PET Preform Manufacturers & Suppliers

PET preforms: specifications and selection guidance

A PET preform is an injection-moulded tube of food-grade PET resin — the intermediate stage in two-stage stretch blow moulding (ISBM) bottle production. The preform is shaped like a thick-walled test tube with a fully formed neck finish at the top. In the second stage, the preform is reheated and placed in a stretch blow mould, where it is axially stretched and radially blown to form the finished bottle. Preform weight determines the wall thickness and strength of the finished bottle: a 1L cooking-oil bottle typically uses a 28–35g preform; a 500ml beverage bottle uses a 20–28g preform; a 2L bottle requires 40–55g. The neck finish on the preform must match the intended closure — PCO 1881 (28mm) for carbonated beverages, 28mm 1881 for still water, 38mm for cooking oil, condiments, and household liquids. Preform colour options are clear (the standard for food and beverage), light blue (cosmetics and water), amber (UV-sensitive products), and custom colours (requiring pigment addition at the injection moulding stage). Food-grade PET preforms must be produced from virgin PET resin with acetaldehyde (AA) content controlled within the specification for the intended application — low-AA grades are required for sensitive beverages like still water. The manufacturer must provide a Declaration of Compliance confirming the preform material meets EU Regulation 10/2011 or FDA 21 CFR for food contact.

Why buy preforms instead of finished bottles

For buyers consuming more than approximately 500,000–1,000,000 bottles per year, importing preforms and blow moulding on-site is typically more economical than importing finished bottles. Preforms are dense — a 28g preform for a 1L bottle is roughly the same physical size as a small tube of toothpaste — meaning a 40ft container can hold 700,000–900,000 preforms versus approximately 50,000–80,000 finished 1L bottles. The logistics cost per bottle is significantly lower for preforms. Additionally, on-site blow moulding allows just-in-time bottle production, reduces finished goods warehouse space, and allows the buyer to run multiple bottle shapes from the same preform if the mould tooling is available. Stretch blow moulding machines range from semi-automatic machines suitable for 1,000–3,000 bottles per hour at relatively low capital cost, to high-speed rotary machines producing 10,000–40,000 bottles per hour. See the plastic bottle blow moulding machines page for equipment guidance and the virgin PET bottle-grade resin suppliers page for resin sourcing if manufacturing preforms in-house.

Frequently asked questions