Injection molding cycle time shortened

The flow behavior of the polymer preferentially influences the uniform shell thickness and is related directly to the molecular structure of the modifying comonomer. Modifications of PET, particularly with CHDM, improve the flow behavior during injection molding and significantly reduce the melting point of the polymer. The decreased melting point of the copolymer allows reduced processing temperatures and therefore correlates with a reduced formation of unwanted A A at shortened cycle times. 

PEN exhibits a very rapid crystallization rate and its Tg is difficult to detect by simply heating the quenched sample. Since the crystallization rate of PEN is much faster than that of PET, its processing cycle time can be shortened. Eecause of its facile processability, PEN can be molded by either injection or extrusion into electrical, electronic, and machine parts. PEN exhibits excellent mechanical strength, heat resistance, dimensional stability, resistance to chemical, acid and alkaline and impermeability to gasoline and gasohol. Therefore, it is particularly suited for making into automobile parts that come in contact with fuel, oil, and combustion gas. In addition, fiber reinforced PEN for high temperature and humidity circumstances has been reported. ... 

Unfortunately, injection molders typically run then-processes at temperatures between 190-240°C in order to improve flow and processability of the material and to shorten cycle time. Molding at these higher temperatures may have a negative impact on the elastomer morphology and thus affect the physical properties of the TPO blend. 

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