A manufacturing process for rubber sealing strips

Abstract

The invention relates to a manufacturing process for a rubber sealing strip. The process comprises the following steps: S1: adding rubber into a banbury mixer and plasticating the rubber for 5-10 minutes at a plasticating temperature of 115-125°C; then adding a functional additive in an amount of 0.5-2.0% by mass of the rubber, and uniformly mixing the mixture in the banbury mixer to obtain a rubber material; titanium dioxide can play a reinforcing role in the sealing strip, so that the sealing strip ages slowly and has high strength; lignin is coated on the surface of the titanium dioxide because the three-dimensional network structure of the lignin plays a framework role, which limits the increase in the particle size of the titanium dioxide and not only plays a role in dispersing the titanium dioxide, thereby obtaining uniformly distributed nano-titanium dioxide; moreover, polyphenols in the lignin can capture free radicals and play a synergistic role with the titanium dioxide, thereby improving the anti-oxidation and anti-aging effects of the sealing strip; tungsten disulfide can form oxides during high-temperature banbury mixing, further preventing the sealing strip from aging; and polyglutamic acid can reduce damage to the sealing strip caused by low temperature during the cooling step.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing strips, and in particular to a manufacturing process of a rubber sealing strip. Background Art

[0002] Sealing strips are used on doors, windows, refrigerators, cars and various industrial parts to prevent the entry of dust, water and air.

[0003] Rubber is currently the most widely used sealing strip material. Rubber itself has good heat resistance, corrosion resistance, water resistance, etc. However, during use, due to the combined effects of external environmental factors, it will cause the physical and mechanical properties to gradually decline and age. Therefore, cracking, hardening, powdering, discoloration and other problems will appear on the surface of the sealing strip, thus affecting the quality of the sealing strip. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a rubber sealing strip manufacturing process, and the specific technical solution is as follows:

[0005] A rubber sealing strip manufacturing process comprises the following steps:

[0006] S1: Add the rubber into a mixer and plasticize for 5-10 minutes at a temperature of 115-125°C. Then, add 0.5-2.0% of the functional additives based on the mass of the rubber and mix uniformly in the mixer to obtain the rubber compound.

[0007] S2 mixing: add carbon black, paraffin oil and stabilizer to the rubber compound, knead at 125-130℃ for 10-15min, finally add peroxide curing agent and accelerator TMTD, knead at 135-140℃ for 5-15min to obtain the rubber compound;

[0008] S3 vulcanization: The mixed rubber is extruded through an extruder and then goes through a high temperature box vulcanization and hot air vulcanization in sequence;

[0009] S4 Cooling: The vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip.

[0010] As an improvement of the above technical solution, the temperature in the high temperature box is 150-170°C, the temperature in the hot air box is 200-220°C, and the extruded rubber passes through the high temperature box and the hot air box in sequence at a speed of 25-30m / min.

[0011] As an improvement of the above technical solution, the functional additives are stearic acid, lignin / lignin derivatives, nano-titanium dioxide and solvent, and the mass ratio thereof is 0.5:10:15:100.

[0012] As an improvement of the above technical solution, the preparation method of the functional additive is: dissolving lignin in a solvent, adding stearic acid and ultrasonically dispersing it, then adding titanium dioxide particles, continuing ultrasonication to evenly disperse the titanium dioxide, heating to 50-200°C, stirring and heating under reflux for 5-24 hours to obtain a lignin-modified titanium dioxide particle dispersion, separating, washing, and drying to obtain lignin-modified titanium dioxide particles.

[0013] As an improvement of the above technical solution, the solvent is at least one of water, tetrahydrofuran, dimethyl sulfoxide, and sodium hydroxide aqueous solution.

[0014] As an improvement of the above technical solution, the stabilizer is a silane coupling agent, polyglutamic acid and tungsten disulfide, and the mass ratio thereof is 0.6:3:2.

[0015] As an improvement of the above technical solution, the mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3.

[0016] Beneficial effects of the present invention:

[0017] Titanium dioxide can play a reinforcing role in the sealing strip, making the sealing strip age slowly and have high strength. Lignin is coated on the surface of titanium dioxide because the three-dimensional network structure of lignin acts as a framework, limiting the increase in the particle size of titanium dioxide. It not only disperses titanium dioxide to form a single dispersed phase, thereby obtaining uniformly distributed nano-titanium dioxide, but also the polyphenols in lignin can capture free radicals, which can synergize with titanium dioxide to improve the anti-oxidation and anti-aging effects of the sealing strip. At the same time, lignin can also play an anti-scaling, corrosion-inhibiting and plasticizing role. Stearic acid can make the lignin more evenly dispersed. Paraffin oil, as a plasticizer, can improve the mixing processability of the rubber compound. Tungsten disulfide can form oxides during high-temperature mixing and coat the rubber surface to further prevent its aging. When the silane coupling agent is between the tungsten disulfide and the rubber interface, a bonding layer of organic matrix-silane coupling agent-inorganic matrix can be formed. Polyglutamic acid can reduce the damage to the sealing strip caused by low temperature during the cooling step, while improving the low-temperature resistance of the sealing strip. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Example 1:

[0020] A manufacturing process for a rubber sealing strip comprises the following steps: S1: adding 150 parts of rubber into a mixing machine and plasticating for 5 minutes at a plasticating temperature of 115° C., then adding a functional additive in an amount of 0.5% by weight of the rubber and uniformly mixing the mixture in the mixing machine to obtain a rubber compound, wherein the functional additive comprises stearic acid, lignin / lignin derivative, nano-titanium dioxide and a solvent in a mass ratio of 0.5:10:15:100, and the rubber is EPDM rubber.

[0021] The preparation method of the functional additive comprises the following steps: dissolving lignin in tetrahydrofuran, adding stearic acid for ultrasonic dispersion, adding titanium dioxide particles, continuing ultrasonic dispersion to uniformly disperse the titanium dioxide, heating to 50° C., stirring, heating under reflux for 5 hours to obtain a lignin-modified titanium dioxide particle dispersion, separating, washing, and drying to obtain lignin-modified titanium dioxide particles.

[0022] S2 mixing: adding carbon black, paraffin oil and stabilizer to the rubber material, kneading at 125°C for 10 minutes, finally adding peroxide vulcanizing agent and accelerator TMTD, kneading at 135°C for 5 minutes to obtain a mixed rubber, wherein the mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3, the stabilizer is a silane coupling agent, polyglutamic acid and tungsten disulfide, and the mass ratio thereof is 0.6:3:2, wherein the peroxide vulcanizing agent is an alkyl peroxide or a diacyl peroxide.

[0023] S3 vulcanization: The mixed rubber is extruded through an extruder and then vulcanized in a high-temperature box and hot air. The temperature in the high-temperature box is 150°C and the temperature in the hot air box is 200°C. The extruded rubber passes through the high-temperature box and the hot air box in turn at a speed of 25m / min.

[0024] S4 Cooling: The vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip.

[0025] Example 2:

[0026] A manufacturing process for a rubber sealing strip comprises the following steps: S1: adding rubber to a mixing machine and plasticating for 7 minutes at a plasticating temperature of 120° C., then adding a functional additive (1.2% by weight of the rubber) and uniformly mixing in the mixing machine to obtain a rubber compound, wherein the functional additive comprises stearic acid, lignin / lignin derivative, nano-titanium dioxide, and a solvent in a mass ratio of 0.5:10:15:100, and the rubber is EPDM rubber;

[0027] The preparation method of the functional additive comprises the following steps: dissolving lignin in sodium hydroxide, adding stearic acid for ultrasonic dispersion, adding titanium dioxide particles, continuing ultrasonic dispersion to uniformly disperse the titanium dioxide, heating to 150° C., stirring, heating under reflux for 15 hours to obtain a lignin-modified titanium dioxide particle dispersion, separating, washing, and drying to obtain lignin-modified titanium dioxide particles.

[0028] S2 mixing: carbon black, paraffin oil and stabilizer are added to the rubber material, and the mixture is kneaded at 128°C for 13 minutes. Finally, peroxide vulcanizer and accelerator TMTD are added, and the mixture is kneaded at 137°C for 10 minutes to obtain a mixed rubber. The mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3. The stabilizer is a silane coupling agent, polyglutamic acid and tungsten disulfide, and the mass ratio thereof is 0.6:3:2.

[0029] S3 vulcanization: The rubber mix is extruded through an extruder and then vulcanized in a high-temperature box and hot air. The temperature in the high-temperature box is 160°C and the temperature in the hot air box is 210°C. The extruded rubber mix passes through the high-temperature box and hot air box in turn at a speed of 27m / min.

[0030] S4 Cooling: The vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip.

[0031] Example 3:

[0032] A manufacturing process for a rubber sealing strip comprises the following steps: S1: adding rubber to a mixing machine and plasticating for 10 minutes at a plasticating temperature of 125° C., then adding a functional additive (2% by weight of the rubber) and uniformly mixing in the mixing machine to obtain a rubber compound, wherein the functional additive comprises stearic acid, lignin / lignin derivative, nano-titanium dioxide, and a solvent in a mass ratio of 0.5:10:15:100, and the rubber is EPDM rubber;

[0033] The preparation method of the functional additive comprises the following steps: dissolving lignin in tetrahydrofuran, adding stearic acid and ultrasonically dispersing the mixture, then adding titanium dioxide particles, continuing ultrasonication to uniformly disperse the titanium dioxide, heating the mixture to 200° C., stirring and heating under reflux for 24 hours to obtain a lignin-modified titanium dioxide particle dispersion, and separating, washing, and drying the mixture to obtain the lignin-modified titanium dioxide particles.

[0034] S2 mixing: adding carbon black, paraffin oil and stabilizer to the rubber material, kneading at 130°C for 15 minutes, finally adding peroxide vulcanizing agent and accelerator TMTD, kneading at 140°C for 15 minutes to obtain a mixed rubber, wherein the mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3, the stabilizer is a silane coupling agent, polyglutamic acid and tungsten disulfide, and the mass ratio thereof is 0.6:3:2, wherein the peroxide vulcanizing agent is an alkyl peroxide or a diacyl peroxide.

[0035] S3 vulcanization: The mixed rubber is extruded through an extruder and then vulcanized in a high-temperature box and hot air. The temperature of the high-temperature box is 170°C and the temperature of the hot air box is 220°C. The extruded rubber passes through the high-temperature box and the hot air box at a speed of 30m / min.

[0036] S4 Cooling: The vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip.

[0037] Comparative Example 1:

[0038] A construction process for manufacturing a rubber sealing strip comprises the following steps:

[0039] S1 ingredients: add rubber into a mixer and plasticize for 7 minutes at a plasticizing temperature of 120°C, and uniformly mix in the mixer to obtain a rubber compound, wherein the rubber is EPDM rubber;

[0040] S2 mixing: adding carbon black, paraffin oil and stabilizer to the rubber material, kneading at 128°C for 13 minutes, finally adding peroxide vulcanizing agent and accelerator TMTD, kneading at 137°C for 10 minutes to obtain a mixed rubber, wherein the mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3, the stabilizer is a silane coupling agent, polyglutamic acid and tungsten disulfide, and the mass ratio thereof is 0.6:3:2, wherein the peroxide vulcanizing agent is an alkyl peroxide or a diacyl peroxide.

[0041] S3 vulcanization: The rubber mix is extruded through an extruder and then vulcanized in a high-temperature box and hot air. The temperature in the high-temperature box is 160°C and the temperature in the hot air box is 210°C. The extruded rubber mix passes through the high-temperature box and hot air box in turn at a speed of 27m / min.

[0042] S4 Cooling: The vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip.

[0043] Comparative Example 2:

[0044] The method comprises the following steps: S1: adding rubber into a mixing machine and plasticating for 7 minutes at a plasticating temperature of 120° C., then adding a functional additive of 1.2% by weight of the rubber and uniformly mixing in the mixing machine to prepare a rubber compound, wherein the functional additive comprises stearic acid, lignin / lignin derivative, nano-titanium dioxide and a solvent in a mass ratio of 0.5:10:15:100, and the rubber is EPDM rubber;

[0045] The preparation method of the functional additive comprises the following steps: dissolving lignin in tetrahydrofuran, adding stearic acid for ultrasonic dispersion, adding titanium dioxide particles, continuing ultrasonic dispersion to uniformly disperse the titanium dioxide, heating to 5150° C., stirring and heating under reflux for 15 hours to obtain a lignin-modified titanium dioxide particle dispersion, separating, washing, and drying to obtain lignin-modified titanium dioxide particles.

[0046] S2 mixing: adding carbon black, paraffin oil and stabilizer to the rubber compound, kneading at 128°C for 13 minutes, finally adding peroxide vulcanizing agent and accelerator TMTD, kneading at 137°C for 10 minutes to obtain a mixed rubber, wherein the mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3, the stabilizer is a silane coupling agent, and the peroxide vulcanizing agent is an alkyl peroxide or a diacyl peroxide.

[0047] S3 vulcanization: The rubber mix is extruded through an extruder and then vulcanized in a high-temperature box and hot air. The temperature in the high-temperature box is 160°C and the temperature in the hot air box is 210°C. The extruded rubber mix passes through the high-temperature box and hot air box in turn at a speed of 27m / min.

[0048] S4 Cooling: The vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip.

[0049] Performance test

[0050] The sealing strips prepared in Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 were selected for tensile strength and elongation at break tests;

[0051] Tensile strength: Prepare and test dumbbell-shaped samples according to national standard GB / T528-2009;

[0052] Elongation at break: Prepare and test dumbbell-shaped samples according to national standard GB / T528-2009;

[0053] Test conditions: Hot air aging resistance test conditions: 100℃×168h.

[0054]

[0055] It can be seen from the above table that the anti-aging effect of the sealing strip can be significantly improved by adding stabilizers and functional additives, and the functional agents and stabilizers can play a synergistic anti-aging role.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rubber sealing strip manufacturing process, characterized in that: The following steps are involved: S1 ingredients: add rubber into an internal mixer and masticate for 5-10 minutes at a mastication temperature of 115-125°C, then add 0.5-2.0% of the rubber mass of functional additives and mix evenly in the internal mixer to obtain a rubber compound; S2 mixing: add carbon black, paraffin oil and stabilizer to the rubber compound, mix at 125-130℃ for 10-15min, finally add peroxide curing agent and accelerator TMTD, mix at 135-140℃ for 5-15min to obtain the rubber compound; S3 vulcanization: The mixed rubber is extruded through an extruder and then goes through a high temperature box vulcanization and hot air vulcanization in sequence; S4 cooling: the vulcanized rubber strip is passed through a water tank at a temperature of 5°C, cooled and naturally restored to room temperature to obtain a sealing strip; the functional additives are stearic acid, lignin, nano-titanium dioxide and solvent, and the mass ratio thereof is 0.5:10:15:100; the preparation method of the functional additives is: lignin is dissolved in a solvent, stearic acid is added for ultrasonic dispersion, titanium dioxide particles are added, and ultrasonic dispersion is continued to uniformly disperse the titanium dioxide, the temperature is raised to 50-200°C, and the mixture is stirred and heated under reflux for 5-24 hours to obtain a lignin-modified titanium dioxide particle dispersion, which is separated, washed and dried to obtain lignin-modified titanium dioxide particles; the stabilizer is a silane coupling agent, polyglutamic acid and tungsten disulfide, and the mass ratio thereof is 0.6:3:

2.

2. A rubber sealing strip manufacturing process according to claim 1, characterized in that: The temperature in the high temperature box is 150-170° C., the temperature in the hot air box is 200-220° C., and the extruded rubber material passes through the high temperature box and the hot air box in sequence at a speed of 25-30 m / min.

3. The manufacturing process of a rubber sealing strip according to claim 1, characterized in that: The solvent is at least one of tetrahydrofuran, dimethyl sulfoxide and sodium hydroxide aqueous solution.

4. The manufacturing process of a rubber sealing strip according to claim 1, characterized in that: The mass ratio of the rubber, carbon black, paraffin oil and stabilizer is 10:3:1:0.3.

Images