Recycled PET use in hot-fill bottles has no significant impact: Study

This study was focused on evaluating virgin PET and two different rPET resins added to virgin PET at 25 percent, 50 percent and 100 percent levels. A 27-gm commercial 500 mL six-panel hot-fill bottle and preform were used for the study. Bottles containing recycled-content variables were processed similarly to maintain equivalent bottle wall thicknesses and maximise preform temperatures. The objective was to ensure that the only difference was the amount of recycled content.

The bottles were then tested to determine hot-fill and top load performance, wall thickness, colour, haze, crystallinity and acetaldehyde (AA) content. Following are the main study conclusions:

The study found that all of samples passed the standard performance specifications for hot fill bottles, even at high percentages of rPET. Shrinkage increased slightly as the recycled content grew above 50 percent, but the bottles remained within the specification. 

The drawbacks of high rPET content are increased yellowing and higher haze levels. However, these are aesthetic issues and do not impact performance.

The study concluded that converters and brand owners can use up to 50 percent good quality rPET in hot-fill bottles without negatively impacting performance. Recycled PET levels greater than 50 percent can also be used, however desired package aesthetics will drive the acceptable level. 

Plastic Technologies Inc provides preform & package design, package development, rapid prototyping, pre-production prototyping, and material evaluation engineering to the plastic packaging industry.