Glossary of terms
The following is a glossary of terms and abbreviations in closure design and testing.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
A
| anti-refill | A safety closure designed to prevent refilling of the bottle. Usually by a one-way valve mechanism, typically for the alcoholic beverages and spirits industries. | |
| application torque | The torque required to securely attach a rotationally operated closure to its container. This is usually the minimum value to provide a proper seal and still permit acceptable ease of removal. |
B
| back-off | Loss of torque once the closure has been applied, caused by the closure physically rotating back from its applied position. This can be caused by design factors or in-service conditions such as liner material properties or top-loading. | |
| breakaway | Static torque required to initiate a closure moving in relation to a container. | |
| bridge torque | Torque required to break bridge segments joining a cap and a tamper-evident band. |
C
| cap adapter | An alternative term for mandrel. | |
| capsule | (or foil) The protective sleeve covering a wine bottle cork. Usually tin or heat-shrink plastic (polyethylene or PVC), or aluminium or polylaminate aluminium. Originally, but no longer made of lead. | |
| carbonation loss | Gas escape from a cap seal or thread. | |
| cellular cork | ISO 7322 2014 composition cork test standard. | |
| Child-Resistant Closure (CRC) | A closure usually featuring a dual or simultaneous action, to resist simple pull or twist removal. | |
| crown cork | Crimped-on metal cap; may be lever-off or twist-off. |
D
| disc closure | Cap featuring a two-position rocking disc with inner stopper, to expose a dispensing orifice. |
E
F
| finish | The container region that engages with the closure, also ‘neck finish’ phrase used in some test standards. | |
| flip-top (flip cap) | Hinged cap with integral stopper. |
G
H
I
| incremental torque | This test is used to measure the removal torque of a cap and then reapply the cap to a specific position beyond the original starting position. This test is designed to be a non-destructive test, and prevent leaking problems by reapplying the cap to a secure position. | |
| induction sealing | Method of fusing a layer to the top of the finish of a container, to effect a seal. |
J
K
L
| liner | Inert layer integral to a cap, to effect a non-contaminating seal. | |
| lug-style | Cap with a small number of lugs engaging an equivalent number of short threads on a container. |
M
| mandrel | Device fitting the profile of a closure to enable circumferential gripping without deformation. |
N
O
| over torque | Another term for strip torque. |
P
| parasitic torque | Additional resistance to removal other than due to pristine closure contact surfaces. |
Q
R
| removal torque | Typical proxy for application torque, measures breakaway and initial running torque. | |
| repeatability | Ability to run a test to identical parameters. | |
| reproducibility | Ability to produce the same results. | |
| re-torque | Required after induction sealing process (torqued to seat on the seal). | |
| reverse ratchet torque | Torque to turn a two-part CRC without internal engagement of the two parts. | |
| ROPP | Roll-on pilfer proof (e.g. Stelvin wine cap). | |
| ROTE | Roll-on tamper evident: ROPP with an additional plastic reveal band. Also used to combat counterfeiting. | |
| running torque | Dynamic torque required to maintain rotation. |
S
| slip torque | Another term for breakaway torque. | |
| strip torque | Torque required to over-tighten a screw cap and over-ride the thread. |
T
| tamper-evident (TE) | Part of a closure that breaks away on first opening to indicate that a container has been opened. | |
| tamper-resistant (TR) | Simple features to inhibit opening (e.g. a label or tape over a join). | |
| TEB | Tamper-evident band. | |
| teeth | Crown cork cap - note also now available as a twist off. | |
| thread-locking | Parasitic torque caused by spilled contents on the thread drying and causing adhesion. | |
| torque | Turning force causing rotation about an axis. | |
| top-load | Axial force to cause engagement between two-part CRCs. |
U
V
W
| wadding | Another term for cap liner. |
