| Experimental and theoretical studies on the blown film extrusion were carried out. The non-isothermal film blowing process was simulated by using an integral-type rheological equation of state.; In the simulation of the film blowing process, the extrudate swell zone and the stretching zone were considered separately. The extent of the extrudate swell depends on the rheological properties of the polymer melt and the take-up force.; The film blowings of PET and LDPE were carried out to investigate the characteristics of the process. Effects of the blow-up ratio, the take-up ratio, the cooling air temperature, the melt extrusion temperature, and the material variables were studied.; With the information obtained from the experiments, the simulation of LDPE film blowing was carried out and compared with the experimental results. And the effects of rheological parameters were investigated by simulation on the maximum extrudate swell and its position, and the film blowing characteristics. |
