CN111087973A - Preparation device and preparation method of vegetable fiber fermentation modified reinforced friction material - Google Patents

Abstract

The invention discloses a preparation device of a plant fiber fermentation modified reinforced friction material, which consists of a reinforced fiber orientation preparation device, a mixed material heating and filling device and a fixed base plate, wherein the reinforced fiber orientation preparation device and the mixed material heating and filling device are fixed on the fixed base plate. The modified fiber and the device have better adaptability, and finally the modified plant fiber with consistent orientation is formed in the finished product of the friction material. The invention also discloses a preparation method of the plant fiber fermentation modified reinforced friction material, and discloses a plant fiber fermentation modification treatment method, which can be used for accurately improving the components and the structure of the fiber, and improving the dispersibility and the interfacial adhesion between the fiber and a matrix.

Description

Preparation device and preparation method of vegetable fiber fermentation modified reinforced friction material

Technical Field

The invention relates to the technical field of brake friction materials, in particular to a preparation device and a preparation method of a plant fiber fermentation modified reinforced friction material.

Background

Friction materials are component materials that rely on friction to perform braking, transmission, or energy transfer functions in a mechanical system, and play an important role in the efficiency and safety of mechanical system operation. The fiber reinforced material is a base material for forming the friction material, which endows the friction product with enough mechanical strength, and because the traditional asbestos fiber material is forbidden, the development of the fiber reinforced material for replacing the fiber becomes a difficult problem to be solved urgently in the field of the brake friction material. Because plant fibers are low in cost, degradable and free of pollution to the environment, the plant fibers are excellent reinforcing fiber choices, but the plant fibers are low in mechanical strength, and usually need to be modified (alkali treatment, coupling agent treatment, discharge treatment and the like) to improve the interface bonding strength between the fibers and a matrix and improve the high-temperature and high-pressure stability, and for example, modified wheat straw fibers (application No. 201610727120.0), modified sisal fibers (application No. 201010143504.0), modified bamboo fibers (application No. 201810941675.4) and the like can be applied to friction materials. As the main components of the plant fiber are cellulose, hemicellulose, lignin and the like, most fiber modification schemes cannot accurately modify specific components, so that the modification effect is limited, and the performance of the finished friction material is limited.

Meanwhile, the working performance of the plant fiber reinforced friction material is not only related to the selection of the fiber type, but also the structure of the plant fiber in the friction material can directly influence the friction performance, researches show that the mechanical property of the material is obviously related to the fiber orientation, if the arrangement mode of the fiber in the friction material can be controlled, the performance of the friction material can be further improved, the fiber orientation can be controlled by an orientation spray head (application number 201710833450.2), a fiber extrusion unit (application number 201810342589.1), 3D printing (application number 201910237087.7) and other modes at the present stage, but the processes of material mixing, heating, mould pressing and the like are usually needed in the preparation process of the friction material, under the condition of ensuring the consistent fiber orientation, the orientation is damaged due to multiple processing, and the finished product performance of the friction material is further influenced.

In summary, the coupling degree of the existing friction material plant reinforced fiber modification method and the orientation positioning device is low, and there is no method that simultaneously satisfies the high efficiency modification and the accurate orientation positioning in the friction material field, and how to keep the high cooperation of the modification method and the orientation method in the friction material is a technical problem that needs to be solved by the technicians in the field.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a preparation method and a device of a plant fiber fermentation modified reinforced friction material. The first purpose of the invention is to provide an efficient plant fiber modification mode, which can accurately improve the components and the structure of the fiber, and improve the dispersibility and the interfacial adhesion between the fiber and a matrix; another purpose is to design a corresponding reinforced fiber orientation preparation device aiming at the modified plant fiber, so that the modified fiber has better adaptability with the device, and finally the modified plant fiber with consistent orientation is formed in the finished product of the friction material.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a plant fiber fermentation modified reinforced friction material preparation device, which consists of a reinforced fiber orientation preparation device, a mixed material heating and filling device and a fixed base plate, wherein the reinforced fiber orientation preparation device and the mixed material heating and filling device are fixed on the fixed base plate;

the reinforced fiber orientation preparation device comprises an organic glass cover, a vacuum valve combination, an organic glass cover plate, a special-shaped funnel sieve, a filler base, a vacuum air pump, an eccentric vibration motor and a fixing frame; the sieve plate combination is fixed in the organic glass cover through a bolt pair, and the special-shaped funnel sieve is fixed in the organic glass cover through a bolt pair and is positioned below the sieve plate combination; the fixing frame is fixed on the outer side of the lower end of the organic glass cover through a bolt pair, the eccentric vibration motor is fixed on the fixing frame through the bolt pair, and the lower end of the fixing frame is fixedly connected to the base through a spring; the filler base is magnetically adsorbed on the fixing frame; the organic glass cover plate is hermetically connected to the top of the organic glass cover, and the vacuum valve assembly is fixed to the top of the organic glass cover plate and communicated with the organic glass cover; the vacuum air pump is positioned outside the organic glass cover and is connected with the vacuum valve through an air duct in a combined manner;

the mixed material heating and filling device consists of a filler interface, a supporting seat, a temperature controller, an electromagnetic coil and a temperature control circuit, wherein the filler interface is arranged at the upper end of the supporting seat; a rectangular groove for placing a filler base and a circular groove for placing an electromagnetic coil are arranged in the supporting seat; the temperature controller and the temperature control circuit are fixedly connected on the fixed bottom plate and control the temperature of the electromagnetic coil together.

Further, the preparation device further comprises an upper silica gel pad and a lower silica gel pad, the upper silica gel pad and the lower silica gel pad are respectively connected to the upper end and the lower end of the organic glass cover in a sealing mode, the upper silica gel pad is compacted by the organic glass cover plate, and the lower silica gel pad is magnetically adsorbed on the fixing frame through the packing base.

Furthermore, the sieve plate combination comprises an upper sieve plate and a lower sieve plate, and the lower sieve plate is connected below the upper sieve plate in a sliding manner; the upper sieve plate consists of a fixed grid plate and a slide rail which are fixedly connected together to provide a moving track for the lower sieve plate, through holes which are uniformly distributed are arranged on the periphery of the fixed grid plate, and each through hole extends to the bottom of the upper sieve plate; the lower sieve plate is composed of a movable sieve plate and a linear motion bearing, and the linear motion bearing is connected to the sliding rail in a sliding mode.

Furthermore, in the special-shaped funnel screen structure, cone structures which are uniformly distributed are arranged above the screen body, and the screen holes on the screen body are also cone structures and used for guiding fibers to vertically fall into the screen holes; the sizes of the sieve holes of the sieve body are changed according to the fibers with different diameters, so that the final friction material finished product can be a fiber bundle orientation reinforcing structure or a single fiber orientation reinforcing structure;

the invention also provides a preparation method of the plant fiber fermentation modified reinforced friction material, which adopts the preparation device of the plant fiber fermentation modified reinforced friction material, and the preparation method sequentially comprises four stages, wherein the first stage is 'plant fiber fermentation modification', the second stage is 'reinforced fiber orientation preparation', the third stage is 'mixed material heating filling', and the fourth stage is 'friction material preparation';

in the plant fiber fermentation modification stage, the surface structure and the internal components of the plant fiber are changed through cellulose chemical reagent treatment, enzyme treatment and fermentation treatment, so that the compatibility of the fiber and a base material is improved, the gravity center position of the fiber is changed, and the fiber can fall in the vertical direction in the free falling process;

the preparation stage of the orientation of the reinforced fibers is carried out by a reinforced fiber orientation preparation device, the fibers vertically fall into a filler base under the multiple actions of free falling of the fibers, negative pressure vacuum and mechanical vibration, and are fixed by the orientation of a hot melt adhesive in the filler base;

in the mixed material heating and filling stage, the filler is heated while the mixed material is mixed, so that the hot-melt adhesive is heated and volatilized, the mixed material is filled into a filler base for prepressing, and preliminary molding is performed;

and the friction material preparation stage is to stack a plurality of fillers subjected to pre-pressing forming in sequence and finally place the fillers in a mould for pressing forming.

The invention also provides a plant fiber fermentation modification treatment method, which comprises the following steps:

step 1, putting plant fibers into distilled water at the temperature of 40-50 ℃ for 2-2.5 hours, after the fibers fully absorb water, cleaning for 0.5-1 hour by using an ultrasonic cleaning machine, and removing a large amount of stains on the surfaces of the plant fibers and a small amount of stains in the plant fibers;

step 2, adding the cleaned plant fiber into a vinyl triethoxysilane coupling agent, wherein the using amount of the coupling agent is 5-10% of the mass of the plant fiber, adding water, uniformly stirring, and reacting for 40-60 min, wherein the using amount of the water is 150-300% of the mass of the plant fiber;

step 3, adding the treated fiber into water, wherein the amount of the water is 100-150% of the mass of the plant fiber, adding ligninase, the content of the ligninase is 1-2% of the mass of the plant fiber, and putting the mixture into a fermentation tank for fermentation at 40 ℃ for 24-30 hours;

step 4, cleaning the plant fibers with water, and then putting the plant fibers into sodium hydroxide alkali liquor with the mass fraction of 0.2-2%, wherein the use amount of the alkali liquor is 100-500% of the mass of the fibers;

step 5, cleaning the plant fibers with distilled water, and drying in a constant-temperature drying oven for 60-120 min at the drying temperature of 70-80 ℃ to obtain a dried fiber sample;

and 6, cutting the fiber to 5-10 mm by using a fiber cutting machine, and filtering fine fibers by using a mesh screen to obtain a final fiber sample.

Compared with the prior art, the invention has the beneficial effects that:

(1) high accuracy of orientation control

The prior art realizes orientation selection only by operating a single fiber, such as an orientation nozzle, a 3D printing technology and the like, can not realize batch fiber control, and has poor compatibility for subsequent reprocessing after the fiber orientation is determined.

(2) Wide application range

Most of the plant fibers are composed of cellulose, hemicellulose and lignin, so the fermentation modification method has universality, and aiming at the treatment of plant fiber components and structures, the modification method can greatly treat impurities such as lignin, hemicellulose and the like, and simultaneously strengthens the cellulose structure, thereby ensuring that the modified plant fibers still have excellent mechanical properties and material compatibility.

(3) Simple process flow

The process flow related by the invention utilizes the phenomenon that an object is not subjected to air resistance under the vacuum condition, combines the effects of free falling, negative pressure vacuum and mechanical vibration, ensures that the modified fiber can control the orientation of the modified fiber without a complex process according to the characteristics of uneven structure and center-of-gravity shift.

Drawings

FIG. 1 is an isometric view of a friction material making apparatus

FIG. 2 is a partial cross-sectional view of the friction material manufacturing apparatus taken along the axis

FIG. 3 is an exploded view of an apparatus for manufacturing orientation of reinforcing fiber

FIG. 4 is an axonometric view of a sliding combined sieve plate structure

FIG. 5 is a schematic view showing an open/close state of a screen plate

FIG. 6 shows a mixing, heating and filling apparatus

FIG. 7 is an axonometric view and internal structure of a shaped funnel screen

FIG. 8 is a top and bottom view of a contoured funnel screen

FIG. 9 is an isometric view of a packing base

FIG. 10 is a schematic view of the distribution of modified plant fibers

FIG. 11 is a schematic view of the upper and lower surfaces of the fixing frame structure

FIG. 12 is a schematic view of a vacuum valve assembly

FIG. 13 is a flow chart of a friction material preparation process

FIG. 14 shows the surface structure of modified plant fiber

In the figure: 1. a reinforcing fiber orientation producing device; 2. a mixed material heating and filling device; 3. a base; 101. an organic glass cover; 102. a vacuum valve assembly; 103. an air duct; 104. an organic glass cover plate; 105. coating a silica gel pad; 106. an upper sieve plate; 107. a lower sieve plate; 108. a special-shaped funnel sieve; 109. a silica gel pad is arranged; 110. a filler base; 111. a vacuum air pump; 112. an eccentric vibration motor; 113. a fixed mount; 114. a spring; 1061. fixing a grid plate; 1062. a slide rail; 1071. moving the grid plate; 1072. a linear motion bearing; 201. a filler interface; 202. a supporting seat; 203. a temperature controller; 204. an electromagnetic coil; 205. a temperature control circuit; 1101. a filler housing; 1102. a magnet placement hole; 4. modifying the plant fiber; 5. a hot melt adhesive; 1021. four-way connection; 1022. an air extraction valve; 1023. an air intake valve; 1024. a negative pressure gauge; 1025. and (4) exhausting the valve.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that certain terms of orientation or positional relationship are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In the description of the present invention, it should be noted that "connected" is to be understood broadly, for example, it may be fixed, detachable, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in FIG. 1, the friction material manufacturing apparatus provided by the present invention is composed of a reinforcing fiber orientation manufacturing apparatus 1, a mixed material heating and filling apparatus 2, and a fixing base plate 3. The device 1 for preparing the orientation of the reinforced fiber is responsible for adjusting the orientation of the fermented and modified plant fiber, so that the finally prepared fiber sample has highly consistent orientation; the mixed material heating and filling device 2 is responsible for uniformly mixing the prepared orientation fibers in the reinforced fiber orientation preparation device 1 so as to facilitate subsequent operations such as prepressing and mould pressing; the base 3 is used for fixing the two devices.

Fig. 2 shows the positional relationship of the internal structures of the reinforcing fiber orientation producing apparatus 1 and the kneaded material heating and filling apparatus 2, and it can be seen from the partial sectional view of the key position that the reinforcing fiber orientation producing apparatus 1 is always in a vacuum state during the operation, and therefore the inside is always a closed space in an operating state after the fiber filling; the mixing heating filling device 2 is an open space, and other friction material fillers are filled from the upper part.

Fig. 3 is a detailed structure of the reinforced fiber orientation preparation apparatus 1, which is composed of an organic glass cover 101, a vacuum valve assembly 102, an air duct 103, an organic glass cover plate 104, an upper silica gel pad 105, an upper sieve plate 106, a lower sieve plate 107, an irregular funnel sieve 108, a lower silica gel pad 109, a packing base 110, a vacuum air pump 111, an eccentric vibration motor 112, a fixing frame 113, a spring 114, and the like, where the spatial position relationship among the above components is shown in fig. 3, where the upper end and the lower end of the organic glass cover 101 are respectively provided with through holes on both sides of the cover body, the upper sieve plate 106 is fixed in the organic glass cover 101 by the upper end through hole through a bolt pair, and the irregular funnel sieve 108, the organic glass cover 101, and the fixing frame 113 are fixed; the eccentric vibration motor 112 is fixed on the fixed frame 113 through a bolt pair; the springs 114 are fixedly connected with the lower end of the fixed frame 113, the number of the springs is 4 for keeping the balance of the operation state, the upper ends of the springs are respectively fixedly connected with four corners of the fixed frame 113, and the lower ends of the springs are fixedly connected with the base 3; the upper silica gel pad 105 and the lower silica gel pad 109 are respectively tightly attached to the upper end and the lower end of the organic glass cover, wherein the upper silica gel pad 105 is compacted by the organic glass cover plate 104, and the lower silica gel pad 109 is magnetically adsorbed on the fixing frame 113 by the filler base 110; a threaded through hole is formed in the center of the organic glass plate, so that gas in the device can be directly connected to the vacuum valve assembly 102; the vacuum pump 111 outside the organic glass cover is directly connected with the vacuum valve combination through the air duct 103, and the inside of the glass cover is directly communicated with the vacuum pump 111.

Fig. 4 is a schematic structural diagram of the upper sieve plate 106 and the lower sieve plate 107, wherein the upper sieve plate is composed of a fixed grid plate 1061 and a slide rail 1062, which are fixedly connected together, a moving track is provided for the lower sieve plate 107, through holes are uniformly distributed around the fixed grid plate 1061, each through hole extends to the bottom of the upper sieve plate 106, when the air pumping stage is performed, the upper sieve plate 106 and the lower sieve plate 107 are in a closed state, the sieve plate and the organic glass cover plate 104, the upper silica gel pad 105 three form a closed space, if no through hole is provided, the gas in the device cannot be sucked out by a vacuum pump, the cavity vacuum effect cannot be realized, and through the arrangement of the through hole, the pressure balance of the whole cavity inside the device is ensured. The lower sieve plate 107 is composed of a movable sieve plate 1071 and a linear motion bearing 1072, the linear motion bearing 1072 can move on a slide rail 1062 during operation, the staggered range of the upper sieve plate 106 and the lower sieve plate 107 is controlled according to the moving distance, the sieve plate is opened and closed, and the linear motion bearing 1072 can be adsorbed by a magnetic material, so that after the whole device is assembled, the movement of the lower sieve plate 107 is controlled by using a strong magnet at the corresponding position outside the device, and the adjustment of the working state of the sieve plate under the internal closed condition of the device is realized.

Fig. 5 is a schematic diagram of the opened/closed states of the upper screen deck and the lower screen deck, in which h represents the maximum distance that the lower screen deck 107 can move on the slide rail, and as shown in the left-right relationship in the diagram, when the lower screen deck 107 moves to the leftmost side, the screen deck holes of the fixed screen deck 1061 and the movable screen deck 1071 coincide with each other, and at this time, the modified fibers on the upper screen deck 106 may drop to the shaped funnel screen 108; when the lower screen deck 107 moves to the rightmost side, the screen deck holes of the fixed screen deck 1061 and the movable screen deck 1071 are completely staggered, and the modified fibers on the upper screen deck cannot fall to the special-shaped funnel screen 108. According to the movable characteristic of the sieve plate combination, the opening/closing state of the sieve plate can be controlled outside the whole reinforced fiber orientation preparation device 1, and the purpose of freely controlling the falling time of the modified fibers in a closed state of the device is achieved. When the sieve plate is in a closed state, the modified fibers are placed on the upper sieve plate 106, the organic glass plate 104 is closed after the modified fibers are completely sealed, and after the whole organic glass cover 101 is completely sealed, the linear moving bearing 1072 is adsorbed on the outer side through a strong magnet, so that the sieve plate is changed from the closed state to an open state.

Fig. 6 is a detailed structure of the mixed material heating and filling device 2, which is composed of a filler interface 201, a support base 202, a temperature controller 203, an electromagnetic coil 204, and a temperature control circuit 205, when the mixed material heating and filling device 2 is used, the reinforced fiber orientation preparation device 1 is operated completely, the filler base 110 has vertically upward oriented fibers uniformly arranged therein, the filler base is fixed in a rectangular groove of the support base 202, the upper side of the filler base is fixed by the filler interface 201, the lower side of the filler base is heated by the electromagnetic coil 204 fixed in a circular groove, the heating strength is adjusted by the temperature controller 203 and the temperature control circuit 205, when other friction material fillers are filled into the filler base 110 through the filler interface 201, the fillers are heated to melt and evaporate the hot melt adhesive, and then the fillers are pre-pressed to further fix the fibers and the fillers.

Fig. 7 is an axonometric view and an internal structure of the special-shaped funnel sieve 108, fig. 8 is a top view and a bottom view of the special-shaped funnel sieve, the structure has the functions of sorting and sieving funnels, cone structures which are uniformly distributed are arranged above a sieve body, when modified fibers fall to the side surface of a cone, the cone cannot provide a stable supporting plane for the fibers, so the fibers can be inclined vertically downwards and fall into sieve holes, and the side surface of the sieve holes is still designed into the cone structures according to the internal structure diagram, so that the fibers can be further guided to fall into the sieve holes vertically; as can be seen from fig. 8, the size of the openings of the shaped funnel determines the throughput of the fibers, so that the size of the openings of the screen plate can be changed according to the fibers with different diameters, so that the final friction material product can be a fiber bundle orientation enhancing structure or a single fiber orientation enhancing structure.

Fig. 9 is an isometric view of a packing base, wherein the packing base 110 is composed of a packing housing 1101 and a magnet placing hole 1102, and because the packing base 110 is applied to both the reinforced fiber orientation preparation device 1 and the mixed material heating and filling device 2, it is required to ensure that the device can be easily disassembled, and a strong magnet with the same size as the placing hole is filled in the magnet placing hole 1102, and when in use, the packing base can be adsorbed at the fixing frame 113 of the reinforced fiber orientation preparation device 1 and also can be adsorbed at the supporting seat 202 of the mixed material heating and filling device 2.

Fig. 10 is a schematic diagram showing the distribution of modified plant fibers, in which the modified plant fibers 4 fall between the shaped funnel sieve 108 and the filler base 110 after the fibers are in the operation of the reinforced fiber orientation preparation device 1 and before the operation of the mixed material heating and filling device 2, and the modified plant fibers are coated with a hot melt adhesive 5 having a certain thickness in order to ensure that the fibers can maintain the vertical orientation even after the filler base 110 is taken out, and the modified plant fibers can be adhered to the filler base 110 after the hot melt adhesive 5 is dried in the air, thereby achieving the stabilization of the orientation.

Fig. 11 is a schematic structural diagram of the upper surface and the lower surface of the fixing frame structure, the fixing frame 113 plays a role of connecting the special-shaped funnel screen 108 and the organic glass cover 101, and simultaneously, two eccentric vibrating motors 112 can be fixed through threaded holes arranged on the surface; on the lower surface of the fixing frame, 4 round tables with the same structure are processed for fixing the function of the spring 114.

Fig. 12 is a schematic diagram of a vacuum valve assembly, which is composed of a four-way 1021, an air suction valve 1022, an air suction valve 1023, a negative pressure gauge 1024, and an air discharge valve 1025. Wherein the air suction valve 1023 sucks air into the reinforced fiber orientation production apparatus 1 through the organic glass cover plate 104, so that negative pressure occurs inside the apparatus; the air pumping valve 1022 is connected with the air duct 103 and the vacuum air pump 111 and is responsible for providing an air suction power source; the negative pressure meter 1024 is used for observing the internal pressure condition of the device; after all the modified fibers are screened, the exhaust valve 1025 is opened to allow external air to enter the device, and meanwhile, downward pushing force is generated on the vertically oriented modified fibers to further fix the fiber orientation.

Fig. 13 is a flow chart of a method for preparing a fiber fermentation modified reinforced friction material according to the present invention, wherein the flow chart is sequentially divided into four stages and six steps, wherein the first stage is "plant fiber fermentation modification", the second stage is "reinforced fiber orientation preparation", the third stage is "mixed material heating filling", and the fourth stage is "friction material preparation". In the first stage, the plant fiber fermentation modification is realized by mainly changing the surface structure and the internal components of the plant fiber through the means of cellulose chemical reagent treatment, enzyme treatment, fermentation treatment and the like, so that the compatibility of the fiber and a base material is improved, and the gravity center position of the fiber is changed, so that the fiber can fall in the vertical direction in the free falling process; in the second stage, the "reinforced fiber orientation preparation device 1" in the friction material preparation device is operated, the modified fibers 4 prepared in the previous stage are placed on the inner sieve plate 106 of the device, then the vacuum valve assembly 102 is used for exhausting air to enable the interior to reach a vacuum state, the eccentric vibration motor 112 is turned on to enable the reinforced fiber orientation preparation device 1 to be in a vibration state, after the sieve plate 106 is opened, the modified fibers 4 can freely fall down due to the action of gravity, at the moment, due to the fact that air resistance basically disappears, the modified fibers 4 can fall down in the vertical direction, and through further adjustment of the special-shaped funnel sieve 108, the modified fibers 4 finally keep the vertical direction and fall into the filler base 110. Because the filler base 110 is filled with a layer of liquid hot melt adhesive 5, after the hot melt adhesive 5 is solidified and the filler base 110 is removed, the modified fibers 4 can still be vertically and uniformly arranged in the filler base 110; the third stage is to operate through the part of the mixing heating and filling device 2 in the friction material preparation device, the filling base 110 removed in the second stage is installed in the mixing heating and filling device 2, because the hot-melt adhesive 5 is air-dried, the orientation of the modified fiber 4 can be kept unchanged all the time in the moving process of the filling base 110, after the filling base 110 is placed in the groove of the supporting seat 202, the filling interface 201 is covered, other necessary fillers of the friction material are filled, meanwhile, the switch of the temperature controller 203 is opened, the constant temperature heating is carried out for 3min at 160 ℃, the hot-melt adhesive 5 is completely volatilized, the filling base 110 without the hot-melt adhesive 5 is taken out, and the pre-pressing is carried out through a hydraulic machine at a small pressure. And the fourth stage is final friction material preparation, the mixing blocks subjected to pre-pressing forming in the third stage are taken out, the previous three stages are repeated for many times, a plurality of mixing blocks are overlapped, the mixing blocks are placed in a die for pressing, and finally the final sample is pressed.

The invention also provides a plant fiber fermentation modification treatment method, which is characterized by comprising the following steps:

step 1, putting the plant fiber into distilled water at the temperature of 40-50 ℃ for 2-2.5 hours, and after the fiber fully absorbs water, cleaning for 0.5-1 hour by using an ultrasonic cleaning machine to remove a large amount of stains on the surface of the plant fiber and a small amount of stains inside the plant fiber.

And 2, adding the cleaned plant fiber into a vinyl triethoxysilane coupling agent, wherein the using amount of the coupling agent is 5-10% of the mass of the plant fiber, adding water, uniformly stirring, and reacting for 40-60 min, wherein the using amount of the water is 150-300% of the mass of the plant fiber.

And 3, adding the treated fiber into water, wherein the amount of the water is 100-150% of the mass of the plant fiber, adding ligninase, the content of the ligninase is 1-2% of the mass of the plant fiber, and putting the mixture into a fermentation tank for fermentation at 40 ℃ for 24-30 hours.

And 4, cleaning the plant fibers with water, and then putting the plant fibers into sodium hydroxide alkali liquor with the mass fraction of 0.2-2%, wherein the use amount of the alkali liquor is 100-500% of the mass of the fibers.

And 5, cleaning the plant fibers with distilled water, and drying in a constant-temperature drying oven for 60-120 min at the drying temperature of 70-80 ℃ to obtain a dried fiber sample.

And 6, cutting the fiber to 5-10 mm by using a fiber cutting machine, and filtering fine fibers by using a mesh screen to obtain a final fiber sample.

Fig. 14 shows the surface structure of the modified plant fiber, in which the fiber surface is damaged more, mainly because lignin in the fiber structure is decomposed during the ligninase fermentation treatment, and most of hemicellulose is removed during the further treatment of the fiber with an alkali solution, and the uniform structure of the internal components of the fiber is destroyed, so that the center of the entire fiber is shifted, and the fiber can be subjected to free-fall movement with the center of gravity down during the adjustment of the fiber orientation, so that the orientation can be adjusted.

All the processing methods of the present invention are further described below by way of examples.

Example 1 preparation of a corn stalk fiber fermentation modified reinforced Friction Material

Step 1, pretreatment of corn straw fiber, which comprises the following specific steps:

step 1.1, putting the corn straw fiber into distilled water at the temperature of 40-50 ℃ for 2.5 hours, and after the fiber fully absorbs moisture, cleaning for 1 hour by using an ultrasonic cleaning machine.

Step 1.2, adding the cleaned corn straw fiber into a vinyl triethoxysilane coupling agent, wherein the dosage of the coupling agent is 10% of the mass of the corn straw fiber, adding water, stirring uniformly, and reacting for 60min, wherein the dosage of the water is 300% of the mass of the plant fiber.

Step 1.3, adding the treated corn straw fiber into water, adding lignin enzyme, wherein the amount of the water is 150% of the mass of the corn straw fiber, the content of the lignin enzyme is 2% of the mass of the corn straw fiber, and putting the mixture into a fermentation tank for fermentation for 24 hours at 40 ℃.

Step 1.4, washing the corn straw fiber with water, and then putting the corn straw fiber into sodium hydroxide alkali liquor with the mass fraction of 2%, wherein the dosage of the alkali liquor is 200% of the mass of the fiber.

Step 1.5, cleaning the corn straw fiber with distilled water, and drying in a constant-temperature drying oven for 120min at the drying temperature of 80 ℃ to obtain a dried fiber sample.

Step 1.6 fiber was cut to 8mm using a fiber cutter and fine fiber was filtered off using a mesh screen to obtain the final fiber sample.

Step 2, adjusting the fiber orientation of the modified corn straws by using a reinforced fiber orientation preparation device, and specifically comprises the following steps:

and 2.1, closing the sieve plate, placing the modified corn straw fibers on the sieve plate, covering the organic glass plate, checking the air tightness of the device, and ensuring the air leakage-free condition.

And 2.2, closing the exhaust valve, opening the suction valve, starting the vacuum pump, continuously sucking the air in the suction device, and observing the negative pressure meter until a specified negative pressure state value is reached.

And 2.3, turning on a vibration motor to enable the device to continuously vibrate under the assistance of a spring.

And 2.4, opening the sieve plate to enable the modified corn straw fibers to freely fall under the action of gravity until the fibers fall into the special-shaped funnel sieve and then slide into the sieve pores.

And 2.5, observing that all the modified corn straw fibers fall to the hot-melt adhesive in the filler base, and ensuring that one end of the fibers is in the special-shaped funnel sieve and the other end of the fibers is adhered by the hot-melt adhesive.

And 2.6, turning off the vibration motor and waiting for the device to be gradually stable.

And 2.7, closing the vacuum pump, closing the air suction valve, opening the exhaust valve, enabling air to enter the device, and further adhering the fibers by the hot melt adhesive under the pushing of the air.

And 2.8, taking out the filler base after the hot-melt adhesive is completely adhered.

And 3, filling on the basis of the modified corn straw fiber by using a mixed material heating and filling device, and specifically comprising the following steps:

and 3.1, placing the filler base in the rectangular groove of the supporting seat, and covering the filler interface.

And 3.2, adding phenolic resin, vermiculite powder, calcium carbonate, crystalline flake graphite, friction powder, composite mineral fiber, petroleum coke, zirconium silicate, aluminum oxide, zinc stearate, precipitated barium sulfate and the like from the filler interface to ensure that all the fillers can be filled into the filler base.

And 3.3, opening a switch of a temperature controller, adjusting the temperature to 160 ℃, and heating for 3 min.

And 3.4, observing the condition of the hot-melt adhesive, and closing a switch of the temperature controller after the hot-melt adhesive is completely volatilized.

And 3.5, taking out the filler base, putting the filler base into a hydraulic press for prepressing at the prepressing pressure of 3MPa, and preparing the flaky mixing model.

And 4, a friction material preparation process.

And 4.1, sequentially overlapping a plurality of sheet-shaped prepressing mixing models together, and controlling the number of the mixing models according to the size of the mould.

And 4.2, placing the plurality of pre-pressed mixing models after being overlapped into a mould, and pressing under a hydraulic press at the pressure of 45 MPa.

Claims (6)

1. A plant fiber fermentation modified reinforced friction material preparation device is characterized by comprising a reinforced fiber orientation preparation device, a mixed material heating and filling device and a fixed base plate, wherein the reinforced fiber orientation preparation device and the mixed material heating and filling device are fixed on the fixed base plate;

the reinforced fiber orientation preparation device comprises an organic glass cover, a vacuum valve combination, an organic glass cover plate, a special-shaped funnel sieve, a filler base, a vacuum air pump, an eccentric vibration motor and a fixing frame; the sieve plate combination is fixed in the organic glass cover through a bolt pair, and the special-shaped funnel sieve is fixed in the organic glass cover through a bolt pair and is positioned below the sieve plate combination; the fixing frame is fixed on the outer side of the lower end of the organic glass cover through a bolt pair, the eccentric vibration motor is fixed on the fixing frame through the bolt pair, and the lower end of the fixing frame is fixedly connected to the base through a spring; the filler base is magnetically adsorbed on the fixing frame; the organic glass cover plate is hermetically connected to the top of the organic glass cover, and the vacuum valve assembly is fixed to the top of the organic glass cover plate and communicated with the organic glass cover; the vacuum air pump is positioned outside the organic glass cover and is connected with the vacuum valve through an air duct in a combined manner;

the mixed material heating and filling device consists of a filler interface, a supporting seat, a temperature controller, an electromagnetic coil and a temperature control circuit, wherein the filler interface is arranged at the upper end of the supporting seat; a rectangular groove for placing a filler base and a circular groove for placing an electromagnetic coil are arranged in the supporting seat; the temperature controller and the temperature control circuit are fixedly connected on the fixed bottom plate and control the temperature of the electromagnetic coil together.

2. The device for preparing a vegetable fiber fermentation modified reinforced friction material according to claim 1, further comprising an upper silica gel pad and a lower silica gel pad, wherein the upper silica gel pad and the lower silica gel pad are respectively connected to the upper end and the lower end of the organic glass cover in a sealing manner, the upper silica gel pad is compacted by the organic glass cover plate, and the lower silica gel pad is magnetically adsorbed on the fixing frame by the packing base.

3. The apparatus for preparing friction-enhancing material by fermenting plant fiber according to claim 1, wherein the sieve plate assembly comprises an upper sieve plate and a lower sieve plate, the lower sieve plate is slidably connected below the upper sieve plate; the upper sieve plate consists of a fixed grid plate and a slide rail which are fixedly connected together to provide a moving track for the lower sieve plate, through holes which are uniformly distributed are arranged on the periphery of the fixed grid plate, and each through hole extends to the bottom of the upper sieve plate; the lower sieve plate is composed of a movable sieve plate and a linear motion bearing, and the linear motion bearing is connected to the sliding rail in a sliding mode.

4. The device for preparing the vegetable fiber fermentation modified reinforced friction material as claimed in claim 1, wherein the shaped funnel screen structure is provided with uniformly distributed cone structures above the screen body, and the screen holes on the screen body are also cone structures for guiding the fibers to vertically drop into the screen holes; the sizes of the screen body screen holes are changed according to the fibers with different diameters, so that the final friction material finished product can be a fiber bundle orientation reinforcing structure or a single fiber orientation reinforcing structure.

5. A preparation method of a plant fiber fermentation modified reinforced friction material is characterized in that the preparation method of the plant fiber fermentation modified reinforced friction material preparation device of claim 1 sequentially comprises the following four stages:

in the stage of fermentation modification of the plant fibers, the surface structure and the internal components of the plant fibers are changed through cellulose chemical reagent treatment, enzyme treatment and fermentation treatment, so that the compatibility of the fibers and a base material is improved, the gravity center position of the fibers is changed, and the fibers can fall in the vertical direction in the process of free falling;

the preparation stage of the orientation of the reinforced fiber is carried out by a reinforced fiber orientation preparation device, the fiber vertically falls into the filler base under the multiple actions of free falling of the fiber, negative pressure vacuum and mechanical vibration, and is fixed by the orientation of the hot melt adhesive in the filler base;

in the mixed material heating and filling stage, the filler is heated while the mixed material is mixed, so that the hot-melt adhesive is heated and volatilized, the mixed material is filled into a filler base for prepressing, and preliminary molding is performed;

and in the friction material preparation stage, a plurality of fillers subjected to pre-pressing forming are sequentially stacked and finally placed in a die for pressing forming.

6. A plant fiber fermentation modification treatment method is characterized by comprising the following steps:

step 1, putting plant fibers into distilled water at the temperature of 40-50 ℃ for 2-2.5 hours, after the fibers fully absorb water, cleaning for 0.5-1 hour by using an ultrasonic cleaning machine, and removing a large amount of stains on the surfaces of the plant fibers and a small amount of stains in the plant fibers;

step 2, adding the cleaned plant fiber into a vinyl triethoxysilane coupling agent, wherein the using amount of the coupling agent is 5-10% of the mass of the plant fiber, adding water, uniformly stirring, and reacting for 40-60 min, wherein the using amount of the water is 150-300% of the mass of the plant fiber;

step 3, adding the treated fiber into water, wherein the amount of the water is 100-150% of the mass of the plant fiber, adding ligninase, the content of the ligninase is 1-2% of the mass of the plant fiber, and putting the mixture into a fermentation tank for fermentation at 40 ℃ for 24-30 hours;

step 4, cleaning the plant fibers with water, and then putting the plant fibers into sodium hydroxide alkali liquor with the mass fraction of 0.2-2%, wherein the use amount of the alkali liquor is 100-500% of the mass of the fibers;

step 5, cleaning the plant fibers with distilled water, and drying in a constant-temperature drying oven for 60-120 min at the drying temperature of 70-80 ℃ to obtain a dried fiber sample;

and 6, cutting the fiber to 5-10 mm by using a fiber cutting machine, and filtering fine fibers by using a mesh screen to obtain a final fiber sample.

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