Fiber-woven needling, sewing and pultrusion composite pipeline and manufacturing method thereof

Abstract

The invention relates to the technical field of pultrusion composite pipeline manufacturing, and discloses a fiber weaving needling sewing pultrusion composite pipeline and a manufacturing method thereof.The pultrusion composite pipeline comprises a reinforcing body formed by a plurality of weaving layers and / or winding layers, and a plurality of sewing yarns penetrating through the reinforcing body are evenly distributed on the annular section of the reinforcing body; the sewing yarns extend in parallel in the extending direction of the pipeline, and the threads extend in a rotating mode or intersect to form net-shaped extension. According to the pultrusion composite pipeline provided by the invention, the plurality of inner and outer reinforced fiber layers are connected together in the radial direction through more than one sewing yarn, and the track of a sewing line is continuously sewn along the axial direction, so that an integral three-dimensional structure of a reinforcement body is formed; the tensile strength and the elastic modulus of the three-dimensional integral reinforced fiber are far higher than those of thermosetting resin, and under the combined action of the reinforced fiber and the resin, the shearing and tearing resistance and the pressure resistance of the pipeline are improved compared with those of a pipeline without reinforcement sewing operation.

Description

Technical Field

[0001] The invention relates to the technical field of pultruded composite pipe manufacturing, and in particular to a fiber braided needle-punched sutured pultruded composite pipe and a manufacturing method thereof. Background Art

[0002] The material used to make pultruded composite pipes is commonly fiber reinforced plastics, also known as FRP, and commonly used reinforcing fiber materials include: carbon fiber, glass fiber, aramid fiber, basalt fiber, etc., among which glass fiber is the largest. Thermosetting resins occupy a large part of reinforced plastics. The main varieties of thermosetting resins are: unsaturated polyester resins, epoxy resins, vinyl resins, phenolic resins, polyurethanes, etc., among which the amount of unsaturated polyester resins far exceeds that of other resins. Unsaturated polyester resins reinforced with glass fiber are commonly known as FRP, which has the advantages of high strength, light weight, chemical corrosion resistance, and good electrical insulation performance.

[0003] Glass fiber reinforced unsaturated polyester resin pipes are widely used in industrial and civil fields such as building water supply and drainage, electric power industry, chemical industry, and communications industry.

[0004] Prior art 1:

[0005] The existing winding pipe forming method is a relatively traditional forming method. After the reinforcing fiber yarn is impregnated with resin through the dipping tank, the winding yarn is wound around the rotating mandrel at a certain angle under a certain tension. The axial winding of the fiber is carried out by a reciprocating yarn feeding head. After the winding is completed, the curing, demoulding, trimming and other processes are carried out. The winding forming process is simple, suitable for making products of different sizes (including large-sized pipes), and the production is relatively flexible.

[0006] Defects of prior art 1:

[0007] However, the production efficiency of winding molding is low, each process requires transportation, the production area is large, each process requires the collection and treatment of VOC and dust, the environmental pressure is high, and a large number of production personnel are required. In addition, the process of winding molding pipe processing makes the product prone to defects such as bubbles and gaps, the strength of the fiber is insufficient, and there is also the problem that the uniformity of the resin is difficult to control during the winding process, resulting in relatively low overall mechanical properties of the pipe, especially low axial tensile strength.

[0008] Prior art 2:

[0009] The application of braided winding pultrusion process has significantly improved the production efficiency and product performance of fiber-reinforced pipes. The braided winding pultruded pipe structure is mainly composed of three layers: the inner and outer layers are reinforced fibers woven into tubes online or pre-woven fabrics (grid cloth or composite felt) are wrapped on the core mold to form a tube, and the middle winding layer can be subdivided into axial laying, radial rotation winding (clockwise winding, counterclockwise winding, and clockwise and counterclockwise winding at the same time). Thermosetting resin is mixed evenly by adding different additives to form a glue solution. The reinforcement can be dipped in the glue first (the winding yarn is dipped in the glue first and then wound), or the fiber reinforcement can be dipped in the glue mold after weaving and winding. The fiber reinforcement after dipping is stretched into the mold by the traction machine. Under the action of heating outside the mold, the thermosetting resin produces gel and solidification. After being pulled out of the mold, a pipe with a certain degree of solidification can be obtained, and then the product can be obtained through fixed-length cutting, trimming and other processes. The braided winding pultrusion process is a continuous production process. The efficiency of producing fiber-reinforced pipes is higher than that of winding molding. It occupies less production space, and the collection and treatment of VOC and dust are more centralized. At the same time, the mechanical properties of the product are also improved compared to winding molding.

[0010] Defects of the second prior art:

[0011] The fiber-reinforced pipe produced by the braided winding pultrusion process has good comprehensive mechanical properties, including certain impact resistance and bending resistance, after being compounded with thermosetting resin by the fiber reinforcement formed by the braiding molding of the inner and outer layers and the winding molding in the middle. However, from the cross-section of the pipe, the inner and outer braided layers and the middle winding layer are only connected into one body by resin. There is no high-strength reinforcing fiber connection between the three layers in the radial and axial directions. The fiber reinforcement formed by the three fiber-reinforced layers does not form a whole. Therefore, the shear and tear resistance of the pipe is poor, and it also affects the pressure resistance of the pipe. Summary of the invention

[0012] In order to overcome or alleviate one or more of the above technical problems, the purpose of the present invention is to provide a fiber braided needle-stitched pultruded composite pipe and a manufacturing method thereof. A needle-stitching process is added to the existing multi-layer fiber weaving process flow, so that the multiple fiber layers are connected together by yarns of the same or different materials as the reinforcement to form an overall three-dimensional fiber structure as a pultruded composite pipe. While maintaining the original performance of the pultruded composite pipe, the shear and tear resistance of the pipe is increased, and the pressure resistance of the pipe is also increased.

[0013] The present invention provides the following technical solutions:

[0014] On the one hand, the present invention provides a fiber woven needle-punched sutured pultruded composite pipe, which includes a reinforcement formed by multiple woven layers and / or winding layers, and a plurality of suture yarns that pierce the reinforcement are evenly distributed on the annular cross-section of the reinforcement, and the suture yarns extend parallel to the extension direction of the pipe, extend in a threaded rotation manner, or cross-thread to form a mesh extension.

[0015] According to some embodiments, the suture yarn is evenly distributed in at least two strips on the annular section of the reinforcement.

[0016] According to some embodiments, the suture routing mode of the suture yarn is single-line unidirectional routing.

[0017] According to some embodiments, the stitching yarn is selected from carbon fibers, glass fibers, aramid fibers or basalt fibers.

[0018] On the other hand, the present invention provides a method for manufacturing the above-mentioned fiber braided needle-punched sutured pultruded composite pipe, which comprises the following steps:

[0019] S1: braiding and winding, online manufacturing of a tube wrapping or a preformed braided tube wrapping of a multi-layer braided layer, and forming a reinforcement body by the multi-layer braided layer or the preformed braided fabric;

[0020] S2: needle suturing, the reinforcement is needle suturing along the pulling direction corresponding to the number of suture yarns of the fiber braided needle suturing pultruded composite pipe;

[0021] S3: Dipping in glue, the reinforcement body after stitching is pulled into the dipping device for dipping in glue;

[0022] S4: Curing and molding: the reinforced body after impregnation is pulled into a molding die and thermosetted into a pipe;

[0023] S5: Cut to length. After forming, the pipe is pulled along the axial direction and cut to length.

[0024] According to some embodiments, in step S1, the multi-layer braided layer is selected from online braiding production molding or pre-braiding molding.

[0025] According to some embodiments, the winding layer is axially laid or radially rotated wound.

[0026] According to some embodiments, in step S2, the acupuncture suturing is performed in multiple groups, and the reinforcement is suturing in sequence on the production line or as a group on the pipe cross section.

[0027] According to some embodiments, in step S3, the dipping method is vacuum dipping.

[0028] According to some embodiments, in step S4, the molding is performed by external heating, which is divided into three stages: a preheating stage, a gel stage, and a curing stage, and the molding temperatures are set separately for the three stages.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a fiber braided needle-stitched pultruded composite pipe and a manufacturing method thereof. The pipe formed by needle-stitching and pultruding a reinforcement body formed by a fiber braided layer is compared with a traditional braided, wound and pultruded pipe. Compared with the cross-section, the inner and outer multiple reinforcing fiber layers are connected together in the radial direction by more than one stitching yarn. Compared with the axial direction, the trajectory of the stitching line is stitched continuously along the axial direction, thereby forming an overall three-dimensional structure of the reinforcing fiber layer. The tensile strength and elastic modulus of the reinforcing fiber of the three-dimensional overall structure are much higher than those of thermosetting resins. Under the joint action of the reinforcing fiber and the resin, the shear tearing resistance and the pressure resistance of the pipe are significantly improved compared with the pipe without reinforcement body stitching. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic cross-sectional view of a fiber braided needle-punched sutured pultruded composite pipe provided in an embodiment of the present invention.

[0032] Figure 2 A partial schematic cross-sectional view of a fiber braided needle-punched sutured pultruded composite pipe provided in an embodiment of the present invention.

[0033] Figure 3 A variety of different stitching yarn forms are provided for embodiments of the present invention.

[0034] Figure 4 A single-line unidirectional suture routing diagram of the suture yarn provided in an embodiment of the present invention.

[0035] Figure 5 A flowchart of the manufacturing process of the fiber braided needle-punched sutured pultruded composite pipe provided in an embodiment of the present invention.

[0036] Figure 6 A cross-sectional view of the alignment of a single-needle, one-way suture provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0038] The present invention will be further described below in conjunction with the accompanying drawings.

[0039] Example 1

[0040] like Figures 1-2 As shown, this embodiment provides a fiber braided needle-punched sutured pultruded composite pipe, which includes three annular braided layers, namely an outer braided layer, an intermediate winding layer and an inner braided layer. The three braided layers form a reinforcement body, and 8 suture yarns that pierce the reinforcement body are evenly distributed on the annular section of the reinforcement body; each suture yarn is parallel to the extension direction of the pipe ( Figure 3 .a), or parallel thread rotation on the pipe ( Figure 3 .b), or in a cross-threaded mesh on the pipe ( Figure 3 .c).

[0041] The function of the suture yarn is to tightly connect the pipes of multiple braided layers, so that a three-dimensional integral braided body is formed between the separated braided layers. While maintaining the original performance of the multi-layer pipe, the shear and tear resistance of the pipe is increased, and the pressure resistance of the pipe is also increased.

[0042] The number of suture yarns in the annular direction of the pipeline is at least two; if the number is an even number greater than or equal to 2, it will be more in line with the principle of mechanical symmetry and have better shear and tear resistance. The material of the suture yarn can be selected according to production needs, and the suture yarn can be the same as or different from the braided layer winding layer for suture. Specifically, the suture yarn is selected from carbon fiber, glass fiber, aramid fiber or basalt fiber.

[0043] like Figure 5 , which is a flow chart of a production line for manufacturing fiber braided needle-punched sutured pultruded composite pipes. The core mold is located in the axial direction of the production line. From left to right, it is the inner braided layer, the middle winding layer, the outer braided layer, needle-punched suture, dipping, molding, traction and cutting. The traction direction in the figure is to the right.

[0044] Accordingly, this embodiment provides a method for manufacturing a fiber braided needle-punched sutured pultruded composite pipe, which comprises the following steps:

[0045] S1: Braided winding

[0046] The multi-layer braided layer is wrapped online or preformed braided fabric is wrapped in a tube. The inner and outer braids are woven into a tube online or pre-woven fabrics (grid cloth or composite felt) are wrapped on a core mold to form a tube. The middle winding layer can be subdivided into axial laying, radial rotation winding (clockwise winding, counterclockwise winding and simultaneous clockwise and counterclockwise winding) and other methods.

[0047] S2: Needle suture

[0048] The reinforcement body composed of the inner and outer braided layers and the middle winding layer enters the acupuncture suturing device along the traction direction.

[0049] like Figure 6 The single needle suturing device adopts the structure of the needle entering from the outside of the reinforcement and the yarn locking device from the inside. The suturing yarn is brought in by the suturing needle and completely penetrates the reinforcement, and the yarn is fixed by the yarn locking device below. When the suturing needle is withdrawn, the yarn is left in the reinforcement without being withdrawn with the needle.

[0050] S3: Dipping

[0051] After the stitching is completed, the reinforcement body enters the dipping device under the action of the traction machine.

[0052] The dipping device usually adopts spray dipping or vacuum dipping. The structure of the reinforcement after stitching is relatively dense. In order to allow the glue to fully infiltrate the reinforcement and expel the air in the reinforcement as much as possible, vacuum dipping is preferred.

[0053] S4: Curing and molding

[0054] After the resin impregnation is completed, the reinforcement body enters the forming mold under the action of the traction machine.

[0055] The molding mold adopts external heating. The materials of the heating plate include: ceramic heating plate, mica heating plate, cast aluminum heating plate, etc. The surface of the cast aluminum heating plate is flat after processing, and it is not easy to deform after heating. At the same time, it has a certain strength. The cast aluminum heating plate is preferred;

[0056] The molding mold is divided into three sections: preheating section, gel section, and curing section. The temperatures of the three sections are set according to the different characteristics of the glue, so that the pipe can reach a certain degree of curing and mechanical strength after leaving the mold.

[0057] S5: Traction and cut to length

[0058] After leaving the forming die, the pipe moves axially under the action of the traction machine, and is cut to a fixed length after passing through the traction machine.

[0059] The following comparative examples are reinforced tubes produced by the existing braided winding pultrusion process, and Examples 2 to 11 are produced by processing according to the structure and manufacturing method of the fiber braided needle-stitched pultruded composite pipe provided in Example 1. In the production process of the comparative examples and Examples 2 to 11, the multi-layer braided body production and dipping steps are the same, and the suturing processes are different.

[0060] Comparative Example:

[0061] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0062] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0063] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0064] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0065] Unsaturated polyester resin is a special resin for pultrusion, combined with a curing agent, a release agent, a small amount of fillers and other additives to form a glue liquid. The glue liquid has good stability and no stratification.

[0066] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0067] Ring stiffness (5%): 28.76 kPa;

[0068] Annular tensile failure load of separation disk: 21.23kN.

[0069] Embodiment 2:

[0070] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0071] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0072] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0073] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0074] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0075] Two needle suture lines are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle suture is 5mm;

[0076] The suture trajectory of the suture line is parallel to the axial direction;

[0077] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0078] Ring stiffness (5%): 30.19 kPa;

[0079] Annular tensile failure load of separation disk: 22.92kN.

[0080] Embodiment 3:

[0081] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0082] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0083] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0084] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0085] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0086] Two needle-punched suture yarns are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle-punched suture is 8mm;

[0087] The suture trajectory of the suture line is parallel to the axial direction;

[0088] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0089] Ring stiffness (5%): 29.91 kPa;

[0090] Annular tensile failure load of separation disk: 22.51kN.

[0091] Embodiment 4:

[0092] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0093] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0094] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0095] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0096] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0097] Four needle-punched suture yarns are evenly distributed in the radial direction of the pipe, and the axial spacing of the needle-punched suture is 5mm;

[0098] The suture trajectory of the suture line is parallel to the axial direction;

[0099] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0100] Ring stiffness (5%): 31.21 kPa;

[0101] Annular tensile failure load of separation disk: 24.41kN.

[0102] Embodiment 5:

[0103] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0104] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0105] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0106] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0107] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0108] Four needle-punched suture yarns are evenly distributed in the radial direction of the pipe, and the axial spacing of the needle-punched suture is 8mm;

[0109] The suture trajectory of the suture line is parallel to the axial direction;

[0110] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0111] Ring stiffness (5%): 30.83 kPa;

[0112] Annular tensile failure load of separation disk: 24.07kN.

[0113] Embodiment 6:

[0114] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0115] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0116] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0117] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0118] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0119] Six needle-punched suture yarns are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle-punched suture is 5mm;

[0120] The suture trajectory of the suture line is parallel to the axial direction;

[0121] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0122] Ring stiffness (5%): 32.04 kPa

[0123] Separation disk circumferential tensile failure load: 25.58kN

[0124] Embodiment 7:

[0125] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0126] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0127] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0128] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0129] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0130] Six needle-punched suture yarns are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle-punched suture is 8mm;

[0131] The suture trajectory of the suture line is parallel to the axial direction;

[0132] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0133] Ring stiffness (5%): 31.72 kPa;

[0134] Annular tensile failure load of separation disk: 25.31kN.

[0135] Embodiment 8:

[0136] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0137] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0138] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0139] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0140] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0141] Eight needle-punched suture yarns are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle-punched suture is 5mm;

[0142] The suture trajectory of the suture line is parallel to the axial direction;

[0143] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0144] Ring stiffness (5%): 32.48 kPa;

[0145] Annular tensile failure load of separation disc: 26.33kN.

[0146] Embodiment 9:

[0147] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0148] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0149] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0150] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0151] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0152] Eight needle-punched suture yarns are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle-punched suture is 8mm;

[0153] The suture trajectory of the suture line is parallel to the axial direction;

[0154] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0155] Ring stiffness (5%): 32.23 kPa;

[0156] Circumferential tensile failure load of separation disk: 26.07kN.

[0157] Embodiment 10:

[0158] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0159] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0160] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0161] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0162] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0163] Four needle-punched suture yarns are evenly distributed in the radial direction of the pipe, and the axial spacing of the needle-punched suture is 5mm;

[0164] The suture line has a spiral trajectory in the axial direction, rotating clockwise, with an angle of 45° to the axial direction;

[0165] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0166] Ring stiffness (5%): 31.26 kPa;

[0167] Annular tensile failure load of separation disk: 24.47kN.

[0168] Embodiment 11:

[0169] Glass fiber reinforced tubes with an inner diameter of 200 mm and a wall thickness of 5 mm are produced by braiding, winding and pultrusion.

[0170] The inner woven layer adopts pre-woven composite felt: 600g / ㎡, width: 650mm;

[0171] The outer braided layer is made of pre-woven woven gingham cloth: 400g / ㎡, width: 700mm;

[0172] The winding yarn is made of alkali-free glass fiber yarn, and both clockwise and counterclockwise winding methods are adopted.

[0173] The unsaturated polyester resin adopts a special resin for pultrusion, and is combined with a curing agent, a release agent, a small amount of filler and other additives to form a glue solution. The raw materials, formula and mixing process of the glue solution are the same as those of the comparative example.

[0174] Eight needle-punched suture yarns are evenly distributed in the radial direction of the pipeline, and the axial spacing of the needle-punched suture is 5mm;

[0175] The suture trajectory of the suture is spiral in the axial direction, with 4 sutures rotating clockwise and 4 rotating counterclockwise. The clockwise sutures and the counterclockwise sutures are distributed alternately. The angle between the clockwise suture and the axial direction is 45°, and the angle between the counterclockwise suture and the axial direction is 135°.

[0176] From the pultruded pipe, 300 mm long samples were taken for ring stiffness test, and 10 mm long samples were taken for separation disc circumferential tensile test to detect the tensile and shear tearing resistance of the pipe.

[0177] Ring stiffness (5%): 32.59 kPa;

[0178] Annular tensile failure load of separation disc: 26.43kN.

[0179] Table 1 Comparison results of experiments on various fiber braided needle-punched sutured pultruded composite pipes

[0180]

[0181] From Table 1 we can see that:

[0182] (1) When the pipeline has the same suture spacing, the more suture lines there are, the higher the ring stiffness and the circumferential tensile failure load of the separation disk;

[0183] (2) When the number of suture lines is the same, the smaller the suture spacing is, the higher the ring stiffness and the annular tensile failure load of the separation disk are;

[0184] (3) When the number of sutures and the suture spacing are the same, the ring stiffness and the annular tensile failure load of the separation disk when the suture trajectory is spiral in the axial direction are higher than those when the suture trajectory is parallel to the axial direction.

[0185] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A fiber braided needle-punched sutured pultruded composite pipe, comprising a reinforcement formed by multiple braided layers and / or wound layers, characterized in that: A plurality of suture yarns piercing the reinforcement are evenly distributed on the annular section of the reinforcement, and the suture yarns extend in parallel along the extension direction of the pipeline, extend in a threaded rotational manner, or extend in a meshed manner by cross-threading.

2. The fiber braided needle-punched sutured pultruded composite pipe according to claim 1, characterized in that: The number of the suture yarns evenly distributed on the annular section of the reinforcement is at least two.

3. The fiber braided needle-punched sutured pultruded composite pipe according to claim 2, characterized in that: The sewing yarn has a single-line unidirectional sewing method.

4. The fiber braided needle-punched sutured pultruded composite pipe according to claim 2, characterized in that: The stitching yarn is selected from carbon fiber, glass fiber, aramid fiber or basalt fiber.

5. A method for manufacturing a fiber braided needle-punched sutured pultruded composite pipe according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: braiding and winding, online manufacturing of a tube wrapping or a preformed braided tube wrapping of a multi-layer braided layer, and forming a reinforcement body by the multi-layer braided layer or the preformed braided fabric; S2: needle suturing, the reinforcement is needle suturing along the pulling direction corresponding to the number of suture yarns of the fiber braided needle suturing pultruded composite pipe; S3: Dipping in glue, the reinforcement body after stitching is pulled into the dipping device for dipping in glue; S4: Curing and molding: the reinforced body after impregnation is pulled into a molding die and thermosetted into a pipe; S5: Cut to length. After forming, the pipe is pulled along the axial direction and cut to length.

6. The manufacturing method according to claim 5, characterized in that: In step S1, the multi-layer braided layer is selected from online braiding production molding or pre-braiding molding.

7. The manufacturing method according to claim 6, characterized in that: The winding layer is axially laid or radially rotated and wound.

8. The manufacturing method according to claim 6, characterized in that: In step S2, acupuncture suturing is performed in groups, one after another on the production line or as a group on the pipe section, to suturing the reinforcement.

9. The manufacturing method according to claim 5, characterized in that: In step S3, the dipping method is vacuum dipping.

10. The manufacturing method according to claim 5, characterized in that: In step S4, the molding is carried out by external heating, which is divided into three stages: preheating stage, gel stage and curing stage, and the molding temperatures are set respectively for the three stages.

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