Research On Pulverization Of Waste Tire Rubber At Ambient Tempreture And Modification Of Powdered Rubber

Millions of waste tires are emerged owing to the growth of auto industryand transportation each year. Waste tires are serious challenges toenvironmental safety and public health and have brought about a great deal ofenvironmental problems. Rubber, metal and fiber materials included in wastetires are valuable and can be reused in many ways, though it’s no longeruseful for waste tires as tires. Therefore, discarding waste tires withoutconsidering their reuse is a great lose to our society. Pulverization especiallyfine pulverization of waste tires and devulcanization of powdered rubber arekey technologies for dealing with waste tires and realizing high reuse of wasterubber resource. Therefore, Research on pulverization of waste tire rubber anddevulcanization of powdered rubber has great theoretical and practical value.Characteristics of powdered rubber obtained from pulverization atambient temperature were investigated, and the effect of particle size ofpowdered rubber and amount of powdered rubber contained in rubbercompounds on such main performance properties as tensile strength andelongation at break of revulcanizates was analyzed. Based on theories andmethods on pulverization at ambient tempreture, take pan mill, one typicalpulverization device at ambient tempreture, as an example, characteristics ofpulverization at ambient temperature and the effect of processing parameterson pulverizing performance were analyzed. One orthogonal test was designedto investigate effect of processing parameters-rotating speed, clearance of panmill and feed rate-on productivity of powdered rubber and proportion of finepowdered rubber, which are the most important aspects for industry to focusattention on. Uniform design and quadratic regression orthogonal design wereintroduced to study more precise relation betion productivity and proportionof fine powdered rubber with processing parameters, and regression modelsbased on productivity and proportion of fine powdered rubber were developedwith the help of statistical theory and regression analysis. Based on analysis of powdered rubber reuse and of characteristics ofpowdered rubber, four chemical modifying agents-TMTD, PA, RX-80and RVwere introduced and single factor experiments were designed to study the fourchemical modifying agents’ effect on improvement of main performanceproperties of direct revulcanizates of powdered rubber after modification bythe four chemical modifying agents. Based on results of single factorexperiments, one orthogonal test was designed to study the effect of the fourmodifying agents on performance properties of direct revulcanizates ofpowdered rubber. Then quadratic orthogonal rotation combination design andregression analysis were introduced to investigate more precise relationbetween performance properties of direct revulcaniates and four modifyingagents.