Low-gram-weight base cloth

Abstract

The invention discloses low-gram-weight base cloth which is characterized in that the gram weight of the low-gram-weight base cloth is 65-95 g / m < 2 >, the warp yarn density of the base cloth is 3-8 times that of the weft yarn density, the warp strength of the base cloth is larger than or equal to 900 N / 5 cm, and the weft strength of the base cloth is 150-400 N / 5 cm. The base cloth is combined with the dust facing surface and the non-dust facing surface to form the filter felt, and the total gram weight of the filter felt is 420-580g / m < 2 >. According to the invention, not only is the low-gram-weight base cloth adopted, but also the strength, especially the warp-direction strength, of the prepared filter felt can be ensured not to be reduced. Therefore, the cost is saved, and the requirements of customers can be met. The method can be suitable for industrial dust removal, waste incineration, solid waste treatment and asphalt smoke dust treatment.

Description

Technical Field

[0001] This invention relates to a low-basis-weight base fabric, and the filter felt made from this base fabric is suitable for industrial dust removal, waste incineration, solid waste disposal, asphalt fume treatment and other fields. Background Technology

[0002] Baghouse dust collectors are widely used in industries such as manufacturing, power generation, steel, and asphalt. Filter bags are the key to dust collection efficiency and are therefore widely and extensively used.

[0003] Currently, the filter bag industry is characterized by numerous manufacturers and a wide variety of products, leading to fierce price competition in order to achieve high sales performance in a limited market. To meet customer requirements while reducing costs, filter bag manufacturers have adopted various methods, one of which is reducing the basis weight of the base fabric. However, ensuring that the strength of the filter felt, especially the warp strength, is maintained even with a reduced base fabric weight has become a pressing problem. This invention not only uses a low-basis-weight base fabric but also guarantees the strength of the filter felt, particularly the warp strength, without any decrease. This saves costs while still meeting customer requirements.

[0004] CN201510371591.8 discloses a low-basis-weight ultrafine fiber ultra-clean high-temperature filter material and its preparation method. It comprises a dust-receiving surface containing polyphenylene sulfide (PPS) composite ultrafine fibers, PPS fine denier fibers, and polytetrafluoroethylene (PTFE) fibers blended in a certain proportion; a clean air surface containing ordinary PPS fibers or PPS fine denier fibers; and a PIFE base fabric located between the dust-receiving surface and the clean air surface; the base fabric basis weight is 80-100 g / m². This patent discloses a filter felt that can save costs and achieve ultra-low emissions, but it is limited to a PTFE base fabric, and there is no detailed description of how to maintain strength at low basis weight, making it difficult to meet customer or even national standard requirements for strength.

[0005] To address the shortcomings of current low-basis-weight base fabrics, this invention provides a base fabric that maintains high warp strength even with low basis weight. This is achieved by adjusting yarn twist, increasing the strength of raw cotton or filaments, appropriately reducing weft fiber density, and minimizing or eliminating the reduction in warp fiber density. This allows for a reduction in base fabric basis weight without compromising warp strength. The warp strength of filter felt largely originates from the base fabric, while the weft strength primarily comes from the non-woven web on the dust-facing and non-dust-facing sides. Therefore, as long as the warp strength of the base fabric remains constant, the overall warp strength of the filter felt will not decrease, meeting customer strength requirements. Furthermore, since the cost of the base fabric for the same basis weight is higher than that of the non-woven web, this effectively reduces the overall cost of the filter felt. Summary of the Invention

[0006] The purpose of this invention is to provide a low basis weight base fabric that reduces costs while maintaining the overall warp strength of the filter felt.

[0007] The technical solution of this invention is as follows: the basis weight of the low-weight base fabric is 65-95 g / m². 2 The warp yarn density of the base fabric is 3-8 times that of the weft yarn density, the warp strength of the base fabric is greater than or equal to 900N / 5cm, and the weft strength of the base fabric is 150~400N / 5cm.

[0008] The filter felt is formed by combining the base fabric, the dust-facing nonwoven fabric, and the non-dust-facing nonwoven fabric, with a total basis weight of 420~580 g / m². 2 .

[0009] The yarns constituting the base fabric are one of polyester yarn, aramid yarn, or PTFE filament. The resulting filter felt has a warp strength greater than or equal to 900 N / 5 cm and a weft strength greater than or equal to 1200 N / 5 cm. The needle-punching density of the filter felt is 800-1200 needles / cm. 2 The filter felt contains 0.1-0.3% by mass of water-soluble polymers.

[0010] The base fabric is woven using a plain weave method. The warp yarns are double or triple strands composed of 15-30 count single yarns, while the weft yarns are single or double strands of 20-40 count. The weft yarns are finer than the warp yarns.

[0011] The filter felt made from this low-grammage base fabric has a dust-facing and non-dust-facing weight ratio of 70:30 to 50:50, and the fibers that make up the filter felt and the fibers that make up the base fabric are the same type of fiber.

[0012] The polyester and aramid yarns that make up the base fabric have a single yarn twist of ≥40T / 10cm, and a double or triple yarn twist of ≥15T / 10cm, with the single yarns and plied yarns exhibiting opposite twist directions. The raw cotton fibers that make up the polyester and aramid yarns have a length of ≥48mm, a fiber density of 1.5D-3.0D, an average raw cotton fiber strength of ≥4.5cN / dtex, a crimp of 14%-19%, and a crimp count of 12-18 crimps / 25mm.

[0013] The PTFE filaments that make up the base fabric have a strength greater than or equal to 5.0 cN / dtex.

[0014] The filter felt made from this base fabric can be used in industrial dust removal, waste incineration, solid waste disposal, and asphalt fume treatment.

[0015] The beneficial effects of the present invention are: since the base fabric of the present invention can maintain high warp strength and achieve low basis weight, the filter felt made by combining it with the dust-facing and non-dust-facing surfaces has a low cost, which can meet the customer's requirements for strength and effectively reduce the overall cost of the filter felt. Detailed Implementation

[0016] This invention discloses a low-basis-weight base fabric with a basis weight of 65-95 g / m². 2 The most important reason for reducing the basis weight of the base fabric is to reduce the overall cost of the filter felt. Basis weights higher than 95 g / m²... 2 It is relatively simple to achieve, and those in this industry can easily meet the requirements. When the weight is below 65g / m³ 2 At that time, the warp strength cannot meet the condition of being greater than or equal to 900 N / 5 cm, or even if the warp strength is increased by reducing the weft density and increasing the warp density, the weight per unit area will not reach 65 g / m. 2 At this point, the weft density has already reached the minimum requirement; further reduction will prevent the fabric from forming a complete structure, resulting in collapse. A weight of 65-75 g / m² is preferred. 2 While ensuring the base fabric can be formed completely, the weight can be further reduced, thus lowering costs.

[0017] The warp yarn density of the base fabric is 3-8 times that of the weft yarn density. The warp strength of the base fabric is greater than or equal to 900 N / 5 cm, and the weft strength is 150-400 N / 5 cm. When the warp density is less than 3 times that of the weft density, due to the low basis weight of this invention, it is difficult to achieve the required warp strength of over 900 N / 5 cm. When the warp density exceeds 8 times that of the weft, the weft becomes too sparse and cannot support the warp to form a complete fabric, causing the fabric structure to collapse.

[0018] The base fabric and the dust-facing and non-dust-facing surfaces are combined to form a filter felt, with a total basis weight of 420~580g / m². 2 The basis weight of filter felt is generally greater than or equal to 550 g / m². 2 The preferred strength for this invention is 420~550 g / m³. 2 More preferably 420~500 g / m 2 When the weight of the kibbles is 65 g / m 2 The minimum basis weight of the filter felt can reach 420g / m². 2 When the base fabric weight is 75g, the minimum weight of the filter felt can reach 430g / m². 2 And so on. The minimum basis weight is specified to ensure the basis weight of the fibers on both the dust-facing and non-dust-facing sides, guaranteeing filtration effectiveness and preventing the base fabric from being exposed. If used in ultra-low emission projects, microfibers need to be added to the dust-facing side or a PTFE membrane structure needs to be used.

[0019] The yarns that make up the base fabric are one of polyester yarn, aramid yarn, or PTFE filament. Polyester is mainly used for room temperature filter media, aramid for high temperature filter media, and PTFE filament for high temperature corrosion-resistant filter media. It is not limited to these three; it can also be composed of PPS, nylon, or other fiber yarns. The aforementioned yarns are short-fiber yarns.

[0020] The filter felt made from a low-basis-weight base fabric has a warp strength greater than or equal to 900 N / 5 cm and a weft strength greater than or equal to 1200 N / 5 cm. The needle-punching density of the filter felt is 800-1200 needles / cm. 2 The needle-punching density should not be too high or too low. Too high a density can easily break the fibers of the filter layer, non-filter layer, and even the base fabric. Too low a density results in insufficient interlacing between the fibers of the filter layer and non-filter layer, leading to low weft strength. The warp strength of the filter felt is mainly related to the warp strength of the base fabric, while the weft strength is mainly related to the upper and lower filter surfaces. Therefore, maximizing the warp strength of the base fabric while ensuring the complete formation of the base fabric structure is crucial.

[0021] The filter felt is coated with 0.1-0.3% by mass of a water-soluble polymer compound, preferably either polyacrylamide or polyvinylpyrrolidone. Studies on improving the overall strength of the filter felt have found that the water-soluble polymer compound, preferably polyacrylamide and more preferably polyvinylpyrrolidone, has a positive effect on improving the strength of the filter felt. Even at a very low adhesion rate of 0.1-0.3% by mass, it has a relatively significant strength-improving effect, increasing both warp and weft strength by 10-15%. When the adhesion rate is less than 0.1%, the strength-improving effect is not significant; when the adhesion rate is greater than 0.3%, it causes the material to harden and reduces filtration performance. There are many methods for adhering the water-soluble polymer compound to the filter felt, including impregnation and spraying, but these methods are not limited to these two. The average molecular weight of the polyacrylamide is preferably 1.3 million to 1.6 million, and the average molecular weight of the polyvinylpyrrolidone is preferably 1 million to 1.2 million. Because the above compounds have a binding effect, if the average molecular weight is too low, the binding effect will be reduced, and the strength enhancement effect will be slightly worse. If the average molecular weight is too high, it will easily agglomerate, resulting in uneven dispersion, and similarly, the strength enhancement effect will be slightly worse.

[0022] The base fabric is woven using a plain weave method. There are many fabric construction methods, but the plain weave construction maintains the integrity of the fabric structure while minimizing weft density. The plain weave construction can achieve a weight of only 65-95 g / m². 2 Under the premise of ensuring that the warp density is 3 times, or even 5 times, greater than the weft density, the fabric structure can still collapse. Other structures, such as double weft, are prone to collapse if the warp density exceeds the weft density by more than 3 times under the same weight.

[0023] The base fabric is needle-punched together between the dust-facing and non-dust-facing sides. The warp yarns are composed of 15-30 count single yarns in double or triple strands, while the weft yarns are 20-40 count single or double strands. The weft yarns are finer than the warp yarns to maximize warp strength. The warp density must not exceed eight times that of the weft; exceeding this will cause the fabric to collapse, even in a plain weave. When the warp yarn count is greater than 30 and consists only of single strands, insufficient yarn strength leads to insufficient warp strength. When the warp yarn count is less than 15 and consists of more than three strands, the yarn is too coarse, resulting in an insufficient fabric density within the weight limit, making it impossible to form a stable, non-collapsed fabric structure.

[0024] The weight ratio of the dust-facing and non-dust-facing surfaces of the filter felt is 70:30 to 50:50. The fibers constituting the filter felt and the fibers constituting the base fabric are the same type of fiber. The fibers constituting the filter felt refer to the fibers with the largest proportion, which in this invention mainly refer to aramid, polyester, or PTFE fibers.

[0025] The polyester and aramid yarns that make up the base fabric have a single yarn twist of ≥40T / 10cm and a ply yarn twist of ≥15T / 10cm, with the single yarns and ply yarns twisting in opposite directions. Insufficient strength occurs when the single yarn twist is less than 40T / 10cm or the ply yarn twist is less than 15T / 10cm. For low-weight base fabrics with fewer yarns, achieving a warp twist of ≥900N / 5cm requires high precision in yarn twist. The optimal twist range is: single yarn twist 50T / 10cm-65T / 10cm and ply yarn twist 20T / 10cm-30T / 10cm. Excessive twist makes the yarn prone to knotting, forming neps, which is detrimental to quality control. In addition, to control neps, it is preferable to perform two steaming processes after the spinning and plying steps of the yarn, with a steaming temperature of 90-100 degrees Celsius and a time of 30-40 minutes. This effectively suppresses knotting and neps at a higher twist level. At the same time, these steaming conditions can also increase the yarn strength by more than 5%, which is one of the important steps for low-grammage base fabrics to achieve the required strength.

[0026] The raw cotton staple fibers used in the polyester and aramid yarns of this invention have a length of 48mm or greater, preferably 50-65mm. If the fiber length is too short, the spun yarn will have weak strength, making it difficult to achieve a warp strength of over 900N / 5cm when producing low-weight base fabrics. Excessively long raw cotton fibers will cause difficulties in combing, making yarn production more challenging and resulting in poorer yarn quality with more knots and other defects. The raw cotton fibers are 1.5D-3.0D, with an average strength of over 4.5cN / dtex. The crimp of the raw cotton fibers is 14%-19%, with 12-18 crimps / 25mm. The definition of crimp and crimp number is provided to address difficulties in yarn production when values ​​exceed these ranges; high values ​​make combing difficult and prone to knotting, while low values ​​make it difficult to achieve the required strength.

[0027] When the base fabric of this invention is PTFE, the strength of the PTFE filaments is greater than or equal to 5.0 cN / dtex.

[0028] This filter material can be used in industrial dust removal, waste incineration, solid waste disposal, asphalt fume treatment and other fields.

[0029] The performance structures described in this invention can all be verified through testing. The following are some examples of testing methods.

[0030] Tensile strength: Based on the specifications in GB / T 3923.1-2013, samples were taken in both the warp and weft directions. The sample size was 20cm × 5cm, the tensile speed was 100m / min, and the clamp spacing was 10cm. The measured value is the average of five strength values ​​in the warp and weft directions of the sample.

[0031] Weight: Based on the specifications in GB / T 4669-2008, the filter material is cut into 200×200 mm squares, and the weight of the filter material is calculated from the weight. Weight = Filter cloth weight / (length × width), n=5, and the average value is taken.

[0032] Example 1: Raw cotton with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, 14 crimps / 25 mm, and a fineness of 2.0 D was spun into yarn. The warp yarn was 20-count double-ply, with each warp single yarn having an S-twist and a twist of 50 T / 10 cm, and the warp ply yarn having a Z-twist and a twist of 23 T / 10 cm. The weft yarn was 22-count single-ply, with an S-twist and a twist of 50 T / 10 cm.

[0033] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a weight of 75 g / m². 2 The warp yarn density is 4 times that of the weft yarn density. The actual measured warp strength of the base fabric is 1050N / 5cm, and the actual measured weft strength is 160N / 5cm.

[0034] Cover the above base fabric with 250g / m 2 Polyester fiber mesh forms the polyester fiber filter surface layer; a 150g / m² layer is then applied under the aforementioned base fabric. 2 Polyester fiber web, forming the non-filter layer of polyester fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 475 g / m². 2 The filter felt has a warp strength of 1080 N / 5 cm and a weft strength of 1460 N / 5 cm.

[0035] The aforementioned surface layer uses 2.0D polyester fiber. This polyester filter material can be used in medium and low temperature environments not exceeding 120 degrees Celsius and can meet the requirement of 20mg / Nm³. 3 Precision emission requirements.

[0036] Example 2: The remaining conditions are completely the same as in Example 1. By using an impregnation process, 0.2% of polyvinylpyrrolidone with an average molecular weight of 1.1 million was applied to the filter felt. The warp strength of the filter felt reached 1310 N / 5 cm and the weft strength reached 1640 N / 5 cm.

[0037] Example 3: All other conditions are exactly the same as in Example 1. The surface layer uses 1.2D polyester fiber. This polyester filter material can be used in medium and low temperature environments not exceeding 120 degrees Celsius and can meet the requirement of 10 mg / Nm³. 3 Precision emission requirements.

[0038] Example 4: The remaining conditions are exactly the same as in Example 1. The surface layer uses 0.9D polyester fiber. This polyester filter material can be used in medium and low temperature environments not exceeding 120 degrees Celsius and can meet the emission requirements with an accuracy of 5 mg / Nm³.

[0039] Example 5: Polyester fibers with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, 14 crimps / 25 mm, and a fineness of 2.0 D were spun into yarn. The warp yarns were 20-count double-ply, with each warp single yarn having an S-twist and a twist of 50 T / 10 cm, and the warp ply yarns having a Z-twist and a twist of 23 T / 10 cm. The weft yarns were 22-count single-ply, with an S-twist and a twist of 50 T / 10 cm.

[0040] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a basis weight of 65 g / m². 2 The warp yarn density is 4 times that of the weft yarn density. The actual measured warp strength is 900N / 5cm, and the actual measured weft strength is 150N / 5cm.

[0041] Cover the above base fabric with 250g / m 2Polyester fiber mesh forms the polyester fiber filter surface layer; a 150g / m² layer is then applied under the aforementioned base fabric. 2 Polyester fiber web, forming the non-filter layer of polyester fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 465 g / m². 2 The filter felt has a warp strength of 910 N / 5 cm and a weft strength of 1440 N / 5 cm.

[0042] Example 6: Polyester fibers with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, a crimp count of 14 crimps / 25 mm, and a fineness of 2.0 D were spun into yarn. The warp yarns were 15-count double-ply, with S-twist and a twist of 50 T / 10 cm, and Z-twist and a twist of 23 T / 10 cm. The weft yarns were 20-count single-ply, S-twist, with a twist of 50 T / 10 cm.

[0043] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a basis weight of 75 g / m². 2 The warp yarn density is 3 times that of the weft yarn density. The actual measured warp strength is 1000N / 5cm, and the actual measured weft strength is 150N / 5cm.

[0044] Cover the above base fabric with 250g / m 2 Polyester fiber mesh forms the polyester fiber filter surface layer; a 150g / m² layer is then applied under the aforementioned base fabric. 2 Polyester fiber web, forming the non-filter layer of polyester fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 475 g / m². 2 The filter felt has a warp strength of 1050 N / 5 cm and a weft strength of 1420 N / 5 cm.

[0045] Example 7: Polyester fibers with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, a crimp count of 14 crimps / 25 mm, and a fineness of 2.0 D were spun into yarn. The warp yarns were 20-count double-ply, with S-twist and a twist of 55T / 10cm, and Z-twist and a twist of 27T / 10cm. The weft yarns were 22-count single-ply, S-twist, with a twist of 55T / 10cm.

[0046] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a basis weight of 75 g / m². 2 The warp yarn density is 4 times that of the weft yarn density. The actual measured warp strength is 1090 N / 5 cm, and the actual measured weft strength is 165 N / 5 cm.

[0047] Cover the above base fabric with 250g / m 2 Polyester fiber mesh forms the polyester fiber filter surface layer; a 150g / m² layer is then applied under the aforementioned base fabric. 2Polyester fiber web, forming the non-filter layer of polyester fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 475 g / m². 2 The filter felt has a warp strength of 1120 N / 5 cm and a weft strength of 1470 N / 5 cm.

[0048] Example 8: Meta-aramid fibers with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, a crimp count of 14 crimps / 25 mm, and a fineness of 2.0 D were spun into yarn. The warp yarns were 20-count double-ply, with S-twist and a twist of 50 T / 10 cm, and Z-twist and a twist of 23 T / 10 cm. The weft yarns were 22-count single-ply, S-twist, with a twist of 50 T / 10 cm.

[0049] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a basis weight of 75 g / m². 2 The warp yarn density is 4 times that of the weft yarn density. The actual measured warp strength is 1050N / 5cm, and the actual measured weft strength is 160N / 5cm.

[0050] Cover the above base fabric with 250g / m 2 Aramid fiber mesh forms the aramid fiber filter surface layer; a 150g / m² layer is then applied to the base fabric. 2 Aramid fiber web, forming the non-filtering layer of aramid fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 475 g / m². 2 The filter felt has a warp strength of 1080 N / 5 cm and a weft strength of 1460 N / 5 cm.

[0051] The aforementioned surface layer uses 2.0D aramid fiber. This polyester filter material can be used in high-temperature environments not exceeding 220 degrees Celsius and can meet the requirement of 20mg / Nm³. 3 Precision emission requirements.

[0052] Example 9: Using PTFE filaments with a filament strength of 5.1 cN / dtex, a plain weave base fabric was woven, with a base fabric weight of 75 g / m². 2 The warp filament density is 4 times that of the weft filament density. The actual measured warp strength is 1150N / 5cm, and the actual measured weft strength is 180N / 5cm.

[0053] Cover the above base fabric with 300g / m 2 PTFE fiber mesh forms the PTFE fiber filter surface layer; a 200g / m² layer is then applied beneath the aforementioned base fabric. 2 PTFE fiber mesh, forming the PTFE fiber non-filter layer, is needle-punched, shaped, and calendered to obtain a basis weight of 575 g / m². 2 The filter felt has a warp strength of 1180 N / 5 cm and a weft strength of 1310 N / 5 cm.

[0054] The aforementioned surface layer uses 4.0D PTFE fiber. This polyester filter material can be used in high-temperature environments not exceeding 260 degrees Celsius and can meet the requirement of 30mg / Nm³. 3 Precision emission requirements. After coating with a PTFE membrane, it can meet the 5mg / Nm³ emission standard. 3 Precision emission requirements.

[0055] Example 10: The remaining conditions are completely the same as in Example 2. By applying 0.2% polyvinylpyrrolidone with an average molecular weight of 800,000 to the filter felt through an impregnation process, the warp strength of the filter felt reaches 1200 N / 5 cm and the weft strength reaches 1520 N / 5 cm.

[0056] Example 11: The remaining conditions are completely the same as in Example 2. By applying 0.2% polyacrylamide with an average molecular weight of 1.4 million to the filter felt through an impregnation process, the warp strength of the filter felt reaches 1280 N / 5 cm and the weft strength reaches 1590 N / 5 cm.

[0057] Comparative Example 1: A yarn was spun from polyester fibers with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, 14 crimps / 25 mm, and a fineness of 2.0 D. The warp yarn was 20-count double-ply, with each warp single yarn having an S-twist and a twist of 50 T / 10 cm, and the warp ply yarn having a Z-twist and a twist of 23 T / 10 cm. The weft yarn was 22-count single-ply, with an S-twist and a twist of 50 T / 10 cm.

[0058] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a weight of 55 g / m². 2 The warp yarn density was four times that of the weft yarn density. As a result, the woven base fabric could not be formed completely, the warp yarns collapsed, and stable mass production could not be achieved.

[0059] Even when a small quantity of the base fabric and filter felt were produced, the warp strength of the base fabric was only 790 N / 5 cm. A 250 g / m² layer was then applied over the aforementioned small-scale produced base fabric. 2 Polyester fiber mesh forms the polyester fiber filter surface layer; a 150g / m² layer is then applied under the aforementioned base fabric. 2 Polyester fiber web, forming the non-filter layer of polyester fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 455 g / m². 2 The filter felt has a warp strength of 820 N / 5 cm and a weft strength of 1460 N / 5 cm.

[0060] The aforementioned base fabric and filter media do not meet the national standard requirement of a warp strength greater than 900N.

[0061] Comparative Example 2: A yarn was spun from polyester fibers with a strength of 4.6 cN / dtex, a length of 51 mm, a crimp of 15%, 14 crimps / 25 mm, and a fineness of 2.0 D. The warp yarn was 20-count double-ply with an S-twist of 50 T / 10 cm and a Z-twist of 23 T / 10 cm. The weft yarn was 22-count single-ply with an S-twist of 50 T / 10 cm.

[0062] The above-mentioned warp and weft yarns are used to weave a plain weave base fabric with a weight of 100 g / m². 2 The warp yarn density is 4 times that of the weft yarn density. The actual warp strength is 1290N / 5cm and the weft strength is 200N / 5cm.

[0063] Cover the above base fabric with 250g / m 2 Polyester fiber mesh forms the polyester fiber filter surface layer; a 150g / m² layer is then applied under the aforementioned base fabric. 2 Polyester fiber web, forming the non-filter layer of polyester fibers, is needle-punched, shaped, and calendered to obtain a basis weight of 500 g / m². 2 The filter felt has a warp strength of 1320 N / 5 cm and a weft strength of 1500 N / 5 cm.

[0064] Although the case involved 100 g / m 2 The base fabric provides sufficient strength, but it is a relatively common method and has no cost advantage.

Claims

1. A low basis weight base fabric, characterized by: The low weight base cloth has a weight of 65-95 g / m2, the warp yarn density of the base cloth is 3-8 times of the weft yarn density, the warp strength of the base cloth is greater than or equal to 900 N / 5 cm, and the weft strength of the base cloth is 150-400 N / 5 cm.

2. A low-grammage base fabric according to claim 1, wherein The filter felt is formed by combining the base cloth with a dust-approaching non-woven fabric and a non-dust-approaching non-woven fabric, and the total weight of the filter felt is 420-580 g / m2.

3. A low-grammage base fabric according to claim 1, wherein The yarns constituting the base cloth are one of polyester yarns, aramid yarns or PTFE filaments, the filter felt made has a warp strength greater than or equal to 900 N / 5 cm, a weft strength greater than or equal to 1200 N / 5 cm, a needle punching density of 800-1200 needles / cm 2 , and the filter felt has 0.1-0.3% of a water-soluble high molecular compound attached thereto.

4. A low-grammage base fabric according to claim 1, wherein The base cloth is woven by a plain weave method, the warp yarn is composed of 15-30 single yarns to form a double or triple yarn, the weft yarn is composed of 20-40 single or double yarns, and the weft yarn is finer than the warp yarn.

5. A low-grammage base fabric according to claim 2, wherein The weight ratio of the dust-approaching surface to the non-dust-approaching surface of the filter felt made of the low weight base cloth is 70:30-50:50, the fiber constituting the filter felt and the fiber constituting the base cloth are the same kind of fiber.

6. A low-grammage base fabric according to claim 2, wherein The twist of the polyester yarn and the aramid yarn constituting the base cloth is greater than or equal to 40 T / 10 cm, the twist of the double or triple yarn is greater than or equal to 15 T / 10 cm, and the twist direction of the single yarn and the strand is opposite.

7. A low-grammage base fabric according to claim 2, wherein The length of the cotton fiber constituting the polyester yarn and the aramid yarn is greater than or equal to 48 mm, the fiber is 1.5D-3.0D, the average strength of the cotton fiber is greater than 4.5 cN / dtex, the crimp degree of the cotton fiber is 14%-19%, and the crimp number is 12-18 / 25 mm.

8. A low-grammage base fabric according to claim 2, wherein The strength of the PTFE filament constituting the base cloth is greater than or equal to 5.0 cN / dtex.

9. A low-grammage base fabric according to claim 1, wherein The filter felt made of the base cloth can be applied in the fields of industrial dust removal, garbage incineration, solid waste disposal, and asphalt smoke dust treatment.