PET fiber for tire cord is many used for an omnibus because the price is cheap and tenacity, modulus are superior than other fibers. But, improvement of tenacity and dimensional stability in tire cord treated latex was demanded continuously. When fiber is made with treated cord, improved dimensional...
PET fiber for tire cord is many used for an omnibus because the price is cheap and tenacity, modulus are superior than other fibers. But, improvement of tenacity and dimensional stability in tire cord treated latex was demanded continuously. When fiber is made with treated cord, improved dimensional stability was very important in tire by fiber reinforcement. Process of polyester was composed of melt-spinning, dry, take-up, drawing step. Although process conditions are analogous, final properties of tire cord are completely differed by diameter of spinneret, spinning speed, position of dry, temperature of drawing roll and draw ratio. In the tire, tire cord is constantly extended, flexed, and compressed. Therefore, it is important to improve the fatigue resistance. Fine structure of fiber in amorphous region is great affected in fatigue resistance. When appling fatigue, crack is developed and fracture is occurred. Therefore, fine structure control is necessary to good fatigue resistance. In this paper, we investigated that fine structure and physical properties of six samples by drawing several take-up velocities and speed of drawing roll and applied to change in the number of repeated extension fatigue test. We investigated fine structure and properties of PET tire cord fiber focused on effective crosslink density. In chapter 2, We focus on fine structure and physical properties on effective crosslink density which calculated from kinetic theory of rubber elasticity and fraction of TTM. First, Specimens are six samples which take-up speed and drawing roll are finely changed. The change is not appeared by process conditions in crystalline structure, long period and density, etc. Effective crosslink density is that sample which take-up speed is high and draw ratio is low is higher than opposites. Fraction of TTM shows on opposite trend. Finally, low take-up speed and high draw ratio are to be profitable for high modulus and high take-up speed and low draw ratio are to be profitable for good dimensional stability. But, because the tenacity is little difference, process conditions of T3, T4 are to be compatible to PET fiber for tire cord of HMLS type. In chapter 3, We investigated fatigue resistance of T1, T6. T1 and T6 showed major difference in effective crosslink density. So T1 and T6 tested which repeated extension fatigue test is prepared at various fatigue cycles. In test of WAXD and DSC, as the number of fatigue cycles increased, there was little change in crystalline structure. As the number of fatigue cycles increased, density and birefringence, mechanical properties are increased by straining-hardening effect until fatigue cycles of 30×10^(4). After fatigue cycles of 30×10^(4) the values are decreased by scission of chain in amorphous region. But the decrease range of T6 which is many of effective crosslink density of is smaller than T1 at birefringence, density, mechanical properties. Finally, fiber with many effective crosslink density showed good fatigue resistance.
PET fiber for tire cord is many used for an omnibus because the price is cheap and tenacity, modulus are superior than other fibers. But, improvement of tenacity and dimensional stability in tire cord treated latex was demanded continuously. When fiber is made with treated cord, improved dimensional stability was very important in tire by fiber reinforcement. Process of polyester was composed of melt-spinning, dry, take-up, drawing step. Although process conditions are analogous, final properties of tire cord are completely differed by diameter of spinneret, spinning speed, position of dry, temperature of drawing roll and draw ratio. In the tire, tire cord is constantly extended, flexed, and compressed. Therefore, it is important to improve the fatigue resistance. Fine structure of fiber in amorphous region is great affected in fatigue resistance. When appling fatigue, crack is developed and fracture is occurred. Therefore, fine structure control is necessary to good fatigue resistance. In this paper, we investigated that fine structure and physical properties of six samples by drawing several take-up velocities and speed of drawing roll and applied to change in the number of repeated extension fatigue test. We investigated fine structure and properties of PET tire cord fiber focused on effective crosslink density. In chapter 2, We focus on fine structure and physical properties on effective crosslink density which calculated from kinetic theory of rubber elasticity and fraction of TTM. First, Specimens are six samples which take-up speed and drawing roll are finely changed. The change is not appeared by process conditions in crystalline structure, long period and density, etc. Effective crosslink density is that sample which take-up speed is high and draw ratio is low is higher than opposites. Fraction of TTM shows on opposite trend. Finally, low take-up speed and high draw ratio are to be profitable for high modulus and high take-up speed and low draw ratio are to be profitable for good dimensional stability. But, because the tenacity is little difference, process conditions of T3, T4 are to be compatible to PET fiber for tire cord of HMLS type. In chapter 3, We investigated fatigue resistance of T1, T6. T1 and T6 showed major difference in effective crosslink density. So T1 and T6 tested which repeated extension fatigue test is prepared at various fatigue cycles. In test of WAXD and DSC, as the number of fatigue cycles increased, there was little change in crystalline structure. As the number of fatigue cycles increased, density and birefringence, mechanical properties are increased by straining-hardening effect until fatigue cycles of 30×10^(4). After fatigue cycles of 30×10^(4) the values are decreased by scission of chain in amorphous region. But the decrease range of T6 which is many of effective crosslink density of is smaller than T1 at birefringence, density, mechanical properties. Finally, fiber with many effective crosslink density showed good fatigue resistance.
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#제조조건 타이어코드 PET섬유 미세구조
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