Traditional rubber inner tube is processed with natural rubber as the main raw material. Although natural rubber has high mechanical strength and good elasticity, its air tightness and aging resistance are poor. Therefore, the life of natural rubber inner tube is generally short. The butyl recycled rubber processed with waste butyl inner tube as the main raw material inherits the excellent air tightness, heat resistance and chemical stability of butyl original rubber. It can be used in natural rubber inner tube formulations to improve air tightness and extend service life Among them, the extrusion process is critical to the quality of natural rubber / butyl recycled rubber inner tube.
When natural rubber rubber inner tube is mixed with butyl recycled rubber, special attention should be paid to filter rubber and extrusion process conditions in the extrusion process.
1. Butyl recycled rubber / natural rubber inner tube filter
The inner tube of the bicycle has strict requirements for airtightness, thin texture itself, and particularly high requirements for the quality of the rubber materials and compounding agents used. Therefore, natural rubber and butyl recycled rubber must be filtered before use. During the gel filtration process, the head temperature should be controlled between 95 ° C and 105 ° C, and the fuselage temperature should be controlled between 45 ° C and 55 ° C. The filter used for the filter gel can be selected from 44 mesh two layers, 20 mesh one layer, 10 mesh For a layer of screen, the temperature of the extruded rubber should not be too high, and the temperature of the natural rubber extruded rubber cannot be higher than 130 ° C.
After the butyl recycled rubber / natural rubber filter is completed, the rubber is hardened for more than an hour. When using sulfur vulcanized butyl recycled rubber / natural rubber blends, sulfur must be screened through a screen of 80 mesh or more before being put into the mixer.
2. Extrusion of butyl recycled rubber / natural rubber inner tube
When butyl recycled rubber / natural rubber is used to extrude the inner tube of the rubber productive car, the extrusion process is generally performed in a single-head screw extruder. The temperature of the extruder head is controlled below 85 ° C and the mouth temperature cannot be higher than 105 ℃, extrusion temperature 1JLYY1223 is controlled between 40-50 ℃. In order to ensure the dimensional stability of the inner tube when the inner tube of the bicycle is extruded, the extruded return rubber must not contain moisture and impurities, and the amount of the returned rubber must not exceed 20%.
At present, the price of butyl recycled rubber on the market is between 5000-7000 yuan per ton. It is used in the production of inner tires with natural rubber as the main raw material. It can replace some high-priced natural rubber and improve the blended rubber. Technological performance improves the airtightness, heat resistance and aging resistance of the inner tube of power bikes. Therefore, the production of inner tubes of car tires using butyl recycled rubber / natural rubber and rubber has gradually become the mainstream production method.
When tyre manufacturers use butyl recycled rubber to reduce the production cost of natural rubber inner tubes and improve the comprehensive indicators of inner tubes, rubber product manufacturers must reasonably adjust various parameters in the extrusion process, timely control the performance of the extrusion process, and avoid the extrusion process. Contaminated with impurities and moisture to improve the product quality and production efficiency of butyl recycled rubber / natural rubber inner tube.