Specifying a PET preform comes down to five decisions, made in order. Get the order right and the rest follows.
1 — Application
Water, CSD, juice/dairy, edible oil or 5-gallon. This fixes the pressure rating, resin IV and base type before anything else.
2 — Bottle volume
Volume sets how much material the preform must carry for an even, blow-able wall.
3 — Neck finish
The neck must match your filling line and closure — e.g. 29/25 for water, PCO 1881 for CSD. See 29/25 vs PCO 1881.
4 — Gram weight
Right-weight for top-load and burst without over-stretching the wall. The weight guide maps weight to volume per application.
5 — Resin & colour
Confirm IV/AA band and any masterbatch. Then validate stretch ratios in the Preform → Bottle Advisor.
Beyond volume: the engineering factors behind the choice
The same bottle volume can need very different preforms across applications, because four engineering factors sit behind the gram weight:
- Blow-up (stretch) ratio — drives uniform wall distribution; special or tall shapes need a specific ratio, so the preform is matched to the bottle, not just its volume.
- Top-load — the stacking and capping load the bottle must carry without buckling; it sets the safe lower weight limit.
- Pressure performance — carbonated drinks need pressure resistance and thicker critical areas; still water can run lighter.
- Filling conditions — cold-fill, hot-fill or aseptic change the heat and shrink resistance required.
For example, a 500 ml bottle takes a heavier, pressure-rated PCO 1881 preform for CSD, but a lighter 29/25 for still water — same volume, different preform. Our Product Finder narrows by application first, and the Preform → Bottle Advisor plus our engineers confirm stretch ratio, top-load and fill/pressure fit before quoting.
Fast path: the Product Finder walks application → volume → neck and returns the matching approved SKU; from there, build an RFQ in a minute.