PET Bottle Caps Guide: Flip-Top, PCO & Alaska Caps Explained

Buyers often finalize a bottle before thinking about the cap, then discover it doesn't seal properly or doesn't fit their filling line. The cap and the bottle's neck finish are one decision, not two. Here's a straightforward look at the three cap types we manufacture and where each one is actually used.

Flip-top caps (27mm / 28mm)

A hinged cap that snaps open and shut without fully detaching — the most common choice for sauces, handwash, shampoo-style liquids, and any product dispensed a little at a time. It's convenient for the end user but offers a weaker initial seal than a screw cap, so it's almost always paired with an induction foil liner for anything shipped any distance.

PCO caps (28mm)

PCO ("Plastic Closure Only") is a standardized neck finish used across the beverage industry — it's what you'll see on most water and juice bottles. Because it's standardized, PCO-finished bottles are compatible with high-speed filling lines built around the PCO 1810 or PCO 1881 spec, which matters if you're filling on shared or rented equipment rather than a custom line.

Alaska caps (27mm)

A screw cap with a tamper-evident band that snaps and stays visibly broken once opened — reassures retail buyers the product hasn't been opened before purchase. Common on edible oil, agro-chemical, and liquid cleaner bottles where tamper-evidence is a trust signal on the shelf, not just a regulatory tick-box.

Matching cap to product — quick reference

• •Drinking water / juice / beverages → PCO cap, for filling-line compatibility.
• •Edible oil, agro-chemicals, cleaners → Alaska cap, for tamper-evidence.
• •Handwash, sauces, dispensed-a-little products → Flip-top cap, for repeat-use convenience.

We supply all three cap types matched to the neck finish of every bottle we manufacture, so you're not sourcing bottle and cap from two different vendors and hoping they fit. Tell us your product and we'll recommend the cap along with the bottle quote.