Tear-off cap mould
A tear-off closure has to hold during transport and then come away in one pull. That is decided by the section of the tear band and by how the two parts are held together, which is why the upper part, the lower part and the assembly are drawn on three sheets, not one.
- ProcessInjection
- PartsUpper part + lower part
- CavitiesQuoted to your output
What is on the drawings
A tear-off closure only works once. Pull the band and it is gone, which is why the depth of that band is cut into the steel and not added afterwards: too deep and it snaps in the crate, too shallow and a customer cannot open the pack.
See every cap mould we cut, from flip tops and two colour caps to tear-off closures.
This closure is drawn on three sheets — the upper part, the lower part, and the assembly that shows how the two sit together with the thread pitch marked. The footage on this page is that tool running: the upper half and the lower half, each on the machine, with the caps kept as they came off. AMAN cuts tear-off tooling in its own workshop, which is also where the upper-and-lower detergent closures and the large overcaps on the neighbouring pages were cut. Buyers in North America ask for the same thing as a tear off cap mold.
Both halves at tryout, and both halves of the tool
Our own tryout footage of this tear-off tooling, and the two halves of the mould with the tool open.
Three sheets for one closure
Our own drawings for the tear-off closure in the footage above.
Seven questions about the tool itself
The seven that decide whether you order, answered for this tooling. Where a figure is on the drawing we print it; where it depends on your part we say which numbers we will ask you for.
Hot runner or cold runner?
A tamper evident closure is usually cold runner at low cavitation and hot runner when the output needs it. The tear band is thin, so the fill balance decides more than the runner type does; both are stated in the quotation.
Cycle time and output
Worked from the part weight and the band section on your machine. Tell us the closures per hour and the cavitation and the cycle are calculated to it.
How the part is ejected
The band cannot be pushed on by a pin, so these closures come off on a stripper plate, and an undercut band needs the stripping force checked before the steel is cut. The layout is approved with the drawing.
Tryout report and acceptance
The tool is run here and the moulded closures ship with it. The acceptance point on a tear-off cap is the break force of the band; tell us the figure you test to and it goes on the list.
Spare parts
Cavities, cores and the band inserts, the parts that wear first on this closure, are cut from the same drawings. Say how many sets to pack.
Warranty
Warranty terms are written into the quotation for that tool.
Will it fit your machine?
Send the make, model and tonnage; platen, tie bars and ejector stroke are checked against it first.
What we will ask you for: the neck, the band break force you test to, the part weight, the output, and the machine.
How many caps an hour do you need?
On a two-part closure the output decides two cavity counts, not one — the upper part and the lower part have to come off the line in step. Give us the number you are planning around.
Tell us your output target
Frequently asked questions
More from the same workshop: See all cap moulds · measuring cup moulds.
Send us your tear-off closure
A photograph of the cap you sell, front and underside, is enough to start. Attach it here.
- ✓A drawing, a 3D file, or clear photos of the closure from every side
- ✓The neck it has to seal on, and whether the ring stays on the neck after opening
- ✓How hard the band should be to break, and how the pack travels
- ✓Cavities you want, or the machine tonnage, or caps per hour