Recognise the symptom before changing settings
Describe what changes, where it first appears and whether it follows a product batch, packaging batch, filling head, lane, speed, temperature or time in the run. Typical observations include:
- one head slows or stops
- dose accuracy deteriorates during the run
- pressure rises upstream
- particles are damaged or separated
Likely causes to separate
A symptom can have several unrelated causes. Treat the following as hypotheses to test rather than a list of settings to change at once.
- minimum internal passage smaller than the largest inclusion
- product drying or cooling in stagnant areas
- filter or strainer loading
- valve geometry trapping fibres, seeds or pieces
- inadequate agitation allowing solids to settle
Check in this order
Check 1
Measure the largest real inclusion, including agglomerates.
Check 2
Trace the minimum passage through hose, valve, manifold and nozzle.
Check 3
Inspect where product first accumulates.
Check 4
Compare temperature and idle time when blockages occur.
Check 5
Check suspension and distribution in the source vessel.
Corrective actions to evaluate
After the cause is demonstrated, select the least disruptive correction that returns the process to a safe, repeatable and approved state.
- increase the minimum unrestricted passage
- use rotary, large-port or product-compatible valves
- keep temperature within the validated range
- remove unnecessary restrictions and dead legs
- provide appropriate agitation without damaging particles
Prevent the problem returning
- trial the worst-case particle distribution
- define maximum idle time before flush or recirculation
- inspect filters and product-contact parts on schedule
- include blockage recovery in operator instructions
Record evidence, not only the final setting
Capture the product and packaging batches, machine recipe, head or lane, speed, temperature, vessel level, symptom frequency, intervention and post-correction results. This creates a usable centreline and allows recurring loss to be prioritised through OEE or downtime analysis.
Common questions
What is the first check for filling nozzle and valve blockages?
Measure the largest real inclusion, including agglomerates.
What commonly causes filling nozzle and valve blockages?
Common causes include minimum internal passage smaller than the largest inclusion, product drying or cooling in stagnant areas, filter or strainer loading.
Should the machine be adjusted immediately?
Change one controlled variable at a time after the measurement method, product condition, packaging and safety state are confirmed.
When should production be stopped?
Stop and follow the site safe-isolation and escalation procedure when there is risk of injury, contamination, fire or explosion, uncontrolled product release, damaged guards, unsafe pressure or an unverified quality result.
What information should be recorded?
Record product and pack batch, recipe, machine settings, filling head or lane, time, temperature, speed, symptom, corrective action and the evidence that performance returned to the approved condition.