Organic zincWith the acceleration of my country’s agricultural modernization process, the demand for agricultural machinery and equipment continues to increase. As an accessory product for agricultural machinery, agricultural tires are very popular among users. However, feedback from the market found that agricultural tires used in the Northeast region in winter and spring often have cracking problems. Through on-site visits, we investigated the usage and environment of winter tires, and analyzed the problem tires. We concluded that winter in Northeast China is cold, the temperature difference between day and night is large, the brittleness temperature of the tread rubber is high, and due to the long crystallization time, the tires are in early use. The rubber material has not completely crystallized, so it is prone to cracks; secondly, due to the long winter time, the annual off-season shutdown period is generally 4 to 5 months, and the tires are inflated and parked for a long time, which causes stress concentration and promotes surface aging. , accelerating the growth of cracks; in addition, because the tires are stored in the open air and cannot be well maintained, they will also cause cracks. This work improves the cold-resistant performance of the tire by adjusting the raw rubber system and protective system in the tread rubber formula of agricultural tires, and improves the problem that tires are prone to cracking in cold areas and cold seasons.
1.1 Main raw materials natural rubber (NR), 20# standard rubber, Malaysian product; D Styrene rubber (SBR), brand 1502; butadiene rubber (BR), brand 9000; carbon black N220; bimodal protective wax; antioxidant 4020.
1.2 Formula Test Formula and Production Formula and Production Formula Components Test Formula 1#2 #3# Production formula NR 30 40 40 30BR 40 40 50 30SBR 30 20 10 40 Single peak protective wax 0 0 0 1.5 Bimodal protective wax 1.5 1.5 1.5 0 Note: The remaining components and dosage of the formula are carbon black N220 60, reclaimed rubber 10, active agent 6, antioxidant 4020/RD 3, softener 10, leveling agent A78 0.5, vulcanizing agent 2.9.
1.3 Main equipment and instruments XK-160 open mixer; F370 internal mixer ; 1L Bunbury small intelligent internal mixer, TCS-2000 electronic tensile testing machine and C2000E high temperature rotorless vulcanizer; 25t flat plate vulcanizer.
1.4 Sample Preparation
1.4.1 Small mix test The small mix test rubber compound is mixed using a two-stage mixing process. The first stage of mixing is carried out in a small intelligent internal mixer, the rotor speed is 50r·min-1, the pressure of the pressure weight is 0.5 MPa, and the mixing process is: raw rubber, protective wax and other small materials → pressure weight → lifting weight → Part of the carbon black → Pressing weight → Remaining carbon black → Softener → Pressing weight → Lifting and pressing weight → Debinding (120℃), park for 4 hours; the second-stage mixing is carried out on the open mill, and the mixing process is: one-stage mixing Add vulcanizing agent to the rubber mixture, mix evenly, take out the tablets, and then vulcanize after 8 hours.
1.4.2 Large mix test The large mix test compound is carried out using a two-stage mixing process. Mix. The first stage of mixing is carried out in the F370 internal mixer, the rotor speed is 50r·min-1, the pressure of the pressure weight is 0.6 MPa, and the mixing process is raw rubber, protective wax and other small materials → pressure weight → lifting weight → part Carbon black → Pressing weight → Remaining carbon black → Softener → Pressing weight → Lifting and pressing weight → Debinding (165℃); the second stage mixing is carried out in the F370 internal mixer, the rotor speed is 20r·min-1 , the pressure of the pressing weight is 0.4MPa, and the mixing process is: one stage of mixing rubber and vulcanizing agent → pressing weight → lifting and pressing weight → rubber discharge (105°C). 1.5Organic zinc All properties of agricultural tire performance tests are tested in accordance with the corresponding national standards or corporate standards.
