PET is one of the few thermoplastics that can be upcycled to achieve resin-like quality through SSP treatment. Today, post-consumer bottle flakes are successfully used for food-contact packaging, high-IV strapping bands, and filaments. Bottle-to-bottle recycling requires the highest standards in terms of decontamination.
Due to its favourable characteristics, the use of PET (polyethylene terephtalate) for food-contact packaging is a success story. But it also causes more PET waste, which in turn raises public interest in this issue. Recycling contributes significantly towards a positive perception of PET packaging: It increases ecological awareness and induces collection of post-consumer waste and obligatory reuse of recycled PET (rPET). Also major brand-owners jump on the bandwagon and promote low carbon footprint and resource conservation.
Be part of the solution
It is projected that within the next ten years the worldwide consumption of PET bottles will double. Even assuming ambitious collection rates, the major share of PET waste will end up in land-fills. Washed and processed PET bottles are a valuable secondary resource. In this context, it is the consumers’ responsibility to contribute to recycling efforts and to welcome products with rPET content – bottles that are turned into fibres, filaments and nonwovens, sheet, strapping, and, most prominently, into bottles again.
Flexibility through modular design:
Flakes from production scrap and post-consumer waste of preforms, bottles and sheet can either be recycled to pellets or processed inline into a final product. PET flakes are decontaminated and IV-increased stand-alone or inline. In combination with the recycling extruder and pelletising system the optional upsteam or downstream vacuum SSP reactor ensures outstanding rPET quality. Inline applications combine energy saving and value-adding in one step.
Due to availability and properties, PET bottle flakes have manifold applications. The largest amount is used for the production of fibres, filaments and nonwovens. Adding PET flakes when recycling production waste is a possibility to increase the viscosity of the rPET pellets. Finest melt filtration is available; use of up to 100 % rPET pellets possible.
PET flakes (of sheet, bottles, preforms) can be pelletised or processed directly inline on a sheet line that produces PET sheet with up to 100 % recycled content. In case of inline application a predrying unit (with or without vacuum) can be installed before the sheet extruder (viscoSHEET) instead of a conventional dryer. In this step, post-consumer material is decontaminated for direct food-contact applications and IV maintained or increased. The combination of recycling step and production step results in a competitive investment costs and helps to reduce energy consumption and maintenance while remaining user-friendly.
PET flakes are also a valuable secondary resource for strapping bands, which can be made from up to 100 % recycling PET (rPET). In order to meet the high intrinsic viscosity (IV) required, the material undergoes a solid state polycondensation (SSP) process with the Starlinger iV+ technology.
In all cases, recoSTAR PET (iV+) offers a competitive solution for superior rPET quality and high reuse rate.
Cleansing efficiency of post-consumer PET is, beside others, the most important aspect to secure food safety for rPET in packaging for direct food contact. Food safety is guaranteed mainly by operating the appropriate equipment with proven cleansing efficiency, continuous process data, rPET quality control, and protocol archiving for traceability. Frequent gas chromatograph tests with rPET deliver even better VOC results than virgin resin.
Recyclers are obliged to strictly comply with the prescribed process parameters and to monitor them – a task which is ensured by the automatic process monitoring system offered by Starlinger.
Various proofs for food contact safety such as the FDA Letter of Non-Objection, Austrian and French approbations, conformity to EFSA, ILSI and German BfR requirements have been achieved. In addition, brand owner approvals underline the superior quality of rPET produced on Starlinger recycling lines recoSTAR PET iV+.
Safety first for the whole value chain
The various stakeholders in a recycling project have different expectations:
- The authorities have to make sure that laws for food-safety are observed.
- The recyclers need efficient and flexible recycling equipment to ensure competitiveness in a volatile industry. Process stability and automatisation guarantee the production of food-contact safe pellets.
- The preform producers demand resin-like quality in terms of viscosity (IV), flow characteristics and processability.
- Bottlers and brand-owners require high rPET content without jeopardizing the visual appearance.
- And finally, all stakeholders including the consumers need to be absolutely certain that the packaging is safe.