Production process of papermaking felt

Abstract

The invention discloses a production process of a papermaking felt. The production process of the papermaking felt comprises the steps of preparation of the middle framework layer, manufacturing of the fiber layer, needling of gray fabric, needling of gray fabric and heat setting. A laminated structure formed by folding a single-layer base net is adopted, and the two ends of the single-layer base net are folded and then subjected to ultrasonic welding to form a ring, so that the middle framework layer is obtained. Compared with the prior art, the ring is formed by using the ultrasonic welding technology, so that the equipment investment is low, the production process is greatly shortened, the production efficiency is remarkably improved, meanwhile, a seam is straighter and easier to loosen on a weaving machine, the labor amount of a weaving machine operator is effectively reduced, and the production efficiency of the weaving machine operator is improved.

Description

Technical Field

[0001] The invention relates to the technical field of papermaking felts, and in particular to a production process of papermaking felts. Background Art

[0002] With the improvement of people's living standards and the improvement of the technical level of the cigarette industry and the printing industry, excessive dust and felt hair are not allowed in the tipping paper. Excessive dust and felt hair will lead to a serious decline in printing efficiency and the printing quality will not meet the market demand for tipping paper. Therefore, there is a higher demand for the felt hair to prevent wear for the papermaking felt for tipping paper. Moreover, the papermaking felt for tipping paper is more controlled by foreign brands, and there is also a demand for improvement in the felt hair. The research and development of the papermaking felt for tipping paper is imminent.

[0003] Papermaking felts are special industrial textiles. With the development of papermaking industry production technology, papermaking felts are required to have the characteristics of high strength, good water filtration, good flatness, good compression resilience and good dimensional stability. In recent years, the research and development of papermaking felts at home and abroad has been continuously deepened to improve the comprehensive use of felts. For example, Sichuan Huanlong Technical Fabric Co., Ltd. and Sichuan Textile Science Research Institute Co., Ltd. have developed multi-axial multi-layer papermaking felts. This new product effectively improves the problems of existing felts. The development of papermaking felts can be traced back to 3000 AD, when they were originally used to make carpets. With the invention and spread of papermaking technology, papermaking felts began to develop. Papermaking felts are mainly used in three stages: paper sheet forming, pressing and drying.

[0004] The blankets used in the papermaking industry generally include traditional woven blankets, ordinary base cloth needle-punched blankets, weftless or sparse weft needle-punched blankets, bottom net needle-punched blankets, base clothless needle-punched blankets, seam needle-punched blankets, etc. The more commonly used bottom net needle-punched blankets are composed of a bottom net layer and a fiber layer, of which the bottom net layer is divided into three types: single layer, double layer, and laminated. Emperor is generally woven with warp and weft threads composed of nylon monofilament or monofilament ply by different weaving methods.

[0005] Papermaking felts play an important role in the papermaking industry, but there are also some defects and challenges in their development process. Papermaking felts have poor air permeability, low mechanical properties, weak wear resistance and short service life. They need to be replaced frequently, which reduces the life of the felts. Summary of the invention

[0006] To achieve the above object, the present invention provides a papermaking felt, characterized in that it includes a surface fiber mesh layer, an inner fiber mesh layer, a middle skeleton layer, and a reverse fiber mesh layer.

[0007] Preferably, the intermediate skeleton layer is a laminated structure formed by folding a single-layer base net in half, and two ends of the single-layer base net are ultrasonically welded to form a ring after being folded in half.

[0008] Preferably, the single-layer base net is composed of warp threads and weft threads; the material of the single-layer base net is nylon thread;

[0009] Preferably, the single-layer base net can be made of a single nylon yarn or a twisted nylon yarn;

[0010] Preferably, the surface fiber mesh layer, the inner fiber mesh layer, and the reverse fiber mesh layer are all made of nylon 66 fiber;

[0011] The invention also discloses a production process of the papermaking felt.

[0012] The production process of papermaking felt includes the following steps:

[0013] (a) Middle skeleton layer

[0014] S1, single-layer base mesh weaving;

[0015] (1) Material: Nylon 6 monofilament

[0016] Material specifications:

[0017] (2) Twisting and plying:

[0018] The warp settings are:

[0019] First twist: Z, 300 twists / m;

[0020] Re-twist: S, 260 twists / m;

[0021] The weft settings are:

[0022] First twist: Z, 300 twists / m;

[0023] Re-twist: S, 260 twists / m;

[0024] Material design and selection: Compared with conventional papermaking felts, it adopts more and more elastic twisted heald wire design. The first twist and second twist design of the twisted wire make the twisted wire of the base net have better adhesion to the fiber and prevent fuzzing and wear. The warp and weft are both fine heald wire strands, making the felt softer and more elastic. The warp and weft of the base net of the paper blanket for cigarette paper are twisted, and the adhesion points are more and the adhesion to the fiber is stronger.

[0025] (3) Warping

[0026] (4) Weft curling

[0027] (5) Weaving: 1 / 1 plain weave;

[0028] The design of the base mesh structure requires the base mesh to be more stable. The traditional 1 / 3 broken twill is adjusted to 1 / 1 plain weave, which has more bonding points and increases the bonding force to the fibers.

[0029] S2, middle frame layer: using ultrasonic welding technology

[0030] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0031] (ii) Fiber layer manufacturing;

[0032] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 2-7dtex nylon 66 fibers; the inner fiber web layer uses 8-11dtex nylon 66 fibers; and the back fiber web layer uses 11-22dtex nylon 66 fibers.

[0033] (3) Needle punched fabric;

[0034] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer and the reverse fiber mesh layer are processed by a needle punching process to obtain a needle punched grey fabric;

[0035] (iv) heat setting treatment to form the finished product.

[0036] Ultrasonic welding uses high-frequency vibration waves to be transmitted to the surfaces of two objects to be welded. Under pressure, the two surfaces of the objects are rubbed against each other to form a fusion between the molecular layers. The drying time of ultrasonic welding is very fast, and the material does not need to stay in the fixture for a long time waiting for the seam to dry or solidify. Therefore, it is used in this embodiment to greatly improve production efficiency. At the same time, the welding area is very clean and almost no repair work is required, which can make the seam mouth straighter. Ultrasonic welding is a fast, clean and effective assembly process. Ultrasonic welding is preferably operated and completed by an ultrasonic welding machine, among which the production process of ultrasonic welding end seam blanket and its ultrasonic seam process diagram are shown.

[0037] By using ultrasonic welding technology to form rings, not only is the equipment investment low, but the production process is also greatly shortened, and the production efficiency is significantly improved. At the same time, the seams are straighter and easier to put on the loom, which effectively reduces the labor of the loom operator and improves the production efficiency of the loom operator.

[0038] Nylon is the common name for polyamide, which is a general term for thermoplastic resins containing repeated amide groups -[NHCO]- on the main chain of the molecule; due to its excellent physical and mechanical properties, electrical insulation, oil resistance, solvent resistance, corrosion resistance and self-lubrication, it has become the largest and most widely used engineering plastic. However, nylon materials contain amide groups (-NH-CO-), which makes them highly hygroscopic. When they absorb too much water, all indicators in mechanical properties are reduced and dimensional stability is also deteriorated. Therefore, a modified nylon 6 monofilament with excellent wear resistance, mechanical properties and hydrophobicity was prepared.

[0039] Therefore, the material used for the single-layer base net can also be modified nylon 6 monofilament;

[0040] Further preferably, the method for preparing the modified nylon 6 monofilament comprises the following steps:

[0041] 80-100 parts by weight of nylon 6 and 8-12 parts by weight of modified graphene nanorods are mixed and dried, discharged in a molten state, cooled, stretched and shaped to obtain modified nylon 6 monofilaments; wherein the monofilament diameter is 0.15 mm.

[0042] The present invention introduces graphene nanorods into nylon 6 to improve its performance. Although the existing graphene nanorods can increase the wear resistance of nylon materials by blending, the graphene nanorods are rich in hydroxyl groups on the surface, which are easy to form hydrogen bonds and introduce agglomeration, resulting in poor dispersibility in nylon and reducing the wear resistance of nylon. The graphene nanorods are modified by adding a silane coupling agent to participate in the blending, thereby improving the dispersibility and compatibility of the graphene nanorods in nylon. However, the existing silane coupling agent cannot achieve the common modification of the graphene nanorods and the nylon material, thereby affecting the wear resistance and mechanical properties thereof.

[0043] Preferably, the method for preparing the modified graphene nanorods comprises the following steps:

[0044] S1, adding 5-10 parts by weight of graphene nanorods and 1-5 parts by weight of a coupling agent to 60-100 parts by weight of a 50-70wt% ethanol aqueous solution, mixing evenly, heating to 70-90°C for reaction for 1-3h, and after the reaction, centrifuging, washing, and drying to obtain pretreated graphene nanorods; the coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyltri(2-methoxyethoxy)silane;

[0045] S2, adding 5-10 parts by weight of pretreated graphene nanorods to 60-100 parts by weight of methanol and mixing them evenly, then adding 0.1-0.5 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.05-0.36 parts by weight of N-hydroxysuccinimide, stirring at a speed of 100-500 rpm for 10-30 min, then adding 2-4 parts by weight of carboxyl POSS, stirring continuously for 1-5 h, after the reaction is completed, centrifuging to obtain a precipitate, washing, and drying to obtain a graphene nanorod containing a POSS group;

[0046] S3, adding 5-10 parts by weight of POSS-based graphene nanorods to 40-60 parts by weight of water and uniformly dispersing them, adding 1-3 parts by weight of isopentyl tetraacrylate, 0.1-1 parts by weight of fluorine-containing monomers, 0.1-3 parts by weight of acrylate monomers, and 0.1-0.5 parts by weight of Tween 40 and mixing them uniformly to obtain a mixed material;

[0047] S4, adding 0.5-2.5 parts by weight of the initiator to 30-60 parts by weight of water and mixing evenly to obtain an initiator solution;

[0048] S5. Evenly mix the mixed material and the initiator solution, heat to 70-90° C. and react for 1-5 hours. After the reaction is completed, centrifuge to obtain the precipitate, wash, and dry to obtain modified graphene nanorods.

[0049] The fluorine-containing monomer is at least one of hexafluorobutyl methacrylate, tridecafluorooctyl methacrylate, and 1H,1H,2H-perfluoro-1-decene;

[0050] The acrylic acid ester monomer is at least one of methyl methacrylate, hydroxyethyl methacrylate, and 2-ethyl methacrylate.

[0051] Using graphene nanorods as raw materials, N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyl tri(2-methoxyethoxy) silane were used to treat the graphene nanorods so that their surfaces contained amino and vinyl groups. Then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were used to graft carboxyl POSS into the graphene nanorods. The cage-like structure can play an elastic function similar to that of rubber "marbles", thereby enhancing the toughness of nylon. , and can effectively transfer stress during the friction process, prevent the generation and expansion of cracks, and improve the wear resistance of nylon; at the same time, the above-mentioned POSS-based graphene nanorods, isopentaerythrityl tetraacrylate, fluorine-containing monomers, and acrylate monomers are prepared under the action of an initiator to obtain modified graphene nanorods with a three-dimensional network structure; the present invention introduces modified graphene nanorods to improve compatibility with nylon, while improving the wear resistance and mechanical properties of nylon, and at the same time improving the hydrophobic properties of nylon materials, thereby improving the dimensional stability of papermaking felts.

[0052] Further preferably, the preparation method of the carboxyl POSS is: add octa-aminophenyl-POSS to N,N-dimethylformamide and mix evenly, then add maleic anhydride, react at 50-60° C. for 5-8 hours, and remove N,N-dimethylformamide by vacuum distillation to obtain carboxyl POSS. The molar ratio of octa-aminophenyl-POSS to maleic anhydride is 1:(1-3).

[0053] Beneficial effects of the present invention:

[0054] 1. The acupuncture process used in the present invention has the following advantages over the traditional acupuncture process:

[0055] The working section is thinner, and the needling is gentler. The three-edge grinding reduces the needling resistance and reduces the damage to the fiber. The tooth depth is shallower, the amount of hair is less, and it is softer, reducing the damage to the fiber.

[0056] 2. Compared with the prior art, the present invention uses ultrasonic welding technology to form a ring, which not only reduces the equipment investment, but also greatly shortens the production process and significantly improves the production efficiency. At the same time, the seam is straighter and easier to install on the loom, which effectively reduces the labor of the loom operator and improves the production efficiency of the loom operator.

[0057] 3. The present invention introduces modified graphene nanorods to improve compatibility with nylon, while improving the wear resistance and mechanical properties of nylon, and at the same time improving the hydrophobic properties of nylon materials, thereby improving the dimensional stability of papermaking felts. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a 3 / 1 broken twill structure of the traditional base mesh;

[0059] Figure 2 It is the 1 / 1 plain weave base mesh structure used in the present invention;

[0060] Figure 3 It is a schematic diagram of the structure of a seamed blanket;

[0061] Figure 4 is a schematic diagram of the joint structure;

[0062] Figure 5 It is the production process of seamed papermaking felt on ring loom;

[0063] Figure 6 It is a diagram of the seaming process of a ring loom;

[0064] Figure 7 It is the production process of twill-woven seamed papermaking felt;

[0065] Figure 8 It is a diagram of the seam process of the bias weave;

[0066] Fig. 9 Ultrasonic welding to end the production process of seamed blankets;

[0067] Fig.10 It is the ultrasonic seam process diagram;

[0068] Fig.11 It is a schematic diagram of the structure of a papermaking felt; DETAILED DESCRIPTION

[0069] The invention discloses a production process of a papermaking felt, comprising the following steps:

[0070] (a) Middle skeleton layer

[0071] S1, single-layer base mesh weaving;

[0072] (1) Material: Nylon 6 monofilament

[0073] Material specifications:

[0074] (2) Twisting and plying:

[0075] The warp settings are:

[0076] First twist: Z, 300 twists / m;

[0077] Re-twist: S, 260 twists / m;

[0078] The weft settings are:

[0079] First twist: Z, 300 twists / m;

[0080] Re-twist: S, 260 twists / m;

[0081] Material design and selection: Compared with conventional papermaking felts, it adopts more and more elastic twisted heald wire design. The first twist and second twist design of the twisted wire make the twisted wire of the base net have better adhesion to the fiber and prevent fuzzing and wear. The warp and weft are both fine heald wire strands, making the felt softer and more elastic. The warp and weft of the base net of the paper blanket for cigarette paper are twisted, and the adhesion points are more and the adhesion to the fiber is stronger.

[0082] (3) Warping

[0083] (4) Weft curling

[0084] (5) Weaving: 1 / 1 plain weave;

[0085] The design of the base mesh structure requires the base mesh to be more stable. The traditional 1 / 3 broken twill is adjusted to 1 / 1 plain weave, which has more bonding points and increases the bonding force to the fibers.

[0086] The traditional base mesh structure is: 3 / 1 broken twill (such as Figure 1 ), when the thin heddle is used as warp and weft, the base net is not stable enough.

[0087] The cigarette paper blanket base web structure design is innovatively 1 / 1 plain weave (such as Figure 2 ), the structure is stable and reliable, and the more bonding points, the stronger the adhesion to the fiber.

[0088] S2, middle frame layer: using ultrasonic welding technology

[0089] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0090] Traditional papermaking felts are endless ring structures, while seamed papermaking felts are open at the ends. The felts are connected into a ring structure by interlocking the rings at the two ends and threading the connecting wire. This method can greatly reduce the difficulty of putting papermaking felts on the machine, save time and labor, and greatly improve the operating efficiency of the papermaking machine; the schematic diagram of the seamed felt structure is as follows: Figure 3 ; Schematic diagram of joint structure, Figure 4 ;

[0091] Traditional papermaking felts with end seams are produced using ring looms and twill weaving technology. The production process of ring loom seam papermaking felts (such as Figure 5 ) and its seam process diagram of ring loom (such as Figure 6 ), but the equipment investment cost of the ring loom is extremely high and the production efficiency is very low, and the seam is difficult to make straight enough; the production process of the twill seam papermaking felt (such as Figure 7 ) and its twill weave seam process diagram (such as Figure 8 ), but the twill weaving technology equipment investment is low, the twill weaving technology seams need to be removed little by little, the seams are difficult to control to be straight, and the production efficiency is difficult to improve. Ultrasonic welding uses high-frequency vibration waves to transmit to the surfaces of two objects to be welded. Under pressure, the two surfaces of the objects rub against each other to form a fusion between the molecular layers. The drying time of ultrasonic welding is very fast, and the material does not need to stay in the fixture for a long time waiting for the seam to dry or solidify. Therefore, it is used in this embodiment to greatly improve production efficiency. At the same time, the welding area is very clean and almost no repair work is required. The seam can be made straighter. Ultrasonic welding is a fast, clean and effective assembly process. Ultrasonic welding is preferably operated and completed by an ultrasonic welding machine, in which ultrasonic welding ends the production process of seamed blankets (such as Fig. 9) and its ultrasonic seam process diagram (such as Fig.10 ).

[0092] By using ultrasonic welding technology to form rings, not only is the equipment investment low, but the production process is also greatly shortened, and the production efficiency is significantly improved. At the same time, the seams are straighter and easier to put on the loom, which effectively reduces the labor of the loom operator and improves the production efficiency of the loom operator.

[0093] (ii) Fiber layer manufacturing;

[0094] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 2-7dtex nylon 66 fibers; the inner fiber web layer uses 8-11dtex nylon 66 fibers; and the back fiber web layer uses 11-22dtex nylon 66 fibers.

[0095] Nylon 66 fiber is more suitable for papermaking in cigarette paper machines that require felt hair. Compared with nylon 6, nylon 66 has stronger breaking strength and larger elastic modulus, which can better resist abrasion and hair loss during paper machine operation, and better eliminate and reduce the felt hair of cigarette paper.

[0096] The fiber of the papermaking felts of traditional low-speed household paper machines, cultural paper machines, and packaging paper machines is mostly nylon 6 fiber, and the selection of carding card clothing for the carding machine is basically mature. The nylon 66 fiber is a new design, and the card clothing of the carding machine is re-customized and designed to ensure the carding uniformity and reduce the damage to the fiber. Nylon 66 fiber is stiff and has a large modulus, which is difficult to card. Metal card clothing is used to achieve the purpose of carding uniformity and reducing damage.

[0097] (3) Needle punched fabric;

[0098] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer and the reverse fiber mesh layer are processed by a needle punching process to obtain a needle punched grey fabric;

[0099] In the needle punching process of papermaking felt production, due to the use of ultra-fine fibers, the needles for needle punching are also redesigned and selected, and the traditional needles (as shown in Table 1);

[0100] Table 1

[0101] Needle No. 619361 Needle Type 15X18X32X3 F080 G 92969 Classification Standard needle type Working section length / mm 27 Initial tooth pitch / mm 6.36 Tooth depth / mm 0.08 Tooth process / mm 0.01 Tooth tip / mm 0 Needle Tip S Angle between hook teeth and needle handle 180 Angle diagram

[0102] Parameters corresponding to the special needling process for papermaking felt in the present invention (as shown in Table 2);

[0103] The needling process used in the present invention has the following advantages over the traditional needling process:

[0104] 1. The working section is thinner and the needling is gentler.

[0105] 2. Three-edge grinding can reduce needle resistance and fiber damage.

[0106] 3. The teeth are shallower, with less hair, softer and less damage to the fiber.

[0107] (iv) heat setting treatment to form the finished product.

[0108] The parameters of specific chemical substances used in the examples are from:

[0109] The preparation method of graphene nanorods is prepared by referring to the preparation method of Example 1 in Patent 2013105635660.

[0110] Nylon 6, product number: P02875, purchased from Shanghai Dingfen Chemical Technology Co., Ltd.;

[0111] The preparation method of carboxyl POSS in the embodiment is: add octa-aminophenyl-POSS to N,N-dimethylformamide and mix them evenly, then add maleic anhydride, react at 50-60° C. for 5-8 hours, and remove N,N-dimethylformamide by vacuum distillation to obtain carboxyl POSS. The molar ratio of octa-aminophenyl-POSS to maleic anhydride is 1:3; octa-aminophenyl-POSS, CAS: 518359-82-5.

[0112] Example 1

[0113] The production process of papermaking felt includes the following steps:

[0114] (a) middle skeleton layer;

[0115] S1, single-layer base mesh weaving;

[0116] (1) Material: Nylon 6 monofilament

[0117] Material specifications:

[0118] (2) Twisting and plying:

[0119] The warp settings are:

[0120] First twist: Z, 300 twists / m;

[0121] Re-twist: S, 260 twists / m;

[0122] The weft settings are:

[0123] First twist: Z, 300 twists / m;

[0124] Re-twist: S, 260 twists / m;

[0125] (3) Warping;

[0126] (4) Weft curling;

[0127] (5) Weaving: 1 / 1 plain weave;

[0128] S2, middle frame layer: using ultrasonic welding technology

[0129] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0130] (ii) Fiber layer manufacturing;

[0131] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 7dtex nylon 66 fibers; the inner fiber web layer uses 11dtex nylon 66 fibers; and the back fiber web layer uses 15dtex nylon 66 fibers.

[0132] (3) Needle punched fabric;

[0133] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer, and the back fiber mesh layer are processed by a needle punching process to obtain a needle-punched grey fabric; the parameters corresponding to the needle punching process of the needle-punched grey fabric are shown in Table 2:

[0134] Table 2

[0135] Needle No. 612681 Needle Type 15X18X36X3 FCG4 G 62919 Classification Teardrop needle Working section length / mm 24 Initial tooth pitch / mm 3.18 Tooth depth / mm 0.07 Tooth process / mm 0 Tooth tip / mm -0.004 Needle Tip S Angle between hook teeth and needle handle -90 Angle diagram

[0136] (iv) heat setting treatment to form a finished product, wherein the structural schematic diagram of the papermaking felt of the present invention is as follows Fig.11 .

[0137] The preparation method of the nylon 6 monofilament is as follows: drying nylon 6, discharging in a molten state, cooling, stretching, and shaping to obtain nylon 6 monofilament; wherein the monofilament has a diameter of 0.15 mm.

[0138] Example 2

[0139] The production process of papermaking felt includes the following steps:

[0140] (a) Middle skeleton layer

[0141] S1, single-layer base mesh weaving;

[0142] (1) Material: modified nylon 6 monofilament

[0143] Material specifications:

[0144] (2) Twisting and plying:

[0145] The warp settings are:

[0146] First twist: Z, 300 twists / m;

[0147] Re-twist: S, 260 twists / m;

[0148] The weft settings are:

[0149] First twist: Z, 300 twists / m;

[0150] Re-twist: S, 260 twists / m;

[0151] (3) Warping;

[0152] (4) Weft curling;

[0153] (5) Weaving: 1 / 1 plain weave;

[0154] S2, middle frame layer: using ultrasonic welding technology

[0155] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0156] (ii) Fiber layer manufacturing;

[0157] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 7dtex nylon 66 fibers; the inner fiber web layer uses 11dtex nylon 66 fibers; and the back fiber web layer uses 15dtex nylon 66 fibers.

[0158] (3) Needle punched fabric;

[0159] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer, and the back fiber mesh layer are processed by a needle punching process to obtain a needle-punched grey cloth; the parameters corresponding to the needle punching process of the needle-punched grey cloth are shown in Table 2;

[0160] (iv) heat setting treatment to form the finished product.

[0161] The preparation method of the modified nylon 6 monofilament is as follows: 90 parts by weight of nylon 6 and 10 parts by weight of modified graphene nanorods are mixed and then dried, discharged in a molten state, cooled, stretched and shaped to obtain the modified nylon 6 monofilament; wherein the monofilament diameter is 0.15 mm.

[0162] The method for preparing the modified graphene nanorods comprises the following steps:

[0163] S1. Add 10 parts by weight of graphene nanorods and 5 parts by weight of a coupling agent to 100 parts by weight of a 70wt% ethanol aqueous solution, mix well, heat to 75°C for 2 hours, and after the reaction, centrifuge to obtain a precipitate, wash, and dry to obtain pretreated graphene nanorods; the coupling agent is prepared by mixing N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyltri(2-methoxyethoxy)silane in a mass ratio of 1:2;

[0164] S2, 10 parts by weight of pretreated graphene nanorods are added to 100 parts by weight of methanol and mixed evenly, then 0.5 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.36 parts by weight of N-hydroxysuccinimide are added, stirred at 500 rpm for 30 min, and then 4 parts by weight of carboxyl POSS are added, and stirring is continued for 5 h. After the reaction is completed, the precipitate is centrifuged, washed, and dried to obtain graphene nanorods containing POSS groups;

[0165] S3. Add 10 parts by weight of POSS-based graphene nanorods to 60 parts by weight of water and disperse them evenly, add 1 part by weight of isopentaerythritol tetraacrylate, 1 part by weight of tridecafluorooctyl methacrylate, 3 parts by weight of acrylate monomer and 0.5 part by weight of Tween 40 and mix them evenly to obtain a mixed material; the acrylate monomer is prepared by mixing methyl methacrylate and hydroxyethyl methacrylate in a mass ratio of 1:1.

[0166] S4, adding 0.8 parts by weight of 2,2-azobis(2-methylpropylamide) dihydrochloride to 30 parts by weight of water and mixing evenly to obtain a 2,2-azobis(2-methylpropylamide) dihydrochloride solution;

[0167] S5. Evenly mix the mixed material and 2,2-azobis(2-methylpropylimidazole) dihydrochloride solution, heat to 75° C. and react for 3 h. After the reaction is completed, centrifuge to obtain the precipitate, wash, and dry to obtain modified graphene nanorods.

[0168] Example 3

[0169] The production process of papermaking felt includes the following steps:

[0170] (a) Middle skeleton layer

[0171] S1, single-layer base mesh weaving;

[0172] (1) Material: modified nylon 6 monofilament

[0173] Material specifications:

[0174] (2) Twisting and plying:

[0175] The warp settings are:

[0176] First twist: Z, 300 twists / m;

[0177] Re-twist: S, 260 twists / m;

[0178] The weft settings are:

[0179] First twist: Z, 300 twists / m;

[0180] Re-twist: S, 260 twists / m;

[0181] (3) Warping;

[0182] (4) Weft curling;

[0183] (5) Weaving: 1 / 1 plain weave;

[0184] S2, middle frame layer: using ultrasonic welding technology

[0185] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0186] (ii) Fiber layer manufacturing;

[0187] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 7dtex nylon 66 fibers; the inner fiber web layer uses 11dtex nylon 66 fibers; and the back fiber web layer uses 15dtex nylon 66 fibers.

[0188] (3) Needle punched fabric;

[0189] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer, and the back fiber mesh layer are processed by a needle punching process to obtain a needle-punched grey cloth; the parameters corresponding to the needle punching process of the needle-punched grey cloth are shown in Table 2;

[0190] (iv) heat setting treatment to form the finished product.

[0191] The preparation method of the modified nylon 6 monofilament is as follows: 90 parts by weight of nylon 6 and 10 parts by weight of modified graphene nanorods are mixed and then dried, discharged in a molten state, cooled, stretched and shaped to obtain the modified nylon 6 monofilament; wherein the monofilament diameter is 0.15 mm.

[0192] The preparation method of the modified graphene nanorods comprises the following steps: adding 10 parts by weight of graphene nanorods and 5 parts by weight of a coupling agent into 100 parts by weight of a 70wt% ethanol aqueous solution, mixing them evenly, heating them to 75°C for reaction for 2 hours, and after the reaction is completed, centrifuging to obtain a precipitate, washing, and drying to obtain the modified graphene nanorods; the coupling agent is prepared by mixing N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyltri(2-methoxyethoxy)silane in a mass ratio of 1:2.

[0193] Example 4

[0194] The production process of papermaking felt includes the following steps:

[0195] (a) Middle skeleton layer

[0196] S1, single-layer base mesh weaving;

[0197] (1) Material: modified nylon 6 monofilament

[0198] Material specifications:

[0199] (2) Twisting and plying:

[0200] The warp settings are:

[0201] First twist: Z, 300 twists / m;

[0202] Re-twist: S, 260 twists / m;

[0203] The weft settings are:

[0204] First twist: Z, 300 twists / m;

[0205] Re-twist: S, 260 twists / m;

[0206] (3) Warping

[0207] (4) Weft curling

[0208] (5) Weaving: 1 / 1 plain weave;

[0209] S2, middle frame layer: using ultrasonic welding technology

[0210] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0211] (ii) Fiber layer manufacturing;

[0212] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 7dtex nylon 66 fibers; the inner fiber web layer uses 11dtex nylon 66 fibers; and the back fiber web layer uses 15dtex nylon 66 fibers.

[0213] (3) Needle punched fabric;

[0214] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer, and the back fiber mesh layer are processed by a needle punching process to obtain a needle-punched grey cloth; the parameters corresponding to the needle punching process of the needle-punched grey cloth are shown in Table 2;

[0215] (iv) heat setting treatment to form the finished product.

[0216] The preparation method of the modified nylon 6 monofilament is as follows: 90 parts by weight of nylon 6 and 10 parts by weight of modified graphene nanorods are mixed and then dried, discharged in a molten state, cooled, stretched and shaped to obtain the modified nylon 6 monofilament; wherein the monofilament diameter is 0.15 mm.

[0217] The method for preparing the modified graphene nanorods comprises the following steps:

[0218] S1. Add 10 parts by weight of graphene nanorods and 5 parts by weight of a coupling agent to 100 parts by weight of a 70wt% ethanol aqueous solution, mix well, heat to 75°C for 2 hours, and after the reaction, centrifuge to obtain a precipitate, wash, and dry to obtain pretreated graphene nanorods; the coupling agent is prepared by mixing N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyltri(2-methoxyethoxy)silane in a mass ratio of 1:2;

[0219] S2. Add 10 parts by weight of pretreated graphene nanorods to 60 parts by weight of water and disperse them evenly, add 1 part by weight of isopentaerythritol tetraacrylate, 1 part by weight of tridecafluorooctyl methacrylate, 3 parts by weight of acrylate monomer, and 0.5 parts by weight of Tween 40 and mix them evenly to obtain a mixed material; the acrylate monomer is prepared by mixing methyl methacrylate and hydroxyethyl methacrylate in a mass ratio of 1:1.

[0220] S3, adding 0.8 parts by weight of 2,2-azobis(2-methylpropylamide) dihydrochloride to 30 parts by weight of water and mixing evenly to obtain a 2,2-azobis(2-methylpropylamide) dihydrochloride solution;

[0221] S4. Evenly mix the mixed material and 2,2-azobis(2-methylpropylimidazole) dihydrochloride solution, heat to 75°C and react for 3 hours. After the reaction is completed, centrifuge to obtain the precipitate, wash and dry to obtain modified graphene nanorods.

[0222] Example 5

[0223] The production process of papermaking felt includes the following steps:

[0224] (a) Middle skeleton layer

[0225] S1, single-layer base mesh weaving;

[0226] (1) Material: modified nylon 6 monofilament

[0227] Material specifications:

[0228] (2) Twisting and plying:

[0229] The warp settings are:

[0230] First twist: Z, 300 twists / m;

[0231] Re-twist: S, 260 twists / m;

[0232] The weft settings are:

[0233] First twist: Z, 300 twists / m;

[0234] Re-twist: S, 260 twists / m;

[0235] (3) Warping;

[0236] (4) Weft curling;

[0237] (5) Weaving: 1 / 1 plain weave;

[0238] S2, middle frame layer: using ultrasonic welding technology

[0239] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0240] (ii) Fiber layer manufacturing;

[0241] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 7dtex nylon 66 fibers; the inner fiber web layer uses 11dtex nylon 66 fibers; and the back fiber web layer uses 15dtex nylon 66 fibers.

[0242] (3) Needle punched fabric;

[0243] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer, and the back fiber mesh layer are processed by a needle punching process to obtain a needle-punched grey cloth; the parameters corresponding to the needle punching process of the needle-punched grey cloth are shown in Table 2;

[0244] (iv) heat setting treatment to form the finished product.

[0245] The preparation method of the modified nylon 6 monofilament is as follows: 90 parts by weight of nylon 6 and 10 parts by weight of modified graphene nanorods are mixed and then dried, discharged in a molten state, cooled, stretched and shaped to obtain the modified nylon 6 monofilament; wherein the monofilament diameter is 0.15 mm.

[0246] The method for preparing the modified graphene nanorods comprises the following steps:

[0247] S1. Add 10 parts by weight of graphene nanorods to 60 parts by weight of water and disperse them evenly, add 1 part by weight of isopentaerythritol tetraacrylate, 1 part by weight of tridecafluorooctyl methacrylate, 3 parts by weight of acrylate monomer, and 0.5 part by weight of Tween 40 and mix them evenly to obtain a mixed material; the acrylate monomer is prepared by mixing methyl methacrylate and hydroxyethyl methacrylate in a mass ratio of 1:1.

[0248] S2, adding 0.8 parts by weight of 2,2-azobis(2-methylpropylamide) dihydrochloride to 30 parts by weight of water and mixing well to obtain a 2,2-azobis(2-methylpropylamide) dihydrochloride solution;

[0249] S3. Evenly mix the mixed material and the initiator solution, heat to 75°C and react for 3 hours. After the reaction is completed, centrifuge to obtain the precipitate, wash and dry to obtain modified graphene nanorods.

[0250] Example 6

[0251] The production process of papermaking felt includes the following steps:

[0252] (a) Middle skeleton layer

[0253] S1, single-layer base mesh weaving;

[0254] (1) Material: modified nylon 6 monofilament

[0255] Material specifications:

[0256] (2) Twisting and plying:

[0257] The warp settings are:

[0258] First twist: Z, 300 twists / m;

[0259] Re-twist: S, 260 twists / m;

[0260] The weft settings are:

[0261] First twist: Z, 300 twists / m;

[0262] Re-twist: S, 260 twists / m;

[0263] (3) Warping;

[0264] (4) Weft curling;

[0265] (5) Weaving: 1 / 1 plain weave;

[0266] S2, middle frame layer: using ultrasonic welding technology

[0267] A single-layer base net is folded in half to form a laminated structure, and two ends of the single-layer base net are folded in half and ultrasonically welded to form a ring to obtain an intermediate skeleton layer.

[0268] (ii) Fiber layer manufacturing;

[0269] The short fibers of different deniers are treated with wool, combed by a carding machine, and finally needled into a web by a pre-needling machine to form a surface fiber web layer, an inner fiber web layer, and a back fiber web layer respectively; the short fibers used in the surface fiber web layer, the inner fiber web layer, and the back fiber web layer are all nylon 66 fibers; the surface fiber web layer uses 7dtex nylon 66 fibers; the inner fiber web layer uses 11dtex nylon 66 fibers; and the back fiber web layer uses 15dtex nylon 66 fibers.

[0270] (3) Needle punched fabric;

[0271] The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer, and the back fiber mesh layer are processed by a needle punching process to obtain a needle-punched grey cloth; the parameters corresponding to the needle punching process of the needle-punched grey cloth are shown in Table 2;

[0272] (iv) heat setting treatment to form the finished product.

[0273] The preparation method of the modified nylon 6 monofilament is as follows: 90 parts by weight of nylon 6 and 10 parts by weight of graphene nanorods are mixed and then dried, discharged in a molten state, cooled, stretched and shaped to obtain the modified nylon 6 monofilament; wherein the monofilament diameter is 0.15 mm.

[0274] Test Example 1

[0275] The mechanical properties of the nylon 6 monofilament and the modified nylon 6 monofilament in the embodiment were tested;

[0276] The tensile strength of nylon 6 monofilament and modified nylon 6 monofilament was determined according to GB / T1040.1-2018 and GB / T1040.2-2022 standards. Each sample was measured three times and the average value was taken.

[0277] The bending strength of the samples was determined according to GB / T9341-2008 standard. Each sample was measured three times and the average value was taken.

[0278] Table 1 Mechanical properties test results of monofilament

[0279] Tensile strength / MPa Bending strength / MPa Example 1 44.1 75.6 Example 2 72.3 103.9 Example 3 59.2 91.4 Example 4 69.5 100.1 Example 5 64.7 96.3 Example 6 53.8 82.5

[0280] As shown in Table 1, the monofilament prepared in Example 2 has good mechanical properties. Compared with Example 6, the tensile properties and bending properties of the monofilament prepared in Example 2 are significantly better than those in Example 6. The possible reason is that Example 6 simply introduces graphene nanorods, and the surface of the graphene nanorods is rich in hydroxyl groups, which are easy to form hydrogen bonds and introduce agglomeration, resulting in poor dispersibility in nylon and reducing the mechanical properties of nylon. Example 2 introduces modified graphene nanorods, using graphene nanorods as raw materials, using N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyltri(2-methoxyethoxy)silane to treat the graphene nanorods so that their surfaces contain amino groups and vinyl groups; then 1-(3-dimethylaminopropyl)- )-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are used to graft carboxyl POSS into graphene nanorods, and the cage-like structure can play an elastic function similar to that of rubber "marbles", thereby producing a toughening effect on nylon, and can also effectively transfer stress during the friction process, prevent the generation and expansion of cracks, and improve the wear resistance of nylon; at the same time, the above-mentioned graphene nanorods containing POSS groups, isopentaerythrityl tetraacrylate, fluorine-containing monomers, and acrylate monomers are prepared under the action of an initiator to obtain modified graphene nanorods with a three-dimensional network structure; the modified graphene nanorods are introduced into the present invention to improve the compatibility with nylon, and at the same time improve the wear resistance and mechanical properties of nylon, and at the same time improve the hydrophobicity of the nylon material, thereby improving the dimensional stability of the papermaking felt.

[0281] Test Example 2

[0282] The test method is: pre-tension 200N, record the initial stress value, record the stress value every 30s in the first 2 minutes, and record the stress value every 1 minute thereafter until the stress value of the papermaking felt remains unchanged, record the stress stability value, the sample size is 259mm×50mm, because the papermaking felt is mainly subjected to warp tension during use, so only the warp stress retention rate is tested.

[0283] The calculation formula is: Stress retention rate = initial stress value / stable stress value × 100%

[0284] Table 2 Test results of stress retention rate of papermaking felt

[0285] Stress retention rate / % Example 1 50.2 Example 2 75.1 Example 3 59.8 Example 4 71.4 Example 5 67.3 Example 6 53.5

[0286] The invention provides a papermaking felt, comprising a surface fiber mesh layer, an inner fiber mesh layer, an intermediate skeleton layer, and a reverse fiber mesh layer; the intermediate skeleton layer is a laminated structure formed by folding a single-layer base mesh in half, and two ends of the single-layer base mesh are folded in half and ultrasonically welded to form a ring; the single-layer base mesh is made of nylon yarn; the invention adopts modified graphene nanorods and nylon 6 to prepare modified nylon 6 monofilaments, takes the graphene nanorods as raw materials, adopts N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane and vinyltri(2-methoxyethoxy)silane to treat the graphene nanorods so that the surfaces of the graphene nanorods contain amino groups and vinyl groups; then adopts 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide Amine hydrochloride and N-hydroxysuccinimide are used to graft carboxyl POSS into graphene nanorods, and the cage-like structure can play an elastic function similar to that of rubber "marbles", thereby producing a toughening effect on nylon, and can also effectively transmit stress during friction, prevent the generation and expansion of cracks, and improve the wear resistance of nylon; at the same time, the above-mentioned graphene nanorods containing POSS groups, isopentaerythrityl tetraacrylate, fluorine-containing monomers, and acrylate monomers are prepared under the action of an initiator to obtain modified graphene nanorods with a three-dimensional network structure; the modified graphene nanorods are introduced into the present invention to improve the compatibility with nylon, and at the same time improve the wear resistance and mechanical properties of nylon, and at the same time improve the hydrophobicity of the nylon material, thereby improving the dimensional stability of the papermaking felt.

[0287] Test Example 3

[0288] The single-layer base web prepared in each example was subjected to a wear resistance test according to ISO6722, and the number of times of wear resistance before damage was recorded.

[0289] Table 3 Wear resistance test results of single-layer base mesh

[0290] Wear times (times) Example 1 5675 Example 2 12358 Example 3 10792 Example 4 12031 Example 5 11274 Example 6 10054

[0291] The invention adopts modified graphene nanorods and nylon 6 to mix to prepare modified nylon 6 monofilaments, and adopts the modified nylon 6 monofilaments to manufacture a single-layer base net, which has good mechanical properties.

[0292] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A process for producing a papermaking felt, characterized in that: The following steps are involved: (a) middle skeleton layer; (ii) Fiber layer manufacturing; (3) Needle-punched grey fabric; (iv) heat setting treatment to form the finished product.

2. The process for producing a papermaking felt according to claim 1, characterized in that: The following steps are involved: (a) middle skeleton layer; S1, single-layer base mesh weaving; S2, middle frame layer: using ultrasonic welding technology; A laminated structure is formed by folding a single-layer base net in half, and two ends of the single-layer base net are ultrasonically welded to form a ring after being folded in half to obtain an intermediate skeleton layer; (ii) Fiber layer manufacturing; The short fibers of different deniers are processed with wool, combed by a carding machine, and finally needled into a web by a pre-punching machine to form a surface fiber web layer, an inner fiber web layer, and a reverse fiber web layer; (3) Needle-punched grey fabric; The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer and the reverse fiber mesh layer are processed by a needle punching process to obtain a needle punched grey fabric; (iv) heat setting treatment to form the finished product.

3. The process for producing a papermaking felt according to claim 1 or 2, characterized in that: The following steps are involved: (a) middle skeleton layer; S1, single-layer base mesh weaving; (1) Material: Nylon 6 monofilament; (2) Twisting and plying; (3) Warping; (4) Weft curling; (5) Weaving; S2, middle frame layer: using ultrasonic welding technology; A laminated structure is formed by folding a single-layer base net in half, and two ends of the single-layer base net are ultrasonically welded to form a ring after being folded in half to obtain an intermediate skeleton layer; (ii) Fiber layer manufacturing; The short fibers of different deniers are processed with wool, combed by a carding machine, and finally needled into a web by a pre-punching machine to form a surface fiber web layer, an inner fiber web layer, and a reverse fiber web layer; (3) Needle punched fabric; The surface fiber mesh layer, the inner fiber mesh layer, the middle skeleton layer and the reverse fiber mesh layer are processed by a needle punching process to obtain a needle punched grey fabric; (iv) heat setting treatment to form the finished product.

4. The process for producing a papermaking felt according to claim 3, characterized in that: The short fibers used in the surface fiber mesh layer, the inner fiber mesh layer and the back fiber mesh layer are all nylon 66 fibers.

5. The process for producing a papermaking felt according to claim 3, characterized in that: Parameter settings for twisting and plying: The warp settings are: First twist: Z, 300 twists / m; Re-twist: S, 260 twists / m; The weft settings are: First twist: Z, 300 twists / m; Re-twist: S, 260 twists / m.

6. The process for producing a papermaking felt according to claim 3, characterized in that: The weaving structure used is 1 / 1 plain weave.

7. The process for producing a papermaking felt according to claim 4, characterized in that: The surface fiber mesh layer is made of 2-7dtex nylon 66 fiber; the inner fiber mesh layer is made of 8-11dtex nylon 66 fiber; and the back fiber mesh layer is made of 11-22dtex nylon 66 fiber.

8. The process for producing a papermaking felt according to claim 3, characterized in that: The material used for the single-layer base net can also be modified nylon 6 monofilament.

9. A papermaking felt, characterized in that: The method is obtained by adopting the production process described in any one of claims 1 to 9.

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