A toothed V-belt airbag for agricultural machinery and its preparation method

Abstract

The invention discloses a toothed V-belt airbag for agricultural machinery and a preparation method thereof. The invention comprises a hard layer and a matrix layer, wherein the toothed surface of the matrix layer is provided with the hard layer; the components of the hard layer are: 100 phr of EPDM rubber, 7-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 40-60 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, 1-6 phr of auxiliary cross-linking agent, 3-15 phr of glycerol methacrylate, and 5-15 phr of pretreated short fibers; the components of the matrix layer are: 100 phr of EPDM rubber, 8-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, and 1-6 phr of auxiliary cross-linking agent. The invention enhances the hardness of the tooth-shaped rubber material of the airbag and prolongs the service life of the airbag.

Description

Technical field:

[0001] The present invention belongs to the technical field of agricultural machinery transmission, and in particular relates to a toothed V-belt airbag for agricultural machinery and a preparation method thereof. Background technology:

[0002] Toothed V-belts for agricultural machinery are suitable for power transmission in working parts of agricultural machinery with different uses. The vulcanization process in its preparation technology requires the use of rubber airbags, through which the teeth are squeezed into the belt blank under high temperature and high pressure to form the product tooth shape.

[0003] Due to the high hardness of the product rubber and the low hardness of the rubber airbag, during the tooth filling process of tooth formation, the softer rubber airbag squeezes the harder product rubber, causing the formed tooth shape to be twisted and crooked. When the vulcanization process is completed, the product tooth shape is twisted and deformed, forming an irregularly tilted tooth shape or even no tooth shape at all, which seriously affects the product appearance and service life.

[0004] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention:

[0005] The purpose of the present invention is to provide a toothed V-belt airbag for agricultural machinery and a preparation method thereof, which enables the airbag to have a hardness close to that of the product rubber through a composite structure while ensuring the service life of the airbag, thereby overcoming the defects in the above-mentioned prior art.

[0006] To achieve the above-mentioned object, the present invention provides a toothed V-belt airbag for agricultural machinery, comprising a hard layer and a matrix layer, wherein the toothed surface of the matrix layer is provided with a hard layer; the components of the hard layer are: 100phr of EPDM rubber, 7-18phr of zinc oxide, 0.5-2phr of stearic acid, 5-18phr of zinc methacrylate, 40-60phr of carbon black, 5-15phr of rubber plasticizer, 2-3phr of antioxidant, and 1.5-5phr of bridging agent. r, 1-6 phr of auxiliary cross-linking agent, 3-15 phr of glycerol methacrylate, and 5-15 phr of pretreated short fibers; the components of the matrix layer are: 100 phr of EPDM rubber, 8-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, and 1-6 phr of auxiliary cross-linking agent.

[0007] Preferably, in the technical solution, the density of the hard layer is 1.14±0.03g / cm3, the hardness is 87±3sha, the tear strength is ≥15MPa, the tear elongation is 200-300%, and the tear strength is ≥35N / mm.

[0008] Preferably, in the technical solution, the density of the hard layer is 1.14±0.03g / cm3, the hardness is 85~90sha, the tensile strength is 16~18MPa, the tensile elongation is 240~300%, the tear strength is 45~50N / mm, and the Mooney viscosity at 120℃(1+4) is 55~65MU.

[0009] Preferably, in the technical solution, the matrix layer has a density of 1.07±0.03 g / cm3, a hardness of 68±3 sha, a longitudinal tensile strength ≥17 MPa, a tear elongation of 200-400%, and a tear strength ≥40 N / mm.

[0010] Preferably, in the technical solution, the matrix layer density is 1.05-1.10 g / cm3, the hardness is 65-68 sha, the longitudinal tensile strength is ≥17 MPa, the elongation at break is 300-400%, the tear strength is 40-45 N / mm, and the Mooney viscosity at 120°C (1+4) is 70-75 MU.

[0011] Preferably, in the technical solution, the components of the hard layer are: 100 phr of EPDM rubber, 7-10 phr of zinc oxide, 1.0-1.5 phr of stearic acid, 10-16 phr of zinc methacrylate, 45-55 phr of carbon black, 8-12 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, 2.5-4 phr of auxiliary cross-linking agent, 8-12 phr of glycerol methacrylate, and 8-12 phr of pretreated short fibers; the Mooney viscosity of the EPDM rubber is 55-65MU, the vinyl content is 50-70%, and the ENB content is <4.8%; the zinc oxide is activated zinc oxide; the carbon black is a combination of super wear-resistant carbon black and high wear-resistant carbon black; the rubber plasticizer is paraffin oil with a flash point > 360F; the pretreated short fibers are polyhexamethylene adipamide RFL pretreated short fibers and polyphenylene phthalate RFL pretreated short fibers.

[0012] Preferably, in the technical solution, the components of the matrix layer are: 100 phr of EPDM rubber, 8-10 phr of zinc oxide, 1-2 phr of stearic acid, 8-15 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, and 1.5-2.5 phr of co-crosslinking agent; the Mooney viscosity of the EPDM rubber is 55-65MU, the vinyl content is 50-70%, and the ENB content is ≤4.8%; the zinc oxide is activated zinc oxide; the carbon black is a combination of high-wear-resistant carbon black and semi-reinforcing carbon black; the rubber plasticizer is paraffin oil with a flash point >360F.

[0013] A method for preparing a toothed V-belt airbag for agricultural machinery comprises the following steps: (1) weighing 100 phr of EPDM rubber, 7-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 40-60 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, 1-6 phr of auxiliary cross-linking agent, 3-15 phr of glycerol methacrylate, and 5-15 phr of pretreated short fibers, and then adding them into an internal mixer in that order; performing internal mixing at 125° C., 10 bar pressure, and 20 rpm speed for 200 s, and obtaining a fully mixed hard layer rubber compound after internal mixing;

[0014] (2) 100 phr of EPDM rubber, 8-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, and 1-6 phr of cross-linking agent were weighed and added to an internal mixer in that order. The mixture was mixed at 120°C, 10 bar pressure, and 20 rpm speed for 240 seconds to obtain a fully mixed matrix rubber material.

[0015] (3) placing the hard layer rubber material and the matrix layer rubber material into a calender to form films of the width and thickness specified by the process; winding the hard layer film and the matrix layer film according to the specified weight and size, and placing the wound hard layer film and the matrix layer film in an environment of 10-28°C and 20-80% humidity for 24 hours for standby use;

[0016] (4) According to the size of the airbag structure, a hard layer film of a designed thickness is coated on a mold of a corresponding size, and then a matrix layer film of a designed thickness is coated on the outermost layer of the hard layer film to obtain a composite film, and the composite film is rolled and compacted with a forming machine roller to obtain an airbag embryo with a composite structure;

[0017] (5) The airbag embryo is placed on the bushing with the tooth shape and placed in a vulcanizing tank, and vulcanized at 176°C and 10 bar pressure for 70 minutes. During the vulcanization process, the polymer material molecular chains within and between the components of the hard layer film and the matrix layer film are cross-linked, and the airbag with the tooth shape is obtained after vulcanization;

[0018] (6) Trim the upper and lower end surfaces of the airbag and set them aside.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The composite airbag structure features a hard layer that increases the hardness of the airbag teeth, bringing the hardness of the rubber compound close to that of the final product. This prevents skewed or even missing teeth during forming. The matrix layer enhances the ductility and flex resistance of the airbag's back, maintaining good stiffness during the vulcanization process, supporting the airbag's teeth without deformation and extending the airbag's service life. Description of the drawings:

[0021] Figure 1 This is a cross-sectional view of a toothed V-belt airbag for agricultural machinery according to the present invention;

[0022] Figure 2 This is a comparison chart of the service life of the toothed V-belt airbag for agricultural machinery of the present invention and a conventional airbag. Specific implementation method:

[0023] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0024] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0025] like Figure 1 As shown, a toothed V-belt airbag for agricultural machinery comprises a hard layer 1 and a matrix layer 2, wherein the hard layer 1 is provided on the toothed surface of the matrix layer 2;

[0026] The components of the hard layer 1 are: 100 phr of EPDM rubber, 7-10 phr of zinc oxide, 1.0-1.5 phr of stearic acid, 10-16 phr of zinc methacrylate, 45-55 phr of carbon black, 8-12 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, 2.5-4 phr of auxiliary cross-linking agent, 8-12 phr of glycerol methacrylate, and 8-12 phr of pretreated short fibers; the Mooney viscosity of the EPDM rubber is 55-65 MU, the vinyl content is 50-70%, and the ENB content is less than 4.8%. ; Zinc oxide is activated zinc oxide; carbon black is a combination of super wear-resistant carbon black and high wear-resistant carbon black; the rubber plasticizer is paraffin oil with a flash point > 360F; the pretreated short fibers are polyhexamethylene adipamide RFL pretreated short fibers and polyphenylene phthalate RFL pretreated short fibers; the hard layer 1 has a density of 1.14±0.03g / cm3, a hardness of 85~90sha, a tensile strength of 16~18MPa, an elongation at break of 240~300%, a tear strength of 45~50N / mm, and a Mooney viscosity of 55~65MU at 120℃(1+4).

[0027] The components of the matrix layer 2 are: 100 phr of EPDM rubber, 8-10 phr of zinc oxide, 1-2 phr of stearic acid, 8-15 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, and 1.5-2.5 phr of auxiliary cross-linking agent; the Mooney viscosity of the EPDM rubber is 55-65 MU, the vinyl content is 50-70%, and the ENB content is 100-150 phr. The amount is ≤4.8%; the zinc oxide is activated zinc oxide; the carbon black is a combination of high-wear-resistant carbon black and semi-reinforcing carbon black; the rubber plasticizer is paraffin oil with a flash point greater than 360F; the matrix layer 2 has a density of 1.05-1.10g / cm3, a hardness of 65-68sha, a longitudinal tensile strength of ≥17MPa, an elongation at break of 300-400%, a tear strength of 40-45N / mm, and a Mooney viscosity of 70-75MU at 120°C (1+4).

[0028] A method for preparing a toothed V-belt airbag for agricultural machinery comprises the following steps: (1) weighing 100 phr of EPDM rubber, 7-10 phr of zinc oxide, 1.0-1.5 phr of stearic acid, 10-16 phr of zinc methacrylate, 45-55 phr of carbon black, 8-12 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, 2.5-4 phr of auxiliary cross-linking agent, 8-12 phr of glycerol methacrylate, and 8-12 phr of pretreated short fibers, and adding them to an internal mixer in that order; and performing internal mixing at 125° C., 10 bar pressure, and 20 rpm speed for 200 s to obtain a fully mixed hard layer rubber compound;

[0029] (2) 100 phr of EPDM rubber, 8-10 phr of zinc oxide, 1-2 phr of stearic acid, 8-15 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, and 1.5-2.5 phr of cross-linking agent were weighed and added to an internal mixer in that order. The mixture was mixed at 120°C, 10 bar pressure, and 20 rpm speed for 240 seconds to obtain a fully mixed matrix rubber material.

[0030] (3) placing the hard layer rubber material and the matrix layer rubber material into a calender to form films of the width and thickness specified by the process; winding the hard layer film and the matrix layer film according to the specified weight and size, and placing the wound hard layer film and the matrix layer film in an environment of 10-28°C and 20-80% humidity for 24 hours for standby use;

[0031] (4) According to the size of the airbag structure, a hard layer film of a designed thickness is coated on a mold of a corresponding size, and then a matrix layer film of a designed thickness is coated on the outermost layer of the hard layer film to obtain a composite film, and the composite film is rolled and compacted with a forming machine roller to obtain an airbag embryo with a composite structure;

[0032] (5) The airbag embryo is placed on the bushing with the tooth shape and placed in a vulcanizing tank, and vulcanized at 176°C and 10 bar pressure for 70 minutes. During the vulcanization process, the polymer material molecular chains within and between the components of the hard layer film and the matrix layer film are cross-linked, and the airbag with the tooth shape is obtained after vulcanization;

[0033] (6) Trim the upper and lower end surfaces of the airbag and set them aside.

[0034] The composite structure of the airbag is used. The hard layer increases the hardness of the airbag teeth, making the hardness of the airbag tooth profile rubber material close to the hardness of the product rubber material, preventing the product tooth profile from being skewed or even missing during the tooth forming process. The matrix layer increases the ductility and flex resistance of the airbag back, maintaining good stiffness during the vulcanization process to support the airbag tooth profile to complete the tooth filling process without deformation, thereby extending the service life of the airbag. Figure 2 As shown, an airbag of conventional structure needs to be replaced after being used 20 times, while an airbag produced by the present invention needs to be replaced after being used 100 times, which greatly extends the service life and reduces the production cost.

[0035] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A toothed V-belt airbag for agricultural machinery, characterized by: The invention comprises a hard layer and a matrix layer, wherein the tooth-shaped surface of the matrix layer is provided with a hard layer; the components of the hard layer are: 100 phr of EPDM rubber, 7 to 18 phr of zinc oxide, 0.5 to 2 phr of stearic acid, 5 to 18 phr of zinc methacrylate, 40 to 60 phr of carbon black, 5 to 15 phr of rubber plasticizer, 2 to 3 phr of antioxidant, 1.5 to 5 phr of bridging agent, 1 to 6 phr of auxiliary cross-linking agent, 3 to 15 phr of glycerol methacrylate, and 5 to 15 phr of pretreated short fibers; the density of the hard layer is 1.14±0.03 g / cm3, hardness of 87±3sha, tensile strength ≥15MPa, elongation at break of 200-300%, and tear strength ≥35N / mm; the components of the matrix layer are: 100phr of EPDM rubber, 8-18phr of zinc oxide, 0.5-2phr of stearic acid, 5-18phr of zinc methacrylate, 35-45phr of carbon black, 5-15phr of rubber plasticizer, 2-3phr of antioxidant, 1.5-5phr of bridging agent, and 1-6phr of cross-linking agent; the density of the matrix layer is 1.07±0.03 g / cm3, hardness of 68±3sha, longitudinal tensile strength ≥17MPa, elongation at break of 200-400%, and tear strength ≥40N / mm.

2. The toothed V-belt airbag for agricultural machinery according to claim 1, characterized in that: The density of the hard layer is 1.14±0.03 g / cm3, the hardness is 85~90sha, the tensile strength is 16~18MPa, the elongation at break is 240~300%, the tear strength is 45~50N / mm, and the Mooney viscosity at 120℃ (1+4) is 55~65MU.

3. The toothed V-belt airbag for agricultural machinery according to claim 2, characterized in that: The components of the hard layer are: 100 phr of EPDM rubber, 7-10 phr of zinc oxide, 1.0-1.5 phr of stearic acid, 10-16 phr of zinc methacrylate, 45-55 phr of carbon black, 8-12 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, 2.5-4 phr of auxiliary cross-linking agent, 8-12 phr of glycerol methacrylate, and 8-12 phr of pretreated short fibers; the Mooney viscosity of the EPDM rubber is 55-65MU, the vinyl content is 50-70%, and the ENB content is less than 4.8%; the zinc oxide is activated zinc oxide; the carbon black is a combination of super wear-resistant carbon black and high wear-resistant carbon black; the rubber plasticizer is paraffin oil with a flash point greater than 360F; the pretreated short fibers are polyhexamethylene adipamide RFL pretreated short fibers and polyphenylene phthalate RFL pretreated short fibers.

4. The toothed V-belt airbag for agricultural machinery according to claim 1, characterized in that: The density of the matrix layer is 1.07±0.03 g / cm3, the hardness is 68±3sha, the longitudinal tensile strength is ≥17MPa, the elongation at break is 200-400%, and the tear strength is ≥40N / mm.

5. The toothed V-belt airbag for agricultural machinery according to claim 4, characterized in that: The matrix layer density is 1.05-1.10 g / cm3, the hardness is 65-68 sha, the longitudinal tensile strength is ≥17 MPa, the elongation at break is 300-400%, the tear strength is 40-45 N / mm, and the Mooney viscosity at 120°C (1+4) is 70-75 MU.

6. The toothed V-belt airbag for agricultural machinery according to claim 5, characterized in that: The components of the matrix layer are: 100 phr of EPDM rubber, 8-10 phr of zinc oxide, 1-2 phr of stearic acid, 8-15 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 2-5 phr of bridging agent, and 1.5-2.5 phr of cross-linking agent; the Mooney viscosity of the EPDM rubber is 55-65MU, the vinyl content is 50-70%, and the ENB content is ≤4.8%; the zinc oxide is activated zinc oxide; the carbon black is a combination of high-wear-resistant carbon black and semi-reinforcing carbon black; the rubber plasticizer is paraffin oil with a flash point >360F.

7. A method for preparing a toothed V-belt airbag for agricultural machinery according to any one of claims 1 to 6, comprising the following steps: (1) weighing 100 phr of EPDM rubber, 7-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 40-60 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, 1-6 phr of auxiliary cross-linking agent, 3-15 phr of glycerol methacrylate, and 5-15 phr of pretreated short fibers, and then adding them to an internal mixer in that order, and performing internal mixing at 125°C, 10 bar pressure, and 20 rpm speed for 200 s to obtain a fully mixed hard layer rubber compound; (2) 100 phr of EPDM rubber, 8-18 phr of zinc oxide, 0.5-2 phr of stearic acid, 5-18 phr of zinc methacrylate, 35-45 phr of carbon black, 5-15 phr of rubber plasticizer, 2-3 phr of antioxidant, 1.5-5 phr of bridging agent, and 1-6 phr of cross-linking agent were weighed and added to an internal mixer in that order. The mixture was mixed at 120°C, 10 bar pressure, and 20 rpm speed for 240 seconds. After mixing, a fully mixed matrix rubber material was obtained. (3) Place the hard layer rubber material and the matrix layer rubber material into a calender to form films of the width and thickness specified by the process; wind up the hard layer film and the matrix layer film according to the specified weight and size, and place the wound hard layer film and the matrix layer film in an environment of 10-28°C and 20-80% humidity for 24 hours for standby use; (4) According to the size of the airbag structure, a hard layer film of designed thickness is coated on a mold of corresponding size, and then a matrix layer film of designed thickness is coated on the outermost layer of the hard layer film to obtain a composite film, and the composite film is rolled and compacted by a forming machine roller to obtain an airbag embryo with a composite structure; (5) The airbag embryo is placed on the bushing with teeth and placed in a vulcanizer. Vulcanization is carried out at 176°C and 10 bar pressure for 70 minutes. During the vulcanization process, the polymer material molecular chains within and between the components of the hard layer film and the matrix layer film are cross-linked, and an airbag with teeth is obtained after vulcanization. (6) Trim the upper and lower end surfaces of the airbag and set aside.

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