Abstract:
The extrusion processing is one of the methods for forming of thethermoplastic products. In the process of extrusion, plastic compound is heatedand passed through die continuously by screw extruder. The extrudate is cooledand calibrated to form shape of product. The performance of this process dependsmainly on its cooling efficiency. The objectives of this research were to developthe heat transfer model for extruded PVC profile cooling in the calibrator and tostudy the effect of the corresponding parameters , eg. extrusion rate , heat transfercoefficient of water and air, thermal conductivity of plastic and water coolingtemperature.Three models were proposed for heat transfer of hollow rectangularplastic profile, the first model assumed onedimension heat transfer and no heattransfer in hollow channel of the profile, the second model assumed two-dimensionheat transfer and no heat transfer in hollow channel of the profile andthe third model assumed two-dimension heat transfer in the profile and substantialheat transfer in the hollow channel.The results showed that the temperature distribution obtained from thethird model and that from the experimental data were in best agreement forlongitudinal distance from the die. The effect of thermal conductivity was themost irnportant parameter for controlling of the temperature profile .The result of this study will be used for designing of higher efficientcalibrators and for better temperature control for higher stability of the productshape.