Anti-drip nozzle behaviour
Diagnose shut-off, suck-back and delayed drips.
Read the guide →Nozzle selection
How do you choose a nozzle for paste filling?
Choose a paste filling nozzle by balancing product passage, container opening, fill position and clean shut-off. The nozzle must be large enough for the product but controlled enough to align with the pack and stop without tails, drips or trapped pressure.
Answer-first guidanceProduct-led selectionUK enquiry support
Selection sequence
Start with the product passage, then prove presentation in the production pack.
A nozzle should not be selected by fill volume alone. The inlet and outlet path, largest inclusion, product elasticity, feed pressure and opening in the actual container all affect whether the nozzle is practical.
- Define the hardest product condition. Include temperature, particles, fibres, aeration and stringing.
- Check the pack opening and fill position. Allow for tolerances, guides and safe nozzle clearance.
- Select the closure principle. Compare open nozzle, positive shut-off, suck-back or diving motion where justified.
- Trial steady running and stops. Inspect the nozzle and first packs after restart.
- Record cleaning and changeover. Confirm access, residue and removal of product-contact parts.
Buyer question
What sets the minimum practical nozzle bore?
The bore must pass the thickest normal product and largest credible inclusion without excessive restriction, blockage or damage. The controlling restriction may be inside the valve or fitting rather than at the visible tip, so review the complete path.
A smaller nozzle can improve placement in a narrow pack but may require more pressure or time. Test passage and cut-off together rather than selecting the smallest nozzle that physically fits.
Buyer question
How does the container opening limit nozzle selection?
The nozzle needs sufficient clearance for container tolerances, guide movement and any diving motion. A nozzle that nearly fills the neck may trap displaced air, touch the pack or smear product during withdrawal.
Use production containers, including dimensional variation where relevant. Confirm nozzle height, centring, headspace and the relationship with cap or seal areas.
Buyer question
When is positive shut-off or suck-back useful?
Positive shut-off is useful where an open tip cannot stop a cohesive or pressurised product cleanly. Suck-back can retract a small amount of product to reduce a hanging tail. Neither feature guarantees a clean result if feed pressure, temperature, nozzle gap or product elasticity is uncontrolled.
Assess the effect on fill quantity and the first pack after a stop, because excessive suck-back or trapped air can create a different defect.
Buyer question
What is the trade-off between a wider nozzle and clean cut-off?
A wider nozzle can reduce restriction and help particles pass, but it releases a larger product column and may be difficult to position in a small opening. A narrower nozzle can improve placement but may increase pressure, fill time, heating or particle damage.
The correct balance is product- and pack-specific. Compare at the same accepted-output target and record both fill quantity and presentation.
Buyer question
How should nozzle choice be proved?
Run the actual product through the complete proposed path into production containers at normal and boundary conditions. Include steady running, low hopper level where relevant, a realistic stop and restart, and the fastest accepted profile.
Inspect blockage, particle damage, tails, delayed drips, neck contamination and cleaning. Use the anti-drip nozzle guide for further cut-off diagnosis.
Related questions and guides
Continue the specification with the next practical decision.
Use the related pages to connect this answer to product trials, machine selection and a quotation-ready application.
Container-neck cleanliness
Connect nozzle choice to rim and thread presentation.
Read the guide →Products with particles
Review passage through valves and nozzles.
Read the guide →Need a nozzle assessed against your product and pack?
Send the product sample, largest inclusions, container opening, fill level and a close video of the current tail, drip or placement problem.