Manufacturing method of epoxy enhanced power supply rail insulation support

Abstract

The invention provides a manufacturing method of an epoxy glass fiber reinforced power supply rail insulating bracket. The manufacturing method comprises the following steps: step 1, mixing and preparing an epoxy resin glue solution; 2, preparing a reinforcing material; step 3, dipping treatment; step 4, carrying out preforming; 5, the preformed product is subjected to forming machining; and 6, traction, cutting and profile drilling are conducted. According to the stent prepared by the invention, each fiber uniformly bears load, the bending strength of the epoxy reinforced composite material is higher, and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to an epoxy-reinforced power supply rail insulating bracket, and particularly to a manufacturing method of an epoxy-reinforced power supply rail insulating bracket. Background Art

[0002] The insulator material for supporting the contact rail part is made of sheet molding compound (SMC). The main raw materials of this material consist of special yarn (GF), unsaturated resin (uP), low shrinkage additive, filler (MD) and various additives. This material has excellent electrical insulation performance, mechanical performance, thermal stability and chemical corrosion resistance. Currently, there are two types of mounting brackets for the under-contact installation method of contact rails commonly used internationally. One is the integral insulating bracket made of fiberglass material commonly used in China at present, and the other is the insulating steel bracket with carbon steel and insulators. The main material of the insulating steel bracket is carbon steel Q235, and its overall mechanical performance is better than that of the integral insulating bracket. At present, both domestic and foreign insulating brackets adopt the SMC compression molding process. During the localization process of insulating brackets, in order to overcome the disadvantage of insufficient mechanical properties of SMC insulating brackets under special working conditions, foreign countries have carried out strengthened design of steel structures at the bottom of the brackets.

[0003] At present stage, insulating brackets adopt glass fiber reinforced unsaturated polyester molding compound (SMC), that is, sheet molding compound, a kind of fiberglass compression molding composite material. The carboxyl group at the end of the unsaturated polyester chain can react with alkaline earth metal oxides or hydroxides [such as MgO, CaO, Ca(OH)2, etc.], so that the unsaturated polyester molecular chain expands, and finally a complex may be formed. The chopped glass fibers are fully impregnated with resin paste and formed into a sheet-like composite material by mechanical rolling until it becomes a non-flowing and non-sticky gel-like substance. When the resin is in this state, it is not cross-linked and can still be dissolved in a suitable solvent, and has good fluidity when heated. The insulating bracket is formed by putting the pre-mixed or pre-impregnated fibrous molding compound into a metal mold and cross-linking and curing it under certain temperature and pressure.

[0004] SMC insulating brackets adopt thermosetting plastics. The production must strictly control the reaction temperature and time. Even under the best reaction temperature and time conditions, the curing reaction is difficult to complete completely. At the same time, SMC insulating brackets adopt randomly distributed chopped fibers, and it is difficult for the fibers to be evenly distributed during the compression molding process. Therefore, the mechanical properties have large discreteness and it is difficult to control the quality. During the production process, defects such as serious surface cracks, micro-cracks, burning, and sand holes are also likely to occur. Summary of the Invention

[0005] To solve the above problems, the present invention discloses a manufacturing method of an epoxy-reinforced power supply rail insulating bracket. Each fiber bears a small load, and the epoxy-reinforced composite material has a higher bending strength and an extended service life.

[0006] A manufacturing method of an epoxy - enhanced power supply rail insulation bracket, comprising the following steps:

[0007] Step 1: Mix and prepare epoxy resin adhesive;

[0008] Step 2: Prepare the reinforcing felt material; the reinforcing felt material includes four layers. The first layer is a chopped fiber layer, the second layer is a transverse fiber layer, the third layer is a longitudinal fiber layer; the fourth layer is a polyester surface layer. After these four layers are pressed together, they are densely stitched together with polyester thread;

[0009] Step 3: Fiber impregnation; adopt layered impregnation;

[0010] Step 4: Pre - forming;

[0011] Step 5: Product molding in a mold;

[0012] Step 6: Traction, cutting, and profile drilling.

[0013] Further, for the mixing and preparation of epoxy resin adhesive: First, add a curing agent into the barrel, with a viscosity of 40 - 140 cps; then add resin, with a viscosity of 7000 - 14000 cps; subsequently, add a release agent. The rotation speed of the stirring paddle starts at 100 revolutions per minute (r / min), and after 10 minutes, it is increased to 1000 r / min and maintained for 10 min; the total stirring time is 20 min, and then the stirring operation ends.

[0014] Further, the specific steps of the pre - forming in Step 4 include

[0015] a. According to the structural characteristics of the product, set 3612 O° reinforcing fibers along the pultrusion direction, with a tension of 5 N - 6 N and a speed of 6 - 8 cm / min to meet the force requirement of the product in the line direction;

[0016] b. At the same time, arrange the reinforcing felt. Four layers of reinforcing felt are arranged in the lower layer along the pultrusion direction, and the width of the reinforcing felt is 75 cm; it is lapped on the reinforcing fiber and fixed into the mold along the lower felt groove to ensure the force requirement of the product in the tensile direction;

[0017] c. Two layers of reinforcing felt are arranged in the upper layer along the pultrusion direction. One layer has a width of 88 cm and the other layer has a width of 85 cm; it is lapped on the reinforcing fiber and fixed into the mold along the upper felt groove to ensure the force requirement of the product in the compressive direction;

[0018] d. One layer of the middle - layer reinforcing felt is arranged in a circular shape, and it enters the mold along the middle felt groove and is wrapped around in a circular shape in the middle to ensure the vertical force requirement of the product.

[0019] This application uses short fiber laminates, which can enable the overall fiber cloth to have good adhesion with the longitudinally pultruded fibers, and at the same time enable the product to have good tolerance in multiple directions; the transverse fiber layer provides the transverse tolerance of the product and enhances the transverse mechanical properties of the product; the longitudinal fiber layer provides the pulling force of the overall fiber mat, avoiding the situation where the fiber mat is torn due to high fiber content during die extrusion; the surface polyester layer can enable the product surface to have a uniform resin layer and improve the anti-ultraviolet aging ability of the product during outdoor use.

[0020] Further, the impregnation tank in the impregnation step 3 needs to adopt a two-layer structure, including a support frame, wherein an upper impregnation tank is provided at the upper part of the support frame and a lower impregnation tank is provided at the lower end; fiber conveying perforated plates are provided at both the left and right ends of the upper impregnation tank and the lower impregnation tank. The number of longitudinal fiber strands is very large, and it is necessary to consider both production sustainability and product quality stability at the same time; and ensure that the fibers can be fully impregnated; therefore, a two-layer impregnation method is adopted.

[0021] Further, the preforming needs to be specially designed for product preforming; the surface felting process is carried out, and through simulation optimization, it is determined that the lower felt is 4 layers, the upper felt is 2 layers, and the felt process of the hollow mandrel being completely wrapped. The short fiber laminate can enable the overall fiber cloth to have good adhesion with the longitudinally pultruded fibers, and at the same time enable the product to have good tolerance in multiple directions.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. Each fiber of the insulating support evenly bears the load, and the epoxy reinforced composite material has a higher bending strength, extending the service life;

[0024] 2. Improve the anti-ultraviolet aging ability of the product during outdoor use;

[0025] 3. The shape of the product is designed with a middle hollow, and the transverse strength of the product is improved.

[0026] 4. Therefore, the double-layer design of the impregnation tank meets the impregnation requirements while avoiding the increase in viscosity caused by excessive placement of the glue solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 - Structural schematic diagram of an epoxy reinforced power supply rail insulating support of the present invention;

[0028] Figure 2 - Schematic diagram of the stress direction principle of the product of the present invention;

[0029] Figure 3 - Structural schematic diagram of the impregnation tank of the present invention;

[0030] Figure 4 - Weaving diagram of the fiber cloth / felt of the present invention;

[0031] Figure 5 , Flow chart of preforming of the present invention;

[0032] Figure 6 , Schematic structural diagram of the forming die of the present invention. Detailed implementation manners

[0033] The present invention will be further clarified below in conjunction with the accompanying drawings and specific implementation manners. It should be understood that the following specific implementation manners are only used to illustrate the present invention and not to limit the scope of the present invention. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the accompanying drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0034] This embodiment provides a method for manufacturing an epoxy-reinforced power supply rail insulating bracket, including the following steps:

[0035] Step 1: Mixing and preparing epoxy resin adhesive; Mixing and preparing epoxy resin adhesive: First add a curing agent into a barrel, with a viscosity of 40 - 140 cps; then add resin, with a viscosity of 7000 - 14000 cps; subsequently add a release agent, and the rotation speed of the stirring paddle starts from 100 revolutions per minute (r / min), and is increased to 1000 r / min after 10 minutes, and continues for 10 min; stir for a total of 20 min to end the stirring operation.

[0036] Step 2: Preparing the reinforcing felt material; The reinforcing felt material includes four layers. The first layer is a chopped fiber layer, the second layer is a transverse fiber layer, the third layer is a longitudinal fiber layer; the fourth layer is a polyester surface layer; after these four layers of structures are pressed together, they are densely stitched together with polyester thread;

[0037] Step 3: Fiber impregnation; Adopt layered impregnation; In the impregnation tank in the impregnation step of Step 3, a two-layer structure is required, including a support frame 1, wherein an upper impregnation tank 2 is provided at the upper part of the support frame 1 and a lower impregnation tank 3 is provided at the lower end; fiber conveying perforated plates are provided at the left and right ends of the upper impregnation tank 2 and the lower impregnation tank 4.

[0038] Step 4: Preforming; The preforming in Step 4 specifically includes

[0039] a. According to the structural characteristics of the product, arrange 3612 O° reinforcing fibers along the pultrusion direction, with a tension of 5 N - 6 N and a speed of 6 - 8 cm / min to meet the force requirement of the product in the line direction;

[0040] b. At the same time, arrange the reinforcing felt. Four layers of reinforcing felt are arranged in the lower layer along the pultrusion direction, and the width of the reinforcing felt is 75 cm; it is lapped on the reinforcing fiber and fixed into the mold along the lower felt groove to ensure the force requirement of the product in the tensile direction;

[0041] c. Arrange 2 layers of reinforcing felts on the upper layer along the pultrusion direction, with one layer having a width of 88 cm and the other layer having a width of 85 cm; lap on the reinforcing fibers and fix them into the mold along the upper felt groove to ensure the force requirement of the product in the compression direction;

[0042] d. Arrange one layer of the intermediate reinforcing felt in a circular shape, feed it into the mold along the intermediate felt groove, and wrap it circumferentially in the middle to ensure the vertical force requirement of the product.

[0043] Step 5: Molding of the product mold;

[0044] Step 6: Traction, cutting, and drilling of profiles.

[0045] Among them, the preforming needs to be specially designed during the product preforming; perform the surface felting process, and through simulation optimization, it is determined that there are 4 layers of lower felts and 2 layers of upper felts, and the felt process of the short fiber laying with the hollow mandrel completely wrapped can make the overall fiber cloth have a good adhesion force with the longitudinal pultruded fibers, and at the same time make the product have good tolerance in multiple directions.

[0046] As shown in Examples 1 and 2 of this embodiment, for the product and the force direction of this embodiment, proceed;

[0047] Through tests, the failure load in the vertical direction and the horizontal along-line direction is above 9 kN, and the failure load in the horizontal perpendicular-line direction is above 15 kN. The overall mechanical properties reach the level of the insulating bracket made of Q235B steel material, and at the same time, the insulation performance is excellent.

[0048]

[0049]

[0050] Comparison of material test data

[0051] Data analysis:

[0052] The epoxy-reinforced insulating bracket adopts the integrated molding process of epoxy resin-based glass fiber pultrusion + braided layer. The glass fiber mainly plays a reinforcing role. The performance of the composite material used in the insulating bracket is affected by the production process level. The epoxy-reinforced power supply rail insulating bracket disperses the continuous glass fiber filaments evenly in the thermoplastic resin through the pultrusion process. By optimizing the ply design, such as the ply angle and ply thickness of the surface braided layer, the performance of the insulating bracket is enhanced.

[0053] The epoxy-reinforced power supply rail insulation bracket is a thermoplastic material. Generally, the higher the glass fiber content and the more uniform the distribution, the better the mechanical properties. Currently, traditional brackets are formed by SMC molding of E-glass fiber and unsaturated polyester resin (Usaturated Po lyester, abbreviated as UPE). As a resin with low price and wide commercial application, its advantage lies in its low cost and good processing fluidity. However, it has low heat resistance, poor mechanical properties and weather resistance, and also has a large shrinkage during the curing process. Unsaturated polyester resin will undergo a cross-linking curing reaction when exposed to a certain temperature. The temperature parameter has a great influence on the performance of the insulation bracket. If the temperature is too high, the curing reaction will occur before the material is filled into the mold. If the temperature is too low, the curing reaction is incomplete, seriously affecting the service performance of the insulation bracket. At the same time, it is very difficult to achieve complete curing degree of the resin.

[0054] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A method for manufacturing an epoxy glass fiber reinforced power rail insulation bracket, characterized in that: The following steps are involved: Step 1: Mix and prepare epoxy resin glue; Step 2: preparing a reinforced felt material; The reinforced felt material consists of four layers: the first layer is a chopped fiber layer, the second layer is a transverse fiber layer, the third layer is a longitudinal fiber layer; the fourth layer is a polyester surface layer; these four layers are pressed together and tightly sewn together with polyester thread; Step 3: Fiber impregnation: layered impregnation; Step 4: Preforming; Step 5: Product mold forming; Step 6: Pulling, cutting, and drilling of profiles.

2. The method for manufacturing an epoxy glass fiber reinforced power rail insulation bracket according to claim 1, characterized in that: Mixing and preparation of epoxy resin glue: first add curing agent into the barrel, viscosity: 40-140cps; then add resin, viscosity: 7000-14000cps; then add release agent, the stirring paddle speed starts from 100 rpm, and after 10 minutes, it speeds up to 1000 rpm, and continues for 10 minutes; stir for a total of 20 minutes, and then end the stirring operation.

3. The method for manufacturing an epoxy glass fiber reinforced power rail insulation bracket according to claim 1, characterized in that: The preforming step 4 specifically includes a. According to the structural characteristics of the product, 3612 O° reinforcing fibers are set along the pultrusion direction; the tension is 5N-6N, and the speed is 6-8cm / min to meet the force requirements of the product along the line direction; b. Arrange reinforcing felt at the same time. Arrange four layers of reinforcing felt in the lower layer along the pultrusion direction. The width of the reinforcing felt is 75cm. Overlap the reinforcing fiber and fix it into the mold along the lower felt groove to ensure the force requirements of the product in the tensile direction. c. Two layers of reinforcing felt are arranged on the upper layer along the pultrusion direction, one layer is 88cm wide and the other is 85cm wide; overlap on the reinforcing fiber and fix into the die along the upper felt groove to ensure the force requirements of the product in the compressive direction; d. The middle layer of reinforcing felt is arranged in a ring shape, fed into the mold along the middle felt groove, and wrapped in the middle ring to ensure the vertical force requirements of the product.

4. The method for manufacturing an epoxy glass fiber reinforced power rail insulation bracket according to claim 1, characterized in that: The dipping tank in the dipping process of step 3 needs to adopt a two-layer structure, comprising a support frame (1), wherein an upper dipping tank (2) is provided at the upper part of the support frame (1) and a lower dipping tank (3) is provided at the lower end; and fiber conveying orifice plates are provided at both left and right ends of the upper dipping tank (2) and the lower dipping tank (4).

5. The method for manufacturing an epoxy glass fiber reinforced power rail insulation bracket according to claim 1, characterized in that: The preforming needs to be specially designed during product preforming; a surface felting process is performed, and after simulation optimization, it is determined that the lower felt is 4 layers, the upper felt is 2 layers, and the hollow core rod is completely wrapped with a felt process.

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