Applicator Cap – A closure designed to apply the contents of the container.

Backing Liner – A compressible material, usually pulp or foamed polyethylene, to which the facing liner is attached or adhered.  This compressible material compensates for any irregularities on the sealing surface.

Band – That portion of the closure that releases when the closure is removed from a bottle.  The band is used for tamper indication.

Bead – A depressed or raised circle or ring around a container or closure.

Binding – Excess drag when the closure is applied to the bottle.  Binding is usually the result of interference.

Bottoming-Out – A condition where the bottom skirt of the closure makes contact with the container (usually the shoulder or transfer bead) before the land area of the container and the closure (lined or linerless) create a seal.

Cavity – A mold component which forms the exterior or external surface of the closure.

Cellulose Band – A band made of hydrated cellulose film extruded in continuous tubing form.  The cellulose tubing is then processed and printed in this form and cut into individual bands of predetermined lengths.  The celon is allowed to air dry when it is applied to the finish of the container.  During the air-drying period, the cellulose band shrinks to form a skin-tight film over the finish of the bottle.

Center Gated Mold – A mold in which the cavity is filled with resin through an orifice interconnecting the nozzle and the center of the cavity area.

Child Resistant Closure (Abbreviated “CR”) – A closure requiring dissimilar motions making removal by a child difficult.  Child Resistant closures are subject to current government regulations.

Chucks – A component of a capping machine which holds the closure for application to the container.

Closure – Any structure or device designed to close off the opening of a container and prevent loss of its contents.

Closure Lining Machine – A high speed, specialized machine using a punch’s die or specialized cutters to automatically cut and insert liners into closures.

Closure Height – The overall height of the closure proper.  Closure height is measured from the closure top to the open end of the closure.  Closure height can be considered in terms of “inside height” or “outside height.”

Closure Removal Torque – The amount of force necessary to loosen, open, or remove a closure from a bottle.

Closure Skirt – The vertical wall of a closure.

Closure Stripping Torque – The amount of force required to cause the closure and/or bottle finish to distort and override the matching closure-bottle threads.

Cocking – Mis-application of a closure to a container.  The closure’s appearance is uneven on the container or it is pulled off to one side, due to an uneven downward pull of threads.  Cocking is normally caused by over torquing or an out of spec. “S” dimension container.

Compression Molding – A molding process whereby thermoset plastic material is dropped into a cavity and formed under pressure by a force.  The process is primarily done on a rotary molding machine.

Continuous Thread Closure (Abbreviated “CT”) – A non-interrupted spiral design threaded closure.  The main purpose of a CT closure is to mate with corresponding bottle threads and provide sealing and re-sealing of the container.

Core – A mold component which forms the internal surface of the closure.  The core also includes the threads.

Curl – A tubular structure formed at the open end of a metal closure to provide a smooth, strong edge.  The curl facilitates automatic handling of the closure.

Cycle – The sequence of operations in a process to complete one set of parts.  The cycle is taken at a point in the operation and ends when this point again starts.

Cycle Time – The time during which one molding cycle is completed.  Cycle time comprises injection of melt, cure, recovery, part ejection, and clamping for next shot. 

Dispensing Closure – A snap on or threaded closure which allows for product dispensing, and usually resealing, without removing the closure from the package.

Dome – A closure which has a rounded top surface.

Dropper Cap – A closure that includes an attached dropper and rubber bulb.

Finish – The configuration of a container top shaped to accommodate a closure.

Fitment – A plastic component that snaps over the land area and functions as an orifice reducer or blocker.

Flash – Excessive undesirable plastic materials on containers or closures formed along mold seams or parting lines.  Flash results from plastic flowing into the clearance between mold components.

Flowed-in – A method of applying fluid sealing compounds with a nozzle.

Friction cap – A closure held on by friction upon application to the container, building up resistance to the movement of the closure.

Gasket – A liner applied between the sealing surface of container lip and closure.  A gasket provides the ultimate seal.

Gate – An orifice through which the molten resin enters the cavity.  A gate is the small restricted opening connecting the runner to the cavity.

Glued-In Closure Liners – Closure liners attached to the inside roof of the closure by a hot melt adhesive.

Induction Seal Liners – A specialized laminate containing aluminum foil and a plastic heat sealable film which hermetically seals a container through use of an “Induction Capsealing Machine.”

Inner Seal – An additional seal of moisture proof material applied to the top of container prior to or during the application of the closure.

Interference – A condition where an exterior diameter in the finish area of the bottle is larger than the mating interior diameter of the closure.

Internal Threads – The threads on the interior of the closure.

Interrupted Threads – Non-continuous threads on the closure causing gaps.  Interrupted threads are normally used in beverage closures  thread on (neck) finish of bottles in which the thread has gaps or discontinuities.  The gaps are at the parting line of the mold.

Injection Mold – A mold into which a plasticated material is introduced from an exterior heating cylinder.

Injection Molding – A process by which a plasticized material is forced into a mold. 

Land – The lip of the container to which the closure liner or land seal linerless feature compresses or conforms to tolerance.

Land Seal – A sealing device which seals by applying pressure to the top or land of the container finish.

Liner – A disk of paper, cork, foam, plastic, etc., retained in a closure to provide a flexible barrier between the closure and the sealing surface of the container.

Liner Well – The space provided in a closure for a liner.

Linerless Closure – A thermoplastic closure incorporating a molded-in sealing feature which, when applied to a container with the appropriate finish, seals most liquids within the container.

Lug Cap – A closure with raised internal impressions that inter-mesh with identical threads on the finish of container.

Mechanical Breakaway Bands – A closure with a portion or section of the skirt perforated or weakened in some manner so when the closure is opened, the section is designed to break apart and either remain on the container or attach to the closure to indicate the package has been opened.

Metallizing – Applying a thin coating of metal to a non-metallic surface.  Metallizing can be done by chemical deposition or by exposing the surface to a vaporized metal in a vacuum chamber.

Modified Buttress Thread – Commonly referred to as “M” style.  The modified buttress thread was developed, with a 10 degree pressure angle, to offer more closure-to-bottle thread contact.

Mold – The combination of mold frame and tooling components needed to form a closure.

Mold Frame – The plates and components required to direct plastic to the tools that form closures and remove the closures from the mold.

Molding (compression) – A process of shaping or forming material through the use of molds, heat, and pressure.

Molding (injection) – A process of shaping or forming plastic objects from powder or granule form in a mold by cooling the previously heated plastic.

Mouth – The open end of the cap opposite the top.

Neck Rings – That part of the mold equipment which forms the finish of the bottle.

Non-Threaded – Designates items which do not require threading action when applied to glass or plastic containers.  Examples of non-threaded closures are snap caps, sifter fitments, pour-out fitments, etc.

Offset Neck – The vertical axis of the neck finish is off center from the vertical axis of the container.

Orifice – An opening in a plug, fitment, or dispensing cap through which the product is dispensed.

Overseal – An additional closure that tamper-proofs the primary closure.  The overseal is usually made of foil or aluminum.

Pipette – The glass or plastic tube portion of a medicinal dropper closure.

Pitch – The number of turns a thread would circle a neck if the neck were extended one inch.  Pitch is commonly referred to as threads per inch. (T.P.I.)

Plastisol – A liquid mixture of resins and plasticizers solidified by the application of heat.

Pour-out Finish – A bottle finish having uniform undercut lips.  The pour-out finish  is designed to facilitate pouring without dripping.

Sealing Surface – The lip portion of the finish which makes contact with the sealing gasket or liner and forms a seal.

Shell – The hat shaped, preliminary form of a metal closure prior to being threaded and knurled.

Shrink Factor – The change in dimension which a closure undergoes after being molded.  Shrinking is generally caused by cooling and subsequent contraction of the plastic material.

Sifter Fitment – A plastic component of a package designed to allow the shaking out of dry products, such as a table salt shaker.  The sifter fitment snaps over the glass bead with a metal or a plastic cap applied over the fitment.

Skirt – The vertical wall of a closure.

Snap Fit Closure – A closure held in place through the use of beads or undercuts rather than threads.

Spout Cap – A closure designed to facilitate the pouring of the contents of the container.

Stacker Cap – A closure designed specifically to nest with the bottom plate of a container to facilitate the stacking of filled containers one on top of each other.

Stress Crack – An external or internal crack in the plastic caused by tensile stress less than that of its short-time mechanical strength.  The development of such cracks is frequently accelerated by the environment to which the plastic is exposed.  The stresses which cause cracking may be present internally or externally or may be combinations of these stresses.  The appearance of a network of fine cracks is crazing.

Stripping Torque – The amount of application torque that causes the threads of the closure to override the container threads.

T.P.I. – See Pitch.

Tamper Band – The tamper-evident feature of the closure.  The tamper band is usually connected to the closure skirt by leaders or bridges.

Tamper Evident Breakaway Band Closure – The section of the closure skirt that is weakened or perforated in some manner.  When the closure is opened that section is designed to either remain on the container or stay partially attached to the closure.  The tamper evident breakaway band closure is designed to reveal removal of the closure was attempted.

Tamper Evident Closure – A closure or liner system incorporating a feature that visually indicates if the closure has been removed or the product has been exposed.  Removal of the closure or liner system activates the indicating feature.

Tamper Evident Tear Band – A closure with a band, usually with a tab for grasping, designed to be detached by the consumer.  The tamper evident tear band is designed to reveal removal of the closure was attempted.

Thermoplastic – A plastic material that repeatedly softens when heated and hardens when cooled.

Thermoset – A material that will undergo or has undergone a chemical reaction by the action of heat, catalysts, ultraviolet light, etc., leading to a relatively infusible and cross-linked state.  Typical of the plastics in the thermosetting family are the epoxies, glytals, melamines, urea formaldehyde resins, and phenolics.  Thermosets are typically supplied in powder, granules, or modules, and are normally processed by compression molding.  Thermosets cannot be remolded once processed.

Thread – Complimentary, helical protrusions on the closure and the container.

Thread Profile – The cross section configuration of a closure thread.

Thread Engagement – The actual contact made by the closure and bottle finish thread.  Thread engagement is usually specified in number of turns.

Thread Start – The position at which the full thread depth toward the open end of the closure first occurs.

Thread Turns – The measurement of thread revolutions in a closure or on a container finish.

Tinplate – A thin sheet of steel with a layer of tin used in manufacturing metal closures.

Tolerance – The permissible maximum deviation from specified dimensions, quantities, or specifications.  The amount of variation allowed from the nominal dimension.

Tooling – The specific components in contact with the plastic that form the closure.

Top Load – The amount of weight bearing on the top of a package.

Torque – The rotational movement used during application or removal of a continuous thread closure from a container.

Torque Meter – A devise used to measure application and removal torque.  It is expressed in pound-force inches and commonly referred to as “inch-pounds.”

Value Seal – A sealing devise which seals on the inside of the neck finish of the container in the fashion of a plug.  A controlled inside finish diameter is required to accomplish a seal.