Picking the right plastic for a shampoo or conditioner bottle is not about "which is better" — it is about which resin matches your formula, your shelf presence, and your budget. For most wash-off personal care products, the decision comes down to HDPE (high-density polyethylene) and PET (polyethylene terephthalate). Here is how we advise buyers on the production floor.
HDPE is a semi-crystalline polyolefin, usually produced by extrusion blow molding. It is the workhorse of the personal-care aisle: opaque, squeezable, and chemically forgiving. PET is a clear polyester, normally made by injection stretch blow molding (ISBM), giving a glass-like gloss and premium hand-feel.
This is where HDPE wins for aggressive formulas. Surfactant-rich shampoos, sulfate systems, and products with essential oils or citrus extracts can stress PET over long storage. HDPE shrugs these off.
| Factor | HDPE | PET |
|---|---|---|
| Clarity | Opaque / can be colored | Transparent, glass-like |
| Squeeze feel | Soft, springy | Firmer, premium |
| Chemical resistance | Excellent (surfactants, oils) | Good; avoid strong solvents |
| Barrier to oxygen | Moderate | Better |
| Unit cost (same volume) | Lower | +15–30% |
| Recyclability | Widely #2 | Widely #1 |
"We moved a 500ml salon line from PET to HDPE and cut bottle cost 22% with zero formula complaints — the opaque bottle actually tested better for 'natural' perception." — Procurement lead, EU private-label client
Whatever you pick, the closure must match. Our standard 24/410 and 28/410 necks fit pumps, disc-tops and flip caps interchangeably. See our neck finish guide for the full dimension table.
Not sure? Send us your formula and target price and we will recommend resin, gram weight and neck finish within 24 hours.
