Lightweight 100% rPET Bottle Design, Tooling for CSD

Sidel’s improved base and stretch-rod designs for StarLITE R are said to widen the process window for making high-quality CSD bottles with 100% rPET. Photo Credit: Sidel

Greater variability in rPET resins leads to a narrower process window and lower bottle quality. Higher temperatures required to process rPET also tends to reduce control over material stretching and distribution in the blow molding process. Both these challenges are said to be overcome by the new StarLITE R bottle design and tooling from Sidel, an extension of its StarLITE ultralight PET bottle technology.

Aimed specifically at 100%r PET bottles for carbonated soft drinks, StarLITE R is easier to blow as it can be done with a wider process window to achieve a high-quality CSD bottle. StarLITE R technology is available for both single-serve and multiserve CSD bottles. Sidel says the bottle weights are the same as for comparable sizes of StarLITE Ultralight bottles in virgin PET, but the company notes that StarLITE Ultralight is a low-cost bottle for hard discount markets with shorter shelf life, while StarLITE R addresses mainstream markets with longer shelf life.

A key feature of StarLITE R is an optimized mold-base profile that improves material distribution and a high base clearance for optimum stability, according to Sidel. Also, advanced stretch-rod end design is said to improve stretching in the base and ensure accurate injection-gate centering. A special combination of grooves and venting holes enables precision base feet formation.

A second important feature is the internal/external base cooling. A mold-base cooling circuit in the mold focuses on the warmer bottle base zones, while the hollow stretch rod requires to additional air supply.

Sidel says the StarLITE R design can be easily installed on existing production lines with the company’s EvoBLOW, Universal and Series 2 stretch-blow machines and can be adapted to fit current bottle designs.