In mould manufacturing, how to decide the mould injection system and how to choose hot runner system, it is a very important issue. In order to get a top quality mould, we have to know the details of mould injection system (hot runner system or cold runner system).
Mould injection system can be devided into two system:
Hot runner plastic injection moulding system can be devided into below tow big types:
- Open hot runner nozzle
- Close hot runner nozzle
Open hot runner nozzle has below different types:
-pin point gate nozzle
-direct gate hot nozzle.
please see below picture to see the two types hot nozzle’s differences.
Close type of injection nozzle, we call it valve gate injection nozzle.
-Pneumatic valve gate nozzle ( use air cylinder to drive the vlave pin moving)
-Hydraulic vlave gate nozzle ( use hydraulic cylinder to drive the valve pin moving)
-Mechanical vlave gate nozzle ( use mechanical moving to drive the valve pin)
If you use soft and high MFI plastic material, then you can choose pin point gate, of course the plastic parts should be so big, for example the part’s weight should not bigger then 200G, otherwise, you should use 2 or more then 2 tips of pin point gate. The suitable material is such like, PP,PE..
But if the plastic part is big then you have to use direct gate or valve gate. But the direct gate shortcoming is that there will be a gate mark and we have to cut the gate tail manually. If you use valve gate, you do not need to do any after moulding treatment and the gate mark is very nice.
Below advantage and shortcoming of each hot nozzle can help you to make better selection.
- Pin point nozzle, suitable for small volume injection, with the very small gate mark do not need to do any treatment to the moulded plastic parts. Compare to valve gate it is much more enconomical cost, but need high pressure injection moulding.
- Direct gate nozzle, suitable for big volume injection moulding, but we need to cut the gate tails after, the cost is similar the pin point gate nozzle, the advantage is easy filling.
- valve gate advantage, easy filling, nice gate marks, no after moulded treatment, the only shortcoming is that the cost will be higher then the other two types of nozzle. In the other hand, the mould cost also will be bigger since we need thicker mould plate to housing the valve gate nozzle.
Please check above advantages and shortcomings of the different type of hot nozzle to decide how to choose hot runner system for your mould injection system.
Anole hot runner system is one of the leading hot runner technologies innovators in China, it can help you to solve where to make the injection gate, how to choose the suitable hot nozzle size and hot nozzle type. How to design injection pressure balance,how to make the colors change during your injection moulding, how to make the fast filling, how to design the hot nozzle tips and nozzles’ quantity.