Sino Mould offers superior PET preform injection molding solutions for various application and volume, such as mineral water, C.S.D., fruit juice, milk, milk-based drinks, tea, functional beverages, etc. So we can see that PET bottles are a huge market in the global. The popular method of making PET bottles is the two-step process: first step - PET is injection molded into a preform (like a tube with screw); second step - the preforms will be reheated, stretched and blown into its final shape. And this article is about the basics of the first step – PET preform injection molding. And hope that you will find where shall pay attention to make preform molding more productive at the beginning after checking the following three tips.
1. About PET material
Polyethylene terephthalate (uses of PET), is the most common thermoplastic polymer resin used in containers for liquids and foods, as the following features:
- Security
- Excellent in gas and fair moisture barrier
- Lightweight
- Strong and impact-resistant
But please note that the special characteristic of PET - hygroscopic, it absorbs water from its surroundings easier. However, when PET is being heated, if there is much water, the PET would be hydrolyzed, then its resilience is reduced. Thus, PET must be dried before it is melted in a molding machine. And the moisture content would be required different for detail items, such as one kind of PET (special model for preform) has to be dried to ensure the moisture content below about 30-40 ppm, and the drying conditions typically used are 180°C for 5 hours; the dew point of the drying air should be at least -40°C, typically injection temperatures of 285°C may be used to get clear preforms.
Otherwise, it would affect the quality of the preforms; finally reduce the bottles' productiveness.
2. Preform injection molding system
There is always a complete PET preform injection molding system for making preforms, in addition to preform injection moulding machine and PET Preform Injection Mould, further comprising: dryer for large amount PET, dehumidifying dryer, chiller, cooling tower, auto loader, preform out robot, conveyor and air dehumidifier for well preform molding environment… The complete system could be simple and complex, which depends on how the production capacity required and budget invested by customers.
Here is a video showing the PET preform molding process simply, hope it could help you.
And this is a video more detailed in PET preform mould, check it to learn more.
3. PET preform molding technical operators
Improving part quality and reducing scrap is the basic aim for the preform molders, and it not only depend on the PET preform injection molding system( equipment and tools), but also the expert preform molding technical operator who can deal with troubles timely, help the total preform molding line run very well in the long time. So the related operators must be knowledgeable about the proper way of processing and troubleshooting.
It’s not so easy for a new factory to find experienced operators at a suitable salary, thus, training the workers is one of the suitable ways for improving the situation.
So regarding the better running for the new factory, it’s better to find the support from the suppliers, such as:
- Setting the optimal molding parameters for preforms
- Regular reviewing the equipment and tool status
- Quick response and solution for troubleshooting
- Training machine operators comprehensively
- …
More about the tricks for efficient PET preform injection molding solutions, welcome to contact us now! Sino Mould would be glad to provide the proposal for highest productivity levels and the lowest production costs.
