A para-aramid fiber drain and a method for preparing the same

Abstract

The application relates to a p-aramid fiber drain pipe and a preparation method thereof, and belongs to the technical field of p-aramid fiber application. The preparation method is as follows: after clean p-aramid fibers without oil agent are activated by a silane coupling agent, the p-aramid fibers are uniformly mixed with polyester resin, and an inner layer pipe blank is obtained by extrusion molding through a first extruding machine; fluorine rubber and polyurethane epoxy resin are uniformly mixed and extruded onto the inner layer pipe blank through a second extruding machine to obtain a composite pipe blank of an intermediate layer; the activated p-aramid fibers are uniformly mixed with polyester resin, a thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate, and a pipe material with a three-layer structure is obtained by extruding the mixture onto the composite pipe blank through a third extruding machine; and after cooling, shaping and cutting treatment, the pipe material is obtained as a finished p-aramid fiber drain pipe. The drain pipe solves the problems of poor strength, poor temperature resistance, easy leakage and difficult discovery of leakage points of common drain pipes.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of para-aramid fiber drain pipe and its preparation method, belong to para-aramid fiber application technical field. BACKGROUND

[0002] Aramid fiber is the general term of fully aromatic polyamide fiber, which can be divided into aramid I, aramid II and aramid III according to the type of synthetic monomer, and can be named as aramid 14, aramid 1313 and aramid 1414 according to the difference of the connection position of carbonyl and imine group in amide bond on benzene ring. Poly (p-phenylene terephthalamide) (PPTA), also known as aramid 1414, is the most widely used aramid fiber, which is also commonly known as para-aramid.

[0003] Traditional drain pipe materials (such as concrete, cast iron, PVC) are easily affected by chemical corrosion (hydrogen sulfide and acidic substances in sewage), electrochemical corrosion (soil environment) and physical abrasion (water flow scouring) during long-term use, resulting in thinning of pipe wall, rupture and even collapse. Leakage of urban drainage pipes can cause groundwater pollution and risk of ground subsidence.

[0004] For example, the patent application with publication number CN119639145A discloses a PVC composition and its application in preparing impact-resistant high-toughness PVC drain pipes. The PVC composition includes PVC resin and modified microspheres, which are composed of an epoxy resin shell and a rubber core. The modified agent reacts with PVC and rubber to form chemical bonds, enhancing the toughness and rigidity of PVC. However, PVC material has poor temperature resistance, and long-term use may cause damage and deformation. The patent application with publication number CN119795358A discloses a prefabricated concrete drain pipe with a corrosion-resistant concrete structure layer and its manufacturing method. The prefabricated concrete drain pipe includes a corrosion-resistant concrete structure layer and a concrete pipe body. The raw materials of the corrosion-resistant concrete structure layer include corrosion-resistant mortar materials and fibers (basalt fibers, glass fibers). The corrosion-resistant mortar materials include cement, active admixture, fine aggregate, admixture and water. The manufacturing method includes: first producing the corrosion-resistant concrete structure layer, then pouring it with the concrete pipe body to form a whole; or pouring the corrosion-resistant concrete structure layer on the inner wall of the produced concrete pipe body. However, the concrete material has poor crack resistance, and the overall pipe material is heavy, which brings many inconveniences to transportation and use.

[0005] From the above analysis, it can be seen that the performance limitations of drain pipe materials are: ordinary PVC pipe has poor high-temperature resistance (> 60℃ easy to deform), concrete pipe has insufficient crack resistance, and new composite materials have superior performance but high cost, which limits large-scale application.

[0006] The high-performance para-aramid fiber drainage pipe and the preparation method thereof can solve the above problems by considering functionality, durability and economy. SUMMARY

[0007] The para-aramid fiber drainage pipe and the preparation method thereof can solve the problems of poor strength, poor temperature resistance, easy leakage and difficult-to-find leakage points of ordinary drainage pipes, and the preparation process is simple.

[0008] The technical scheme for solving the above technical problems is as follows: a preparation method of a para-aramid fiber drainage pipe, the preparation method comprises the following steps:

[0009] S1, clean para-aramid fibers without oil agent are activated by a silane coupling agent, and then mixed with polyester resin to form an inner layer pipe blank by a first extruder;

[0010] S2, a mixture of fluorine rubber and polyurethane epoxy resin is added to a second extruder, and the mixture is extruded onto the inner layer pipe blank of step S1 to form a composite pipe blank of the intermediate layer by extrusion molding;

[0011] S3, clean para-aramid fibers without oil agent are activated by a silane coupling agent, and then mixed with polyester resin, thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate to form a pipe material by a third extruder;

[0012] S4, the pipe material is cooled, shaped and cut to obtain a finished para-aramid fiber drainage pipe.

[0013] Further, the diameter of the high-strength para-aramid fiber is 50-70 μm, and the length of the high-strength para-aramid fiber is 15-25 mm.

[0014] Further, in step S1, the mass ratio of the para-aramid fiber to the polyester resin is 40: (30-70).

[0015] Further, in step S2, the mass ratio of the polyurethane epoxy resin to the fluorine rubber is 40: (15-55).

[0016] Further, in step S3, the mass ratio of the para-aramid fiber, the polyester resin, the thermoplastic elastomer, the polytetrafluoroethylene resin and the anhydrous copper sulfate is 40: (30-70): (4-12): (10-30): (5-25).

[0017] Further, the mass ratio of the para-aramid fiber in step S1 to the polyurethane epoxy resin in step S2 is 1: (1-2) ; and the mass ratio of the para-aramid fiber in step S3 to the polyurethane epoxy resin in step S2 is 1: (1-1.5).

[0018] Further, in step S1, the para-aramid fiber after the activation treatment is mixed with the polyester resin at 60-100 DEG C, and then is extruded by a first extruder;

[0019] In step S2, the polyurethane epoxy resin and the fluororubber are mixed at 35-75 DEG C, and then are extruded by a second extruder;

[0020] In step S3, the para-aramid fiber after the activation treatment is mixed with the polyester resin, the thermoplastic elastomer, the polytetrafluoroethylene resin and the anhydrous copper sulfate at 60-100 DEG C, and then is extruded by a third extruder.

[0021] Further, the polyester resin is a vinyl ester resin, and the thermoplastic elastomer is a hydrogenated styrene-butadiene-styrene block copolymer.

[0022] Further, the para-aramid fiber is washed by using distilled water and ethanol, and then is dried at 65-75 DEG C, and is activated by using a silane coupling agent, which is gamma-glycidoxypropyltrimethoxysilane.

[0023] The application further discloses a para-aramid fiber drainage pipe prepared by the preparation method.

[0024] The application has the following advantages:

[0025] The para-aramid fiber drainage pipe has excellent ring stiffness, impact strength, tensile strength, solvent resistance, flame resistance and air tightness repair rate, and the reasonable use of the materials in the layers and the three-layer extrusion molding process can make the materials in the layers have good performance, ensure the reasonable use of the para-aramid fiber in the drainage pipe product, make the layers closely adhere to each other, improve the comprehensive performance of the drainage pipe, and solve the problems of poor strength, poor temperature resistance, easy leakage and difficult discovery of the leakage points of the ordinary drainage pipe.

[0026] The inner layer pipe blank material in the preparation method is composed of high-strength para-aramid fiber and vinyl ester resin, the high-strength para-aramid fiber has high strength, corrosion resistance, fatigue resistance, light weight and flame retardancy, and solves the short board of traditional materials in a complex environment, and is more beneficial to prolong the service life and reduce maintenance. The unique structure of the epoxy skeleton + unsaturated double bond of the vinyl ester resin realizes the balance of corrosion resistance, mechanical strength and process convenience, and the combination of the two provides better high-strength performance for the drainage pipe.

[0027] The intermediate layer pipe blank material in the preparation method is composed of polyurethane epoxy resin and fluororubber, the polyurethane epoxy resin has excellent mechanical properties, fatigue resistance, corrosion resistance, biological adhesion resistance, aging resistance, temperature resistance, light weight performance, and is convenient to construct, has strong designability, and the material is more environmentally friendly. At the same time, the fluororubber has chemical corrosion resistance, oxidation resistance, high temperature resistance, low temperature elasticity retention, leakage resistance, tear resistance, wear resistance and aging resistance, and strong elastic recovery force, sanitary and environmentally friendly. After the combination of the polyurethane epoxy resin and the fluororubber, the polyurethane epoxy resin can realize self-repairing function through dynamic covalent bond, supramolecular interaction and microcarrier technology, and the specific performance in the drainage pipe is to respond to temperature, humidity, light and other environmental stimuli to actively repair; at the same time, the fluororubber can realize self-repairing function through dynamic chemical bond, nano-composite and ionic liquid modification, and light, heat and mechanical stress can activate repair. The combination of the two as the intermediate layer pipe blank material enables the drainage pipe to be automatically repaired in time after being pierced, improves the safety and reliability of the drainage pipe, reduces the probability of drainage pipe leakage, and prolongs the service life.

[0028] The outer layer pipe blank material in the preparation method is composed of high-strength para-aramid fiber, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate, the hydrogenated styrene-butadiene-styrene block copolymer combines the elasticity of rubber and the processing performance of plastic, and has outstanding performance in weather resistance, flexibility and environmental protection. The polytetrafluoroethylene resin has a unique perfluorocarbon chain structure, which has good extreme chemical resistance, self-cleaning and durability, and is more suitable for high-corrosion, high-purity or high-temperature drainage scenes. The present application adds anhydrous copper sulfate to the outer layer pipe blank material, which will change color after coming into contact with water, and the leakage can be found by observing the surface. DETAILED DESCRIPTION

[0029] For the above-mentioned purposes, features and advantages of the present application to be more apparent and easy to understand, the specific embodiments of the present application are described in detail below. In the following description, a number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways from those described herein without departing from the scope of the present application and it can be apparent to those skilled in the art that similar modifications of structure, materials, or use can be practiced as structural and / or use equivalents within the scope of the present application. Therefore, the present application is not intended to be limited to the particular embodiments described herein, but it is intended to include all possible embodiments falling within the scope of the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] A preparation method of para-aramid fiber drain pipe, the preparation method is:

[0032] S1, the clean and remove oil agent para-aramid fiber after silane coupling agent activation treatment, mixed with polyester resin, extruded into the inner layer pipe blank by the first extruder;

[0033] S2, the mixture of fluorine rubber and polyurethane epoxy resin is mixed uniformly and added to the second extruder, the mixture is extruded onto the inner layer pipe blank of step S1, and the composite pipe blank of the intermediate layer is obtained by extrusion molding;

[0034] S3, the clean and remove oil agent para-aramid fiber after silane coupling agent activation treatment, mixed with polyester resin, thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate, extruded onto the composite pipe blank in step S2 by the third extruder, and the pipe material with ternary layer structure is obtained by extrusion molding;

[0035] S4, the pipe material is cooled, shaped and cut to obtain the finished para-aramid fiber drain pipe.

[0036] Specifically, the diameter of the high-strength para-aramid fiber is 50-70 μm, and the length of the high-strength para-aramid fiber is 15-25 mm.

[0037] Specifically, in step S1, the mass ratio of the para-aramid fiber to the polyester resin is 40: (30-70).

[0038] Specifically, in step S2, the mass ratio of the polyurethane epoxy resin to the fluorine rubber is 40: (15-55).

[0039] Specifically, in step S3, the mass ratio of the para-aramid fiber, the polyester resin, the thermoplastic elastomer, the polytetrafluoroethylene resin and the anhydrous copper sulfate is 40: (30-70): (4-12): (10-30): (5-25).

[0040] Specifically, the mass ratio of the para-aramid fiber in step S1 to the polyurethane epoxy resin in step S2 is 1: (1-2); and the mass ratio of the para-aramid fiber in step S3 to the polyurethane epoxy resin in step S2 is 1: (1-1.5).

[0041] Specifically, further, in step S1, the para-aramid fiber after the activation treatment is mixed with the polyester resin at 60-100℃ for 20min-2h and then extruded into a shape by a first extruder;

[0042] In step S2, the polyurethane epoxy resin is mixed with the fluoro rubber at 35-75℃ for 40min-3h and then extruded into a shape by a second extruder;

[0043] In step S3, the para-aramid fiber after the activation treatment is mixed with the polyester resin, the thermoplastic elastomer, the polytetrafluoroethylene resin and the anhydrous copper sulfate at 60-100℃ for 2-5h and then extruded into a shape by a third extruder.

[0044] Specifically, the para-aramid fiber is washed with distilled water and ethanol, then dried at 65-75℃, and then activated by a silane coupling agent, which is γ-glycidoxypropyltrimethoxysilane.

[0045] Specifically, the specific method for activating the para-aramid fiber by the silane coupling agent is as follows: the para-aramid fiber is added to an acetone solution and ultrasonically cleaned, then dried in an oven, the dried para-aramid fiber is surface-activated by plasma treatment (power 50-200W, treatment time 1-10min), then the surface-activated para-aramid fiber is dried in an oven, then the surface-activated para-aramid fiber is immersed in a silane coupling agent hydrolysis solution with a mass fraction of 0.5%-1.5% (room temperature, 10-30min), then drained, quickly rinsed with ethanol, preliminarily dried at low temperature (60-80℃), and gently cured (100-110℃, 30-60min, in N2 environment) to finally obtain the para-aramid fiber activated by the silane coupling agent.

[0046] More specifically, the method for activating the para-aramid fiber using a silane coupling agent in the embodiment of the present application is as follows: the para-aramid fiber is added to an acetone solution and ultrasonicated, then washed and dried in an oven, the dried para-aramid fiber is surface-activated by plasma treatment (power 100 W, treatment time 5 minutes), then the surface-activated para-aramid fiber is dried in an oven, then the surface-activated para-aramid fiber is immersed in a 1% silane coupling agent hydrolysate (room temperature, 30 min), then drained, quickly rinsed with ethanol, low-temperature preliminary dried (80°C), and gently cured (100°C, 40 min, under N2 environment) to obtain the silane coupling agent-activated aramid fiber.

[0047] More specifically, the inner pipe blank of the drain pipe is composed of high-strength para-aramid fiber and polyester resin, the polyester resin is vinyl ester resin, and the inner pipe blank is prepared by extrusion with an extruder.

[0048] The composite pipe blank of the intermediate layer of the drain pipe is composed of polyurethane epoxy resin and fluororubber, the polyurethane epoxy resin is the repairing agent in the microcapsule self-repairing rubber layer, and the composite pipe blank of the intermediate layer is prepared by extrusion onto the inner pipe blank with an extruder.

[0049] The outermost pipe blank of the drain pipe is composed of high-strength para-aramid fiber, high-performance polyester resin, thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate, the high-performance polyester resin is vinyl ester resin, the thermoplastic elastomer is hydrogenated styrene-butadiene-styrene block copolymer, the polytetrafluoroethylene resin is a resin with excellent properties such as temperature resistance, corrosion resistance and electrical insulation, the anhydrous copper sulfate changes from white to blue after contacting with water and is used for detecting the position of water leakage, and the outermost pipe blank is prepared by extrusion with an extruder.

[0050] The present application also discloses a para-aramid fiber drain pipe prepared by the preparation method.

[0051] More specifically, the raw materials used in the embodiment of the present application are as follows:

[0052] Para-aramid fiber: diameter 50-70 μm, length 15-25 mm;

[0053] Vinyl ester resin: model: R139412; brand: Luoen;

[0054] Polyurethane epoxy resin: model: EPU-253; brand: Luohang;

[0055] Fluororubber: model: F52605 / FE2605Z; brand: San'ailu;

[0056] Hydrogenated styrene-butadiene-styrene block copolymer: Model: YH-501T; Brand: Balin Petrochemical;

[0057] Polytetrafluoroethylene resin: Model: A75723; Brand: Innochem;

[0058] Anhydrous copper sulfate: Model: A64739; Brand: Innochem.

[0059] Example 1

[0060] A high-performance para-aramid fiber drain pipe is prepared by the following method:

[0061] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers are washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then placed in a vacuum oven at 75°C for drying for 2 hours, and then activated by silane coupling agent to obtain activated para-aramid fibers. Then, the activated para-aramid fibers are mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then added to the first extruder after uniform mixing, and extruded to form the inner layer pipe blank.

[0062] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:50.

[0063] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluoro rubber are mixed at a certain mass ratio at 55°C for 2 hours, and then added to the second extruder after uniform mixing, and extruded onto the inner layer pipe blank to form the intermediate layer pipe blank.

[0064] In this embodiment, the mass ratio of polyurethane epoxy resin to fluoro rubber is 40:35.

[0065] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate are mixed at a certain mass ratio at 80°C for 4 hours, and then added to the third extruder after uniform mixing, and extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0066] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate is 40:50:8:20:15.

[0067] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5; and in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5.

[0068] (4) After the pipe material with a three-layer structure is subjected to cooling, setting and cutting treatment, a para-aramid fiber drainage pipe product is obtained.

[0069] Example 2

[0070] A preparation method of a high-performance para-aramid fiber drainage pipe is provided.

[0071] (1) Preparation of an inner layer pipe blank: high-strength para-aramid fibers are washed with distilled water and ethanol to remove the oil agent contained in the para-aramid fibers, and then the para-aramid fibers are dried in a vacuum oven at 75°C for 2 hours, and then subjected to activation treatment with a silane coupling agent to obtain activated para-aramid fibers. Then, the activated para-aramid fibers are mixed with a vinyl ester resin at a certain mass ratio at 90°C for 1.5 hours, and then added to a first extruder to be extruded and molded to obtain an inner layer pipe blank.

[0072] In this embodiment, the mass ratio of the high-strength para-aramid fibers to the vinyl ester resin is 40:60.

[0073] (2) Preparation of an intermediate layer pipe blank: a polyurethane epoxy resin and a fluororubber are mixed at a certain mass ratio at 65°C for 2.5 hours, and then added to a second extruder to be extruded onto the inner layer pipe blank to be molded to obtain an intermediate layer pipe blank.

[0074] In this embodiment, the mass ratio of the polyurethane epoxy resin to the fluororubber is 40:45.

[0075] (3) Preparation of an outer layer pipe blank: activated para-aramid fibers, a vinyl ester resin, a hydrogenated styrene-butadiene-styrene block copolymer, a polytetrafluoroethylene resin and anhydrous copper sulfate are mixed at a certain mass ratio at 90°C for 4.5 hours, and then added to a third extruder to be extruded onto the intermediate layer pipe blank to be molded to obtain an outer layer pipe blank.

[0076] In this embodiment, the mass ratio of the high-strength para-aramid fibers, the vinyl ester resin, the hydrogenated styrene-butadiene-styrene block copolymer, the polytetrafluoroethylene resin and the anhydrous copper sulfate is 40:60:10:25:20.

[0077] In the step (1), the mass ratio of the para-aramid fibers to the polyurethane epoxy resin in the step (2) is 1:2; and in the step (3), the mass ratio of the para-aramid fibers to the polyurethane epoxy resin in the step (2) is 1:1.5.

[0078] (4) After the pipe material with a three-layer structure is subjected to cooling, setting and cutting treatment, a para-aramid fiber drainage pipe product is obtained.

[0079] Example 3

[0080] A high-performance para-aramid fiber drain pipe is prepared by the following method:

[0081] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers are washed with distilled water and ethanol to remove the oil agent contained in the para-aramid fibers, and then dried in a vacuum oven at 75°C for 2 hours. The dried para-aramid fibers are then activated by a silane coupling agent to obtain activated para-aramid fibers. The activated para-aramid fibers are then mixed with vinyl ester resin at a certain mass ratio at 100°C for 2 hours. After uniform mixing, the mixture is added to a first extruder to form an inner layer pipe blank.

[0082] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:70.

[0083] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluororubber are mixed at a certain mass ratio at 75°C for 3 hours. After uniform mixing, the mixture is added to a second extruder to form an intermediate layer pipe blank.

[0084] In this embodiment, the mass ratio of polyurethane epoxy resin to fluororubber is 40:55.

[0085] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate are mixed at a certain mass ratio at 100°C for 5 hours. After uniform mixing, the mixture is added to a third extruder to form an outer layer pipe blank.

[0086] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate is 40:70:12:30:25.

[0087] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1; in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.

[0088] (4) After cooling, shaping, and cutting, a para-aramid fiber drain pipe product is obtained.

[0089] Example 4

[0090] A high-performance para-aramid fiber drain pipe is prepared by the following method:

[0091] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers are washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then placed in a vacuum oven at 75°C for drying for 2 hours, and then activated by a silane coupling agent to obtain activated para-aramid fibers, which are then mixed with vinyl ester resin at a certain mass ratio at 70°C for 40 minutes, and then added to the first extruder after uniform mixing, and extruded to form the inner layer pipe blank.

[0092] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:40.

[0093] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluororubber are mixed at a certain mass ratio at 45°C for 1 hour, and then added to the second extruder after uniform mixing, and extruded onto the inner layer pipe blank to form the intermediate layer pipe blank.

[0094] In this embodiment, the mass ratio of polyurethane epoxy resin to fluororubber is 40:25.

[0095] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate are mixed at a certain mass ratio at 70°C for 3 hours, and then added to the third extruder after uniform mixing, and extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0096] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate is 40:40:6:15:10.

[0097] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5; and in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5.

[0098] (4) After cooling, shaping, and cutting treatment, the ternary layer structure pipe is obtained to form the para-aramid fiber drainage pipe product.

[0099] Example 5

[0100] A high-performance para-aramid fiber drainage pipe is prepared by the following preparation method:

[0101] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers were washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then were placed in a vacuum oven at 75°C for drying for 2 hours, and then were activated by silane coupling agent to obtain activated para-aramid fibers, which were then mixed with vinyl ester resin at a certain mass ratio at 60°C for 20 minutes, and then were added into the first extruder after uniform mixing, and were extruded to form the inner layer pipe blank.

[0102] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:30.

[0103] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluoro rubber were mixed at a certain mass ratio at 35°C for 40 minutes, and then were added into the second extruder after uniform mixing, and were extruded onto the inner layer pipe blank to form the intermediate layer pipe blank.

[0104] In this embodiment, the mass ratio of polyurethane epoxy resin to fluoro rubber is 40:15.

[0105] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate were mixed at a certain mass ratio at 60°C for 2 hours, and then were added into the third extruder after uniform mixing, and were extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0106] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:30:4:10:5.

[0107] In this embodiment, the mass ratio of para-aramid fibers in step (1) to polyurethane epoxy resin in step (2) is 1:1.5; and the mass ratio of para-aramid fibers in step (3) to polyurethane epoxy resin in step (2) is 1:1.5.

[0108] (4) After cooling, shaping and cutting treatment of the pipe material with a three-layer structure, the para-aramid fiber drainage pipe product was obtained.

[0109] Comparative Example 1

[0110] High-performance para-aramid fiber drainage pipes were prepared by the same method as in Example 1, except that glass fibers (model: A01232; brand: Innochem) were used instead of high-strength para-aramid fibers for the inner layer pipe blank and the outer layer pipe blank, and the specific preparation process was as follows:

[0111] (1) Preparation of inner layer pipe blank: The glass fiber is washed with distilled water and ethanol to remove the oil contained in the glass fiber, and then is placed in a vacuum oven at 75°C for drying for 2 hours, and then is activated by silane coupling agent to obtain activated glass fiber. Then, the activated glass fiber is mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then is added into the first extruder to be extruded to obtain the inner layer pipe blank.

[0112] In this embodiment, the mass ratio of the glass fiber to the vinyl ester resin is 40:50.

[0113] (2) Preparation of intermediate layer pipe blank: The polyurethane epoxy resin and the fluororubber are mixed at a certain mass ratio at 55°C for 2 hours, and then are added into the second extruder to be extruded onto the inner layer pipe blank to obtain the intermediate layer pipe blank.

[0114] In this embodiment, the mass ratio of the polyurethane epoxy resin to the fluororubber is 40:35.

[0115] (3) Preparation of outer layer pipe blank: The activated glass fiber, the vinyl ester resin, the hydrogenated styrene-butadiene-styrene block copolymer, the polytetrafluoroethylene resin and the anhydrous copper sulfate are mixed at a certain mass ratio at 80°C for 4 hours, and then are added into the third extruder to be extruded onto the intermediate layer pipe blank to obtain the outer layer pipe blank.

[0116] In this embodiment, the mass ratio of the glass fiber, the vinyl ester resin, the hydrogenated styrene-butadiene-styrene block copolymer, the polytetrafluoroethylene resin and the anhydrous copper sulfate is 40:50:8:20:15.

[0117] The mass ratio of the para-aramid fiber in step (1) to the polyurethane epoxy resin in step (2) is 1:1.5, and the mass ratio of the para-aramid fiber in step (3) to the polyurethane epoxy resin in step (2) is 1:1.5.

[0118] (4) The pipe material with the ternary layer structure is cooled, shaped and cut to obtain the para-aramid fiber drainage pipe product.

[0119] Comparative Example 2

[0120] The same method as in Example 1 is used to prepare the high-performance para-aramid fiber drainage pipe, except that the inner layer pipe blank and the outer layer pipe blank use ortho-phenyl unsaturated polyester resin (model: TM-189T; brand: Changzhou Tianma) instead of vinyl ester resin. The specific preparation process is as follows:

[0121] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers were washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then were placed in a vacuum oven at 75°C for drying for 2 hours, and then were activated by silane coupling agent to obtain activated para-aramid fibers, which were then mixed with ortho-phenyl unsaturated polyester resin at a certain mass ratio at 80°C for 1 hour, and then were added into a first extruder after uniform mixing, and were extruded to form the inner layer pipe blank.

[0122] In this embodiment, the mass ratio of high-strength para-aramid fibers to ortho-phenyl unsaturated polyester resin is 40:50.

[0123] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluororubber were mixed at a certain mass ratio at 55°C for 2 hours, and then were added into a second extruder after uniform mixing, and were extruded onto the inner layer pipe blank to form the intermediate layer pipe blank.

[0124] In this embodiment, the mass ratio of polyurethane epoxy resin to fluororubber is 40:35.

[0125] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, ortho-phenyl unsaturated polyester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate were mixed at a certain mass ratio at 80°C for 4 hours, and then were added into a third extruder after uniform mixing, and were extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0126] In this embodiment, the mass ratio of high-strength para-aramid fibers, ortho-phenyl unsaturated polyester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:50:8:20:15.

[0127] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5; in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5.

[0128] (4) After cooling, shaping and cutting treatment of the pipe material with a three-layer structure, the para-aramid fiber drainage pipe product is obtained.

[0129] Comparative Example 3

[0130] High-performance para-aramid fiber drainage pipes were prepared by the same method as in Example 1, except that the intermediate layer pipe blank was replaced by epoxy resin (model: 4133652A; brand: Adamas), and the specific preparation process was as follows:

[0131] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers were washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then were placed in a vacuum oven at 75°C for drying for 2 hours, and then were activated by silane coupling agent to obtain activated para-aramid fibers, which were then mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then were added into a first extruder to be extruded and formed into an inner layer pipe blank.

[0132] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:50.

[0133] (2) Preparation of intermediate layer pipe blank: epoxy resin and fluoro rubber were mixed at a certain mass ratio at 55°C for 2 hours, and then were added into a second extruder to be extruded onto the inner layer pipe blank to be formed into an intermediate layer pipe blank.

[0134] In this embodiment, the mass ratio of epoxy resin to fluoro rubber is 40:35.

[0135] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate were mixed at a certain mass ratio at 80°C for 4 hours, and then were added into a third extruder to be extruded onto the intermediate layer pipe blank to be formed into an outer layer pipe blank.

[0136] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:50:8:20:15.

[0137] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5; in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5.

[0138] (4) After cooling, shaping and cutting treatment, the pipe material with a ternary layer structure was obtained to be a para-aramid fiber drainage pipe product.

[0139] Comparative Example 4

[0140] High-performance para-aramid fiber drainage pipes were prepared by the same method as in Example 1, except that chloroprene rubber (model: P466846; brand: Aladdin) was used to replace fluoro rubber in the intermediate layer pipe blank, and the specific preparation process was as follows:

[0141] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers were washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then were placed in a vacuum oven at 75°C for drying for 2 hours, and then were activated by silane coupling agent to obtain activated para-aramid fibers, which were then mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then were added into a first extruder after uniform mixing, and were extruded to form an inner layer pipe blank.

[0142] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:50.

[0143] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and chlorobutyl rubber were mixed at a certain mass ratio at 55°C for 2 hours, and then were added into a second extruder after uniform mixing, and were extruded onto the inner layer pipe blank to form an intermediate layer pipe blank.

[0144] In this embodiment, the mass ratio of polyurethane epoxy resin to chlorobutyl rubber is 40:35.

[0145] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate were mixed at a certain mass ratio at 80°C for 4 hours, and then were added into a third extruder after uniform mixing, and were extruded onto the intermediate layer pipe blank to form an outer layer pipe blank.

[0146] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:50:8:20:15.

[0147] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5; in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5.

[0148] (4) After cooling, shaping and cutting treatment of the pipe material with a three-layer structure, a para-aramid fiber drainage pipe product is obtained.

[0149] Comparative Example 5

[0150] A high-performance para-aramid fiber drainage pipe was prepared by the same method as in Example 1, except that the outer layer pipe blank was replaced by styrene-butadiene-styrene block copolymer (model: ZS-10091; brand: Zzstandard), and the specific preparation process was as follows:

[0151] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers were washed with distilled water and ethanol to remove the oil agent contained in the para-aramid fibers, and then were placed in a vacuum oven at 75°C for drying for 2 hours, and then were activated by a silane coupling agent to obtain activated para-aramid fibers, which were then mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then were added into a first extruder to be extruded and molded to obtain the inner layer pipe blank.

[0152] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:50.

[0153] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluoro rubber were mixed at a certain mass ratio at 55°C for 2 hours, and then were added into a second extruder to be extruded onto the inner layer pipe blank to be molded to obtain the intermediate layer pipe blank.

[0154] In this embodiment, the mass ratio of polyurethane epoxy resin to fluoro rubber is 40:35.

[0155] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate were mixed at a certain mass ratio at 80°C for 4 hours, and then were added into a third extruder to be extruded onto the intermediate layer pipe blank to be molded to obtain the outer layer pipe blank.

[0156] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:50:8:20:15.

[0157] In step (1), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5; in step (3), the mass ratio of para-aramid fibers to polyurethane epoxy resin in step (2) is 1:1.5.

[0158] (4) After cooling, shaping and cutting treatment of the pipe material with a ternary layer structure, the para-aramid fiber drainage pipe product is obtained.

[0159] Comparative Example 6

[0160] The same method as in Example 1 was used to prepare high-performance para-aramid fiber drainage pipes, except that the outer layer pipe blank used phthalic polyester resin (model: M-199; brand: Nantong Meide) instead of polytetrafluoroethylene resin, and the specific preparation process was as follows:

[0161] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers are washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then placed in a vacuum oven at 75°C for drying for 2 hours, and then activated by silane coupling agent to obtain activated para-aramid fibers, then mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then added to the first extruder after uniform mixing, and extruded to obtain the inner layer pipe blank.

[0162] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:50.

[0163] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluororubber are mixed at a certain mass ratio at 55°C for 2 hours, and then added to the second extruder after uniform mixing, and extruded onto the inner layer pipe blank to form the intermediate layer pipe blank.

[0164] In this embodiment, the mass ratio of polyurethane epoxy resin to fluororubber is 40:35.

[0165] (3) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, meta-benzene polyester resin and anhydrous copper sulfate are mixed at a certain mass ratio at 80°C for 4 hours, and then added to the third extruder after uniform mixing, and extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0166] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, meta-benzene polyester resin and anhydrous copper sulfate is 40:50:8:20:15.

[0167] The mass ratio of para-aramid fibers in step (1) to polyurethane epoxy resin in step (2) is 1:1.5; and the mass ratio of para-aramid fibers in step (3) to polyurethane epoxy resin in step (2) is 1:1.5.

[0168] (4) After cooling, shaping and cutting treatment of the pipe material with a three-layer structure, the para-aramid fiber drainage pipe product is obtained.

[0169] Comparative Example 7

[0170] The same method as in Example 1 is used to prepare high-performance para-aramid fiber drainage pipe, except that the high-strength para-aramid fibers used in the inner layer pipe blank and the outer layer pipe blank are not activated by silane coupling agent. The specific preparation process is as follows:

[0171] (1) Preparation of inner layer pipe blank: high-strength para-aramid fiber is washed with distilled water and ethanol to remove the oil contained in the para-aramid fiber, and then placed in a vacuum oven at 75°C for drying for 2 hours, and then mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then added into the first extruder after uniform mixing, and then extruded to form the inner layer pipe blank.

[0172] In this embodiment, the mass ratio of high-strength para-aramid fiber to vinyl ester resin is 40:50.

[0173] (2) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluororubber are mixed at a certain mass ratio at 55°C for 2 hours, and then added into the second extruder after uniform mixing, and then extruded onto the inner layer pipe blank to form the intermediate layer pipe blank.

[0174] In this embodiment, the mass ratio of polyurethane epoxy resin to fluororubber is 40:35.

[0175] (3) Preparation of outer layer pipe blank: para-aramid fiber, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate are mixed at a certain mass ratio at 80°C for 4 hours, and then added into the third extruder after uniform mixing, and then extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0176] In this embodiment, the mass ratio of para-aramid fiber, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:50:8:20:15.

[0177] In this embodiment, the mass ratio of para-aramid fiber in step (1) to polyurethane epoxy resin in step (2) is 1:1.5; and the mass ratio of para-aramid fiber in step (3) to polyurethane epoxy resin in step (2) is 1:1.5.

[0178] (4) After cooling, shaping and cutting treatment of the pipe material with a three-layer structure, the para-aramid fiber drainage pipe product is obtained.

[0179] Comparative Example 8

[0180] The same method as in Example 1 is used to prepare a high-performance para-aramid fiber drainage pipe, except that in this comparative example 8, the mass ratio of para-aramid fiber in step (1) to polyurethane epoxy resin in step (2) is 2:1; and the mass ratio of para-aramid fiber in step (3) to polyurethane epoxy resin in step (2) is 2:1. The specific preparation process is as follows:

[0181] A preparation method of a high-performance para-aramid fiber drainage pipe is provided.

[0182] (1) Preparation of inner layer pipe blank: high-strength para-aramid fibers were washed with distilled water and ethanol to remove the oil contained in the para-aramid fibers, and then were placed in a vacuum oven at 75°C for drying for 2 hours, and then were activated by silane coupling agent to obtain activated para-aramid fibers, which were then mixed with vinyl ester resin at a certain mass ratio at 80°C for 1 hour, and then were added into a first extruder to be extruded to obtain the inner layer pipe blank.

[0183] In this embodiment, the mass ratio of high-strength para-aramid fibers to vinyl ester resin is 40:50.

[0184] (4) Preparation of intermediate layer pipe blank: polyurethane epoxy resin and fluoro rubber were mixed at a certain mass ratio at 55°C for 2 hours, and then were added into a second extruder to be extruded onto the inner layer pipe blank to obtain the intermediate layer pipe blank.

[0185] In this embodiment, the mass ratio of polyurethane epoxy resin to fluoro rubber is 40:35.

[0186] (5) Preparation of outer layer pipe blank: activated para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate were mixed at a certain mass ratio at 80°C for 4 hours, and then were added into a third extruder to be extruded onto the intermediate layer pipe blank to obtain the outer layer pipe blank.

[0187] In this embodiment, the mass ratio of high-strength para-aramid fibers, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:50:8:20:15.

[0188] The mass ratio of para-aramid fibers in step (1) to polyurethane epoxy resin in step (2) is 2:1; the mass ratio of para-aramid fibers in step (3) to polyurethane epoxy resin in step (2) is 2:1.

[0189] (4) After cooling, shaping and cutting treatment of the pipe material with ternary layer structure, the para-aramid fiber drainage pipe product is obtained.

[0190] Blank Example 1

[0191] High-performance para-aramid fiber drainage pipes were prepared by the same method as in Example 1, except that no fibers were used as composite materials for the inner layer pipe blank and the outer layer pipe blank, and the specific preparation process was as follows:

[0192] (1) Preparation of inner layer pipe blank: vinyl ester resin was added into a first extruder at 80°C to be extruded to obtain the inner layer pipe blank.

[0193] (2) Preparation of the intermediate layer pipe blank: polyurethane epoxy resin and fluororubber are mixed at a certain mass ratio at 55°C for 2 hours, and then added to the second extruder after uniform mixing, extruded onto the inner layer pipe blank, and molded to obtain the intermediate layer pipe blank.

[0194] In this embodiment, the mass ratio of polyurethane epoxy resin and fluororubber is 40:35.

[0195] (3) Preparation of the outer layer pipe blank: vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate are mixed at a certain mass ratio at 80°C for 4 hours, and then added to the third extruder after uniform mixing, extruded onto the intermediate layer pipe blank, and molded to obtain the outer layer pipe blank.

[0196] In this embodiment, the mass ratio of vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate is 50:8:20:15.

[0197] (4) After cooling, shaping, and cutting treatment of the pipe material with a ternary layer structure, the para-aramid fiber drainage pipe product is obtained.

[0198] Blank Example 2

[0199] The same method as in Example 1 is used to prepare the high-performance para-aramid fiber drainage pipe, except that anhydrous copper sulfate is not used as a composite material for the outer layer pipe blank, and the specific preparation process is as follows:

[0200] (1) Preparation of the inner layer pipe blank: glass fibers are washed with distilled water and ethanol to remove the oil contained in the glass fibers, and then placed in a vacuum oven at 75°C for drying for 2 hours, and then activated by a silane coupling agent to obtain activated para-aramid fibers. Then, vinyl ester resin is mixed with the activated para-aramid fibers at a certain mass ratio at 80°C for 1 hour, and then added to the first extruder after uniform mixing, and extruded and molded to obtain the inner layer pipe blank.

[0201] In this embodiment, the mass ratio of glass fibers and vinyl ester resin is 40:50.

[0202] (2) Preparation of the intermediate layer pipe blank: polyurethane epoxy resin and fluororubber are mixed at a certain mass ratio at 55°C for 2 hours, and then added to the second extruder after uniform mixing, extruded onto the inner layer pipe blank, and molded to obtain the intermediate layer pipe blank.

[0203] In this embodiment, the mass ratio of polyurethane epoxy resin and fluororubber is 40:35.

[0204] (3) Preparing the outer layer pipe blank: the activated para-aramid fiber, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, and polytetrafluoroethylene resin are mixed at a certain mass ratio at 80°C for 4 hours, and then added to the third extruder and extruded onto the intermediate layer pipe blank to form the outer layer pipe blank.

[0205] In this embodiment, the mass ratio of the para-aramid fiber, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate is 40:50:8:20.

[0206] The mass ratio of the para-aramid fiber in step (1) to the polyurethane epoxy resin in step (2) is 1:1.5, and the mass ratio of the para-aramid fiber in step (3) to the polyurethane epoxy resin in step (2) is 1:1.5.

[0207] (4) The pipe with a ternary layer structure is cooled, shaped, and cut to obtain the para-aramid fiber drainage pipe product.

[0208] The specifications of the drainage pipes prepared in the above examples, comparative examples, and blank examples are as follows: the inner diameter is 40 mm, the outer diameter is 46.4 mm, the total thickness of the pipe wall is 3.2 mm (wherein the thickness ratio of the inner layer, the intermediate layer, and the outer layer is 0.9:1:1.3), and the length of the cut drainage pipe is 500 mm.

[0209] The drainage pipes prepared in the above examples, comparative examples, and blank examples are tested:

[0210] The contents of the experimental tests include ring stiffness, impact strength, tensile strength, solvent resistance, flame retardancy, air tightness repair rate, and steel needle puncture test on the drainage pipe under constant water pressure conditions to observe whether the puncture position is broken and whether there is leakage at the broken opening, and then dripping water from the outer wall at the broken opening to observe whether the broken opening is colored. The specific results are shown in Table 1.

[0211] The test standard method for ring strength is ISO 9969 / GB / T 9647.

[0212] The test standard method for impact strength is ISO 3127 (falling weight impact), and the test result is characterized by impact energy.

[0213] The test standard method for tensile strength is ISO 6259 / GB / T 8804.1.

[0214] The test standard method for solvent resistance is ASTM D543, and the test result is characterized by whether the drainage pipe swells and cracks.

[0215] The standard test method for flame retardancy is ISO 4589, and the test result is characterized by the oxygen index.

[0216] The test method for air tightness repair rate is ISO 13968 / GB / T 19472.2, and the air pressure of the drain pipe that is not punctured is taken as 100%.

[0217] Table 1: Drain pipe performance test data

[0218]

[0219] From the data comparison of Examples 1-5, it can be seen that the high-performance para-aramid fiber drain pipe prepared by the preparation method of the application has good comprehensive performance, and with the change of the mixing ratio of the composite material and the change of the premixing temperature and time of the composite material, the ring stiffness, impact strength, tensile strength, solvent resistance, flame retardancy and air tightness repair rate of the high-performance para-aramid fiber drain pipe do not decrease significantly, which can well solve the problems of poor strength, poor temperature resistance, easy leakage and difficult to find leakage points of ordinary drain pipes.

[0220] From the data comparison of Examples 1 and Comparative Examples 1 and 2, it can be seen that when high-strength para-aramid fiber and vinyl ester resin are used together to form the inner pipe blank material, the ring stiffness, impact strength, tensile strength and flame retardancy of the high-performance para-aramid fiber drain pipe can be effectively improved. If glass fiber is used to replace high-strength para-aramid fiber (Comparative Example 1), the ring stiffness, impact strength, tensile strength, solvent resistance and flame retardancy of the drain pipe will decrease significantly, because high-strength para-aramid fiber has the characteristics of ultra-high strength, corrosion resistance and light weight, which revolutionizes the performance boundary of the drain pipe, especially in harsh environments such as deep sea, high temperature and corrosion, and its advantages as a composite material for drain pipes are obvious; if ortho-phenyl unsaturated polyester resin is used to replace vinyl ester resin (Comparative Example 2), the ring stiffness, impact strength, tensile strength and flame retardancy of the drain pipe will also decrease significantly, because vinyl ester resin has better corrosion resistance, mechanical properties, temperature resistance and environmental protection.

[0221] From the data comparison of Example 1 and Comparative Example 3, Comparative Example 4, it can be seen that when polyurethane epoxy resin and fluororubber are used together to compound as the intermediate layer pipe blank material, the air tightness repair rate of the high-performance para-aramid fiber drainage pipe can be effectively improved, thereby prolonging the service life of the high-performance para-aramid fiber drainage pipe. If epoxy resin is used instead of polyurethane epoxy resin as the repair agent of the intermediate layer pipe blank (Comparative Example 3), the self-repairing ability of the drainage pipe will be significantly reduced, because polyurethane epoxy resin combines the high bonding strength of epoxy resin and the flexibility of polyurethane, and can firmly bond various materials such as metal, concrete, plastic, wood, etc., and is especially suitable for structural repair or composite material repair; if chloroprene rubber is used instead of fluororubber (Comparative Example 4), the solvent resistance of the drainage pipe will be significantly reduced, mainly because fluororubber has good chemical resistance, high temperature resistance, and durability, especially in harsh environments (such as industrial wastewater, high temperature corrosive medium).

[0222] From the data comparison of Example 1 and Comparative Example 5, Comparative Example 6, it can be seen that when high-strength para-aramid fiber, vinyl ester resin, hydrogenated styrene-butadiene-styrene block copolymer, polytetrafluoroethylene resin, and anhydrous copper sulfate are used together to compound as the outer layer pipe blank material, the ring stiffness, impact strength, tensile strength, and flame retardancy of the high-performance para-aramid fiber drainage pipe can be effectively improved. If styrene-butadiene-styrene block copolymer is used instead of hydrogenated styrene-butadiene-styrene block copolymer (Comparative Example 5), the ring stiffness, impact strength, tensile strength, and flame retardancy of the drainage pipe will be reduced, because the hydrogenated styrene-butadiene-styrene block copolymer is superior to the styrene-butadiene-styrene block copolymer in durability, weather resistance, and temperature resistance, and is more suitable for high-end or harsh environment drainage pipe applications; if meta-phenyl polyester resin is used instead of polytetrafluoroethylene resin (Comparative Example 6), the solvent resistance of the drainage pipe will be significantly reduced, mainly because polytetrafluoroethylene resin has excellent chemical resistance and high temperature resistance.

[0223] From the data comparison of Example 1 and Comparative Example 7, it can be seen that when the high-strength para-aramid fiber used in the inner layer pipe blank and the outer layer pipe blank is activated by a silane coupling agent, the surface activity of the high-performance para-aramid fiber can be effectively improved, thereby improving its bonding force with other composite materials. If the high-strength para-aramid fiber is not activated by a silane coupling agent, all the properties of the drainage pipe will be reduced.

[0224] From the data comparison of Example 1 and Comparative Example 8, it can be seen that if the addition amount of the para-aramid fiber and the addition amount of the polyurethane epoxy resin are not suitable, the drainage pipe will have a delamination problem, which will cause a cracking problem. A suitable ratio of the para-aramid fiber and the polyurethane epoxy resin is more conducive to the para-aramid fiber in the inner layer or the outer layer and the polyurethane epoxy resin in the middle layer forming strong hydrogen bonding and dipole interaction, thereby forming core interface force, and ultimately improving the comprehensive performance of the drainage pipe.

[0225] From the data comparison of Example 1 and Blank Example 1, it can be seen that when the composite material used in the inner layer pipe blank and the outer layer pipe blank does not use fiber, the strength, service life and solvent resistance of the drainage pipe will all decrease, the reliability and safety of the drainage pipe will be greatly reduced, and the advantage of lightweight of the fiber will not be applied.

[0226] From the data comparison of Example 1 and Blank Example 2, it can be seen that when the composite material in the outer layer pipe blank does not add anhydrous copper sulfate, if the drainage pipe leaks, the leakage point will not be easily detected in time and intuitively, so that it cannot be repaired in time when applied.

[0227] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, it should be considered as the scope of the present application.

[0228] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for preparing a para-aramid fiber drainage pipe, characterized in that, The preparation method is as follows: S1. Cleaned and degreased para-aramid fibers are activated with silane coupling agent and then mixed evenly with polyester resin. The mixture is then extruded by the first extruder to obtain the inner tube blank. S2. Add the uniformly mixed fluororubber and polyurethane epoxy resin to the second extruder, and extrude the mixture onto the inner tube blank of step S1. After extrusion molding, the composite tube blank of the middle layer is obtained. S3. After the cleaned and degreased para-aramid fibers are activated by silane coupling agent, they are mixed evenly with polyester resin, thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate, and extruded onto the composite pipe blank in step S2 through a third extruder. The pipe with a ternary layer structure is obtained by extrusion molding. S4. After cooling, shaping and cutting the pipe, the finished para-aramid fiber drainage pipe is obtained. The mass ratio of para-aramid fiber in step S1 to polyurethane epoxy resin in step S2 is 1:(1-2); the mass ratio of para-aramid fiber in step S3 to polyurethane epoxy resin in step S2 is 1:(1-1.5). The polyester resin is a vinyl ester resin, and the thermoplastic elastomer is a hydrogenated styrene-butadiene-styrene block copolymer.

2. The method for preparing a para-aramid fiber drainage pipe according to claim 1, characterized in that, The diameter of the para-aramid fiber is 50-70 μm, and the length of the para-aramid fiber is 15-25 mm.

3. The method for preparing a para-aramid fiber drainage pipe according to claim 1, characterized in that, In step S1, the mass ratio of the para-aramid fiber to the polyester resin is 40:(30-70).

4. The method for preparing a para-aramid fiber drainage pipe according to claim 1, characterized in that, In step S2, the mass ratio of the polyurethane epoxy resin to the fluororubber is 40:(15-55).

5. The method for preparing a para-aramid fiber drainage pipe according to claim 1, characterized in that, In step S3, the mass ratio of para-aramid fiber, polyester resin, thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate is 40:(30-70):(4-12):(10-30):(5-25).

6. The method for preparing a para-aramid fiber drainage pipe according to claim 1, characterized in that, In step S1, after activation treatment, para-aramid fibers and polyester resin are mixed evenly at 60-100℃ and then extruded through the first extruder. In step S2, the polyurethane epoxy resin and fluororubber are mixed evenly at 35-75°C and then extruded through a second extruder. In step S3, after activation treatment, para-aramid fibers are mixed evenly with polyester resin, thermoplastic elastomer, polytetrafluoroethylene resin and anhydrous copper sulfate at 60-100℃ and then extruded through a third extruder.

7. The method for preparing a para-aramid fiber drainage pipe according to claim 1, characterized in that, The para-aramid fibers were washed with distilled water and ethanol, dried at 65-75°C, and then activated with a silane coupling agent, namely γ-glycidoxypropyltrimethoxysilane.

8. A para-aramid fiber drainage pipe, characterized in that, The para-aramid fiber drainage pipe is prepared according to the preparation method described in any one of claims 1-7.

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