Study On Thermal Oxidizing Aging Of Arimad Fiber Reinforced Elastomer Sealing Material

As a substitute of compressed asbestos fiber sheet (CAF), compressednon-asbestos fiber sheet (CFS) is used widely with the development of new sealingmaterial. Experience in-service and investigation indicate that aging is a main reasonof performance deterioration of sealing material, which results in failure of sealingunder high temperature condition. There is no enough application experience of CFS,so it is important to study on its aging performance. In this paper, the thermaloxidizing aging property of compressed non-asbestos fiber sheet reinforced witharmaid fiber (CAS) is studied with the financial support from Education Departmentof Jiangsu Province. The main content and results are described as follows.1. Thermal oxidizing aging of rubber binder, fiber and adhesion of CAS isstudied. Moreover, the influence of aging process on each main composition isanalyzed by using the aging theory of macromolecule polymer, especiallyauto-catalyze oxidizing mechanism and aging theory of fiber.2. On the base of damage theory of composite, the conception of aging damageof compressed non-asbestos fiber sheet is put forward, which reflects the aging degreeof sealing material. The aging damage variable and aging damage factor of CAS areobtained through the analysis of aging damage characteristic of rubber binder andfiber. The aging damage model of CAS is established, and the expression of the agingdamage model is obtained through experiments.3. The influence of thermal oxidizing aging on main performances of CAS isstudied. Relationships between aging damage factor and main performances of CASincluding compressibility, resilience and stress relaxation are founded, which can beused as reference on the establishment of performance evaluation method of CAS andspecification for new developed sealing material.4. Aging of sealing materials is an important factor affecting sealing capability ofgasket. The relationship between aging damage factor and leakage rate of CAS is setup through experiments of sealing performance of aging CAS, which reflects theeffect of deterioration of aging material on sealing capability of CAS. The service lifeof CAS gasket could be predicted by this relationship.