Recycled PET (rPET) Thermoformed Packaging: Specification & Food-Contact Compliance

Overview #

rPET thermoformed packaging sits at the intersection of two pressures brand partners feel simultaneously: sustainability commitments that require post-consumer recycled content, and food-contact compliance frameworks that are becoming stricter in the US, EU, and Australia. Getting the specification wrong on either axis creates real problems — either the packaging fails migration testing and cannot enter the EU market, or the recycled content percentage is too low to satisfy your ESG reporting targets. On our thermoforming lines, we work with rPET sheet from 0.25mm to 1.5mm gauge, and the compliance pathway for food-contact applications starts at the raw material certificate, not at the finished tray. That distinction is what most brands miss when they first brief us.

Key Quality Parameters for rPET Thermoformed Parts #

The first parameter we lock down is sheet gauge tolerance. For food-contact trays and clamshells, we specify ±0.05mm on nominal gauge — a 0.5mm sheet must measure between 0.45mm and 0.55mm at any point across the web. Gauge variation beyond this range causes uneven wall thickness after thermoforming, which creates stress concentration points and increases the risk of cracking during transit. We measure gauge at five points per sheet sample using a calibrated digital micrometer, and we log these values against each production batch.

Clarity is the second critical parameter for rPET. Post-consumer recycled PET inherently carries more haze than virgin PET due to contamination history and reprocessing. We specify a maximum haze value of 12% for clear food-contact applications, measured per ASTM D1003. Virgin PET typically measures below 3% haze; food-grade rPET from certified reprocessors we work with typically runs 6–10%. If a brand partner requires optical clarity comparable to virgin PET, we recommend a rPET/virgin PET blend at 50/50 ratio, which brings haze down to approximately 4–5% while still qualifying for recycled content claims.

Tensile strength and elongation at break are tested per ASTM D882. Our minimum acceptance threshold for food-contact rPET sheet is 45 MPa tensile strength in the machine direction and 35% elongation at break. Sheet falling below these values is rejected before it reaches the thermoforming press — thin-wall trays formed from degraded rPET will crack at seal flanges during lidding operations.