Changing preform supplier is mostly de-risking: match the spec exactly, validate before you switch the whole volume, and keep a fallback until the new lots prove out.
1. Match the spec, not just the weight
Capture neck finish, gram weight (± tolerance), IV, AA limit, colour and resin grade from your current datasheet. A preform that matches weight but differs in neck or IV will behave differently on your blow line. Translate your spec into a SKU with the Product Finder or the read-a-drawing guide.
2. Request samples and a first article
Ask for samples, a dimensional report and material certificates (FSSC 22000, food-contact). Run a blow trial on YOUR line before committing volume.
3. Validate the first production lots
Inspect to your AQL: top-load, burst, stress-whitening, and compare against the incumbent. Identify any defect with the Defect Library and the incoming-inspection routine.
4. Phase the changeover
Run the new supplier in parallel on one SKU or line first, keep buffer stock, then scale. Confirm lead time and MOQ up front (lead time & MOQ).
Make the switch with Delta
Send your current spec or drawing and build an RFQ — Delta matches the SKU and provides certificates and samples so you can validate before you move.