Pet Blow Molding
Plastix blow molding process can be controlled by controlling various parameters such as Temperature, Pressure, Stretch time, Stretch rate, Reheat time, Cooling time, clamping pressure and relations between these parameters. Temperature of perform for blow molding is ranging from 90ºC to 110ºC. Temperature increases from bottom to top of perform. So that more material can move towards the bottom of the bottle during blowing stage. For pressure there are two phases one pre-blowing (Low air pressure 10 bar) and then final blowing (High pressure 40 bar). In pre-blowing stretch pin move forward and push perform and low air pressure (Pre-blowing). There should be synchronizing in stretch pin and pre-blow pressure. If the stretch pin is late than pre-blow pressure then there will be error in the bottom center and if high there will be tress whitening. The high pressure is applied so that perform take the shape of mold. High pressure is required to mark the detailed and sharp corner.