Caprolactam resin glass fiber composite molding material and production process and device thereof

Abstract

The invention relates to the technical field of composite material molding, and discloses a caprolactam resin glass fiber composite molding material, which at least contains polycaprolactam and fiber material sheets, the fiber material sheets are cross glass fibers, and the polycaprolactam is thermoplastic plastic; according to the mass percentage, the content of the crisscross glass fiber is 23%-60%; the invention further discloses a production process of the caprolactam resin and glass fiber composite molding material. The caprolactam resin and glass fiber composite molding material provided by the invention can be applied to the field of thin-wall parts such as automobile sealing covers and automobile lower trays, the tensile strength can reach 292.37 MPa at most when the glass fiber content is 45%, the caprolactam resin and glass fiber composite molding material has excellent application prospects, and the caprolactam resin and glass fiber composite molding material can be prepared by weighing for several times, introducing molten caprolactam and molten curing agent into the molten curing agent, so that the caprolactam resin and glass fiber composite molding material is suitable for large-scale production. And the caprolactam is wrapped by the curing agent, so that the production of the caprolactam resin glass fiber composite molding material is realized, the equipment cost is reduced, and the production process is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material forming, in particular to a caprolactam resin glass fiber composite forming material, application and production process and device thereof. BACKGROUND

[0002] Automobile body composite parts generally use epoxy resin, polyurethane and other materials, and the materials of epoxy resin and polyurethane are mainly single direction reaction, which cannot be repeatedly heated and cooled, and it is difficult to recycle the materials. In order to improve the strength of the material and facilitate the recycling of the material, a kind of polyamide (PA) material is provided, which is a kind of thermoplastic plastic, which can be repeatedly heated and cooled, and the material can still be used, and has good application prospect in automobile and other mechanical manufacturing.

[0003] However, such material is not easy to produce, because one of its components is caprolactam, which is a new thermoplastic material that can react with oxygen, moisture and impurities, resulting in its own non-polymerization. Therefore, it is necessary to strictly control the air and moisture during production, and ordinary material mixing is difficult to produce. The production of PA generally adopts high pressure resin transfer molding technology (HP-RTM), which includes the placement of preform and resin injection. The production process is as shown in Figure 1 .

[0004] The resin injection step is to inject the low viscosity liquid resin heated above the melting point into the high temperature sealed mold from the top center of the mold by using high pressure injection equipment after the whole system of the mold is vacuumized and inert gas is introduced for protection. The resin injection is specifically shown in Figure 2 . In order to ensure that the resin base A and the curing agent can be mixed in the sealed state according to the proportion, high precision metering pump is generally used in HP-RTM to accurately measure and control the proportion of the resin two-component system. After the resin enters the mixing head under the action of high pressure metering pump and is mixed by high pressure opposite collision, the resin is injected into the high temperature mold cavity, and the mold is closed to make the resin infiltrate the glass fiber reinforced material and quickly solidify.

[0005] High pressure resin transfer molding technology is not suitable for the research and development of forming materials, and its defects are as follows: (1) in the research and development process of material forming, the proportion of material often needs to be adjusted, so the accuracy of mixing proportion of multi-component material is higher. In order to reduce the influence of oxygen, moisture and air pressure on the injection pressure of pump body, the measurement accuracy of metering pump is easily affected by the power of pump body motor and the pressure of raw material; (2) before injecting the resin mixed material, special vacuumizing equipment and inert gas introducing equipment are needed to treat the mold, the procurement and use cost of HP-RTM machinery is high, and the vacuumizing will lead to slow production rhythm, low production efficiency and long research and development cycle. SUMMARY

[0006] The caprolactam resin glass fiber composite forming material and the production process and device thereof aim to solve the technical problem that the caprolactam resin glass fiber composite forming material is not easy to prepare in the prior art.

[0007] To solve the above technical problems, the application specifically provides the following technical solutions: The caprolactam resin glass fiber composite forming material contains at least polyhexamethylene adipamide and fiber pieces. The fiber pieces are cross-over glass fibers, and the polyhexamethylene adipamide is a thermoplastic plastic. The content of the cross-over glass fibers is 23%-60% according to the percentage of mass.

[0008] As a preferred scheme of the application, the tensile strength of the caprolactam resin glass fiber composite forming material is 52.00-400.00 MPa.

[0009] The application provides an application of the caprolactam resin glass fiber composite forming material in the field of thin-walled parts.

[0010] As a preferred scheme of the application, the thin-walled part is any one of an automobile sealing cover and an automobile lower tray.

[0011] The application provides a production process of a caprolactam resin glass fiber composite forming material, which comprises the following steps: S100, cross-over glass fibers are laid on a mold to form fiber pieces, and the mold is preheated; S200, caprolactam and a curing agent are respectively placed in sealed tanks, the two sealed tanks are sent into an oven, and are heated to 90-100 DEG C to be melted, and the heating time is 4.5 h; S300, the curing agent is sent into a mass proportioning platform through a continuous extruder for primary weighing, and after the primary weighing, the caprolactam is passed into the bottom of the curing agent through the continuous extruder for secondary weighing, so that the curing agent forms a package for the caprolactam, and a mixture is obtained; S400, the mixture is uniformly stirred and placed into the mold for mold closing treatment, and the caprolactam resin glass fiber composite forming material is obtained.

[0012] The application further provides a production device of a caprolactam resin glass fiber composite forming material, which comprises a continuous extruder and a mass proportioning platform, the curing agent and the caprolactam are sequentially extruded into the mass proportioning platform through the continuous extruder for continuous and divided weighing, and the continuous extruder comprises a rotary extrusion mechanism and a storage rack. The shelf is provided with two sealing tanks arranged side by side, the sealing tank upstream of the mass proportion platform is used for containing a curing agent, the sealing tank downstream of the mass proportion platform is used for containing caprolactam, the top of the sealing tank is connected with the rotary extrusion mechanism, the bottom of the sealing tank is provided with a discharge pipe, and the rotary extrusion mechanism extrudes the material in the sealing tank into the mass proportion platform in batches through extrusion. The mass proportion platform comprises a conveying belt, a first telescopic rod arranged on the conveying belt in sequence from top to bottom, and a mixing tank, an electronic scale is arranged between the mixing tank and the first telescopic rod, the conveying belt drives the mixing tank to reciprocate from the bottom of the two sealing tanks and is weighed once and twice respectively, before the second weighing, the first telescopic rod drives the mixing tank to ascend so that the discharge pipe extends into the bottom of the mixing tank.

[0013] As a preferred scheme of the present application, the sealing tank comprises a tank body and a cover arranged on the top of the tank body, the tank body is clamped on the shelf, the cover is screwed with the inner wall of the tank body, and the cover slides in the tank body by rotating the cover; The discharge pipe is vertically arranged at the bottom of the tank body, a valve is arranged between the discharge pipe and the tank body, the valve is opened to extrude the material downward from the discharge pipe as the cover extrudes the material in the tank body; The rotary extrusion mechanism is arranged on the cover and rotates the cover.

[0014] As a preferred scheme of the present application, the top of the tank body is provided with a sealing ring, the sealing ring is arranged on the connection between the tank body and the cover, and the cover is separated from the sealing ring as the cover slides downward.

[0015] As a preferred scheme of the present application, the top of the tank body is provided with a plurality of limiting clamping corners, the limiting clamping corners are uniformly distributed on the cover, grooves are arranged on the two sides of the limiting clamping corner, the grooves are connected with the rotary extrusion mechanism, the rotary extrusion mechanism rotates the cover to drive the cover to descend or ascend.

[0016] As a preferred solution of the present invention, the rotary extrusion mechanism includes a track installed above the conveyor belt, a second telescopic rod is connected to the track through a motion module, the motion module moves back and forth between the two sealed cans on the track through a motor, the top of the second telescopic rod is connected to a rotating motor, the rotating motor can drive the second telescopic rod to rotate, a claw body is provided at the bottom of the second telescopic rod, the claw body can be attached to the cover body, and a protrusion is provided on the side of the claw body, which can be embedded in the groove body when the claw body rotates.

[0017] As a preferred solution of the present invention, the second telescopic rod includes a first rod body connected to the rotating motor and a second rod body sleeved under the first rod body, the first rod body and the second rod body are buckled together in the vertical direction so that the second rod body can slide up and down within the first rod body without relative rotation, and the claw body is set at the bottom of the second rod body.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a caprolactam resin glass fiber composite molding material containing polycaprolactam (thermoplastic) material, which can be used in thin-walled parts such as automotive sealing covers and automotive lower trays. The tensile strength can reach up to 400 MPa, and it has excellent application prospects. The present invention provides a molding process for thermoplastic resin caprolactam, wherein a curing agent and caprolactam are continuously conveyed to a mass proportioning platform in sequence. Caprolactam is injected from the bottom of the curing agent so that the raw materials form a sealed wrap around the caprolactam, significantly reducing its contact with oxygen and water in the air and reducing side reactions of the caprolactam. Compared with pump-based proportioning, the production pace is accelerated, and the metering is not easily affected by the pump body and the raw material pressure. At the same time, the transfer and weighing of the caprolactam can be ensured to be in a relatively sealed state, providing a good production foundation for the polymerization of caprolactam and the curing agent to form polycaprolactam. The present invention provides a discharging and mixing device for caprolactam. A small amount of caprolactam is automatically squeezed directly to the bottom of the curing agent on a proportioning platform through a rotating extrusion mechanism, without opening and closing a sealed tank. The discharging process is automated so that the caprolactam is wrapped in the curing agent during injection, thereby reducing the contact area and contact time of the caprolactam with the air during material transfer and weighing, and achieving accurate weighing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0020] Figure 1 The present invention provides a schematic flow chart of the high pressure resin transfer molding technology in the prior art; Figure 2 The present invention provides Figure 1 The schematic diagram of the resin injection process in the prior art is shown; Figure 3 The present invention provides a schematic flow chart of a production process of a caprolactam resin glass fiber composite molding material; Figure 4 Provided is a statistical graph of the cross glass fiber content and tensile strength in a caprolactam resin glass fiber composite molding material; Figure 5 The present invention provides a product picture of a caprolactam resin glass fiber composite molding material used as an automobile lower tray; Figure 6 The present invention provides a structural schematic diagram of a production device for caprolactam resin glass fiber composite molding materials; Figure 7 The present invention provides Figure 6 A schematic structural diagram of the synchronous movement of the rotary extrusion mechanism and the mixing tank in the production device for caprolactam resin glass fiber composite molding material in the embodiment shown; Figure 8 The present invention provides Figure 6 A schematic diagram of the internal side structure of the sealed can in the embodiment shown; Figure 9 The present invention provides Figure 6 A schematic diagram of the internal side structure of the embodiment shown in which the cover body descends within the tank body; Figure 10 The present invention provides Figure 6 A schematic structural diagram of the cover body in the illustrated embodiment; Figure 11 The present invention provides Figure 6 Schematic diagram of the structure of the claw body in the embodiment shown.

[0021] The numbers in the figure represent the following: 1-rotating extrusion mechanism; 2-shelf; 3-sealed tank; 4-discharging pipe; 5-conveyor belt; 6-first telescopic rod; 7-mixing tank; 8-electronic scale; 101 - track; 102 - movement module; 103 - second telescopic rod; 104 - rotary motor; 105 - claw body; 106 - protrusion; 1031 - first rod body; 1032 - second rod body; 301 - tank body; 302 - cover body; 303 - thread; 304 - valve; 305 - sealing ring; 306 - limit corner; 307 - groove body. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] The present application provides a caprolactam resin glass fiber composite molding material, at least containing polycaprolactam and fiber sheet; the fiber sheet is cross-over glass fiber, the polycaprolactam is thermoplastic plastic, and the content of the cross-over glass fiber is 23%-60% according to the percentage of mass.

[0024] Polycaprolactam originates from BASF in Germany and is a world-leading material in China. After being combined with glass fiber, it can be applied in the field of thin-walled parts, such as automobile sealing cover and lower tray. The caprolactam resin glass fiber composite molding material contains the characteristics of polycaprolactam, can be repeatedly heated and cooled, and the material can still be used, which is convenient for material recycling and reuse, and meets the energy saving and environmental protection requirements. At the same time, the cross-over glass fiber can improve the tensile strength and impact resistance of polycaprolactam, and can be fully used in the field of thin-walled parts.

[0025] Further, the production of polycaprolactam needs to use HP-RTM process, but HP-RTM process needs to rely on high-precision metering pump, vacuum pumping equipment and the like to provide a sealed environment, not only the cost of equipment purchase is high, and the production line condition is harsh, which is very unfavorable to the research and development and production of polycaprolactam material and its composite material. The present application provides a caprolactam resin glass fiber composite molding material production process, comprising the following steps: S100, laying cross-over glass fiber on a mold to form a fiber sheet, and preheating the mold; S200, placing caprolactam and curing agent into a sealed tank respectively, and sending the two sealed tanks into an oven, heating at 130 DEG C to 90-100 DEG C, and melting caprolactam and curing agent at 90-100 DEG C, heating time is 4.5h; S300, the curing agent is sent into the mass proportioning platform through a continuous extruder for primary weighing, and after the primary weighing is completed, the caprolactam is sent into the bottom of the curing agent through the continuous extruder for secondary weighing, so that the curing agent is wrapped around the caprolactam, and a mixture is obtained; S400, the mixture is stirred uniformly and is placed into the mold for mold closing treatment, and the caprolactam resin glass fiber composite molding material is obtained.

[0026] The caprolactam resin glass fiber composite molding material obtained by the non-sealed production method has caprolactam and a curing agent that can be polymerized to a certain extent to obtain a poly caprolactam material. The existing HP-RTM technology is mainly used to obtain a poly caprolactam thick material, but the present application is not intended to obtain a thick material, but based on the material properties of the poly caprolactam, the poly caprolactam is compounded with a fiber sheet to obtain a thin material with high tensile strength and impact resistance, which can be applied to the field of thin-walled parts, such as automobile sealing covers, lower trays and the like.

[0027] Since it is applied to the field of thin-walled parts, the caprolactam resin glass fiber composite molding material process needs to consider the adaptation of the product, and the single production quantity of the product is much less than that of a thick piece. For example, when a HP-RTM process is used to produce a thick-walled piece, dozens of kilograms of material are involved in the reaction of a single product, but only a few kilograms of material is needed for each thin-walled piece. Therefore, the characteristics of the raw material, such as easy reaction with air, are weakened, so the single melting material is less, the time is short, and the material is more easily polymerized, which meets the demand for lightweight products.

[0028] The above production process can be used for manual weighing and transportation line production, or can be matched with a die pressing process for full automatic production. It is worth noting that the product produced by the present application is different from the product produced by the HP-RTM technology, and the application field is also different. The HP-RTM technology can be used to produce the present product, but compared with the HP-RTM technology, the present application does not need to use a vacuum instrument and does not need to be sealed throughout the process. The material ratio is easy to control.

[0029] Further, the mass proportioning platform is used to weigh the caprolactam and the curing agent conveyed thereto. The mass proportioning platform can be a common tray balance or an electronic balance. The mass of the caprolactam and the curing agent is controlled by the balance to have a specific mass ratio, which is defined by the staff in advance. Compared with the weighing of the metering pump, the mass of the components is controlled by the balance, which is not only simple in control method, but also not affected by the pressure of the raw material, and not affected by the pressure and metering accuracy of the pump body or motor of any device.

[0030] Particularly, in the present application, the curing agent and caprolactam are continuously fed to the mass proportioning platform in sequence, the caprolactam is injected from the bottom of the curing agent, which can significantly reduce the contact of the caprolactam with oxygen and water in the air, and reduce the side reaction of the caprolactam. After the fusion of the two-component raw materials, the present application directly continuously weighs the molten components by using the direct weighing method until the required mass proportion is reached, and then stirs and discharges, realizing continuous production. Compared with the pump volume proportioning, the production rhythm is accelerated, the metering is not easily affected by the pump and the raw material pressure, and at the same time, the transfer and weighing of the caprolactam can be ensured in a relatively sealed state, providing a good production basis for the subsequent polymerization of caprolactam and curing agent to form polyamide.

[0031] In the method disclosed in the present application, the proportioning of caprolactam and curing agent is not affected by the motor power of the conveying device, nor by the air pressure, but only by the weighing value. The weighing value absolutely affects the final resin component metering ratio, the influencing factors are few, and with the improvement of the weighing accuracy, the accuracy can be further improved, and the accuracy is high.

[0032] The proportioning of the two components in the present application is more flexible and controllable, and in the research and development process, the relationship between the proportioning and the forming can be better researched, so that the material proportioning can be selected according to different forming requirements, the influence of the proportion of the mixed raw materials on product forming is more clear and obvious, and a wider application prospect is provided for obtaining more performance two-component resin material and glass fiber composite forming material.

[0033] Further, the present application uses a wet molding process to preliminarily replace the HP-RTM process of the raw material caprolactam, the production of the system is sealed by mutual wrapping of the materials, the cost of vacuum pumping and inert gas introduction is saved, the cost of purchasing vacuum pumps and other equipment during research and development is saved, the automobile parts manufacturers and research and development teams with original molding equipment are more convenient, and batch production can be ensured to speed up the production rhythm.

[0034] The present application further provides specific embodiments to illustrate the steps of production.

[0035] Example 1: Device selection: 2 containers with lids, oven, pipeline, electronic balance, mold, scissors, stirrer Material: caprolactam, curing agent, and cross-shaped glass fiber fabric 1. Pre-treatment: clean and dry 2 containers with lids, oven, pipeline, electronic balance, mold, scissors, stirrer, cut the glass fiber size that fits the mold and nylon system, lay the glass fiber in the preforming cavity of the mold to the appropriate thickness, cut the cross-laid glass fiber cloth according to the design requirements, which can be laid by hand or mechanically, pay attention to the direction, number of layers and stacking order of the fiber during the laying process to ensure that the fiber cloths fit tightly without wrinkles, bubbles and other defects.

[0036] 2. Melt caprolactam raw material: put 1.5 kg of caprolactam and curing agent raw material into a sealed cover, seal the container with the cover, set the oven to 130 degrees Celsius, put the container into the oven, melt for 4.5 hours, and mix the polymerization within 15 minutes of melting; At this time, the mold is heated to a temperature of 160 degrees Celsius, the actual measured mold temperature is 145-147 degrees Celsius, the mold pressure is 500 t, and the mold pressing time is 5-10 min.

[0037] 3. Two-component caprolactam raw material ratio and resin transfer: after the caprolactam raw material is melted at a temperature of 80 degrees Celsius and the infrared measured material temperature is 90 degrees Celsius, the sealed tank is taken out of the oven, the curing agent in the sealed tank is first introduced into the mass ratio platform using the discharging assembly, until the required mass, i.e. 100 g, is reached, and then by changing the height of the sealed tank, the caprolactam in the other sealed tank is introduced from the bottom of the curing agent into the mass ratio platform, i.e. the total mass of the substances on the platform reaches 200 g, until the required mass is reached. 4. Mix the 100 g of molten caprolactam with 100 g of curing agent together and stir for 10-15 s: after the curing agent is evenly mixed, pour it directly into the mold, close the mold, the mold pressure is 500 t, and the mold pressing time is 5 min, then open the mold and take out the product. The mold is made of steel and the corresponding mold structure is designed according to different molding processes.

[0038] The time from taking the raw material out of the oven to the last time of pouring into the mold needs to be precisely controlled within 30 s to prevent the caprolactam and curing agent from being denatured due to excessive oxidation, which makes it difficult to polymerize.

[0039] Example 2: The other production steps are the same as in Example 1, except that during the material melting process, the initial temperature is set to 150 degrees Celsius for 1 hour, then the temperature is lowered to 100 degrees Celsius for 1 hour, and then the temperature is lowered to 85 degrees Celsius for 0.5 hours, for a total of 2.5 hours of melting time, to reduce the melting time.

[0040] Example 3: Other production steps are same with example 1, different is that in the process of material melting, set the initial temperature to 150 degrees Celsius melt 1.5h, then reduce the temperature to 85 degrees Celsius melt 1.5h, total melt time is 3h.

[0041] Example 4: Other production steps are same with example 1, different is that after the caprolactam and curing agent completely melt, mix the material within 5min.

[0042] Example 5: Other production steps are same with example 1, different is that after the caprolactam and curing agent completely melt, mix the material within 10min.

[0043] The following example 1 to example 5 are characterized and analyzed: I. Material tensile test The detection standard is shown in table 1: Detection steps: the sample for this time is 1 type product actual thickness, number the test piece (example 1-example 5), and use vernier caliper to measure the test piece, take the average value for numbering, polish the middle of the test piece, pay attention to the intensity when polishing, try to reduce the damage of the surface to the minimum, clean the test sample surface, pay attention to the centering of the test piece during installation, complete the installation and debugging, set the collection frequency to 2Hz, zero the control device, start the test at a speed of 2mm / min; in low temperature and high temperature humid test, first push the environment box into the tester, repeat the above operation to test. Until the test piece is damaged, record the test data, take pictures of the typical test piece, and record the test failure mode. The number of effective samples is at least 5 PCS.

[0044] The tensile test results are shown in table 2: From table 2, it can be seen that when the raw material ratio is fixed, the minimum tensile strength of caprolactam resin glass fiber composite forming material is 240.24MPa, and the maximum tensile strength reaches 292.37MPa, which has excellent tensile property. It can be seen that using the method disclosed in the application, polyhexamethylene caprolactam + glass fiber composite forming material is successfully obtained. Compared with large dose of production of polyhexamethylene caprolactam, the application successfully reduces the influence of caprolactam denaturation on polymerization degree by reducing the production metering, and the caprolactam resin glass fiber composite forming material obtained can be applied to the production of thin-walled parts.

[0045] Compared with example 1, although the material temperature setting process is increased, the melting time is greatly shortened, the melting time is reduced, the production cost is reduced, and the product performance is almost not affected. Further, by comparing example 1, example 4 and example 5, it can be seen that the shorter the time of mixing the material after the product is melted, the better the tensile strength, and it can be speculated that the polymerization performance of the product is good.

[0046] Further, the present application prepares a caprolactam resin glass fiber composite forming material by changing the content of glass fiber, and finally obtains the relationship between the content of cross-shaped glass fiber and the final tensile strength of the material as shown in Figure 8 Figure 4 , wherein the tensile strength of the caprolactam resin glass fiber composite forming material is 52.00-400.00MPa, and the highest can reach 400.00MPa, so it has excellent application range.

[0047] II. Bottom ball impact experiment Select example 1, the bottom ball impact experiment result of example 1 is shown in table 3.

[0048] As shown in table 3, the caprolactam resin glass fiber composite forming material disclosed by the present application has excellent ball impact resistance, that is, excellent strength.

[0049] III. Product application The caprolactam resin glass fiber composite forming material is molded by using a mold pressing machine under a car tray, wherein different color powders are used to modify the caprolactam resin glass fiber composite forming material.

[0050] According to the market needs of the car tray and the sealing cover, the polymerization degree of the thermoplastic caprolactam composite glass fiber product is as high as 97%, and will further complete the continuous polymerization over time. The product thickness interval produced by the method of mold pressing polymerization is 0.8mm-3mm, and the glass fiber content ratio is further increased, for example, the tensile strength of the product with 60% glass fiber content can reach 400MPa, and the product performance is excellent.

[0051] The car tray produced by the caprolactam resin glass fiber composite forming material is shown in Figure 5 , wherein the product has different colors, such as translucent primary color, translucent gray and matte black, different colors represent different color powders during mold pressing, and the product application scene is diversified.

[0052] As shown in Figure 1 ​As shown, the HP-RTM technology system needs to customize a complete set of production equipment that can be heated, sealed, vacuumized, inert gas, high-precision high-temperature resistant metering pump, and high-pressure glue injection. By adjusting the melting temperature of the material, the configuration time and the material ratio, the polyhexalactam can be successfully polymerized by the steps disclosed in the application. For automobile parts manufacturers or resin molding research teams, there is no need to customize professional HP-RTM equipment, and the molding machine can be used to directly realize the mass production of nylon system products.

[0053] The sealed tank for high-temperature melting raw materials only needs to use two containers with lids, an oven, weighing tools and a plurality of pipelines capable of conveying liquid materials. By controlling the melt temperature and time and the discharge speed, continuous production can be realized. The whole system does not need to be vacuumized and protected by inert gas, and does not need to use accurate high-temperature resistant high-pressure metering pumps and high-pressure glue injection heads to complete the molding of products, which greatly saves the cost of new material equipment research and development and production. The tensile strength of the polyhexalactam resin glass fiber composite molding material obtained is 240.24-292.37 MPa, which has excellent impact resistance, and provides a new material for producing thin-walled parts such as automobile sealing covers and automobile lower trays.

[0054] The key of the above preparation method is to reduce the single polymerization amount of the material, so that it can be fully mixed and uniform when mixed, so as to achieve the condition of being able to polymerize to form polyhexalactam. However, the production amount of raw materials is reduced in the whole production system, and a small amount of hexalactam is still easy to react with oxygen or air in the air during transfer, causing insufficient polymerization degree. In order to solve this problem, the method provided by the application is to perform extrusion treatment on the sealed tank, directly extruding a small amount of hexalactam to the bottom of the curing agent of the proportioning platform, so that it is wrapped by the curing agent when injected, thereby reducing the contact area and contact time of hexalactam with air during material transfer and weighing.

[0055] The above method needs a special production device for production, such as Figures 6 to 11 As shown, the application provides a polyhexalactam resin glass fiber composite molding material production device, which comprises a continuous extruder and a mass proportioning platform. The continuous extruder extrudes the curing agent and hexalactam into the mass proportioning platform for continuous and multiple weighing. The continuous extruder comprises a rotary extrusion mechanism 1 and a storage rack 2. The rotary extrusion mechanism 1 can extrude the curing agent and hexalactam in the storage rack 2 into the mass proportioning platform. The rotary extrusion mechanism 1 is used for extruding the curing agent and hexalactam. The mass proportioning platform is used for weighing the materials extruded from the storage rack 2.

[0056] Specifically, the shelf 2 is provided with two parallel sealing tanks 3, the sealing tank 3 upstream of the mass proportioning platform is used to contain the curing agent, and the sealing tank 3 downstream of the mass proportioning platform is used to contain the caprolactam. The top of the sealing tank 3 is connected with the rotary extrusion mechanism 1, and the bottom of the sealing tank 3 is provided with a discharge pipe 4. The rotary extrusion mechanism 1 extrudes the material in the sealing tank 3 into the mass proportioning platform in batches through extrusion.

[0057] In particular, different materials are extruded to the mass proportioning platform at different distances, and the mass proportioning platform includes a conveying belt 5, a first telescopic rod 6 arranged on the conveying belt 5 from top to bottom, and a mixing tank 7. An electronic scale 8 is arranged between the mixing tank 7 and the first telescopic rod 6. The conveying belt 5 drives the mixing tank 7 to reciprocate at the bottom of the two sealing tanks 3 and is weighed once and twice respectively. When the mixing tank 7 is placed at the bottom of the downstream sealing tank 3, the first telescopic rod 6 drives the mixing tank 7 to rise before the second weighing, so that the discharge pipe 4 extends into the bottom of the mixing tank 7. At this time, the discharge pipe 4 extends into the bottom of the curing agent, and the curing agent is discharged at the bottom of the curing agent, so that the curing agent can wrap the caprolactam to a certain extent.

[0058] The main function of the caprolactam resin glass fiber composite molding material production device is to transfer and weigh the material. The specific use mode is as follows: 1. The caprolactam and the curing agent are respectively put into the sealing tank 3, and it is recommended to fill it full. After filling, it is sealed, and after sealing, it is manually put into the oven for heating; 2. Take out the two sealing tanks 3 in the oven, and place the two sealing tanks 3 on the shelf 2 in turn; 3. The mixing tank 7 is placed into the first sealing tank 3 through the conveying belt 5, the rotary extrusion mechanism 1 extrudes the sealing tank 3 to discharge, the curing agent is extruded from the discharge pipe 4, and the electronic scale 8 weighs the mass of the curing agent during the extrusion process until the appropriate mass is reached; 4. After the first weighing is completed, the mixing tank 7 is conveyed to the bottom of the second sealing tank 3 through the conveying belt 5. The motor in the electronic telescopic rod is driven to move the electronic telescopic rod upward until the discharge pipe 4 extends into the bottom of the mixing tank 7. The rotary extrusion mechanism 1 moves above the second sealing tank 3, so that the second sealing tank 3 is extruded and discharged. The caprolactam is wrapped in the curing agent during discharging, forming a sealed space, which reduces the contact area of the caprolactam with air during discharging; 5. The second weighing is carried out when discharging, after the second weighing is finished, the electronic telescopic rod is lowered, the mixing tank 7 is taken off from the conveying belt 5, is sealed, is mixed in a shaking mode, after mixing, the mixing tank 7 can be opened and the mixed material is poured into the mould.

[0059] In the application, the sealing tank 3 can be selected in any range, since in the embodiment, the sealing tank 3 needs to be heated to a high temperature, so it is generally made of hard material, such as ceramic, alloy and the like, which is not conducive to direct extrusion.

[0060] In order to facilitate the discharge of the curing agent and caprolactam, the sealing tank 3 comprises a tank body 301 and a cover 302 arranged on the top of the tank body 301, the tank body 301 can be clamped on the shelf 2, the cover 302 is screwed with the inner wall of the tank body 301 through a thread 303, the rotary extrusion mechanism 1 can be arranged on the cover 302 and drive the cover 302 to rotate, and the cover 302 slides in the tank body 301 as the cover 302 rotates.

[0061] The discharge pipe 4 is vertically arranged at the bottom of the tank body 301, and a valve 304 is arranged between the discharge pipe 4 and the tank body 301, as the rotary extrusion mechanism 1 drives the cover 302 to rotate, the cover 302 slides downward in the tank body 301, thereby extruding the material in the tank body 301, the valve 304 is opened to make the material extrude downward from the discharge pipe 4, when the rotary extrusion mechanism 1 drives the cover 302 to rotate reversely, the cover 302 moves upward to return to the original position.

[0062] The valve 304 can be an elastic valve, that is, a soft rubber sheet is arranged between the connection between the discharge pipe 4 and the tank body 301, the rubber sheet is provided with a cross port, when the material extrudes the cross port, the rubber sheet will be deformed, so that the discharge pipe 4 is opened to discharge. When there is no corresponding pressure, the rubber sheet will automatically close because it has elasticity. The rubber sheet is heat-resistant rubber, and the diameter of the discharge pipe 4 is 1-2 cm, within this diameter range, the material will not flow out of the valve 304 directly, and it is also convenient for weighing.

[0063] In the disclosed embodiment of the present application, the sealing of the tank body 301 is provided by the threaded connection between the cover body 302 and the tank body 301, but since the threaded connection is limited in sealing to a certain extent, in order to improve the sealing effect of the connection between the cover body 302 and the tank body 301 when the cover body 302 is on the top, the top of the tank body 301 is provided with a sealing ring 305 that can fit at the connection between the tank body 301 and the cover body 302, and the cover body 302 separates from the sealing ring 305 as it slides down. When the cover body 302 is on the top of the tank body 301, the sealing ring 305 can wrap around the connection between the tank body 301 and the cover body 302, thereby improving the sealing effect of the tank body 301 when it is in use, preventing air from entering the tank body 301 when it is heated.

[0064] The connection between the rotating extrusion mechanism 1 and the cover body 302 can be a snap fit, a suction cup, a magnetic fit, etc. If it is a magnetic fit, the cover body 302 needs to be made of iron, cobalt, or nickel. In the disclosed embodiment of the present application, the rotating extrusion mechanism 1 can be connected to the cover body 302 by a snap fit for easy separation of the two. Specifically, the top of the tank body 301 is provided with a plurality of limiting corners 306, which are evenly distributed on the cover body 302, and the two sides of the limiting corners 306 are provided with grooves 307 that can be connected to the rotating extrusion mechanism 1, and the rotating extrusion mechanism 1 drives the cover body 302 to rotate, thereby driving the cover body 302 to descend or ascend.

[0065] When the sealed tank 3 is placed on the shelf 2, the rotating extrusion mechanism 1 is attached to the cover body 302, and as it rotates, it can be fitted into the groove 307 and held by the groove 307, preventing the cover body 302 from separating from the cover body 302 when it is raised or lowered. It can be seen that the rotating extrusion mechanism 1 can also open the cover of the tank body 301.

[0066] The main function of the rotating extrusion mechanism 1 is to move the cover body 302. The present embodiment provides a simple rotating extrusion mechanism 1 structure for moving the cover body 302. Specifically, the rotating extrusion mechanism 1 includes a track 101 mounted above the conveyor belt 5, a second telescopic rod 103 connected to the track 101 by a movement module 102, the movement module 102 moving back and forth between two sealed tanks 3 on the track 101 by a motor, a rotating motor 104 connected to the top of the second telescopic rod 103, the rotating motor 104 driving the second telescopic rod 103 to rotate, a claw body 105 provided at the bottom of the second telescopic rod 103, the claw body 105 being able to fit on the cover body 302, and a protrusion 106 provided on the side of the claw body 105, the protrusion 106 being able to fit into the groove 307 when the claw body 105 rotates.

[0067] The motion module 102 is a common structure, which is internally provided with a motor and can move on the track 101. A controller can be used to control the motion of the motion module 102. The main action of the motion module 102 is to reciprocate between the two sealed tanks 3 and be stationary during the discharging process.

[0068] The claw body 105 can be limited in the horizontal direction by the limiting clamping corner 306 on the cover body 302. In the normal state, the claw body 105 can be placed on the cover body 302 and is not limited. When the second telescopic rod 103 rotates, the claw body 105 rotates correspondingly, so that the protrusion 106 is buckled in the groove body 307. With continuous rotation, the claw body 105 can drive the cover body 302 to rotate. When the second telescopic rod 103 rotates in the opposite direction, the protrusion 106 on the claw body 105 is separated from the groove body 307. At this time, the claw body 105 and the cover body 302 are in a relatively separated state. When the second telescopic rod 103 rotates in the opposite direction, the protrusion 106 on the other side of the claw body 105 is embedded in the groove body 307 on the other side, so as to realize the connection again.

[0069] In the embodiment disclosed in the present application, no matter how the second telescopic rod 103 rotates, it can be buckled on the cover body 302. When the cover body 302 is to be separated from it, the second telescopic rod 103 is rotated to a suitable angle, and the protrusion 106 can be separated from the groove body 307.

[0070] The length of the second telescopic rod 103 can be automatically telescopic according to rotation, or can be telescopic according to the height of the cover body 302 according to the embodiment disclosed in the present application. The second telescopic rod 103 includes a first rod body 1031 connected with the rotating motor 104 and a second rod body 1032 sleeved below the first rod body 1031. The first rod body 1031 and the second rod body 1032 are buckled together in the vertical direction, so that the second rod body 1032 can slide up and down in the first rod body 1031 without relative rotation. The claw body 105 is arranged at the bottom of the second rod body 1032. The rotating and extruding mechanism 1 disclosed in the present application has simple structure and low purchase cost.

[0071] The first telescopic rod 6 and the second telescopic rod 103 are both electric telescopic rods, which can be automatically telescopic under electric control.

[0072] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application. Such modifications or equivalent replacements should also be considered to fall within the protection scope of the present application.

Claims

1. A caprolactam resin glass fiber composite molding material, characterized in that: The caprolactam resin glass fiber composite molding material contains at least polycaprolactam and fiber sheets; The fiber sheet is cross-glass fiber, and the polycaprolactam is a thermoplastic plastic; Calculated by mass percentage, the content of the cross glass fiber is 23%-60%.

2. An application of the caprolactam resin glass fiber composite molding material as claimed in claim 1 in the field of thin-walled parts.

3. The use according to claim 2, characterized in that The thin-walled part is any one of an automobile sealing cover and an automobile lower tray.

4. A process for producing a caprolactam resin glass fiber composite molding material, for preparing the caprolactam resin glass fiber composite molding material according to claim 1, characterized in that: The steps include: S100, laying cross-glass fibers on a mold to form a fiber sheet, and preheating the mold; S200, placing caprolactam and curing agent into sealed cans respectively, placing the two sealed cans into an oven, heating to 90-100° C. to melt, and heating time is 4.5 hours; S300, feeding the curing agent into a mass proportioning platform through a continuous extruder for primary weighing, and after the weighing is completed, passing caprolactam through the continuous extruder to the bottom of the curing agent, and performing a secondary weighing so that the curing agent forms a coating on the caprolactam to obtain a mixed material; S400, stirring the mixed material evenly, placing it into the mold and performing mold closing processing to obtain the caprolactam resin glass fiber composite molding material.

5. A production device based on the production process of caprolactam resin glass fiber composite molding material according to claim 4, characterized in that: It comprises a continuous extruder and a mass proportioning platform, wherein the continuous extruder sequentially extrudes the curing agent and caprolactam into the mass proportioning platform for continuous weighing in batches, and the continuous extruder comprises a rotary extrusion mechanism (1) and a storage rack (2); Two sealed tanks (3) are arranged in parallel on the storage rack (2); the sealed tank (3) located upstream of the mass proportioning platform is used to hold a curing agent, and the sealed tank (3) located downstream of the mass proportioning platform is used to hold caprolactam; the top of the sealed tank (3) can be connected to the rotary extrusion mechanism (1); a discharge pipe (4) is provided at the bottom of the sealed tank (3); and the rotary extrusion mechanism (1) squeezes the material in the sealed tank (3) into the mass proportioning platform in batches. The mass proportioning platform comprises a conveyor belt (5), a first telescopic rod (6) and a mixing tank (7) arranged on the conveyor belt (5) in sequence from top to bottom, an electronic scale (8) is arranged between the mixing tank (7) and the first telescopic rod (6), the conveyor belt (5) drives the mixing tank (7) to move back and forth from the bottom of the two sealed tanks (3) and perform a first and a second weighing respectively, and before the second weighing, the first telescopic rod (6) drives the mixing tank (7) to rise so that the discharge pipe (4) extends into the bottom of the mixing tank (7).

6. The device for producing a caprolactam resin glass fiber composite molding material according to claim 5, characterized in that: The sealed can (3) comprises a can body (301) and a cover body (302) arranged on the top of the can body (301); the can body (301) can be snap-fitted onto the storage rack (2); the cover body (302) is screwed to the inner wall of the can body (301) via a thread (303); and as the cover body (302) rotates, the cover body (302) slides inside the can body (301); The discharge pipe (4) is vertically arranged at the bottom of the tank body (301), and a valve (304) is provided between the discharge pipe (4) and the tank body (301). As the cover body (302) squeezes the material in the tank body (301), the valve (304) opens to allow the material to be squeezed downward from the discharge pipe (4); The rotary extrusion mechanism (1) can be fitted on the cover body (302) and drive the cover body (302) to rotate.

7. The device for producing a caprolactam resin glass fiber composite molding material according to claim 6, characterized in that: A sealing ring (305) is provided on the top of the tank body (301), and the sealing ring (305) can be attached to the connection between the tank body (301) and the cover body (302). As the cover body (302) slides down, the cover body (302) and the sealing ring (305) are separated.

8. The device for producing a caprolactam resin glass fiber composite molding material according to claim 7, characterized in that: The top of the tank body (301) is provided with a plurality of limiting clamping angles (306), the limiting clamping angles (306) being evenly distributed on the cover body (302), and grooves (307) being provided on both sides of the limiting clamping angles (306), the grooves (307) being capable of engaging with the rotary extrusion mechanism (1), and the rotary extrusion mechanism (1) drives the cover body (302) to rotate, thereby driving the cover body (302) to descend or ascend.

9. The device for producing a caprolactam resin glass fiber composite molding material according to claim 8, characterized in that: The rotary extrusion mechanism (1) comprises a track (101) mounted above the conveyor belt (5); a second telescopic rod (103) is connected to the track (101) via a motion module (102); the motion module (102) reciprocates between the two sealed cans (3) on the track (101) via a motor; a rotary motor (104) is connected to the top of the second telescopic rod (103); the rotary motor (104) can drive the second telescopic rod (103) to rotate; a claw body (105) is provided at the bottom of the second telescopic rod (103); the claw body (105) can be attached to the cover body (302); a protrusion (106) is provided on the side of the claw body (105); when the claw body (105) rotates, the protrusion (106) can be embedded in the groove body (307).

10. The device for producing a caprolactam resin glass fiber composite molding material according to claim 9, characterized in that: The second telescopic rod (103) comprises a first rod body (1031) connected to the rotating motor (104) and a second rod body (1032) sleeved below the first rod body (1031). The first rod body (1031) and the second rod body (1032) are buckled together in a vertical direction so that the second rod body (1032) can slide up and down in the first rod body (1031) without rotating relative to each other. The claw body (105) is arranged at the bottom of the second rod body (1032).

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