Allot Tech
Foaming During Liquid Filling: Find the Source and Test the Remedy
Foam can occupy bottle space without supplying the intended liquid dose. First locate where it starts: product preparation, the supply circuit or the filling jet. A slower machine can hide the symptom while leaving air ingress or an unsuitable product path unresolved.
Locate foam before changing the nozzle
| Observation | Check first | Useful evidence |
|---|---|---|
| Foam already in the holding tank | Agitation, returning product and vortexing at suction | Product condition before the filler and tank level |
| Air visible after transfer | Suction seals, priming and product feed continuity | Timing after cleaning, refill or low level |
| Foam appears when the jet hits the bottle | Free fall, velocity, nozzle height and bottle geometry | Side view at normal production rate |
| Carbonated product foams on release | Approved temperature, pressure and pressure-release sequence | Actual product and package under specified process conditions |
Use a controlled still-liquid trial
- Keep product batch, temperature, bottle and upstream conditions unchanged for the baseline. Record nozzle position and speed profile.
- Change one factor: for example the final-stage speed, then measure dose, foam settling time, overflow and accepted bottles.
- If testing a diving nozzle, verify its movement clears the bottle, allows air to escape and follows the intended liquid level. Check wash access and product-contact cleanliness.
- Repeat at normal tank level, low level and after a production stop. A change that works only for the first few bottles is not a stable remedy.
Do not confuse appearance with delivered liquid
Compare net product mass or validated volume after the agreed measurement procedure. Bubbles settling can change the apparent level; a clear upper space at the moment of filling does not prove correct dosing. Record overflow losses and contaminated necks as well as the average dose. A return circuit can reintroduce air, and returned product must remain within the approved hygienic process.
Carbonated drinks need a separate process review
Bottom-up filling of a still detergent is not a substitute for a carbonated beverage filling process. Check the specified beverage temperature, pressure balance, gas content, valve sequence and container suitability with the equipment supplier. Do not improvise pressure changes or bypass process protections. Antifoam additives require product-process approval; a machine adjustment must not silently change the formulation.
Turn the trial into an acceptance record
Define an acceptable dose range, settling time, neck cleanliness, reject count and sustained good output before the trial. An initial diagnostic run could include ten consecutive bottles per head, followed by a longer agreed run covering supply changes and restarts. This is an example starting point, not a legal sampling plan. Keep individual observations, settings and time stamps so the result can be repeated.