1)The cost of the extrusion blow molding machine is cheaper than that of injection molding machine, about one third of the injection blow molding machine.
2)On blowing molding, the preform is formed under low pressure through the extrusion equipment heat, in this circumstance, the residual stress of the products is small. With its good performance in tensile, impact, bending and other variety of environments, It have the good function.
3)In the injection blow molding, the plastic melt at high pressure
(15–140Mpa) through the mold runner and gate, which will lead to uneven stress distribution.
4)The moleculars of blowing mold grade plastics
(e.g,PE)are more than that of injection mold.
Such blow molding products have a high impact toughness and high resistance to environmental stress cracking performance, which is very favorable for the large-capacity production of plastic bottles.
5)The wall thickness of the blow molding products can be very thin while the injection molding products cannot be so thin as blowing mold process.
6)Blow molding process can shape complex and irregular products, but the injection molding process has to produce two or more pieces, and then stick it by the glue or bond it or using ultrasonic welding.