Polymer valve gates are used with a hot runner design in order to control how the cavity is filled, and to regulate the flow through each gate.
A polymer valve gate system opens and closes the gate with assistance of hydraulic or pneumatic cylinders. This topic details some issues to remember when setting polymer valve gates.
Valve gate uses
A polymer valve gate system is used to control:
- How the cavity fills.
- Weld lines.
- Part weight.
- Cavity pressure.
- Overpacking.
- Flashing and drooling.
Valve gate guidelines
- Valve gates can only be used in conjunction with hot runners (See picture above).
- There is no limit on the number of valve gates that can be assigned to a model.
- A valve gate must be assigned to a single hot gate element in each hot drop. For Gas-assisted Fill+Pack analysis, a valve gate can also be assigned to an overflow well (modeled using Midplane or beam elements for Midplane models, and tetrahedral elements for 3D models).
- A valve gate must not be assigned to the same element as an injection location. You should either model the feed system ahead of the valve gate, or ensure that the gate is meshed with more than one element along its length and then assign the valve gate to the gate element attached to the part.
- A valve gate is assigned to a hot gate or overflow well element by selecting a valve gate controller on the Valve Control tab of the properties dialog for the element. The properties that you assign to the valve gate controller specify the initial state and on/off timings of the valve gate.
- Each valve gate controller should have a unique name to identify it. The same valve gate controller can be assigned to more than one hot gate or overflow well element. To ensure you have set the correct controller at each gate, use a different property name for each valve gate controller and gate element.
- Valve gate controllers operate independently. One valve gate does not have the ability to close when the flow front reaches another valve gate.
Note: You cannot set a valve gate directly onto a runner. In order to set a valve gate, you must first select an existing hot gate or overflow well element.
(