Does the deioniser affect the quality of the film seal?

Electrostatic charges versus a tight seal. What role does the deioniser play?

Does the deioniser affect the quality of the film seal? The short answer is: yes, and significantly. Neutralising electrostatic charge reduces contamination in the weld, stabilises film guidance, improves aesthetics and repeatability of the weld and reduces rejection. Below you will find a practical guide: mechanism of operation, effects in sealing, in-line settings and measurements and maintenance.

Why do electrostatic charges spoil the weld?

• Does electrostatics attract dust and particles to the edges of the weld?

  Yes - the electrified film acts as a 'magnet' for dust, product crumbs or label particles. Contaminants in the tab result in sublimation, micro displacement and complaints.

• Does the charge cause layer sticking and guidance problems?

  Yes - the 'cling' effect makes it difficult to open the pockets and vent the pack, which generates wrinkles and air pockets under the jaws.

• Do ESD discharges affect temperature and control stability?

  They can - load jumps interfere with sensors, the PID controller and HMI communication, which in extreme cases disrupts T-t-P performance.

How does the deioniser improve the quality and OEE of the line?

• Does charge neutralisation reduce the number of leaks?

  Usually yes - a cleaner overlap and evenly adhering layers mean fewer 'fish eyes', sub-heats and leaks in leak tests.

• Is the weld more aesthetically pleasing and repeatable?

  Yes - an even weld, no scorching from local film 'sticking' and fewer wrinkles are a direct result of the reduced charge.

• Are downtime and microstops decreasing?

  Yes - fewer feeding disruptions, fewer manual corrections and jaw cleaning increases productivity (OEE) and clock stability.

Where and how to install deionisers on the packaging line?

• Is the first point a film unwinder?

  Yes - neutralisation already at unwind reduces charge accumulation from roller and brake friction. This 'cleans' the film before printing, forming and sealing.

• Is it worth adding neutralisation before moulding and just before the jaws?

  Yes - in front of the forming collar (VFFS/HFFS) facilitates the opening of the sleeve and the just before the welding zone improves edge grip.

• What distance and active width are optimal?

  Usually 20-100 mm from the film (according to the electrode manufacturer), a active length should cover the width of the material with a margin of 10-20 mm to avoid 'dead' zones.

• Are air systems better at high speeds?

  Often yes - air-assisted ionisation (air-assist) increases ion coverage in fast lines and at long film distances.

How do we measure deionisation efficiency in the context of sealing?

• Will an electrostatic meter suffice?

  That's the bottom line - control levels before and after neutralisation. Strive to < ±1 kV on the film surface and in the sealing zone perfectly < ±0.5 kV.

• Are leakage and tear-off tests necessary?

  Yes - after implementation of deionisers compare leak test / burst / peel and discard rates on Party A/B.

• Is it worth monitoring defects visually online?

  Yes - the vision system will pick up wrinkles and dust inclusions in the weld, correlating them with the charge level.

How do you select the deionisation technology for the material and application?

• Does thin PE/CPP require a different approach than rigid laminates?

  Yes - thin films are easier to neutralise with a standard strip, while stiffer laminates and wide strips may need to be stronger electrodes or double setting.

• Does humidity affect the results?

  Yes - a very dry environment promotes charge buildup; RH control (e.g. 40-50%) increases deionisation efficiency.

• Do printing and varnishing change the behaviour of the film?

  Yes - coatings can modify surface conductivity; in such cases it is useful to stronger ionisation or less distance.

Maintenance and health and safety - how do you look after deionisers so they don't lose power?

• Do the emitter needles need to be cleaned regularly?

  Yes - dust and product mist reduce performance. Clean as instructed (usually every 1-4 weeks), at a standstill and when unplugged.

• Does the compressed air have to be clean and dry?

  If you use air-assist - filtration and drying are mandatory in order not to apply moisture and oil to the film and electrodes.

• Does ionisation generate ozone and is it safe?

  Minimum quantities - maintain recommended distance, good ventilation and service; modern slats are within standards when installed correctly.

Most common mistakes when implementing deionisation - what to avoid?

• Will a single 'anywhere' strip solve the problem?

  No - spotlight i zonal load sources require multipoint neutralisation (unwinding, forming, just before sealing).

• Does being too far away from the film reduce effectiveness?

  Yes - a decrease in ion density avalanches the effect; stick to the recommended distance and alignment to the tape.

• Is it possible to disregard measurements and rely on 'impression'?

  No - without kV logs and discard control difficult to prove impact; enter checklist of measurements in QA reports.

Mini implementation procedure - how to quickly check the impact on the weld?

• How to plan an A/B test in production?

  Run the batch with ionisation off (A), then with ionisation at the points: unwind + pre-weld (B). Collect: kV levels, OEE, rejects from leak tests, weld aesthetics (vision).

• What thresholds should be considered a success?

  The kV drop to < ±1reduction in discards by ≥20% and an increase in speed or shortening of the microstops without loss of quality.

FAQ - quick answers?

• Is a deioniser needed for impulse and fixed-temperature welders?

  Yes - in both technologies, a clean, dust-free film facilitates a strong and aesthetically pleasing joint.

• Will neutralisation replace good T-t-P settings?

  No - it's a supplement. Deionisation removes interference, but you still need to get the temperature, time and pressure right.

• Will I always see the effect with the 'naked eye'?

  Often yes (less dust, smoother weld), but the full impact can be seen in leak tests and reject statistics.

Summary

Deionizer really improves the sealing quality of the film, because it eliminates electrostatics - a major source of contamination in the weld, guidance problems and micro-alloying. Successful implementation means: multi-point neutralisation (unwinding, moulding, before jaws), proper distance and active width, regular kV measurements and emitter service. The result is stronger, cleaner and more reproducible welds, fewer rejects and higher OEE - with no changes to the T-t-P recipe.