A drum friction plate with long fiber woven structure and a preparation method thereof

Abstract

The application discloses a drum type friction plate with long fiber woven structure and a preparation method. The drum type friction plate is prepared by adding a continuous net fiber reinforced material. The continuous net fiber reinforced material is a woven cloth with a net structure prepared by using continuous fiber material. The structure relies on a common bagging process of the drum type friction plate. The woven cloth with the net structure and friction material premix are alternately laid on a film material. The film is folded to wrap the friction material premix and the woven cloth. The wrapped material is heated and fused to form a closed bag covering all the materials. The bag is hot-pressed to obtain the drum type friction plate with the net structure reinforcement effect. The drum type friction plate with the long fiber woven structure has high mechanical strength and can guarantee the overall structural performance of the drum type friction plate product. The drum type friction plate product is not prone to cracking and falling off under violent impact and harsh working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drum friction plate, and particularly relates to a drum friction plate with long fiber woven structure and a preparation method. BACKGROUND

[0002] The friction plate is a key safety component of the automobile braking system, and plays a decisive role in the braking effect. The drum friction plate is the most commonly used friction plate for vehicles. During use, cracking of the friction plate often occurs under the conditions of heavy load, high-speed braking and poor road conditions, and this phenomenon is particularly obvious at the corner position and the rivet hole position. Although the impact of the material impact and bending strength is usually considered during the design process of the drum friction plate, for example, fiber reinforced materials such as glass fiber, aramid fiber and carbon fiber are added during the preparation of the friction plate, the commonly used fiber reinforced materials in the prior art are all short fibers, and the fiber length is mostly below 5 mm. Although such short fiber materials can also increase the strength of the drum friction plate, the overall strength enhancement effect is not good, especially the enhancement effect on the special area is not targeted.

[0003] Some researchers in the prior art have also tried to use long fiber reinforced materials to prepare the friction plate product, but the long fibers are not easy to disperse in the friction plate product, and do not have a fixed fiber arrangement, so the long fiber friction plate product has poor enhancement effect.

[0004] Therefore, it is urgent to develop a preparation process of a friction plate with higher strength to solve the problems in the prior art. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a drum friction plate with long fiber woven structure and a preparation method. The drum friction plate adds a continuous network fiber reinforced material during preparation. The continuous network fiber reinforced material is a fiber woven cloth with a network structure prepared by using continuous fiber material. The structure relies on the common bagging process of the drum friction plate. The network structure fiber woven cloth and the friction material premix are alternately laid on the film material, and then the film is folded to wrap the friction material premix and the fiber woven cloth. The material bag is formed by hot melting, and the material bag is hot pressed to obtain the drum friction plate with the network structure enhancement effect.

[0006] To achieve or at least partially achieve the above purpose, the present application provides the following technical scheme:

[0007] In a first aspect, the present application provides a preparation method of a drum friction plate with long fiber woven structure, comprising the following steps:

[0008] First, prepare a continuous fiber material;

[0009] Secondly, the continuous fiber material is woven to form a fiber woven cloth with a grid structure;

[0010] Thirdly, the friction material is mixed to form a friction material premix; the components of the friction material include phenolic resin, acrylonitrile butadiene rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite, basalt wool;

[0011] Fourthly, the friction material premix and the fiber woven cloth are alternately laid on the surface of the film in sequence, the number of layers of the fiber woven cloth is 1-3, and the fiber woven cloth is between the friction material premix; after the laying is completed, the film is folded to wrap the friction material premix and the fiber woven cloth, and hot melting is performed to form a closed package covering all the materials;

[0012] Fifthly, the package formed in the fourth step is hot-pressed to form a drum brake pad with a long fiber woven structure.

[0013] Further, in the first step, the fiber single filament diameter of the continuous fiber material is 0.5-50 μm, the number of single filaments per bundle of the formed fiber bundle is 1000-24000, and the fiber denier is 100-3000D.

[0014] Further, in the first step, the continuous fiber material includes at least one of continuous long fibers or a fiber material formed by twisting short fibers.

[0015] Further, the continuous long fibers include at least one of alkali-free glass fibers, continuous carbon fibers, aramid fibers (long fibers).

[0016] Further, in the first step, the short fibers include at least one of cellulose fibers, aramid fibers (short fibers).

[0017] Further, in the second step, the fiber woven cloth has a square grid structure with ±90° weaving or a regular triangle grid structure with 0 / 60° / 120° weaving, and the grid size side length is 5-25 mm.

[0018] Further, in the third step, the components of the friction material, in terms of mass fraction, are as follows: phenolic resin 6%-15%, acrylonitrile butadiene rubber powder 3%-10%, antimony sulfide 3%-8%, synthetic graphite 10%-30%, calcium sulfate whisker 3%-8%, light calcium carbonate 10%-25%, zirconium powder 3%-8%, precipitated barium sulfate 10%-20%, vermiculite 3%-8%, and basalt wool 3%-8%.

[0019] Further, in the fourth step, the material of the film is any one of polypropylene (PP), polyethylene (PE), and polyvinyl alcohol (PVA), and the thickness of the film is 0.02-0.05 mm.

[0020] Further, in the fourth step, the paving thickness of each layer of the friction material premix is 3-5 mm.

[0021] In a second aspect, the application provides a drum brake pad with long fiber woven structure, which is prepared by the foregoing method.

[0022] The drum brake pad with long fiber woven structure and the preparation method provided by the application have at least the following beneficial effects compared with the prior art:

[0023] 1. The drum brake pad with long fiber woven structure provided by the application has extremely high mechanical strength, which can ensure the overall structural performance of the product and prevent the product from cracking and falling off under severe impact and harsh working conditions.

[0024] 2. The drum brake pad with long fiber woven structure provided by the application has strong designability. In the preparation process of the drum brake pad, a fiber woven cloth with a reticular morphological structure woven by continuous fiber material is added. The film material is wrapped around the alternately paved friction material premix and the fiber woven cloth relying on the bagging process commonly used for drum brake pads. The material bag is formed by hot melting to form a closed package containing all materials. According to actual needs, different combinations of friction material and fiber woven cloth can be configured in the bottom area, middle layer area, and surface layer area of the brake pad, so as to realize the differential fiber reinforcement effect of different areas, selectively enhance one or more mechanical properties of the brake pad material such as shear and tensile, and balance the performance and production cost of the brake pad.

[0025] 3. Some drum brake pads with long fiber woven structure provided by the application have the mixing advantage of composite fibers. In these drum brake pads, a plurality of fiber materials are twisted to obtain composite fibers, thereby having the advantages of a plurality of fiber materials. For example, the twisting of aramid fiber and continuous carbon fiber enables the branched structure of aramid fiber to adsorb more powder material, ensuring the uniformity of the friction and wear of the brake pad, and the carbon fiber can provide strong tensile strength in the fiber direction, thereby ensuring the structural strength of the brake pad product. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure is a schematic view of the paving structure of the drum brake pad with long fiber woven structure of the embodiment of the application, wherein 1 is a film, 2 is a friction material premix, and 3 is a fiber woven cloth. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0028] Those skilled in the art can understand that, unless specifically stated otherwise, "said" and "the" and "the foregoing" used in the present application can also include the plural form. It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, steps, operations exist, but does not exclude the existence or addition of one or more other features, integers, steps.

[0029] In the present application, the terms "first", "second", etc. are used to distinguish the same or similar items with basically the same function and role, only for the purpose of clearly describing the technical scheme of the embodiments of the present application, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features.

[0030] The embodiments of the present application use a bagging process to integrate the friction material and the fiber material with a net-like woven structure to form a material bag on the basis of the existing drum friction plate preparation technology, and then the material bag is hot-pressed and cut to form a drum friction plate. The prepared drum friction plate has extremely high mechanical strength, which can ensure the overall structural performance of the product and prevent the phenomenon of cracking and falling off under severe impact and harsh working conditions.

[0031] Based on this, the embodiments of the present application provide a preparation method of a drum friction plate with a long fiber woven structure, comprising the following steps: first, preparing a continuous fiber material, the continuous fiber material comprising at least one of continuous long fibers or short fibers formed by twisting into a fiber material; second, weaving the continuous fiber material at a fixed angle to form a fiber woven cloth with a grid structure; third, mixing the friction material to form a friction material premix, the components of the friction material comprising phenolic resin, nitrile rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite, basalt wool; fourth, alternately laying the friction material premix and the fiber woven cloth on the surface of the film in order, the number of layers of the fiber woven cloth being 1-3, and the fiber woven cloth being between the friction material premixes; after laying, folding the film to wrap the friction material premix and the fiber woven cloth, and hot melting to form a closed material bag covering all the materials; fifth, hot-pressing the material bag formed in the fourth step, and cutting to obtain a drum friction plate with a long fiber woven structure.

[0032] In the embodiments of the present application, the type of the fiber woven cloth of each layer and the type of the friction material pre-mixture of each layer can be combined arbitrarily, for example, different continuous fiber materials can be used for weaving each layer of the multi-layer fiber woven cloth, and one or more continuous fiber materials can be used for weaving each layer of the fiber woven cloth; the component formula of each layer of the friction material pre-mixture can be the same or different, and the laying thickness of each layer of the friction material pre-mixture can also be limited according to actual needs.

[0033] Figure 1 The drum brake friction plate laying structure prepared in some embodiments is shown in the schematic diagram, and it can be seen from the diagram that the drum brake friction plate comprises three layers of friction material pre-mixtures 2 and two layers of fiber woven cloths 3.

[0034] In some embodiments, in the first step, the fiber filament diameter of the continuous fiber material is 0.5-50 μm, the fiber bundle formed has 1000-24000 filaments per bundle, and the fiber denier is 100-3000D.

[0035] In some embodiments, in the first step, the continuous long fiber includes at least one of an alkali-free glass fiber and a continuous carbon fiber.

[0036] In some embodiments, in the first step, the short fiber includes at least one of a cellulose fiber and an aramid fiber.

[0037] In some embodiments, in the second step, the fiber woven cloth has a square grid structure woven with ±90° or a regular triangle grid structure woven with 0 / 60° / 120°, and the grid size side length is 5-25 mm.

[0038] In some embodiments, in the third step, the components of the friction material, in terms of mass fraction, are as follows: phenolic resin 6%-15%, nitrile rubber powder 3%-10%, antimony sulfide 3%-8%, synthetic graphite 10%-30%, calcium sulfate whisker 3%-8%, light calcium carbonate 10%-25%, zirconium powder 3%-8%, precipitated barium sulfate 10%-20%, vermiculite 3%-8%, and basalt wool 3%-8%.

[0039] In some embodiments, in the fourth step, the material of the film is any one of polypropylene (PP), polyethylene (PE), and polyvinyl alcohol (PVA), and the thickness of the film is 0.02-0.05 mm.

[0040] In some embodiments, in the fourth step, the laying thickness of each layer of the friction material pre-mixture is 3-5 mm.

[0041] In some embodiments, in the fifth step, the hot-pressing process comprises: putting the package obtained in the fourth step into a hot-pressing mold, using an upper mold temperature of 160±10℃ and a lower mold temperature of 145±10℃, and using a forming pressure of 150kg / cm 2 , and taking out after static pressure for 10-20 minutes, and heat treating at 160-180℃ for 8-12 hours.

[0042] In some embodiments, in the fifth step, the hot-pressing process obtains a drum brake pad, and the laid thickness of the premixed material in the drum brake pad is reduced to 2-3mm.

[0043] Based on this, the embodiments of the present application further provide a drum brake pad prepared by the above preparation method.

[0044] The technical solutions and the technical effects achieved by the present application are described in more detail below through more specific embodiments.

[0045] Embodiment 1

[0046] The embodiment provides a preparation method of a drum brake pad with long-fiber woven structure, and the specific steps comprise:

[0047] (1) Selecting alkali-free glass fibers and aramid fibers (long fibers) to weave glass fiber woven cloth and aramid fiber woven cloth, respectively, wherein the woven structure of the glass fiber woven cloth is a square grid structure with a grid side length of 10mm, and the woven structure of the aramid fiber woven cloth is a square grid structure with a grid side length of 5mm;

[0048] (2) mixing friction materials to form a premixed material of friction materials; the components of the friction materials comprise phenolic resin, nitrile rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite, and basalt wool; using PP as a film material, laying the premixed material of friction materials and the fiber woven cloth on the surface of the film in sequence to form three layers of the premixed material of friction materials and two layers of the fiber woven cloth, wherein the thickness of the first layer of the premixed material of friction materials is 2.5mm, the thickness of the second layer of the premixed material of friction materials is 6mm, the thickness of the third layer of the premixed material of friction materials is 7mm, the first layer of the fiber woven cloth is the glass fiber woven cloth, and the second layer of the fiber woven cloth is the aramid fiber woven cloth;

[0049] (3) folding the film to wrap the premixed material of friction materials and the fiber woven cloth after laying, and hot melting to form a closed package covering all materials; putting the formed package into a hot-pressing mold for hot-pressing, using an upper mold temperature of 160℃ and a lower mold temperature of 145℃, and using a forming pressure of 150kg / cm 2 , and taking out after static pressure for 15 minutes, and cutting into a drum brake pad with long-fiber woven structure of 410*220mm in size after heat treating at 180℃ for 8 hours.

[0050] Example 2

[0051] The embodiment provides a preparation method of a drum type friction plate with long fiber woven structure, and specific steps comprise the following steps:

[0052] (1) respectively select alkali-free glass fiber and continuous carbon fiber to weave glass fiber woven cloth and carbon fiber woven cloth, wherein the woven structure of the glass fiber woven cloth is a square grid structure, and the grid side length is 10 mm; the woven structure of the carbon fiber woven cloth is a square grid structure, and the grid side length is 3.5 mm;

[0053] (2) mixing friction materials to form friction material premix; components of the friction materials comprise phenolic resin, nitrile rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite and basalt wool; PVA is used as a film material, and the friction material premix and the fiber woven cloth are sequentially laid on the surface of the film to form three layers of friction material premix and two layers of fiber woven cloth, wherein the thickness of the first layer of friction material premix is 3.5 mm, the thickness of the second layer of friction material premix is 7 mm, the thickness of the third layer of friction material premix is 8 mm, the first layer of fiber woven cloth is the glass fiber woven cloth, and the second layer of fiber woven cloth is the carbon fiber woven cloth;

[0054] (3) after the laying is completed, the film is folded to wrap the friction material premix and the fiber woven cloth, hot melting is performed to form a closed material package covering all materials; the formed material package is put into a hot press mold for hot pressing, a temperature of 150 DEG C of an upper mold and 135 DEG C of a lower mold is adopted, a forming pressure of 150 kg / cm 2 is adopted, the formed product is taken out after being statically pressed for 20 minutes, and is cut into a drum type friction plate with long fiber woven structure with a size of 410*220 mm after being heat treated at 160 DEG C for 10 hours.

[0055] Comparative Example 1

[0056] The comparative example provides a preparation method of a drum type friction plate, and specific steps comprise the following steps:

[0057] (1) preparing the same glass fiber and aramid fiber as in the example 1, and cutting the glass fiber and the aramid fiber into chopped glass fibers and chopped aramid fibers with a length of 4.5 mm respectively, and waiting for use;

[0058] (2) mixing the friction material to form a friction material premix; the components of the friction material include phenolic resin, nitrile rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite, basalt wool; using PP as the film material, sequentially laying the friction material premix and the chopped fiber material (without weaving) on the surface of the film to form three layers of friction material premix and two layers of fiber woven cloth, wherein the thickness of the first layer of friction material premix is 2.5 mm, the thickness of the second layer of friction material premix is 6 mm, and the thickness of the third layer of friction material premix is 7 mm; the first layer of chopped fiber material is chopped glass fiber material, and the second layer of chopped fiber material is chopped aramid fiber;

[0059] (3) after the laying is completed, folding the film to wrap the friction material premix and the chopped fiber material, and hot melting to form a closed package covering all the materials; putting the formed package into a hot press mold for hot pressing, using a temperature of 160°C for the upper mold and 145°C for the lower mold, and using a forming pressure of 150 kg / cm 2 After 15 minutes of static pressing, taking out, and cutting into a drum brake pad with a size of 410*220 mm after heat treatment at 180°C for 8 hours.

[0060] Comparative Example 2

[0061] The present comparative example provides a preparation method of a drum brake pad, and the specific steps include:

[0062] (1) preparing the same glass fiber and carbon fiber as in Example 2, and cutting the glass fiber and the carbon fiber into chopped glass fiber and chopped carbon fiber with a length of 4.5 mm respectively for later use;

[0063] (2) mixing the friction material to form a friction material premix; the components of the friction material include phenolic resin, nitrile rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite, basalt wool; using PVA as the film material, sequentially laying the friction material premix and the chopped fiber material (without weaving) on the surface of the film to form three layers of friction material premix and two layers of fiber woven cloth, wherein the thickness of the first layer of friction material premix is 3.5 mm, the thickness of the second layer of friction material premix is 7 mm, and the thickness of the third layer of friction material premix is 8 mm; the first layer of chopped fiber material is chopped glass fiber, and the second layer of chopped fiber material is chopped carbon fiber;

[0064] (3) after the laying is completed, folding the film to wrap the friction material premix and the chopped fiber material, and hot melting to form a closed package covering all the materials; putting the formed package into a hot press mold for hot pressing, using a temperature of 150°C for the upper mold and 135°C for the lower mold, and using a forming pressure of 150 kg / cm 2After static pressure for 20 minutes, the drum brake pads were taken out and cut into 410*220mm size after heat treatment at 160℃ for 10 hours.

[0065] The components of the friction material and the fiber material in the drum brake pads prepared in Examples 1, 2 and Comparative Examples 1, 2 are shown in Table 1 below in terms of mass fraction:

[0066] Table 1

[0067] Component (%) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Phenolic resin 12 8 12 8 Acrylonitrile-butadiene rubber powder 4 4 4 4 Antimony sulfide 4 7 4 7 Synthetic graphite 13 20 13 20 Calcium sulfate whisker 5 3 5 3 Light calcium carbonate 15 20 15 20 Zirconium powder 5 5 5 5 Precipitated barium sulfate 18 15 18 15 Vermiculite 6 5 6 5 Basalt wool 6 5 6 5 Woven glass fabric 8 5 0 0 Woven carbon fabric 0 3 0 0 Woven aramid fabric 4 0 0 0 Chopped glass fiber 0 0 8 5 Chopped aramid fiber 0 0 4 0 Chopped carbon fiber 0 0 0 3 Total 100 100 100 100

[0068] The drum brake pads prepared in Examples 1, 2 and Comparative Examples 1, 2 were subjected to mechanical property tests such as bending strength, impact strength and compressive strength, and the test standards are as follows:

[0069] Bending strength: GB / T 5764-2011 Clutch facings for automobiles;

[0070] Impact strength: GBT 33835-2017 Test method for impact strength of friction materials;

[0071] Compressive strength: GB / T 1041-2008 Plastics-Determination of compressive properties.

[0072] The final mechanical property test results are shown in Table 2 below:

[0073] Table 2

[0074] Test item Example 1 Example 2 Comparative Example 1 Comparative Example 2 Bending strength / Mpa 51.9 59.8 31.6 41.7 Impact strength / J / cm 2 ]] 0.619 0.772 0.428 0.409 Compressive strength / Mpa 114.5 90.4 87.6 79.2

[0075] As can be seen from the results in Table 2, the bending strength, impact strength and compressive strength of the drum brake pads prepared in the examples having a long fiber woven structure are all significantly improved compared with the drum brake pads prepared in the comparative examples, because the fibers in the drum brake pad preparation method in the examples are woven to have a specific structural arrangement from the originally disordered fibers, and the woven fiber structure has better overall performance under stress, which is more conducive to force dispersion and avoids stress concentration, thereby greatly improving the mechanical properties of the product.

[0076] The above has described the present application in detail, and the principles and implementation modes of the present application have been described by applying specific examples. The above description of the examples is only to help understand the present application and the core idea. It should be noted that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method of manufacturing a drum-type friction plate having a long fiber woven structure, characterized by, The method comprises the following steps: In the first step, a continuous fiber material is prepared; In the second step, the continuous fiber material is woven to form a fiber woven cloth with a grid structure; In the third step, a friction material is mixed to form a friction material premix; the components of the friction material include phenolic resin, nitrile rubber powder, antimony sulfide, synthetic graphite, calcium sulfate whisker, light calcium carbonate, zirconium powder, precipitated barium sulfate, vermiculite, and basalt wool; In the fourth step, the friction material premix and the fiber woven cloth are alternately laid on the surface of a film in sequence, the number of layers of the fiber woven cloth is 1-3, and the fiber woven cloth is between the friction material premixes; After the laying is completed, the film is folded to wrap the friction material premix and the fiber woven cloth, and is hot melted to form a closed package containing all the materials; In the fifth step, the package formed in the fourth step is hot pressed to form a drum brake pad with a long fiber woven structure. The material obtained in the fourth step is put into a hot press mold, the temperature of the upper mold is 160±10 ℃, the temperature of the lower mold is 145±10 ℃, the molding pressure is 150 kg / cm 2 , and after static pressure for 10-20 minutes, it is taken out and heat treated at 160-180 ℃ for 8-12 hours. In the first step, the fiber single filament diameter of the continuous fiber material is 0.5-50 μm, the formed fiber bundle is 1000-24000 single filaments per bundle, and the fiber denier is 100-3000 D; In the third step, the components of the friction material, in terms of mass fraction, are as follows: phenolic resin 6%-15%, nitrile rubber powder 3%-10%, antimony sulfide 3%-8%, synthetic graphite 10%-30%, calcium sulfate whisker 3%-8%, light calcium carbonate 10%-25%, zirconium powder 3%-8%, precipitated barium sulfate 10%-20%, vermiculite 3%-8%, and basalt wool 3%-8%.

2. The production method according to claim 1, characterized by, In the first step, the continuous fiber includes at least one of alkali-free glass fiber, continuous carbon fiber, and medium-length aramid fiber.

3. The preparation method according to claim 1, characterized in that, In the first step, the continuous fiber is at least one of cellulose fiber and aramid fiber in the form of short fiber formed by twisting.

4. The method of claim 1, wherein, In the second step, the fiber woven cloth has a square grid structure woven by ±90° or a regular triangle grid structure woven by 0 / 60° / 120°, and the grid side length is 5-25 mm.

5. The preparation method according to claim 1, characterized in that, In the fourth step, the film is made of any one of polypropylene, polyethylene, and polyvinyl alcohol, and the thickness of the film is 0.02-0.05 mm.

6. The method of claim 1, wherein, In the fourth step, the laying thickness of each layer of the friction material premix is 3-5 mm.

7. A drum type friction plate having a long fiber woven structure, characterized by, The drum brake pad is prepared by the method of any one of claims 1-6.

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