-facing layer, the antistatic layer, and the high-strength filter layer are sewn together by snap fasteners; the weight ratio of the dust-facing layer, the antistatic layer, and the high-strength filter layer is 150:180:150;

[0119] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 94.6%, and the breaking strength retention rate is 93.2%.

[0120] This comparative example also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0121] Step 1: Open the 38mm meta-aramid fiber on the opening roller at a speed of 2000rpm, then feed it into the carding machine at a speed of 20m / min, and card it into single fibers of 20g / m on the cylinder at a speed of 900rpm. 2The fiber web is laid on which a polyolefin elastic fiber with a total mass ratio of 1:9 to the meta-aramid fiber, a linear density of 44 dtex, and a 90° cross is laid. The fiber web is then fed into a web laying machine and folded back and forth at a speed of 30 times / min to form 16 layers of 300 g / m 2 , dust-proof fiber web with uniformity (CV) ≤ 4.5%;

[0122] The dust-proof fiber web was stretched by a stretching machine at a ratio of 1.5 times and then passed through a 5.0*10 6 The low-pressure water needle of Pa was used for hydroentanglement, and after drying at 120℃ for 5min, the weight of the obtained 2 The dust layer;

[0123] The polyolefin elastic fiber has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%;

[0124] Step 2, the meta-aramid fiber, the para-aramid fiber and the conductive fiber, all of which are 38 mm in a mass ratio of 93:6:1, are opened at an opening roller speed of 2000 rpm, and then enter the feeder at a speed of 20 m / min to be conveyed to the carding machine at a cylinder speed of 800 rpm for carding, and then enter the drawing frame to combine 6 carded slivers and then draft them at 7.5 times, and continue to stretch them at a twist coefficient of 85 and a stretching multiple of 1.2 to produce roving, and at a twist coefficient of 360 and a stretching multiple of 32 to produce spun yarn, and then doff the bobbins to prepare an anti-static yarn with a yarn count of 32S / 2;

[0125] The antistatic yarn is woven into an antistatic mesh with a basket weave structure by a high-speed air-jet loom. The warp density of the antistatic mesh is 260 yarns / 10cm and the weft density is 200 yarns / 10cm. The weight is 180g / m 2 Antistatic layer;

[0126] The moisture regain of the meta-aramid fiber is 4%, the moisture regain of the para-aramid fiber is 3%, and the moisture regain of the conductive fiber is 0.5%;

[0127] Step 3: The multi-leaf structure polyimide filament with a fineness of 400D is woven in a rigid rapier loom with a 2-up 2-down right twill structure. The warp density is 170 strands / 10cm and the weft density is 160 strands / 10cm, and the weight is 150g / m 2 High-strength filter layer;

[0128] The breaking strength of the polyimide filament is 25.4 cN / dtex;

[0129] Step 4: The dust-receiving layer, the antistatic layer and the high-strength filter layer are sewed together with 200D*3 twisted para-aramid yarn, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread to obtain the multi-layer aramid fiber high-temperature resistant material.

[0130] Comparative Example 3

[0131] The present comparative example provides a multi-layer aramid fiber high-temperature resistant material, which is divided into three layers, which are respectively divided into a dust-receiving layer, an antistatic layer, and a high-strength filter layer according to the material flow direction; the dust-receiving layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, the antistatic layer is a woven fabric made of meta-aramid, para-aramid, and conductive fiber in a basket weave structure, and the high-strength filter layer is a woven fabric made of polyimide filaments in a plain weave structure. The dust-receiving layer, the antistatic layer, and the high-strength filter layer are sewn together by snap fasteners; the weight ratio of the dust-receiving layer, the antistatic layer, and the high-strength filter layer is 150:180:150;

[0132] The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 96.7%, and the breaking strength retention rate is 96.1%.

[0133] This comparative example also provides a method for preparing the multi-layer aramid fiber high temperature resistant material, comprising the following steps:

[0134] Step 1: Open the 38mm meta-aramid fiber on the opening roller at a speed of 2000rpm, then feed it into the carding machine at a speed of 20m / min, and card it into single fibers of 20g / m on the cylinder at a speed of 900rpm. 2 The fiber web is laid on which a polyolefin elastic fiber with a total mass ratio of 1:9 to the meta-aramid fiber, a linear density of 44 dtex, and a 90° cross is laid. The fiber web is then fed into a web laying machine and folded back and forth at a speed of 30 times / min to form 16 layers of 300 g / m 2 , dust-proof fiber web with uniformity (CV) ≤ 4.5%;

[0135] The dust-proof fiber web was stretched by a stretching machine at a stretching ratio of 1.5 and then passed through a 5.0*10 6 The low-pressure water needle of Pa was used for hydroentanglement, and after drying at 120℃ for 5min, the weight of the obtained 2 The dust layer;

[0136] The polyolefin elastic fiber has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%;

[0137] Step 2, the meta-aramid fiber, para-aramid fiber and conductive fiber with a mass ratio of 93:6:1, each with a length of 38 mm, are opened at an opening roller speed of 2000 rpm, then fed into a feeder and transported to a carding machine at a speed of 20 m / min, carded at a cylinder speed of 800 rpm, and then fed into a drawing frame to combine 6 slivers, drawn at a draft of 7.5 times, and then drawn at a twist factor of 85 and a draft of 1.2 to form a roving, and drawn at a twist factor of 360 and a draft of 32 to form a yarn, and wound into a drum to prepare an anti-static yarn with a yarn count of 32S / 2;

[0138] The anti-static yarn is woven into an anti-static mesh fabric by a high-speed air-jet loom with a basket weave structure, the anti-static mesh fabric has a warp density of 260 ends / 10 cm and a weft density of 200 ends / 10 cm, and then is treated with a 3.0*10 6 2 The anti-static layer has a grammage of 180 g / m 2

[0139] The meta-aramid fiber has a moisture regain of 4%, the para-aramid fiber has a moisture regain of 3%, and the conductive fiber has a moisture regain of 0.5%;

[0140] Step 3, the multi-leaf structure polyimide filament with a fineness of 400D is woven into a plain weave structure on a rigid rapier loom, the weaving has a warp density of 170 ends / 10 cm and a weft density of 160 ends / 10 cm, and a high-strength filter layer with a grammage of 150 g / m 2

[0141] The polyimide filament has a breaking strength of 25.4 cN / dtex;

[0142] Step 4, the dust-impinging layer, the anti-static layer and the high-strength filter layer are stitched with a 200D*3 ply para-aramid thread, the dust-impinging layer and the anti-static layer are stitched with a single thread, and the anti-static layer and the high-strength filter layer are stitched with a double thread, to obtain the multi-layer aramid fiber high-temperature-resistant material.

[0143] The dust-impinging layer, the anti-static layer and the high-strength filter layer in the examples and comparative examples are left with a live thread port when stitched, facilitating replacement of each layer.

[0144] Table 1 is the performance of the multi-layer aramid fiber high-temperature-resistant material in the examples and comparative examples

[0145]

[0146] ​As can be seen from the table, the multi-layer aramid fiber high-temperature resistant material described in the present invention has high filtration efficiency and stable efficiency, and at the same time, has a high breaking strength retention rate, which can meet high-intensity usage requirements. The filtration efficiency is not affected after repeated use, and the temperature resistance is also good. The dust-facing layer in Comparative Example 1 is only meta-aramid fiber, which causes the dust-facing layer to be unable to be reused after adsorbing impurities, and its filtration efficiency is also greatly reduced. The anti-static layer in Comparative Example 2 has not been hydro-jetted with a low-pressure water needle, and the entanglement and cohesion between fibers are small, resulting in a decrease in filtration efficiency and a significant decrease in breaking strength retention rate. The high-strength filter layer in Comparative Example 3 is woven with a conventional plain weave structure. The plain weave structure is relatively flat and compact, and the specific surface area is small, so its filtration effect is slightly reduced. In addition, the warp and weft yarns are interwoven many times during the weaving process, and the yarn strength loss is relatively large, which causes its breaking strength to be slightly reduced.

[0147] The test conditions for the filtration efficiency described in the present invention are as follows: the test is carried out using an automatic filter material filtration tester, the sample is kept at 200°C for 12 hours and then the filtration test is carried out, wherein the aerosol particle model uses 0.3 μm NaCl particles, the air flow rate is 85 L / min, and the test area is 100 cm 2 .

[0148] Based on the above, it can be seen that the multi-layer aramid fiber high-temperature resistant material of the present invention has a wide range of applications, low cost, and extremely high market prospects.

[0149] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent variation based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A multi-layer aramid fiber high temperature resistant material, characterized in that: The multi-layer aramid fiber high-temperature resistant material is divided into three layers, which are respectively divided into a dust-facing layer, an antistatic layer and a high-strength filter layer according to the material flow direction; the dust-facing layer is a non-woven fabric made of meta-aramid and polyolefin elastic fiber, which is obtained by stretching, low-pressure water needle spunlace and drying; the antistatic layer is a woven fabric made of meta-aramid, para-aramid and conductive fiber in a plain weave structure or a square weave structure, which is obtained by low-pressure water needle spunlace and then drying; the high-strength filter layer is a woven fabric made of multi-lobal polyimide filaments in a 2-up 2-down right twill structure or a honeycomb structure; the dust-facing layer, the antistatic layer and the high-strength filter layer are sewn together by a 200D*2 or 200D*3 or 200D*4 ply-aramid twisted yarn; the gram weight ratio of the dust-facing layer, the antistatic layer and the high-strength filter layer is (130-180): (180-220): (150-180); The polyolefin elastic fibers in the dust-facing layer melt as the ambient temperature rises, and regenerate a crystalline network after cooling. The molecular network can still remain intact at 220°C. The filtration efficiency of the multi-layer aramid fiber high-temperature resistant material is 99.5-99.8%, the breaking strength retention rate is 96.0-97.4%, the temperature resistance of the dust-facing layer is ≥200°C, and the temperature resistance of the antistatic layer and the high-strength filtration layer is ≥300°C.

2. A method for preparing the multi-layer aramid fiber high temperature resistant material according to claim 1, characterized in that: The following steps are involved: Step 1: The meta-aramid fiber is opened under an opening roller, and then enters a feeder to be transported to a carding machine to be carded into a single fiber web. After polyolefin elastic fiber is laid on the fiber web, it enters a web laying machine for reciprocating folding to form a dust-proof fiber web; The dust-receiving fiber web is stretched by a stretching machine, and then hydroentangled by a low-pressure water needle, and then dried to obtain a dust-receiving layer; Step 2, opening the meta-aramid fiber, the para-aramid fiber and the conductive fiber under an opening roller, then feeding the fibers into a feeder and conveying them to a carding machine for combing, then feeding the fibers into a drawing frame for drawing, and then drawing the fibers, and then continuing to process the coarse and fine yarns, and doffing the fibers to prepare an antistatic yarn; weaving the antistatic yarn into an antistatic mesh by a high-speed air-jet loom, and then hydroentangling the yarn with a low-pressure water needle, and then drying the yarn to obtain an antistatic layer; Step 3, weaving the polyimide filaments in a rigid rapier loom to obtain a high-strength filter layer; Step 4: sew the dust-receiving layer, the antistatic layer and the high-strength filter layer together, wherein the dust-receiving layer and the antistatic layer are sewed with a single thread, and the antistatic layer and the high-strength filter layer are sewed with a double thread, to obtain the multi-layer aramid fiber high-temperature resistant material.

3. The preparation method according to claim 2, characterized in that The total mass ratio of the polyolefin elastic fiber to the meta-aramid fiber in step 1 is (0.5-1): (9-9.5).

4. The preparation method according to claim 2, characterized in that The polyolefin elastic fiber in step 1 has an elongation at break of 53%, a breaking strength of 1.15 cN / dtex, and a moisture regain of 0.1%.

5. The preparation method according to claim 2, characterized in that The mass ratio of the meta-aramid fiber, the para-aramid fiber and the conductive fiber in step 2 is (92-96): (6-8): (1-2).

6. The preparation method according to claim 2, characterized in that The yarn count of the antistatic yarn in step 2 is 32-40S / 2.

7. The preparation method according to claim 2, characterized in that The high-speed air-jet loom in step 2 is used for weaving in a plain weave structure or a basket weave structure.

8. The preparation method according to claim 2, characterized in that The rigid rapier loom in step 3 is used for weaving in a 2-up 2-down right twill structure or a honeycomb structure.

9. The preparation method according to claim 2, characterized in that The ply-twisted para-aramid yarn used for the snap-button suture in step 4 is a ply-twisted yarn of 200D*2, 200D*3 or 200D*4.

10. A flue gas filter, characterized in that: The smoke filter is made of the multi-layer aramid fiber high-temperature resistant material according to claim 1.

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