In general, there are two types of preforming methods for Pet Bottle Preform, such as "direct blow molding" and "extended blow molding":
Direct blow molding: This method is to first spray the molten preform on the same machine (usually called Injection Stretch Blow Molding) and then stretch blow molding in the hollow mold. Since the molding of the preform and the stretch blow molding are carried out in the same machine, it is called "a one-step molding method: One Step". Moreover, this method is also called "hot bottle embryo method" when the preform is not cooled, that is, the heat is retained by the retained heat.
Extended blow molding method: This method firstly shoots the preform with an injection machine, and then heats the cooled preform to a stretch blow molding machine, and stretch blow molding in the hollow mold. Since this method is subjected to secondary processing by an injection machine and a blow molding machine, it is called a "two-stage molding method". Moreover, this method is performed by heating and stretching the air after the preform is cooled, so it is also called "cold bottle embryo method". The processing flow is as follows: dehumidification drying of the PET material -> injection of the molten material into the mold by the injection machine -> PET preform cooling forming -> biaxial stretching blow molding by a stretch blow molding machine (Stretch Blow Molding). Note: The so-called "biaxial extension" refers to the longitudinal extension of the extension rod and the horizontal extension with high pressure air.
The application of the two: In general, one-stage method is more suitable for a small number of specifications, and the second-stage rule is suitable for a large number of small-scale production.
Jilian Plastic Mould is an experienced Chinese pet product design and manufacturer. We can provide a wide range of products, from 5-Gallon Pet Preform to some small pet products, we are able to bring you a good satisfaction. Product products, so what are you still hesitating? Come and leave us a message now!