stretchblow
Stretchblow, more commonly referred to as stretch blow molding, is a plastics manufacturing process used to form hollow plastic parts, especially bottles and containers. The term usually denotes the two-stage variant in which a polymer is first formed into a close-ended preform and then blown into a final shape, with biaxial stretching invoked to orient the polymer and improve performance. A related one-step variant combines injection and blowing in a single machine.
In the two-stage process, a thermoplastic such as polyethylene terephthalate (PET) is first injection molded into
Materials commonly used include PET, with PETG and other polymers used in specialized applications. One-step stretch
Advantages of stretchblow molding include improved mechanical strength, gas and moisture barrier properties, and the ability
Applications are dominated by beverage bottles, but the technique is also used for cosmetic and household containers,