What to Know Before Blow Molding Tritan Bottles

Eastman Tritan™ is a BPA-free copolyester known for clarity and toughness. Several Tritan grades can be used for different blow molding applications, including baby products, water bottles, cosmetic packaging, and medical or lab containers. Grade selection should follow the product use, heat requirement, chemical exposure, and processing method.

Tritan must be thoroughly dried before processing. A common recommendation is drying at 88 °C for 4-6 hours with dry air below -35 °C dew point, and moisture below 0.05% (500 ppm). Insufficient drying can cause material degradation and weak parts. For extrusion blow molding, melt temperature is commonly around 235-255 °C depending on the grade and product. Lower settings may improve melt strength, while higher settings may improve surface gloss.

Tritan has better heat resistance than PETG but lower heat resistance than PC. Tritan, PETG, and PC are hygroscopic and must be dried; HDPE usually does not require the same drying process. Tritan and PETG have thicker melt behavior and need gentler processing than HDPE. Tritan is selected when clarity, toughness, BPA-free positioning, and heat resistance are required.

Drying is the most important step. Wet Tritan can create weak or brittle products. Use gentle processing to avoid excessive shear heat; brown specks can indicate overheating or contamination. Keep the machine and die head clean because transparent products show residue easily. Use even mold cooling, avoid sharp corners that create stress concentration, and do not use Tritan for high internal pressure bottles such as carbonated drinks unless the design has been validated. Regrind may be used in limited amounts only if it is also dried properly.

Tritan can be used for sports bottles, travel cups, baby bottles, sippy cups, personal-care containers, cosmetic bottles, sample bottles, wash bottles, cold-water pitchers, and selected food containers. It is chosen for clarity, impact resistance, odor resistance, BPA-free positioning, and better heat tolerance than common PETG.