The useful measurement is a matched bottle-and-closure record
External bottle diameter or nominal capacity does not define the fit of a bar-top closure. The inserted shank works against the internal neck, while the decorative top determines feeding, chuck contact and clearance. Measurements should therefore be tied to physical samples and to the finished-height datum used during the trial.
| Part | Record | Why it matters |
|---|---|---|
| T‑cork shank | Diameter at defined positions, length, taper, material and batch | Controls the interference and contact through the bottle neck. |
| Decorative top | Diameter, height, shape, concentricity, finish and directional feature | Controls feeding, chuck contact, clearance and visible alignment. |
| Bottle neck | Internal bore at agreed depths, profile, ovality, neck face and depth | Controls fit, insertion resistance, finished height and retention. |
| Bottle body | Overall height, base stability, body shape and support reference | Controls centring, reaction load and automatic handling. |
Which T‑cork dimensions should be measured before a machine trial?
Measure the shank diameter at agreed positions, shank length, taper, top diameter and height, concentricity, material, surface finish and any directional feature. Identify the batch and note whether the shank is moulded, compressible or naturally variable. These measurements support tooling and feeder design but do not replace insertion and retention testing with the real bottle.
Which bottle-neck measurements matter for a T‑cork shank?
Measure the internal bore at the depths the shank will occupy, the internal profile or taper, ovality, usable depth, neck-face condition and any internal obstruction. Also record bottle height and the stable support reference. A single reading at the mouth can miss a restriction or change in profile deeper in the neck.
How should a tapered or compressible T‑cork shank be measured?
Define the positions from the underside of the decorative top and use the same method for every sample. Record uncompressed dimensions and, where the closure supplier provides a controlled method, any compression or recovery information. Do not force a soft or tapered shank into a single nominal diameter; keep the profile and sample variation visible in the record.
How many bottles and closures should be measured for a format study?
Use enough samples to represent normal production variation and any known extremes, rather than relying on one bottle and one closure. The appropriate quantity depends on supplier control, batch history and the consequence of failure. Ask both packaging suppliers which dimensions and tolerance samples they can provide, then retain the measured parts for the machine trial.
Can bottle drawings replace physical samples?
Bottle and closure drawings help define nominal geometry, datums and tolerances, but they do not show every production condition, surface characteristic or interaction between the actual parts. Physical samples remain necessary for feeding, support, insertion, cosmetic inspection and retention work. Where drawings and samples disagree, the discrepancy should be resolved before tooling is approved.
How should measurement records be linked to sample batches?
Give each bottle and closure sample a traceable identifier and record supplier, batch or lot, date received, measurement positions, instrument and result. Use the same identifier in photographs, trial sheets and reject records. This allows a high-force, low-retention or cosmetic result to be connected to the exact parts rather than averaged into an unhelpful general conclusion.