Resin fiber profile with functional coating and preparation method thereof

Abstract

The invention discloses a resin fiber profile with a functional coating, which is composed of a body and the functional coating, and the body and the functional coating are formed by sequentially injecting glue and then integrally curing. The preparation method adopts two times of glue injection; the first glue injection is a mixture of body resin and a curing agent, and closed-mold pultrusion glue injection or open type glue dipping is adopted; a functional resin and curing agent batch is injected for the second time, and mold-closing pultrusion glue injection is adopted; and after glue injection is sequentially carried out twice, the composite material synchronously enters a mold to be cured, and finally one-time curing forming is carried out. Interpenetration exists in the interface of the functional coating and the body, the combination degree of the functional coating and the body is good, layer separation is not prone to being generated, and the advantages of being high in production efficiency and low in cost are achieved.

Description

Technical Field

[0001] The invention relates to a resin fiber material pultrusion product and a preparation method thereof, in particular to a one-time pultrusion technology of a functional coating and a resin fiber profile. Background Art

[0002] Conventional closed-die pultrusion process for resin fiber composite materials (see Figure 1 ), the specific process is: first, the reinforcing fiber passes through the yarn guide plate; then the reinforcing fiber is dipped in glue through the glue injection box; after the dipping is completed, it is heated and cured in the mold; the cured profile is sent to the cutting machine through the traction machine and cut according to demand. The traction power of the entire production process comes from the traction machine. During the pultrusion process, only one type of injection resin product can be formed at a time, such as epoxy resin pultrusion products, vinyl resin pultrusion products, polyurethane resin pultrusion products, etc.

[0003] Usually, the closed-die pultrusion process first designs the fiber content and layer structure (fiber + fabric) according to the product size and mechanical property requirements; the fibers and fabrics that meet the layer design requirements enter the closed-die pultrusion mold (including pre-forming cold mold + curing mold) for pultrusion, during which a resin (epoxy resin, unsaturated polyester resin, vinyl resin, polyurethane resin, phenolic resin and other types of curable liquid resins) is injected.

[0004] The traditional open pultrusion process of resin fiber composite materials is that the reinforcing fiber, under the action of the traction machine, passes through the open glue tank for dipping, cold mold for extrusion, and mold heating and curing to form a resin fiber composite material. The specific process is: first, the reinforcing fiber passes through the yarn guide plate; then the reinforcing fiber passes through the open glue tank for dipping; after the dipping is completed, the excess glue is squeezed out through the cold mold, and then the mold is heated and cured; the cured profile is sent to the cutting machine through the traction machine and cut according to demand. The traction power of the entire production process comes from the traction machine. During the pultrusion process, only one type of injection resin product can be formed at a time, and the open dip pultrusion process is applicable to a small range of resins. It is not applicable to resins with high requirements for the use environment, such as polyurethane resin. Polyurethane resin has strict requirements on moisture in the air, mainly because water will affect the curing reaction activity of polyurethane resin. Therefore, it is not suitable to use the open dip pultrusion process to produce polyurethane composite materials.

[0005] For resin fiber profiles used in special places, they need to have specific functionalities, such as heat resistance, corrosion resistance, UV resistance, conductivity, flame retardancy and other characteristics. There are generally two production methods for such resin fiber profiles with specific functional requirements. The first is to modify the resin to give the resin various special functions, and then use these functional resins to produce composite materials through the traditional closed-die pultrusion process. The cost of the resin used in this method is too high, and the cost of the molded profile is high. The second is to use ordinary resin to produce resin fiber profiles according to the traditional closed-die pultrusion process, and then secondary process the surface of the resin fiber profile to give the surface of the resin fiber profile a functional coating, such as heat resistance, corrosion resistance, UV resistance, conductivity, flame retardancy and other material coatings, so that the resin fiber profile has specific functionality. For example, the Chinese invention patent "Online coating device for polyurethane pultrusion composite materials" (patent number 202010148903.X) discloses the mold and coating method of the above-mentioned secondary processing coating, which coats the pultruded and cured profile through a mold with an elastic section. However, this process method requires secondary processing of the resin fiber profile, which increases the production links, increases the production cost and reduces the efficiency. In addition, there are problems with the adhesion between the surface functional coating and the resin fiber profile, resulting in delamination. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art and propose a resin fiber profile with a functional coating, wherein the surface functional coating and the profile body are formed by secondary injection and primary pultrusion curing, so that the functional coating of the profile and the profile have a certain interlayer penetration during the curing process, and the functional coating and the profile body have better integration.

[0007] The present invention is a novel pultrusion process method implemented for pultruded composite material products that need to add functional coatings. A closed-die pultrusion molding process or a mixed process of open-die pultrusion and closed-die pultrusion is adopted, and two injections are performed. The resins of the two injections are different. The first injection is a bulk resin that meets the mechanical properties and basic performance requirements of the product. The second injection resin is a functional resin that meets the special surface performance requirements of the product, such as appearance, corrosion resistance, UV resistance, heat resistance, conductivity, wear resistance, etc. The two resins have affinity and can achieve synergistic curing. There is no need to add expensive release oil that affects performance to the first injection resin. It only needs to be added to the second injection resin, which is conducive to release from the mold.

[0008] For the closed-mold pultrusion process, the design of the pultrusion cavity should be noted. The cavity for the first injection is slightly smaller, smaller than the size of the final product, and the shape is exactly the same. After the second injection, the cavity becomes larger to the size of the final product, and it is ensured that the second layer of functional coating can completely wrap the pultruded product inside the first injection and the interface performance is excellent, while meeting the shape and size requirements of the final product. In addition, during production, the pressure of the second injection is slightly greater than the pressure of the first injection to ensure that the second injection resin can fully cover the surface of the product.

[0009] For the open-die pultrusion and closed-die pultrusion hybrid process, the order of the two dipping processes is first through the open-die pultrusion glue tank and then through the closed-die glue injection. There is a cold mold between the two dipping processes. The cavity size of the cold mold is slightly smaller than that of the closed-die mold, and the shapes are exactly the same.

[0010] The technical solution adopted by the present invention to achieve the purpose of the invention is as follows: A resin fiber profile with a functional coating is composed of a body and a functional coating, wherein the functional coating is coated on the outer surface of the body. The characteristic is that the body and the functional coating are integrally solidified after sequentially injecting glue.

[0011] There is a permeation layer between the body and the functional coating, and the permeation layer is formed by mutual permeation of the body material and the functional coating material before solidification.

[0012] A method for preparing a resin fiber profile with a functional coating is characterized by: using two injections; the first injection is a mixture of a bulk resin and a curing agent, using closed-die pultrusion injection or open-die dipping; the second injection is a mixture of a functional resin and a curing agent, using closed-die pultrusion injection; after the two injections are performed in sequence, the composite material simultaneously enters a mold for curing, and is finally cured and formed in one step.

[0013] Both injections are made by closed mold pultrusion injection, which is characterized in that the injection box used is divided into a first injection cavity and a second injection cavity. In order to ensure that the second functional coating can completely and evenly wrap the first injected body injection resin, the second injection cavity is slightly larger than the first injection cavity. Therefore, the first injection cavity is smaller than the final size of the profile, and the difference between the two sizes is the set functional coating thickness. The size of the second injection cavity is the final size of the profile. During production, the second injection pressure is slightly greater than the first injection pressure to ensure that the second injection resin can fully cover the product surface. After two injections, the composite material enters the mold synchronously for curing. The curing process is designed according to the different two resins, including injection pressure, curing temperature, pultrusion speed, etc., and finally cured and formed in one time.

[0014] The two injections are open-type dipping and closed-die pultrusion injection, respectively. The first injection is open-type dipping, and then passes through a cold mold. The cavity size of the cold mold is slightly smaller than that of the closed mold mold, and the shape is exactly the same; the second injection is closed-die pultrusion injection, and the cavity size is slightly larger than the product size. The curing process is designed according to the two different resins, including injection pressure, curing temperature, pultrusion speed, etc., and finally cured and formed in one time.

[0015] The second injection resin is based on the requirements of the material's intended use, such as corrosion-resistant polyurethane resin, heat-resistant epoxy resin, conductive epoxy resin and other resins with special functions.

[0016] The resin fiber profile with functional coating of the present invention has mutual penetration at the interface between the functional coating and the body, the two have good bonding, are not easy to be delaminated, and have excellent interface performance. The preparation method provided has the advantages of high production efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the closed-die pultrusion process flow of the prior art; Figure 2 It is a schematic diagram of the internal structure of the closed-die pultrusion injection box and the die used in the present invention; Figure 3 It is a schematic flow chart of a closed-die pultrusion preparation method of a resin fiber profile with a functional coating according to the present invention; Figure 4 The present invention is a schematic flow chart of a method for preparing a resin fiber profile having a functional coating by a mixed process of open die pultrusion and closed die pultrusion. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0019] A polyurethane resin-glass fiber composite material profile with a UV-resistant surface was prepared. The specific parameters of the profile were a rectangle with a cross-sectional size of 5*120 mm, a length of 3.0 m, and a UV-resistant coating thickness of 0.5 mm.

[0020] The mold size used for preparation is: 1200mm long, the first injection port ( Figure 2 The position of the second injection port ( Figure 2 The position of (202) is 400 mm from the mold inlet, the mold cross-sectional dimensions between the first injection port and the second injection port are 4.17 mm*119.2 mm, and the mold cross-sectional dimensions between the second injection port and the mold outlet are 5.17 mm*120.2 mm.

[0021] The specific process is as follows: (1) Under the traction of the traction machine, the reinforced glass fiber first passes through the first injection port. The first injected resin is a polyol compound (the main agent is polyether polyol), and the curing agent is an isocyanate compound (the main agent is diphenylmethane diisocyanate). The weight ratio of the resin and the curing agent is 100: (110-120), and the first injection pressure is 0.5MPa. (2) After passing through the first injection port, the glass fiber is soaked by the mixture of resin and curing agent, and then passes through the second injection port. The second injected resin is a UV-resistant polyurethane resin compound (the main agent is polyether polyol), and the curing agent is a UV curing agent compound (the main agent is aliphatic isocyanate). The weight ratio of the resin and the curing agent is 100: (110-120), and the second injection pressure is 0.7MPa. (3) After passing through the second injection port, the surface of the reinforced fiber is soaked by the corrosion-resistant resin and curing agent mixture, and then heated and cured by the mold. (4) The cured glass fiber composite material is cut into 3m lengths by a cutting machine to obtain a UV-resistant polyurethane resin composite material that meets the UV resistance requirements of the pultruded composite surface. The specific test data are: Test items Performance Data Test Standards Fiber volume content% 71.3 ISO 1172 UV irradiation resistance tensile strength retention rate % 90 ISO 4892 and ISO 527 Tensile strength MPa 1394.9 ISO 527 Tensile modulus GPa 64.2 ISO 527 Compression strength MPa 1298.6 ISO 14126 Compression modulus GPa 63.7 ISO 14126

[0022] Embodiment 2: A high temperature resistant composite material, wherein the surface layer is a high temperature resistant epoxy resin and the body is a common epoxy resin, that is, an epoxy resin-glass fiber composite material profile having a high temperature resistant functional coating.

[0023] An epoxy resin-glass fiber composite material profile with a surface having high temperature resistance requirements is prepared. The specific parameters of the profile are a rectangle with a cross-sectional size of 5*120 mm, a length of 3.0 m, and a high temperature resistant coating thickness of 0.5 mm.

[0024] The mold used to prepare the product is the same as in Example 1.

[0025] The specific process is as follows: (1) Under the traction of the traction machine, the reinforced glass fiber first passes through the first injection port. The first injection resin is a common epoxy resin compound (the main agent is E51 epoxy resin), and the curing agent is an acid anhydride curing agent compound (the main agent is methyltetrahydrophthalic anhydride curing agent). The weight ratio of the resin to the curing agent is 100: (80-90), and the first injection pressure is 0.5MPa. (2) After passing through the first injection port, the glass fiber is soaked by the mixture of resin and curing agent, and then passes through the second injection port. The second injection resin is a high-temperature resistant epoxy resin compound (the main agent is a tetrafunctional heat-resistant epoxy resin), and the curing agent is a high-temperature resistant curing agent compound (the main agent is dicyandiamide). The weight ratio of the resin to the curing agent is 100: (80-90), and the second injection pressure is 0.7MPa. (3) After passing through the second injection port, the surface of the reinforced fiber is soaked by the mixture of high-temperature resistant epoxy resin and curing agent, and then heated and cured by the mold. (4) The cured glass fiber composite material is cut into 3m lengths by a cutting machine to obtain a high-temperature resistant epoxy resin composite material, which meets the high-temperature resistance requirements of the pultruded composite material surface. The specific test data are: Test items Performance Data Test Standards Fiber volume content% 70.3 ISO 1172 Surface material Tg ℃ 190.6 ISO 11357-2 Tensile strength MPa 1351.2 ISO 527 Tensile modulus GPa 63.2 ISO 527 Compression strength MPa 1273.6 ISO 14126 Compression modulus GPa 62.9 ISO 14126

[0026] An epoxy resin-glass fiber composite material profile with a surface having corrosion resistance requirements is prepared. The specific parameters of the profile are a rectangular cross-sectional size of 5*120 mm, a length of 3.0 m, and a high-temperature resistant coating thickness of 0.5 mm.

[0027] The mold used to prepare the product is the same as in Example 1.

[0028] The specific process is as follows: (1) Under the traction of the traction machine, the reinforced glass fiber first passes through the first injection port. The first injection resin is a common epoxy resin compound (the main agent is E51 epoxy resin), and the curing agent is an acid anhydride curing agent compound (the main agent is methyltetrahydrophthalic anhydride curing agent). The weight ratio of the resin and the curing agent is 100: (80-90), and the first injection pressure is 0.5MPa. (2) After passing through the first injection port, the glass fiber is impregnated with the mixture of resin and curing agent, and then passes through the second injection port. The second injection resin is a corrosion-resistant modified epoxy resin compound (the main agent is tung oil modified epoxy resin), and the curing agent is an acid anhydride curing agent compound (the main agent is methyltetrahydrophthalic anhydride curing agent). The weight ratio of the resin and the curing agent is 100: (80-90), and the second injection pressure is 0.7MPa. (3) After passing through the second injection port, the surface of the reinforced fiber is impregnated with the mixture of corrosion-resistant tung oil modified epoxy resin and curing agent, and then heated and cured by the mold. (4) The cured glass fiber composite material is cut into 3m lengths by a cutting machine to obtain a corrosion-resistant epoxy resin composite material that meets the surface corrosion resistance requirements of the pultruded composite material. The specific test data are: Test items Performance Data Test Standards Fiber volume content% 69.8 ISO 1172 Salt spray resistance No abnormality in appearance ASTM B117 Tensile strength MPa 1329.7 ISO 527 Tensile modulus GPa 63.1 ISO 527 Compression strength MPa 1252.7 ISO 14126 Compression modulus GPa 62.5 ISO 14126

[0029] A vinyl-epoxy resin glass fiber composite material profile with conductive properties on the surface was prepared. The specific parameters of the profile were a rectangle with a cross-sectional size of 5*120 mm, a length of 3.0 m, and a thickness of 0.5 mm for the epoxy conductive resin coating.

[0030] The mold used for preparation is the same as that in Example 1.

[0031] The specific process is as follows: (1) Under the traction of the traction machine, the reinforced glass fiber first passes through the first injection port. The first injection resin is a common epoxy resin compound (the main agent is E51 epoxy resin), and the curing agent is an acid anhydride curing agent compound (the main agent is methyltetrahydrophthalic anhydride curing agent). The weight ratio of the resin and the curing agent is 100: (80-90), and the first injection pressure is 0.5MPa. (2) After passing through the first injection port, the glass fiber is impregnated with the resin mixture and then passes through the second injection port. The second injection resin is a conductive epoxy-vinyl resin compound (the main agent is a modified conductive epoxy-vinyl resin), and the curing agent is an acid anhydride compound (the main agent is methyltetrahydrophthalic anhydride curing agent). The weight ratio of the resin and the curing agent is 100: (80-90), and the second injection pressure is 0.7MPa. (3) After passing through the second injection port, the surface of the reinforced fiber is impregnated with the conductive modified conductive epoxy-vinyl resin and the curing agent mixture, and then heated and cured by the mold. (4) The cured glass fiber composite material is cut into 3m lengths by a cutting machine to obtain a surface conductive epoxy resin composite material that meets the surface conductivity requirements of the pultruded composite material. The specific test data are: Test items Performance Data Test Standards Fiber volume content% 71.4 ISO 1172 Surface resistivity Ω 112 GB / T 1410 Tensile strength MPa 1385.1 ISO 527 Tensile modulus GPa 64.6 ISO 527 Compression strength MPa 1288.4 ISO 14126 Compression modulus GPa 63.4 ISO 14126

[0032] An unsaturated resin glass fiber composite material profile with flame retardant surface performance is prepared. The specific parameters of the profile are a rectangle with a cross-sectional size of 5*120 mm, a length of 3.0 m, and a flame retardant conductive resin coating thickness of 0.5 mm.

[0033] The mold used for preparation is the same as that in Example 1.

[0034] The specific process is as follows: (1) Under the traction of the traction machine, the reinforced glass fiber first passes through the first injection port. The first injected resin is an unsaturated polyester resin compound (the main agent is S901 resin), the curing agent is a dibenzoyl peroxide compound (the main agent is dibenzoyl peroxide), the weight ratio of the resin to the curing agent is 100: (1-2), and the first injection pressure is 0.5MPa. (2) After passing through the first injection port, the glass fiber is soaked in the resin mixture and then passes through the second injection port. The second injected resin is a flame retardant unsaturated polyester resin compound (the main agent is flame retardant polyester resin), the curing agent is a methyl ethyl ketone peroxide compound (the main agent is methyl ethyl ketone peroxide), the weight ratio of the resin to the curing agent is 100: (1-2), and the second injection pressure is 0.7MPa. (3) After passing through the second injection port, the surface of the reinforced fiber is soaked in the flame retardant unsaturated resin and curing agent mixture, and then heated and cured by the mold. (4) The cured glass fiber composite material is cut into 3m lengths by a cutting machine to obtain a flame-retardant unsaturated polyester resin composite material that meets the flame retardancy requirements of pultruded composite materials. The specific test data are: Test items Performance Data Test Standards Fiber volume content% 71.2 ISO 1172 Limiting oxygen index% (V / V) 43.6 GB / T 8924 Tensile strength MPa 1365.6 ISO 527 Tensile modulus GPa 64.1 ISO 527 Compression strength MPa 1272.4 ISO 14126 Compression modulus GPa 63.3 ISO 14126

[0035] Example 6: A high temperature resistant composite material, the surface layer is a high temperature resistant epoxy resin, and the body is a common epoxy resin, that is, an epoxy resin-glass fiber composite material profile with a high temperature resistant functional coating.

[0036] An open-die pultrusion and closed-die pultrusion hybrid process was used to prepare epoxy resin-glass fiber composite material profiles with high temperature resistance requirements on the surface. The specific parameters of the profiles were a rectangular cross-sectional size of 5*120mm, a length of 3.0m, and a high temperature resistant coating thickness of 0.5mm.

[0037] The cross-sectional dimensions of the cold mold cavity are 4.17mm*119.2mm; the dimensions of the closed mold pultrusion mold are: 1200mm long and 5.17mm*120.2mm cross-sectional dimensions.

[0038] The specific process is as follows: (1) Under the traction of the traction machine, the reinforced glass fiber first passes through an open dipping tank, in which there is a mixture of ordinary epoxy resin and curing agent, wherein the ordinary epoxy resin compound (the main agent is E51 epoxy resin) and the curing agent are acid anhydride curing agent compounds (the main agent is methyltetrahydrophthalic anhydride curing agent), and the weight ratio of the resin to the curing agent is 100: (80-90). (2) After passing through the dipping tank, the glass fiber is impregnated with the mixture of resin and curing agent, and then passes through a cold mold to squeeze out the excess mixture. (3) After the cold mold extrusion, the fiber impregnated with resin then enters the second injection mold. The resin injected for the second time is a high-temperature resistant epoxy resin compound (the main agent is a tetrafunctional heat-resistant epoxy resin), and the curing agent is a high-temperature resistant curing agent compound (the main agent is dicyandiamide), and the weight ratio of the resin to the curing agent is 100: (80-90). The secondary injection pressure is 0.7MPa. (4) After passing through the second injection port, the surface of the reinforcing fiber is infiltrated with a mixture of high-temperature resistant epoxy resin and curing agent, and then heated and cured by the mold. (5) The cured glass fiber composite material is cut into 3m lengths by a cutting machine to obtain a high-temperature resistant epoxy resin composite material that meets the high-temperature resistance requirements of the pultruded composite material surface. The specific test data are: Test items Performance Data Test Standards Fiber volume content% 70.6 ISO 1172 Surface material Tg ℃ 192.1 ISO 11357-2 Tensile strength MPa 1321.6 ISO 527 Tensile modulus GPa 63.6 ISO 527 Compression strength MPa 1289.7 ISO 14126 Compression modulus GPa 63.1 ISO 14126

Claims

1. A resin fiber profile with a functional coating, consisting of a body and a functional coating, wherein the functional coating is coated on the outer surface of the body; characterized in that: The main body and the functional coating are integrally solidified after sequentially injecting glue.

2. The resin fiber profile with functional coating according to claim 1, characterized in that: A permeation layer is provided between the bulk and the functional coating.

3. The resin fiber profile with functional coating according to claim 2, characterized in that: The permeation layer is formed by mutual permeation of the bulk material and the functional coating material before solidification.

4. A method for preparing the resin fiber profile with functional coating according to claim 1, 2 or 3, characterized in that: Two injections are used; the first injection is a mixture of bulk resin and curing agent, using closed mold pultrusion injection or open mold dipping; the second injection is a mixture of functional resin and curing agent, using closed mold pultrusion injection; after two injections in sequence, the composite material simultaneously enters the mold for curing, and finally is cured and formed in one step.

5. The method for preparing a resin fiber profile having a functional coating according to claim 4, characterized in that: Both injections are made by closed mold pultrusion. The injection box used is divided into a first injection cavity and a second injection cavity. The second injection cavity is larger than the first injection cavity, and the size difference between the two depends on the thickness of the functional coating. The second injection pressure is greater than the first injection pressure to ensure that the second injection resin covers the product surface. After two injections in sequence, the composite material simultaneously enters the mold for curing, and finally is cured and formed in one step.

6. The method for preparing a resin fiber profile having a functional coating according to claim 4, characterized in that: The first glue injection is open-type dipping, and then it passes through a cold mold. The cavity size of the cold mold is smaller than that of the closed mold, and the shape is exactly the same. The size difference between the two depends on the thickness of the functional coating; the second glue injection is closed-type pultrusion injection; and the final curing is performed once.

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