What methods can be used to mitigate hot runner vibration?

Three strategies can be used to mitigate hot runner vibration: lowering excitation at the source, preventing system resonance, and using damper to absorb energy. For certain situations, alternative approaches can be used directly:

1. Lowering the source of vibration excitation

Reduce injection speed, smoothly adjust holding pressure, lessen the pulsating impact of melt injection, and lessen fluid-induced vibration at the source. Lower the injection molding machine's mold opening and closing speed to lessen external vibration input and mold closing impact force.

Optimize the runner structure by grinding the runner's inner wall, increasing the runner turning radius, minimizing sudden cross-sectional changes, minimizing turbulent melt flow disturbances, and minimizing the creation of pulsating vibration sources.

Active vibration adaptation: If the hot runner has an active vibration feature, immediately reduce the vibration frequency that the apparatus has set, keeping it within the 30 Hz safe range.

2. Modify Natural Frequency to Prevent Resonance

raise Support to Improve Stiffness: Modify the natural frequency, avoid the excitation resonance range, shorten the unsupported span, add auxiliary support blocks to the manifold, and raise the hot runner system's overall stiffness.

Add Counterweight to Adjust Frequency: To alter the system's natural frequency and prevent resonance amplification brought on by overlap with the excitation frequency, install high-temperature resistant counterweights in the manifold's non-working area.

3. To absorb vibration energy, increase damping

To directly prevent vibration transfer and absorb excess vibration energy, install high-temperature resistant damping pads between the manifold and the template (copper-based composite pads or high-temperature damping rubber pads are recommended).

To reduce the nozzle's own vibration amplitude and stop minor vibrations from being magnified and transferred to the entire system, add separate dampening fixing sleeves to the hot nozzles.

To stop loose screws from exacerbating vibration, use anti-loosening designs for fastening screws (such as adding anti-loosening washers or applying high and low temperature resistant anti-loosening glue).