Difference between Extrusion Blow Molding and Injection Blow Molding
Extrusion blow molding and injection blow molding is widly used to produce hollow products with small and big size. Most engineers and manufacturers in plastic industry may know very well for the difference between extrusion blow molding and injection blow molding. They can check very fast for a bottle or product how it is made or how to produce the kind of plastic containers or products.But as a layman,most people may be confused for how a product is made. Here we will talk about how the find out the differece of the extrusion blow molding process and injection blow molding process.
Extrusion Blow Molding Process
Extrusion blow molding process is start from the material is melted and plasticized in the barrel. And then extruded from the head of the extruder with conventional downward tube.When the hube parison reaches a predetermined length, a section of tube embryo is intercepted and placed in the blow mold while still hot. The mould is closed catching and holding the neck end open and pinching the bottom end closed. the compressed air blown into the parison through the air blowing nozzle. The tube prison will be precisely inflated as the desired shape of the mold cavity. After the mould is completely cooled and then the mold can be opened to take out the product.
Injection Blow Molding Process
Injection blow moulding process can be separated as injection moulding process and blow moulding process.
1. Injection moulding process: The injection molding is finished by an plastic injection molding machine. In this process we will produce a semi-finished product called preform or parison. Raw material is melt in a barrel and feed to the nozzles, injected to a injection mold, then we have the perform with kinds of bottle neck types.
2. Blow Moulding process: The blow molding is we put the performs or prisons to a blowing mold and use high pressure air to blow it up as a bottles or other hollowed containers.
Injection blowing molding process can be all finished with Guanxin horizontal injection blowing molding machines. This optimized injection blowing moulding system can be run with 28 cavity mold of tablet bottle mold in about 25 seconds cycle time. This is high speed, energy-saving and stable for 24 hours running. Can beat the production line running vertical injection blow molding machines and extrusion blow molding machine very easy, but the investment cost is lower.
Comparison between Extrusion Blow Moulding and Injection Blow Moulding:
| Extrusion Blow Moulding | Injection Blow Moulding | ||
|---|---|---|---|
| More easy for production | More difficult to produce | ||
| One step forming process | Two steps forming process | ||
| Lower cost | Higher cost | ||
| Recycle Materail is used | Mostly Brand new material | ||
| Multi-layers | One layer only | ||
| Product size from few ml up to hundreds liters | Product size from few ml up to dozens liters | ||
| Slow production | Fast production | ||
| Cheap or good quality | Good quality only | ||
| Bigger leaking risk | Smaller leaking risk | ||
| Have parking lines | Almost no parking lines | ||
| Poor precision | Better accuracy | ||
| Have flash and trimming | No flash and trimming | ||
| Not Energy Saving | Energy Saving | ||
| Thickness depends on extrude head/parison controller | Thickness depends on the core and cavity of the mold | ||
| Only one set blowing mold | Have injection mold and blowing mold | ||
| All cool runner mold | cool and hafe hot runner mold | ||
| More difficult for automatic running | Easy for automatic running | ||
| Cavities number depends on die-head number | Cavities number depends on mold cavities | ||
| Wide range of materials | Narrow range of materials | ||
| * Advantage and disadvantage of extrusion blow molding and injection blow molding. | |||
By reading here, hope all of you are know the difference between extrusion blow molding and injection blow molding very clear. And know what`s process that a hollow product is made. If not, please click for how to know a product is made my extrusion blow moulding or injection blow moulding.
