In this paper the influences of the drawing temperature on physical structures and properties of PET filaments have been studied. The results show that the temperatures of the first-stage drawing will have significant...In this paper the influences of the drawing temperature on physical structures and properties of PET filaments have been studied. The results show that the temperatures of the first-stage drawing will have significant effects on birefringence development of filaments during the second stage drawing, as well as the oriented amorphous filaments change to crystanine-oriented filaments after heat treatment. Increasing temperature of the second-stage drawing can be greatly increasing the crystallinity and decreasing the dry heat shrinkage of the filaments.展开更多
The lifetime of dies is an important factor in raising the economic efficiency in production.Through the microscopic analysis as well as metalloscopy on the failure status of the cold forgingdie destined,for manufactu...The lifetime of dies is an important factor in raising the economic efficiency in production.Through the microscopic analysis as well as metalloscopy on the failure status of the cold forgingdie destined,for manufacture of copper contact heads of electric switches,the paper reaches theconclusion that the inhomogeneous distribution of carbides will cause fatigue breaking.And themeasures to control the quality of material and to improve the heat treatment technology are pro-posed.展开更多
文摘In this paper the influences of the drawing temperature on physical structures and properties of PET filaments have been studied. The results show that the temperatures of the first-stage drawing will have significant effects on birefringence development of filaments during the second stage drawing, as well as the oriented amorphous filaments change to crystanine-oriented filaments after heat treatment. Increasing temperature of the second-stage drawing can be greatly increasing the crystallinity and decreasing the dry heat shrinkage of the filaments.
文摘The lifetime of dies is an important factor in raising the economic efficiency in production.Through the microscopic analysis as well as metalloscopy on the failure status of the cold forgingdie destined,for manufacture of copper contact heads of electric switches,the paper reaches theconclusion that the inhomogeneous distribution of carbides will cause fatigue breaking.And themeasures to control the quality of material and to improve the heat treatment technology are pro-posed.
