Servo Valves for Injection Speed & Velocity Control in Injection Molding
Injection speed control is one of the most sensitive parts of an injection molding cycle because instability in the velocity can show up as fill inconsistencies including flash and short shots. For precise, predictable injection speed, Domin servo valves offer dynamic control through high bandwidth and fast response rates.
The Challenges in Controlling Injection Speed and Velocity
In most injection molding machines, the injection phase relies on the valve’s ability to deliver repeatably consistent flow. When the valve cannot respond quickly enough, the press may not function optimally by overshooting, slowing, or incorrectly switching from velocity control to pressure control.
Because the injection phase is short and highly dynamic, the system benefits from valves with fast step response, wide bandwidth, and low hysteresis. Domin’s advanced valve algorithms and onboard spool-positioning feedback improve precision and repeatability across the molding process, supporting tighter control of injection velocity and reducing scrap. Consistent, optimized injection speeds promote uniform cavity filling and reduce flow marks, voids, and uneven material distribution.
How the S6 Pro Controls Speed in Injection Molding
For injection speed and velocity control in injection molding applications, Domin’s S6 Pro servo valve is well suited due to its combination of highly dynamic performance and adequate flow capacity. The S6 Pro delivers the following characteristics that make it specifically suited for stable control. See the chart below.
|
Flow Rate |
2.6 to 16.6 gpm (5 to 63 lpm) |
|
Flow Maximum |
36.9 gpm (140 lpm) |
|
Leakage at 100 bar |
<0.3 gpm (<1.1 lpm) |
|
Response Time at 100% Step Input |
<3.5 ms |
|
Frequency Response |
>250 Hz |
|
Hysteresis |
<0.2% |
|
Mass |
1.36 lbs (0.62 kg) |
These characteristics ensure that the valve can open quickly, while maintaining a predictable flow.
Our recommended valves
Domin S6 Pro is recommended for highly dynamic injection speed and velocity control applications, while the Domin P6 Pro (proportional valve) is recommended for smaller or less dynamic systems, as the flow range (5 to 40 lpm), response times (10 ms), and frequency response (100 Hz) are lower. This can be well suited for smaller injection axes that need precision with lower speed control.