Flip Top Caps for Glass Bottles: Size, Orifice and Seal

What a Flip Top Cap Interfaces With: Finish, Bead, Orifice and Shell

A flip top cap is sized by the neck it sits on, not by the bottle underneath it. That single sentence prevents more waste in this category than any other, because the number in a trade name such as 24/410 reads as though it described the closure, and it does not. The millimetre figure in front of the separator is the nominal neck diameter. The figure after the separator is a finish designation that describes the thread form, the height at which the shell comes to rest, and therefore where every sealing surface ends up relative to the glass. The public finish definitions published by glass packaging bodies, including the GPI finish standards, describe the dimensions behind those codes; the dimensions applied to any specific bottle are read from the neck drawing rather than assumed from the code.

Four interfaces sit inside a single flip top specification, and each of them can be got wrong independently. The first is the neck interface: a thread for a screw-on shell, or a bead and sometimes a groove for a press-on or snap-on shell. These are not interchangeable formats, because the neck geometry itself differs, and a shell drawn for one will not work on the other however similar the two necks look on a shelf. The second is the shell height against the finish height. If the shell is deeper than the neck allows, it bottoms out on the land before the lid reaches its closed position and the whole assembly is loaded through the shell rather than through the seal. If it is too shallow, the retaining bead never reaches the feature it has to sit behind, and the lid lifts with almost no effort.

The third interface is the orifice, and it is the most commonly misread element on the page. The orifice is the hole through which the product leaves, and it is set by the closure tool rather than by the neck diameter. A 24 mm flip top can be moulded with a narrow pour hole for a thin dressing and a wide one for a ketchup-style sauce, on the same neck, at the same shell diameter, at the same capping setting. Buyers who assume that a step up in closure size widens the pour are usually paying for glass they did not need, and buyers who assume that a wide pour requires a bigger bottle are changing a mould to solve a closure problem.

The fourth interface is the sealing stack, and it is where a flip top differs most from its neighbours. A hinged flip top normally closes the passage with an inner plug, also called a spud or a pin, that enters the orifice when the lid is swung down. That contact is what keeps a part-used pack from weeping when it is laid on its side. It is not the same contact as the seal that holds the pack closed in transit, which on many designs is a liner or gasket pressed onto the sealing land of the neck by the shell. Treating the plug as the transit seal is one of the most expensive assumptions in the category, and it is dealt with in its own section below.

Flip Top, Disc Top and Pump: Where the Opening Action and the Leak Path Differ

Three closures compete for the same pack, and the choice between them is made by the opening action and by what the product has to do once the pack is open, not by the size of the bottle. A pump dispenses a metered dose from a dip tube and needs a flat palm pressing down on a head. A disc top is a shell with a disc set into its rim, closed by pressing the disc flat and opened by lifting its free edge. A flip top is a shell with a lid carried on a visible hinge, which swings clear of the opening and leaves a mouth that is usually wider and more accessible than either of the other two.

The one-handed requirement is met differently by each. A flip top asks the user to get a thumb or a fingernail under the free edge of the lid and flick it back, which works well on a pack held in the other hand but depends on the lid standing proud enough to be caught. That same proud lid is the format’s weakness: it catches on carton flaps, on a bag lining and on a shelf edge, and it can be knocked open, which is why a transport lock or a tamper feature is a specification item rather than an accessory. A disc top closes flush with the shell rim, resists being knocked open rather better and presents a tidier line on a narrow pack, but it offers a smaller opening and is harder to wipe clean. A pump needs no opening action at all but adds height above the shoulder, needs a dip tube cut to the bottle depth and does not travel comfortably in a bag.

The leak paths differ as much as the actions. On a flip top the passage is closed by the plug entering the orifice, with the lid-to-rim contact around the edge acting mainly against dust, splashes and airborne contamination between uses. On a disc top the same two contacts exist in a flatter geometry. On a pump the product is held behind a valve and a gasket, and the leak path runs through the valve seat and around the closure gasket rather than through a plug. This is the reason a closure that seals perfectly on a pump body can weep as a flip top: the sealing contact has moved from a compressed gasket to an interference fit between two moulded parts, and that fit is far more sensitive to the fill temperature, to the resin grade and to the capping load than a gasket is.

One practical consequence follows from the geometry alone. Because the flip top opens further and leaves a wider mouth, it suits thick fills and products that are applied directly at the opening, such as a sauce poured over food or a paste squeezed onto a cloth. Because the disc top opens within the shell rim, it suits fills that pour in a controlled stream and packs that must store flat. Neither format meters: unlike a pump, neither applies pressure to the product, so the dose depends on the tilt angle, the fill level and the orifice. A pack whose dose has to repeat belongs with a pump, and the comparison between metered and poured delivery is a decision taken before the closure size is discussed.

Closure Diameter and Orifice Size: A Reverse Lookup from Neck Finish to Pour

The table below is the working form of the matching decision. Read across from the closure diameter and the orifice band to the neck finish the shell normally engages, the fill the band suits, the position where the seal actually sits, and the transport lock that keeps the lid shut. The bands are the ranges seen across flip top closures normally stocked for glass packaging. The diameter and orifice actually applied to a pack are confirmed against the neck drawing and against the fill on enquiry rather than published as a fixed catalogue value, because the same nominal size is supplied with several tools.

Two observations apply to every row of that table. The first is that the orifice is a drawing decision separate from the diameter, so a specification that names only a closure size is not a specification and cannot be quoted against with any confidence. The second is that the neck bore, and not the orifice alone, governs whether a thick fill can be filled and poured at all: a wide orifice sitting over a narrow bore gives a slow, glugging pour, while a small orifice sitting over a generous bore gives control without restricting the filling nozzle. Where the fill is thick enough that the two conflict, the wider neck is a glass decision taken before the closure is chosen, and no hinge geometry compensates for it afterwards.

Orifice Band Against Fill: Sauce, Syrup, Powder and Oil

What decides the orifice is the flow behaviour of the fill, not the shelf the product belongs on. Three properties matter together: the viscosity of the product at the temperature at which it is used, the yield value that has to be exceeded before it moves at all, and the surface tension that decides whether a thin liquid runs back into the bottle or creeps over the shell rim after pouring. A product that pours from a 4 mm hole in a warm kitchen can hold in the same hole in a cold one, and a sauce that flows well at 25 degrees can stand in the neck at 15 degrees.

For a ketchup or a table sauce the thickening behaviour matters more than the nominal viscosity, because the product is shear-thinning and moves only once it is pushed. The orifice has to be generous enough that the sauce does not bridge across it, and the neck bore has to be generous enough that the sauce does not move in slugs, drawing air back through the same passage. This is the classic glug, and it is a neck problem, not a closure problem. Where the pack is stored cap-down, as many sauce packs are, the transit seal on the land carries the whole load of the fill, and a plug-only construction will weep regardless of how well the orifice is sized.

Syrups sit at the other end of the same argument. They are thin enough to run, sticky enough to leave a thread, and prone to creeping over the rim between uses, so the practical answer is usually a moderate orifice with a lip or a raised rim around it rather than a wide hole. A syrup pack also benefits from a smaller air-return path, so the lid comes off with a slight resistance rather than a rush of product. Where a syrup is filled hot, the closure has to tolerate the vacuum that forms as the pack cools, and that is discussed with the filling line requirements below.

Oils and other low-viscosity, non-aqueous fills are governed by surface tension and by drip control rather than by viscosity. A small orifice with an internal restrictor, or a narrowed channel inside the lid, gives a controlled stream and reduces the chance of product running down the outside of the bottle after the pour. Because a rigid glass bottle cannot be squeezed to control the flow, the closure has to do more of the metering than it would on a squeezable plastic pack, and the user controls the rate with the tilt angle and with the remaining fill level. A closure sized for a viscous fill will over-pour an oil badly, and this is one of the most frequent mismatches seen on a repackaged product.

Powders and dry fills sit outside the viscosity reasoning altogether. A flip top can close a dry pack and will keep moisture and airborne dust out better than an open shaker top, but the flow of a powder is governed by its angle of repose and by ambient humidity, so the orifice has to be sized against a flow test rather than against a viscosity figure. A powder orifice also has to be checked for bridging and caking after storage, and where the product needs a moisture barrier as well, that barrier belongs to the liner specification and is handled with the gasket rather than with the hinge. Powder packs usually want a wider, shorter orifice throat and a steeper internal slope in the lid, which is a tool decision made at the sampling stage.

Compatible Pairs and Pairs That Only Look Compatible

Compatibility in this category is decided by four checks, and a pair that passes all four is genuinely interchangeable. The shell must be drawn for the same finish family as the neck, which means the same thread form or the same bead geometry, not merely the same nominal diameter. The shell depth must match the finish height so that the shell lands on the seal rather than on the glass or in mid-air. The orifice must exist in the tool at the required diameter, because an orifice cannot be adjusted after moulding. And where the closure carries a liner, the liner thickness must be matched to the compression the shell can apply, because a liner that is too thick holds the shell off the land and a liner that is too thin never develops a seal.

Pairs that only look compatible fail in a small number of recognisable ways. Two necks sharing a nominal diameter but carrying different finish designations are the first and most common case: a shell drawn for one will usually wind onto the other far enough to look correct in the hand, and the assembled height, the seal contact and the lid position will all be wrong in ways that appear only under load, in transit or after a few weeks on a shelf. A press-on shell on a threaded neck is the second case, and it is a hard failure rather than a marginal one, because there is no bead for the shell to snap behind. A deep shell on a short finish bottoms out, so the lid sits high and the plug never fully enters the orifice; the pack looks closed and weeps on its side. A shallow shell on a tall finish leaves the retaining bead short of the feature it has to sit behind, and the lid can be flicked open with almost no force, which will show up as a complaint about the pack arriving open rather than as a defect at the line.

Two further mismatches are worth naming because they are bought rather than inherited. A flip top specified with a wide orifice over a narrow neck bore is a purchase that cannot deliver what it promises, since the flow is limited by the glass; the honest answer is a wider neck or a different delivery format. And a flip top that is expected to seal by its plug alone on a pack that will travel inverted or be stored cap-down is a construction mismatch, not a tolerance problem; that pack needs a liner on the sealing land, and the liner is specified with the gasket rather than with the hinge.

Sealing Position and Transport Lock: Rim Face, Inner Plug and the Anti-Open Feature

A flip top has to do two different jobs that are frequently quoted as one. It has to keep product in and contamination out while it is closed, and it has to stay closed while it is being shipped. The first job is done by the plug entering the orifice, assisted where the design provides one by a liner or gasket pressed onto the sealing land of the neck. The second job is done by the latch or snap that holds the lid down, by the stiffness of the shell rim, and by whatever additional lock or tamper feature the format carries.

The distinction matters because the two jobs fail under different conditions. The plug contact is a friction and interference fit between two moulded polymer parts, so it depends on the moulded dimensions being held, on the temperature of the fill, and on the product not attacking the resin. The lid-to-rim contact around the edge is a dust and splash barrier rather than a pressure seal, and it should not be relied on to hold a liquid. The liner on the land is the only one of the three that behaves like a conventional seal, and it is also the only one whose compression is set at the capping head rather than at the mould. Where a pack must be transported on its side or inverted, the specification has to say which of the three is doing the work, because a plug-only construction and a land-sealed construction are different products with the same appearance.

Transport locking takes several forms and they are not equivalent. The simplest is the latch itself, which holds the lid down until a deliberate lift is applied. A stronger variant adds a security tab or a drop ring that has to be broken before the lid can be opened, which also serves as a visible tamper indicator. A third form is a shrink band or an adhesive tab applied after capping, covering the lid and the shell so the pack cannot be opened without leaving a mark. Where the pack is filled on a high-speed line, the lock has to be compatible with the closing head: a tab that has to be folded down by hand is not a specification that a line can meet, and a lock that interferes with the capping chuck will damage both the closure and the machine.

Three complaints account for most of the trouble seen with flip tops in transit. The first is a shell rim that is not stiff enough, which lets the latch release under stacked load so the pack arrives open. The second is a plug that does not seat fully in the orifice, which shows up not as a visible defect at the line but as product on the shoulder and in the carton after a few days on its side. The third is a land seal that has lost its compression, which happens when the shell is applied at too low a load or when the liner has been chosen thinner than the shell needs; that fault is invisible at filling and typically appears in a warm container after several weeks.

Hinge Construction and How Many Cycles It Is Built For

A hinged flip top is a mechanism, and like any mechanism it has a finite number of cycles. Three constructions are common. The first is a living hinge, a thin web of polymer that is flexed every time the lid moves and that relies on the material rather than on a joint. The second is a bridge or butterfly hinge, in which two leaves fold together and distribute the flex over a longer section. The third is a snap or spring hinge, in which a moulded feature holds the lid in the open and closed positions and gives the lid a positive feel at each end of its travel.

Polypropylene is the usual material for a living hinge because it tolerates repeated flexing, and the practical life of the hinge is decided by the grade, the web thickness, the angle through which it is flexed, the temperature of use and the product that contacts it. A hinge flexed through a wide angle and left open for long periods relaxes faster than one worked through a short travel. A pack stored in a warm place ages faster than the same pack in a cool one. And a product containing alcohol, a solvent or an aggressive oil can stress-crack some polymer grades at the hinge line, which is a chemistry problem that no wall thickness solves.

Because all of those variables apply at once, a cycle life cannot honestly be quoted as a single number for a closure family. What can be established is a cycling result for a specific pack. Take units from production, open and close each one until the first failure appears, record which failure mode occurred, and repeat the test at an elevated but realistic temperature, since heat accelerates the relaxation that drives every mode. Compare that result with the number of cycles the intended use implies: a pack opened twice a week for a year is a different duty from one opened three times a day, and the gap between those two duties is usually wider than the gap between two candidate closures. Where the hinge is a spring hinge rather than a living hinge, the test also has to record whether the lid still holds its open position, because a spring that has relaxed leaves the lid dropping onto the user’s hand.

Reordering and Replacing a Flip Top Without Changing the Glass

Reordering goes wrong when the record kept is a photograph and a size rather than a specification. The minimum record for a flip top is the neck finish code, the closure diameter, the orifice diameter, the shell height, the closed height of the assembled pack, the plug diameter, the seal construction, the latch or lock type, the hinge type, the resin grade, the colour or masterbatch reference, and where present the liner specification. With that list, a repeat order can be checked against the original rather than identified by eye, and a claim about a change in feel or in seal performance can be resolved against data instead of opinion.

Colour changes are usually harmless, because a masterbatch change does not alter the moulded dimensions, but two other changes are not. A change of resin grade, even within the same polymer family, can shift the shrinkage enough to alter the snap interference and the plug diameter, which shows up first as a lid that no longer stays down and second as a pack that weeps. A change of moulder, or the same moulder running the tool on a different press, can move the same dimensions by a similar amount, and the change is invisible on a sample that is only inspected at arm’s length. Where any of those changes has occurred, the verification is the same: assembled height, plug fit, a side-lay leak test, a short cycle test, and a capping run at the intended load.

Replacement is a different exercise from reordering, and it starts with deciding which variable may move. If the glass is fixed, then the finish is fixed, and the replacement closure has to be found within that finish family with the same shell depth and an orifice that suits the fill. If the closure is fixed, perhaps because a retailer specifies it, then the neck has to be re-cut, and that is a glass decision with consequences for the label panel, the carton and the filling nozzle. Only one of the two variables should move at a time: a new closure on a new bottle at the same time removes the ability to tell which of the two caused a change in pour or in seal performance, which is the most common reason a replacement project stalls for weeks.

Two habits keep a replacement programme honest. The first is to keep the tool reference, because the same nominal size is supplied from more than one tool and the tools are not identical in orifice or in plug diameter. The second is to record the fill temperature and the capping load used on the original pack, because a replacement closure judged on a bench at room temperature will behave differently on a warm filling line, and the difference will be attributed to the closure rather than to the conditions.

Related Pages That Own the Neighbouring Questions

Three pages complete this one. The glass itself, and the neck finish families against which the closure sizes above are built, is described across the glass bottle range and the neck finishes it is produced with, which is the right place to start when the neck has not yet been fixed. The machine that applies the closure, including head type, orientation and load control, is covered by the capping machine setup and its load control, and a flip top specification is incomplete until the closing method has been chosen. Where the pack is a fragrance or a crimp-closed container, the closure is a decorative shell over a crimped pump or a sealed neck rather than a hinged pour closure, and those shapes, duties and interfaces are handled under the perfume bottle cap and crimp closure family. A buyer choosing between that family and a flip top is choosing between a spraying pack and a pouring pack, and that decision is taken before any closure size is discussed.

The boundaries with the rest of this site’s closure material are equally direct. The press-disc alternative, with its own size series and orifice bands, sits on the disc top page. The gasket or liner that presses onto the sealing land, and the compression it needs, sits on the cap liner page. The survey of shell formats across the site sits on the cap types and closure systems page. Read this page for the matching between neck finish, closure diameter, orifice and fill; read those pages for the glass, the seal and the machine that together make the closure work.

Leakage and Hinge Failure: The Four Causes Worth Checking in Order

Four faults account for most flip top complaints, and they are best checked in a fixed order so that a fix is not applied to the wrong element. The first check is the plug against the orifice. If the shell bottoms out on the land before the lid is fully down, or if the orifice has taken a set from a hot fill, the plug never seats and the pack weeps whenever it is laid on its side. The test is to measure the assembled height against the drawing and to inspect the plug for ovality or deformation rather than to test the closure by hand.

The second check is the land seal. Where the construction relies on a liner or gasket on the sealing land, that element is the transit seal, and a shell applied at too low a load leaves the liner under-compressed: the pack seals on the day of filling and stops sealing weeks later. The third check is the hinge line, because a stress crack there removes the spring that holds the lid open and eventually the retention that holds it shut. A hinge crack is usually traced to one of three causes: an aggressive product attacking the resin grade, a lid left open for long periods under tension, or a shell that was distorted at capping so that the hinge is permanently loaded. The fourth check is the transport lock, since a latch that has been overridden by a stacked carton, or a shell rim that has been pushed out of shape by an excessive capping load, produces a pack that arrives open with no visible damage to the closure itself.

Two line habits prevent a large share of these faults without any change to the closure. The first is keeping the fill nozzle clean, because a drip that dries across the shell rim glues the lid to the shell and is the most common reason a new pack feels stuck on first use. The second is controlling headspace and fill temperature, because a hot fill closed immediately pulls a small vacuum as it cools, and a lid drawn down against the rim can take a set that leaves it loose once the pack is warm again. Both habits also improve the performance of the liner on the land, since a pack that cools under a controlled vacuum load holds its compression better than one that is closed hot and then inverted.

Capping and Filling Line Requirements for Flip Top Closures

A threaded flip top is applied by the same equipment as any other screw closure, and it has to be specified with the same discipline. The applied torque is the first variable, and it has a narrow window on this format. Too high a load cracks the shell skirt or distorts the rim the lid has to latch against, and because flip top shells are usually thin-walled and made in a grade chosen for hinge life rather than for stiffness, the shell tolerates less torque than a solid screw cap of the same diameter. Too low a load is equally damaging: the shell works loose in transit and the liner on the land, where there is one, loses the compression it needs. The window is established by measuring the assembled height and by running a side-lay leak test at the low and high ends of the setting rather than by reading a single torque value.

Orientation is the second variable. Where the hinge or the lid has to sit in a fixed position for the label panel, or where the security tab must face the front of the carton, the capping head needs an orientation feature and the closure needs a corresponding locating feature. Orientation is a head capability rather than a closure capability, and a closure specified with a tab but filled on a head without orientation will be closed with the tab in a random position. Press-on flip tops are a separate case again: they are applied with a press head rather than a chuck, they need a bead or a groove on the neck to snap over, and the press load has to be controlled so that the bead takes the load rather than the shell wall.

Two filling conditions affect the closure as much as the machine does. Headspace and fill temperature decide the pressure the pack holds when it cools, and a hot fill closed tight with a small headspace pulls a vacuum that can draw a thin lid down and hold it against the rim. Products containing alcohol, solvents or aggressive oils also need the resin grade checked for compatibility, because the failure appears at the hinge rather than in the body of the shell. Finally, a flip top needs the same attention to closure cleaning and storage as any other shell: dust on the plug or on the land is pressed into the seal at capping and is a defect that no inspection afterwards will find. Where closures arrive at the head rather than being handled on a tray, the feeding and orientation step is a separate subject and is owned by the cap feeder page rather than here.

Flip Top Against a Plain Screw Cap with a Separate Insert

The alternative most buyers compare against is a plain screw cap with a separate reducer or spout insert dropped into the neck. The combination is usually cheaper per unit, it is more flexible at filling because the insert and the shell can be sourced separately, and it allows an orifice to be changed without retooling the shell. Against that, it costs the user two actions rather than one, and it leaves a loose insert that can be dropped, lost or put back at the wrong angle, which is the complaint that most often drives a switch to a hinged closure.

A flip top is a single moulded assembly with the reducer captive and the lid attached, so the opening action is one flick and the pour is repeatable from the same orifice every time. That convenience is paid for in unit cost, in tooling, in the cycle-life question described above, and in the need to orient the closure on the line. The deciding question is not which closure is better but how often the pack is opened and where it is used: a pack opened once at a table is well served by a screw cap and an insert, while a pack opened repeatedly in a shower, over a pan or at a workbench is the case the hinged flip top exists for. Where the choice is genuinely balanced, the sample stage settles it, because the difference between the two is felt in the hand rather than seen on a specification sheet.

Frequently Asked Questions About Flip Top Caps

What does the number in a flip top cap size actually measure?

It measures the neck, not the closure. A code such as 24/410 names a 24 mm nominal neck diameter followed by a finish designation that describes the thread form and the height at which the shell comes to rest. The closure is built to that neck, and its own outside diameter is a consequence of the tool rather than of the code. Two necks that share the nominal diameter but carry different finish designations are not interchangeable: a shell drawn for one will often wind onto the other and then seal badly, stand high on the neck, or bottom out before the plug has entered the orifice.

Will a flip top cap drawn for one finish fit another neck of the same diameter?

Usually it will thread on and usually it will not seal. That is what makes the mistake expensive, because the assembly feels correct to the operator and the fault only appears under load, in transit or after a few weeks on a shelf. The finish designation after the separator describes the thread form and the landing height, so two necks of the same nominal diameter but different designations present different sealing geometry. Read the finish code from the neck drawing and match the shell to it rather than matching the millimetre figure alone.

Which orifice size suits ketchup, syrup, oil or a powder?

The orifice follows the flow behaviour of the fill rather than the product category. A ketchup or table sauce usually needs a generous orifice and, more importantly, a generous neck bore, because a thick product in a narrow neck moves in slugs and draws air back through the same passage. A syrup is better served by a moderate orifice with a lip or raised rim, since thin sticky product creeps over a wide opening. An oil is usually best served by a small orifice with an internal restrictor, because a rigid glass bottle cannot be squeezed and the closure has to do more of the metering. A powder sits outside this reasoning altogether and has to be sized against a flow test, since its movement depends on its angle of repose and on ambient humidity.

Where does a flip top cap actually seal, on the rim face or on the plug?

Both contacts exist, but they do different jobs. The plug, or spud, enters the orifice and closes the passage, which is what stops a part-used pack weeping when it is laid on its side. The lid-to-rim contact around the edge acts mainly against dust, splashes and airborne contamination between uses and is not a pressure seal. Where the pack has to remain sealed in transit, especially if it travels inverted or is stored cap-down, the transit seal is a liner or gasket pressed onto the sealing land of the neck by the shell, and that compression is set at the capping head rather than at the mould.

How many times can a flip top hinge be opened and closed?

There is no single figure that applies to the format, because the answer depends on the polymer grade, the hinge construction, the angle through which the lid is flexed, the temperature of use and the product in contact with the closure. What can be established is a cycling result for a specific pack: take units from production, open and close each one until the first failure appears, record whether the lid stops staying shut, stops holding open, cracks at the hinge or weeps, and repeat the test at an elevated but realistic temperature because heat accelerates the relaxation behind every one of those modes. Compare that result with the number of cycles the intended use implies, since a pack opened twice a week and one opened three times a day place very different demands on the same hinge.

Why does the lid come open in transit, and how is it prevented?

It usually comes from one of three causes. A shell rim that is not stiff enough will release the latch under stacked load, so the pack arrives open with no visible damage. A capping load that is too high can distort the same rim, with the same result. And a lock that was never designed for the closing head, such as a tab that is meant to be folded by hand, may be left unengaged on the line. Prevention is a specification matter: choose a construction with a security tab or a drop ring, or add a shrink band or adhesive tab after capping, and confirm that the closing head can actually engage whatever lock the closure carries.

What information is needed to match a flip top to a specific bottle?

Four things. The neck, given as a finish code and preferably as a drawing, since the finish family and the landing height decide the shell rather than the nominal diameter alone. The fill, described by what it is, how it flows at the temperature of use, whether it carries oils, alcohol or solvents, and whether it is filled hot or cold. The pour the user needs, whether that is a narrow controlled stream, a wide fast stream or a spout, together with an idea of how often the pack is opened. And the closing equipment, including whether the head applies by torque or by press, whether the closure has to be oriented, and what load the head can hold. With those four inputs a closure diameter, an orifice and a sealing arrangement can be proposed together with the sample checks worth running before the balance of an order.

Send the viscosity of the fill, the orifice size the pour needs and the neck finish you intend to use, and a flip top closure diameter can be proposed together with the sealing points that would confirm it on your line.