The covalent cross-linking of tire rubbers is prerequisite for acquiring high elasticity and environmental resistance. However, the irreversibility of these chemical cross-links make the recycling of tire rubber products inherently difficult, which is a persistent obstacle encountered in thermosetting polymers. About 150 thousand tons of waste rubbers is scrapped each year in domestic, the bulk of which is incinerated for lowefficiency energy recovery and dumped as landfill, causing serious environmental pollution and resource wastage. The goal of this project is to develop a continuous process for production of reclaimed waste tire rubber using a co-rotating twin screw extruder and evaluate the possibility of recycling waste tire rubber. The project have already reached the following goal：(1). Completed the continuous devulcanization process stability of 1 metric ton waste tire rubber, the sol component content is about 18.6-26.3%；decrosslinking degree degree is about 71.7-76.0%；mooney viscosity ML (1+4)100°C is about 36.4-44.7, and the ash, carbon black and crosslink density of reclaimed waste tire rubber quality is evaluated with a ASTM standards. Completed the continuous devulcanization process stability of 10 metric ton waste tire rubber, the sol component content is about 19.2-30.2%；decrosslinking degree degree is about 70-77%；mooney viscosity ML (1+4)100°C is about 38.8-48.9, and the ash, carbon black and crosslink density of reclaimed waste tire rubber quality is evaluated with a ASTM standards. (2). Completed the physical properties of continuous devulcanization of the 1 metric ton reclaimed rubber re-cured, that the density (Mg/m3) is about 1.15, tensile strength is about 10.4 MPa, elongation at break is about 312%, and tensile strength retention is about 105% which attain tocomply with a CNS 2230 requirements. Completed the physical properties of continuous devulcanization of the 10 metric ton reclaimed rubber re-cured, that the density (Mg/m3) is about 1.15, tensile strength is about 10.9 MPa, elongation at break is about 320%, and tensile strength retention is about 107% which attain to comply with a CNS 2230 requirements. (3). Completed the continuous devulcanization of the reclaimed waste tyre rubber were formulated with virgin rubber (70/30 wt% ratio) and re-cured. The physical properties of cover layer (CVC-30) that the density (Mg/m3) is about 1.178, tensile strength is 151 kgf/cm2, elongation at break is about 402.5%, tear strength is 41 kgf/cm2, hardness (Shore A) is 60, and tensile strength retention is about 79% which attain to the project objective. The physical properties of middle layer (CVL-30) that the density (Mg/m3) is about 1.189, tensile strength is 62 kgf/cm2, elongation at break is about 623.2%, tear strength is 26 kgf/cm2, and hardness (Shore A) is 48 which attain to the project objective.

Waste tire, Extruder, Reclaimed rubber