Multi-Cavity Two-Color & Threaded Cap Moulds — Hot-Runner Closure Tooling for a Closures Maker in Pakistan

Customer name withheld. Results as observed on the customer's running line.

The requirement

A cap is a small part with big consequences. A threaded lotion-jar cap that doesn't seat, or a two-color cap whose two shots don't bond cleanly, undoes an otherwise good bottle — and mismatched caps and necks are a constant headache when the two come from different tooling sources. This Pakistani maker needed closures engineered to match their bottles, not approximate them, including premium two-color threaded caps.

Volume and complexity make it harder. Caps are high-count, cost-sensitive parts, so the tooling has to run many cavities at once while keeping every cavity identical — an out-of-spec cavity means a leaking or mis-fitting closure slips through. Two-color caps add a second injection stage that has to register perfectly shot to shot. Cavity-to-cavity imbalance, cold-runner scrap, and thread geometry that doesn't precisely match the mating bottle neck are the usual pain points.

The line AMAN delivered

AMAN builds injection cap and closure moulds in-house — the decisive advantage here. The moulds were specified as multi-cavity with hot-runner systems: the hot runner feeds all cavities through heated manifolds and nozzles, keeping melt balanced across cavities, eliminating cold-runner scrap, and supporting the fast cycles closure economics demand. For the two-color threaded caps, the tooling registers the two shots accurately so the colours meet cleanly and the thread stays true. Cavities were cut from hardened tool steel for high-volume cap production, holding their critical thread and sealing dimensions over long runs.

Because AMAN also makes the blow moulds and supplies the machines for the bottles, cap tooling can be designed to match the mating bottle neck from the outset — thread pitch, sealing surface and fit engineered together rather than reconciled after the fact. That in-house, cap-to-bottle-matched approach is exactly what prevents the leak-on-this-bottle problem. The footage here is that tooling in production at the customer's plant. Built in-house at AMAN and matched to the customer's own bottle from the outset, it gave them a genuine one-stop bottle-and-cap solution.

The results

• Multi-cavity hot-runner injection moulds for threaded and two-color caps and closures
• Two-shot registration for two-color caps so colours meet cleanly and the thread stays true
• Balanced melt delivery for consistent cap weight and dimensions cavity-to-cavity, with no cold-runner scrap
• Hardened tool-steel cavities holding critical thread and sealing dimensions over long runs
• In-house tooling lets caps be matched to their mating bottle necks by design — one-stop bottle-and-cap sourcing

See the line running

On site