Method for blow molding

The present invention generally relates to blow-molding processes used to form hollow articles of a blow-moldable resin. More specifically, the present invention relates to processes whereby a polybutylene terephthalate resin is blow-molded to form hollow articles thereof. A method for controlling the hang time of a tubular parison formed from a thermoplastic resin is provided with a second higher melting thermoplastic resin as an additive, and blow molding the resulting resin at a temperature below the glass transition temperature (Tg) of the higher melting component. In the case where the lower melting base resin is PBT and the higher melting additive resin is PET, the temperature of molding is below the Tg of the PET additive.