When jars and bottles are the right route
Rigid packs provide a stable presentation surface and a wide choice of closure and decoration methods, but they make container quality, mouth geometry and closure compatibility critical.
Jars
Common for preserves, chutneys, pickles and premium sauces; wide mouths can improve piece passage and filling access.
Squeeze bottles
Useful for pourable or squeezable sauces; neck size, bottle recovery and cap cleanliness need review.
Shaped bottles
Can support brand differentiation but may require orientation, dedicated guides or front-and-back labelling.
Glass versus plastic
Glass is dimensionally stable but breakable; plastic can distort under heat, vacuum, gripping or conveyor pressure.
Measure the container and closure as a system
Provide dimensional drawings and physical samples from the intended supplier. Record manufacturing tolerances because nominally identical packs may handle differently.
| Feature | Record | Machine implication |
|---|---|---|
| Mouth and neck | Internal opening, finish, threads/lugs and height. | Nozzle size, cap head, guides and drip protection. |
| Body | Maximum diameter/width, height, taper and panels. | Conveyor width, sensors, side belts and label setup. |
| Base | Push-up, heel, flatness and stability. | Transfer gaps, star wheels and accumulation behaviour. |
| Closure | Diameter, height, liner, thread/lug and application range. | Feeding, placement, torque and verification. |
| Thermal limit | Supplier-supported fill/cooling conditions. | Hot-fill route, dwell and cooling method. |
Select the filler around product behaviour and the opening
For smooth products, several volumetric approaches may be possible. As viscosity, fibres and pieces increase, the product path, valve clearances and nozzle become more important than the headline dose range.
- Keep the nozzle comfortably within the usable opening while allowing for pack tolerance and misalignment.
- Review whether a diving or rising fill reduces splash, aeration or wall coating.
- Keep the jar finish and threads clean so the closure can seat correctly.
- Test dose repeatability after the product reaches its normal production temperature.
- Include hopper refill or vessel transfer in the sustained output test.
Apply and verify the closure without cross-threading or contamination
Closure success starts before the capper. Check that the finish is clean, headspace is controlled and the cap arrives in the correct orientation.
Twist-off lug caps
Review cap presentation, lug engagement, application force and any hot-fill/vacuum sequence.
Continuous-thread caps
Define torque range, thread start, cap liner and whether a chuck, spindle or other method is appropriate.
Pump or dispensing closures
Long dip tubes and complex closures may need dedicated feeding, insertion and anti-tangle measures.
Tamper evidence
Use a band, label, sleeve, membrane or closure feature compatible with the pack and distribution route.
Cap presence alone does not prove a good seal. Depending on the application, checks may include height, skew, torque sampling, vacuum indication, leak testing or visual inspection.
Make the container stable, clean and dry before decoration
Hot-filled glass and plastic containers behave differently during cooling. Condensation, product smears or a warm flexible panel can reduce label quality.
Control discharge spacing
Prevent containers touching too aggressively while hot or before closures settle.
Cool or dwell as required
Define the condition needed before labelling; avoid unverified thermal shock.
Remove moisture and residue
Dry the label panel and clean any product from the finish or body.
Orient if needed
Use a feature, seam, handle, panel or printed datum when label position is not random.
Apply label and code
Verify label wrap, overlap, top tamper label and variable information.
What to prove during a jar or bottle trial
| Trial item | Pass evidence |
|---|---|
| Container handling | No jams, tipping, scuffing or uncontrolled pressure across the stated tolerance. |
| Fill | Repeatable dose/headspace with clean cut-off at normal product temperature. |
| Pieces | Representative largest inclusions pass without unacceptable damage or blockage. |
| Closure | Consistent placement and agreed verification result; sealing surface remains clean. |
| Thermal route | Pack remains acceptable through fill, closing, dwell and cooling conditions. |
| Decoration | Label and code position/readability remain acceptable at production speed. |