Blending-Granulating Technology And Equipment For Raw Materials Of Composite Friction Materials

Granulating technology is a main method for processing and treatingpowdered materials including micro-fibers. The method is very important anduseful in protecting air environment, increasing automotive level of some products.Composite friction materials are fundamental materials used for somefrictional parts of vehicles and machines. A composite friction material consists ofthe mixture of many powdered granular and fibered materials. The conventionalmethod for blending raw materials for composite friction materials easily resultssome problems, such as environmental pollution, non-uniform distribution ofmaterial components, much more requirement of bridging-liquid and bakelite asadhesive and much lower porosity. In order to solve these problems, the blendingtechnology for granulating materials of composite friction materials was studied inthis work. This method transferred the design of composite friction materials fromthe componential design to componential-structural combination design.Blending modes include flowing mixture, impacting-crashing mixture andsticking-diffusing mixture of powdered materials due to adhesion force andelectrostatic attraction according to the mixing motion of the powdered materials.The three blending modes bring into actions simultaneously during oneblending-granulating procedure. But, their effects on the blending quality of thepowdered materials were dependent on the physical nature of the powderedmaterials and the structural functions and features of the blending machines used.The granulating technology of composite friction materials is of a complexprocedure during which the granular particles was growing due to severalmechanisms, including the prior nucleation by dry mixing, filling of cavities,adhesion and breakage, enveloping and grinding, kneading and ripping, slippagefilling, plastic flowing filling, and rolling and tamping.A model machine was designed and manufactured based on the technicalrequirements for blending and granulating property of the raw materials ofcomposite friction materials. Special attentions were paid to the features of the...