How to Detect Hot Runner Vibration

There are two types of hot runner vibration detection: professional precision detection and basic on-site detection. The techniques are quite useful:

1. Easy On-Site Detection (fast evaluation, no need for specialized equipment)

Ideal for quick troubleshooting on the manufacturing floor. The following are the operational steps:

Touch Sensing Method: Verify that the equipment is stationary once the injection molding machine has stabilized, production has ceased entirely, and the power has been turned off. Put your palm on the exterior of the mold close to the hot runner. Excessive vibration is indicated by a perceptible tingling or even shaking sensation; mild vibration without tingling is considered normal.

Auscultation Method: Use a medical stethoscope in close proximity to the hot runner manifold or nozzle installation site. Only a consistent and steady operating sound is normal; hearing distinct high-frequency noises or irregular aberrant sounds suggests abnormal vibration.

Product Verification Method: Make 100 molds of products on a continuous basis and examine how the dimensions of products with the same cavity vary. It can be inferred that the vibration exceeds the standard if the dimensional deviation is greater than one-third of the tolerance or if surface vibration marks show up in the batch. 2. Expert and Accurate Testing (Precise Amplitude/Frequency Measurement for Issue Diagnosis)

To get precise vibration characteristics, specialist equipment are needed:

Method of Vibration Measurement: The vibration meter's magnetic base is attached to the exterior of the hot runner manifold or template. Measurements are performed immediately after the injection molding process is started and output is stabilized. Vibration frequency and vibration amplitude are the two fundamental metrics that it may directly output. Excessive vibration is defined as a frequency greater than 30 Hz and an amplitude greater than 0.2 mm.

Modal Analysis Testing: To determine whether the natural frequency of the hot runner system coincides with the melt excitation frequency in order to precisely locate the resonance fault, a professional modal analyzer can be employed to evaluate the natural frequency of the system.