Chopped fiber premix preparation device

Abstract

The utility model relates to a chopped fiber premix preparation device, and relates to the technical field of chopped fiber preparation equipment. The chopped fiber premix preparation device comprises a conveying mechanism for conveying chopped fibers, a discharging hopper used for releasing chopped fibers to the conveying mechanism, a spraying mechanism used for spraying a resin solution to the chopped fibers on the conveying mechanism and a drying mechanism used for drying the solution on the chopped fibers are sequentially arranged above the conveying mechanism in the conveying direction of the conveying mechanism. The output end of the conveying mechanism is further provided with a material collecting mechanism used for collecting chopped fiber premix. The fiber monofilaments in the chopped fiber premix prepared by the device disclosed by the utility model are tightly combined, the premix is not easy to agglomerate and pill, and the used solvent is low in dosage and small in residual quantity; in addition, the method has the advantages of simple process and high production efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of short fiber preparation equipment, in particular to a short fiber premix preparation device. BACKGROUND

[0002] With the rapid development of science and technology and the increasing demand of industry, fiber reinforced composites have become an important research object in the field of global material science. These materials have been widely used in many fields such as aerospace, military protection, automobile industry and sports goods due to their unique properties such as high strength, light weight, high temperature resistance, etc. Fiber reinforced composites can be divided into continuous fiber reinforced composites, woven composites, short fiber reinforced composites and hybrid fiber reinforced composites according to the form of reinforcing materials. Among them, short fiber reinforced composites are widely used in various fields due to their lower cost and more flexible forming method.

[0003] Short fibers generally refer to fibers with a length range of 3mm to 25mm, which can be glass fibers, carbon fibers, boron fibers, aramid fibers, silicon carbide fibers, asbestos fibers, whiskers, etc. In the two-step method for preparing short fiber reinforced composites, short fibers and resins are mixed and impregnated in advance to form a semi-finished product, i.e. a composite premix, and then the semi-finished product is formed into a composite product.

[0004] In order to obtain short fiber reinforced composite raw materials, industrial production usually adopts a solvent method to produce a premix. This method is to dissolve the resin in an organic solvent such as ethanol, impregnate the short fibers in the solvent, mix uniformly, and then remove the solvent by vacuum filtration and drying. This method has the defects of complex process, large amount of solvent, and solvent residue affecting the quality of the composite material. Another method for preparing short fiber reinforced composite raw materials is dry mixing. This method uniformly disperses the short fibers used for reinforcement in the resin powder matrix material by using a ball mill and a rotary mixer, etc. to obtain a fiber resin mixture. This method has the problem that the fibers are easily flocculated after mixing and cannot be uniformly mixed with the resin powder. Content of the utility model

[0005] In order to improve the uniformity of short fiber premix and reduce solvent residue, the application provides a short fiber premix preparation device.

[0006] The short fiber premix preparation device provided by the application adopts the following technical scheme:

[0007] The application discloses a short-cut fiber premix preparation device, which comprises a conveying mechanism for conveying short-cut fibers, a feeding hopper arranged above the conveying mechanism and used for releasing short-cut fibers onto the conveying mechanism, a spraying mechanism arranged above the conveying mechanism and used for spraying a resin solution onto the short-cut fibers on the conveying mechanism, and a drying mechanism arranged above the conveying mechanism and used for drying the solution on the short-cut fibers; and an output end of the conveying mechanism is further provided with a collecting mechanism used for collecting the short-cut fiber premix.

[0008] The cut short-cut fibers are placed in the feeding hopper, and the short-cut fibers are evenly laid on the conveying mechanism by controlling the feeding speed; the conveying mechanism carries the short-cut fibers and moves forward; the spraying mechanism is arranged at the front end of the conveying mechanism and the resin solution is uniformly sprayed on the surface of the short-cut fibers through the spraying mechanism; then the short-cut fibers enter the drying mechanism for drying; after the short-cut fiber premix is output from the output end of the conveying mechanism, the short-cut fiber premix enters the collecting mechanism, so that the short-cut fibers with closely combined single fibers and the short-cut fibers which are not prone to agglomeration and balling are obtained.

[0009] By adopting the technical scheme, the defects of the dry mixing method are overcome, and the problem that the irregular dispersion of single fibers of the short-cut fibers during the dispersion of the short-cut fibers in the matrix leads to the agglomeration of the short-cut fibers and affects the uniformity of the mixture is effectively solved. Meanwhile, the preparation device in the application has the advantages of low resin solution consumption, simple process and high production efficiency when the short-cut fiber premix is prepared.

[0010] Optionally, the conveying mechanism comprises a rack, driving rollers and driven rollers which are arranged in parallel and at intervals on the rack, and a conveying belt which is sleeved on the driving rollers and the driven rollers; a cutting mechanism for cutting long fibers into short-cut fibers is arranged above an input end of the conveying belt; a feeding port of the feeding hopper is opposite to a discharging port of the cutting mechanism, and a discharging port of the feeding hopper is located above the input end of the conveying belt.

[0011] By adopting the technical scheme, the driving rollers are driven to rotate to drive the conveying belt to run; after the conveying mechanism is started, the rotation speed of the driving rollers can be adjusted through the conveying mechanism to control the advancing speed of the conveying belt, so that the uniformity of the distribution of the short-cut fibers on the conveying belt is ensured. The cutting mechanism for cutting long fibers into short-cut fibers is arranged above the input end of the conveying belt; long fiber raw materials are placed in the cutting mechanism, and the cutting, feeding, spraying of the resin solution, drying and recycling and other processes are sequentially performed, so that the short-cut fiber premix is integrally and automatically processed and prepared, the degree of automation is high, the work efficiency is high, the production process is simplified, the influence of human operation is reduced, and the quality and consistency of the product are improved.

[0012] Optionally, the spraying mechanism comprises a storage tank for storing the resin solution and a spraying pipe arranged on the conveying belt, the spraying pipe is arranged along the width direction of the conveying belt, one end of the spraying pipe is connected with the storage tank, and a plurality of nozzles facing the conveying belt are connected with the spraying pipe.

[0013] By adopting the above technical scheme, the chopped fibers are orderly laid and uniformly sprayed during the conveying process, the uniformity of the contact between the chopped fibers and the resin solution is improved, and the problems of easy agglomeration of the chopped fibers and uneven mixing in the traditional dry mixing method are effectively solved. Further, by optimizing the fiber pretreatment process, the solvent usage is reduced, the production process is simplified, the production efficiency is improved, and the quality stability of the chopped fiber premix is ensured.

[0014] Optionally, the drying mechanism comprises a drying oven arranged along the conveying direction of the conveying belt, the drying oven is arranged on the upper side of the conveying belt, the drying oven is provided with an electric heating wire and a thermometer, and a tail gas reflux treatment assembly is further arranged on the drying oven and connected with the inside of the drying oven.

[0015] By adopting the above technical scheme, the electric heating wire in the drying oven ensures the uniformity and stability of the drying temperature, and is precisely adjustable, the thermometer monitors the temperature in the drying oven in real time, and the drying effect is ensured. The tail gas reflux treatment assembly effectively collects and treats the waste gas generated during the drying process, reduces environmental pollution, and improves production safety. This scheme not only simplifies the process flow, reduces the solvent usage, but also improves the quality of the chopped fiber premix, solves the problems of easy agglomeration of the fibers and uneven mixing in the traditional dry mixing method, and achieves the production goals of high efficiency and environmental protection. Optionally, the output end of the conveying belt is provided with a driving roller and a driving motor for driving the driving roller to rotate, the driving roller is arranged along the width direction of the conveying belt, and cleaning brushes are uniformly distributed on the outer periphery of the driving roller.

[0016] By adopting the above technical scheme, the driving roller and the cleaning brushes can effectively remove the residual fibers on the conveying belt during the preparation of the chopped fiber premix, prevent the accumulation of the chopped fibers on the conveying belt, ensure the uniform distribution and mixing effect of the subsequent chopped fibers, and improve the quality and production efficiency of the final product.

[0017] Optionally, the collecting mechanism comprises a collecting tank and a vacuum pump, the collecting tank is arranged below the cleaning brush, the upper end of the collecting tank is provided with an inlet opening opposite to the output end of the conveying belt, and the vacuum pump is connected with the collecting tank to form negative pressure in the collecting tank.

[0018] By adopting the technical scheme, the short-cut fiber premix is efficiently collected. Specifically, the collecting box is arranged below the cleaning brush, so that the short-cut fiber premix can be smoothly dropped into the collecting box after being cleaned by the cleaning brush; the vacuum pump is communicated with the collecting box, so that the negative pressure is formed in the collecting box, the collection efficiency of the fiber is further improved, the loss and pollution of the premix fiber premix are reduced, and the quality and purity of the short-cut fiber premix are ensured.

[0019] Optionally, the discharging funnel is a strip-shaped funnel, and a cross section of a discharging port of the discharging funnel is a rectangular frame type, and the discharging port of the discharging funnel is arranged along a width direction of the conveying belt.

[0020] By adopting the technical scheme, the short-cut fiber is uniformly distributed and smoothly discharged.

[0021] Optionally, a control structure for controlling a discharging speed of the short-cut fiber is arranged at the discharging port of the discharging funnel.

[0022] By adopting the technical scheme, the discharging speed of the short-cut fiber can be accurately controlled, the uniform distribution of the short-cut fiber on the conveying belt is ensured, the mixing uniformity of the fiber and the resin solution is improved, the fiber agglomeration is effectively prevented, and the quality of the final premix is improved.

[0023] In summary, the present application has at least one of the following beneficial technical effects:

[0024] 1. The device in the present application overcomes the defects of the dry mixing method, and effectively solves the problem that the irregular dispersion of the fiber filaments of the short-cut fiber during the matrix dispersion process leads to the agglomeration of the short-cut fiber, and affects the mixing uniformity.

[0025] 2. When the preparation device in the present application prepares the short-cut fiber premix, the spraying resin solution is used, the amount of solvent used is small, the production cost is reduced, and the adverse effects of the solvent residue on the fiber reinforced composite material are reduced.

[0026] 3. The preparation device in the present application has simple process, high automation degree and high production efficiency when preparing the short-cut fiber premix. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a front view structural schematic diagram of the preparation device in the present application.

[0028] Figure 2 is a partial three-dimensional structural schematic diagram of the preparation device in the present application.

[0029] In the drawings:

[0030] 10, conveying mechanism; 11, rack; 12, driving roller; 13, driven roller; 14, conveying belt;

[0031] 20, a feeding hopper;

[0032] 30, a spraying mechanism; 31, a storage box; 32, a spraying pipe; 33, a spraying head;

[0033] 40, a drying mechanism; 41, a drying oven; 42, a tail gas reflux treatment assembly;

[0034] 50, a collecting mechanism; 51, a collecting box;

[0035] 60, a cutting mechanism;

[0036] 70, a driving roller;

[0037] 80, a cleaning brush. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. Figure 1 - the accompanying drawings Figure 2 The embodiments described are only possible technical implementations of the present application, and are not all possible implementations. Those skilled in the art can certainly obtain other embodiments by combining the embodiments of the present application without creative labor, and these embodiments are also within the protection scope of the present application.

[0039] Referring to Figs. 1 and 2, Figure 1 and Figure 2 As shown in the drawings, the short-cut fiber premix preparation device in the present application comprises a conveying mechanism 10 for conveying short-cut fibers, a feeding hopper 20 for releasing short-cut fibers onto the conveying mechanism 10, a spraying mechanism 30 for spraying a resin solution onto the short-cut fibers on the conveying mechanism 10, and a drying mechanism 40 for drying the solution on the short-cut fibers, which are sequentially arranged above the conveying mechanism 10 along the conveying direction thereof, and a collecting mechanism 50 for collecting short-cut fiber premix arranged at the output end of the conveying mechanism 10.

[0040] Specifically, referring to Figs. 1 and 2, Figure 1 and Figure 2 As shown in the drawings, the conveying mechanism 10 comprises a rack 11, a driving roller 12 and a driven roller 13 which are arranged in parallel and at intervals on the rack 11, and a conveying belt 14 which is sleeved on the driving roller 12 and the driven roller 13; a cutting mechanism 60 for cutting long fibers into short-cut fibers is arranged above the input end of the conveying belt 14; the cutting mechanism 60 is a prior art, and its specific structure will not be described here. The feeding hopper 20 is a strip-shaped hopper, and the discharge port of the feeding hopper 20 is in the shape of a rectangular frame. The discharge port of the feeding hopper 20 is arranged along the width direction of the conveying belt 14, the inlet of the feeding hopper 20 is opposite to the discharge port of the cutting mechanism 60, and the discharge port of the feeding hopper 20 is located above the input end of the conveying belt 14, so that uniform distribution and smooth feeding of the short-cut fibers can be achieved.

[0041] Further, the discharge port of the feeding hopper 20 in the embodiment is provided with a control structure for controlling the feeding speed of the chopped fibers. Specifically, the control structure can be a valve provided at the discharge port of the feeding hopper 20, and the feeding speed of the chopped fibers in the feeding hopper 20 is controlled by controlling the opening degree of the valve. Alternatively, the control structure can be a guide plate provided at the discharge port of the feeding hopper 20, the guide plate is arranged obliquely, and one side of the guide plate is hinged to the bottom of the feeding hopper 20, and the feeding speed of the chopped fibers in the feeding hopper 20 is controlled by adjusting the oblique angle of the guide plate. In this way, the feeding speed of the chopped fibers can be accurately controlled and dynamically adjusted as needed, so as to ensure the uniform distribution of the chopped fibers on the conveying belt 14, and further improve the mixing uniformity of the fibers and the resin solution, effectively prevent the fiber from agglomeration, and improve the quality of the final premix.

[0042] Referring to Figure 2 The spraying mechanism 30 includes a storage tank 31 for storing the resin solution and a spraying pipe 32 arranged on the conveying belt 14, the spraying pipe 32 is arranged along the width direction of the conveying belt 14, one end of the spraying pipe 32 is in communication with the storage tank 31, and a plurality of nozzles 33 facing the conveying belt 14 are communicated on the spraying pipe 32. The installation position of the storage tank 31 can be higher than the position of the spraying pipe 32, the spraying pipe 32 is connected at the bottom position of the storage tank 31, and the spraying is automatically performed by the gravity of the resin solution, or a water pump is arranged on the spraying pipe 32, so that the resin solution is driven to flow to the nozzles 33 of the spraying pipe 32, the spraying operation of the resin solution is realized, and the uniform spraying of the chopped fibers during the conveying process is ensured.

[0043] Referring to Figure 2 The drying mechanism 40 includes an oven 41 arranged along the conveying direction of the conveying belt 14, and the oven 41 is arranged on the upper side of the conveying belt 14; the oven 41 is provided with an electric heating wire and a thermometer; and the oven 41 is further provided with an exhaust gas reflux treatment assembly 42 in communication with the inside of the oven 41. The electric heating wire ensures the uniformity and stability of the drying temperature, and is accurately adjustable, and the thermometer monitors the temperature in the oven 41 in real time, so as to ensure the drying effect. The exhaust gas reflux treatment assembly 42 can be a suction pump, and then the exhaust gas is recycled and filtered, and is discharged after reaching the environmental protection standard. The exhaust gas reflux treatment assembly 42 effectively collects and treats the waste gas generated in the drying process, and also recycles the solvent, reduces the cost, and reduces the environmental pollution. Referring to Figure 1 and Figure 2As shown, the output end of the conveying belt 14 is provided with a driving roller 70 and a driving motor for driving the driving roller 70 to rotate, the driving roller 70 is arranged along the width direction of the conveying belt 14, and the outer periphery of the driving roller 70 is uniformly provided with a cleaning brush 80. In this embodiment, the driving roller 70 and the cleaning brush 80 are used to effectively remove the residual fibers on the conveying belt 14, prevent the accumulation of the chopped fibers on the conveying belt 14, ensure the uniform distribution and mixing effect of the subsequent chopped fibers, and improve the quality and production efficiency of the final product. The collecting mechanism 50 includes a collecting box 51 and a vacuum pump, the collecting box 51 is arranged below the cleaning brush 80, the upper end of the collecting box 51 is provided with an inlet opening which is opposite to the output end of the conveying belt 14, and the vacuum pump is communicated with the collecting box 51 for forming negative pressure in the collecting box 51. The chopped fiber premix is smoothly dropped into the collecting box 51 after being removed by the cleaning brush 80; the negative pressure formed in the collecting box 51 further improves the collection efficiency of the fibers, reduces the loss and pollution of the premix fibers, and ensures the quality and purity of the chopped fiber premix.

[0044] The chopped fiber in the present application is a fiber with a length ranging from 3 mm to 25 mm, which can be glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, whisker, etc. The resin solution is a macromolecular polymer with solubility, which can be dissolved in an organic solvent or water, and can be any one or a mixture of multiple of phenolic resin, polyester resin, thermosetting polyimide resin, epoxy resin, furan resin.

[0045] The implementation principle of the present embodiment is that when the preparation device in the present application prepares the chopped fiber premix, 10 bundles of 12k and T700 carbon fiber filaments are cut into 10 mm chopped fibers at a speed of 20 m / min by passing through the cutting mechanism 60. The cut chopped fibers fall into the discharging hopper 20 and are laid on the conveying belt 14 at a discharging speed of 50 g / min; the phenolic resin is dissolved in 95% ethanol solution to prepare a resin solution with a viscosity of 2000 mPa·s, and the resin solution is placed in the storage box 31 of the spraying mechanism 30, the solution in the storage box 31 is pressurized by a water pump and sprayed out through the spray head 33, and then uniformly sprayed on the surface of the chopped fibers on the conveying belt 14, the spraying pressure is about 2.0-4.0 bar, and the spraying distance is 15-20 cm. The spraying process is carried out in a closed shell as much as possible; the chopped fibers sprayed with the resin solution enter the oven 41, the oven 41 is 15 meters long and is divided into five zones, each zone is 3 meters long, and the temperature devices are 60℃, 70℃, 80℃, 70℃ and 60℃ respectively, the oven 41 is provided with an exhaust gas reflux treatment assembly 42 at the top for treating the exhaust gas and recycling the solvent. The output end of the conveying belt 14 is provided with the cleaning brush 80 and the collecting box 51, and the chopped fibers sprayed with the resin and dried are collected into the collecting box 51.

[0046] The preparation device in the application can control and adjust the discharging speed of the chopped fibers, and can also control and adjust the speed of the conveying belt 14, so as to ensure that the chopped fibers are uniformly laid on the conveying mechanism 10 and stably move forward. The spraying mode is adopted, the amount of solvent used is small, the production cost is reduced, the adverse effects of solvent residues on the fiber reinforced composite material are reduced, and the problem that the irregular dispersion of the fiber filaments in the dispersion process of the chopped fibers leads to the agglomeration of the chopped fibers and affects the uniformity of the mixture is effectively solved. The entire preparation device has high automation degree, high work efficiency, and simplifies the production process, reduces the influence of human operation, and improves the quality consistency of the product.

[0047] The embodiments of the specific implementation are the preferred embodiments of the application, and are not intended to limit the protection scope of the application, wherein the same parts are denoted by the same reference numerals. Therefore: any equivalent changes made according to the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A device for preparing a short-cut fiber premix, characterized in that The application discloses a short-cut fiber mixing device.

2. The short fiber premix preparation apparatus according to claim 1, wherein The conveying mechanism (10) comprises a rack (11), driving rollers (12) and driven rollers (13) which are arranged in parallel and at intervals on the rack (11), and a conveying belt (14) which is sleeved on the driving rollers (12) and the driven rollers (13).

3. The short fiber premix preparation apparatus according to claim 2, wherein The spraying mechanism (30) comprises a storage tank (31) for storing a resin solution and a spraying pipe (32) which is arranged on the conveying belt (14) and in the width direction of the conveying belt (14), one end of the spraying pipe (32) is communicated with the storage tank (31), and a plurality of nozzles (33) which are directed to the conveying belt (14) are communicated on the spraying pipe (32).

4. The short-cut fiber premix production apparatus according to claim 2 or 3, characterized in that, The drying mechanism (40) comprises an oven (41) which is arranged in the conveying direction of the conveying belt (14) and covers the upper side of the conveying belt (14), an electric heating wire and a thermometer are arranged in the oven (41), and an exhaust gas backflow treatment assembly (42) which is communicated with the inside of the oven (41) is further arranged on the oven (41).

5. The short-cut fiber premix production apparatus according to claim 2 or 3, characterized in that, The output end of the conveying belt (14) is provided with a driving roller (70) and a driving motor which drives the driving roller (70) to rotate, the driving roller (70) is arranged in the width direction of the conveying belt (14), and cleaning brushes (80) are uniformly distributed on the outer circumferential surface of the driving roller (70).

6. The short fiber premix preparation apparatus according to claim 5, wherein The collecting mechanism (50) comprises a collecting tank (51) and a vacuum pump, the collecting tank (51) is arranged below the cleaning brushes (80), the upper end feeding opening of the collecting tank (51) is opposite to the output end of the conveying belt (14), and the vacuum pump is communicated with the collecting tank (51) and is used for forming negative pressure in the collecting tank (51).

7. The short-cut fiber premix production apparatus according to claim 2 or 3, characterized in that, The discharging funnel (20) is a strip-shaped funnel, the discharging opening of the discharging funnel (20) is in a rectangular frame type, and the discharging opening of the discharging funnel (20) is arranged in the width direction of the conveying belt (14).

8. The short fiber premix preparation apparatus according to claim 7, wherein The discharging opening of the discharging funnel (20) is provided with a control structure which is used for controlling the discharging speed of the short-cut fibers.

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