What material are PET bottle closures made from?

Most Delta closures are HDPE — water (29/25, 48 mm), CSD (PCO 1881), juice/dairy (32/15, 37 mm, 38 mm) and 29/21 oil caps. The 55 mm 5-gallon lid is PP; the 55 mm standard closure is LDPE.

Why is the 5-gallon lid PP and not HDPE?

The 55 mm lid uses PP for its rigidity and snap behaviour on the returnable 5-gallon format, while the 55 mm standard closure uses LDPE for a softer, conforming seal.

How do I pick the right closure material?

Match the closure to the preform neck and application — HDPE for most caps, PP for the 55 mm lid, LDPE for the 55 mm standard. Use the Product Finder to match a closure to your neck.

Closure Material Guide: When to Use HDPE, PP or LDPE

Q: What is a 2-piece oil closure made of?

The 29/21 two-piece oil closure pairs an HDPE shell with an LDPE liner for a clean pour and reliable oil seal; the one-piece version is all-HDPE.

Closure material decides seal performance, application torque and cost. Delta El Nile for Industry selects the polymer per format and filling line.

HDPE — the default

Most Delta closures are HDPE: water (29/25, 48 mm), CSD (PCO 1881), juice & dairy (32/15, 37 mm press-on, 38 mm) and the 29/21 oil caps. HDPE balances stiffness, sealing and low cost.

PP — the 55 mm lid

The 55 mm lid is PP for its rigidity and snap behaviour on the returnable 5-gallon format.

LDPE — the 55 mm standard

The 55 mm standard closure uses LDPE for a softer, conforming seal on the 5-gallon neck.

2-piece oil — HDPE + LDPE

The 29/21 2-piece oil closure pairs an HDPE shell with an LDPE liner for a clean pour and reliable oil seal; the 1-piece version is all-HDPE.

Pick the right closure

Browse all 12 closure formats.
Match a closure to your preform neck in the Product Finder.
See specs on pages like DEN-CLO-PCO_1881 or DEN-CLO-55MM_STANDARD.