The Swiss Bachmann Group, a packaging manufacturer, has embarked on an ambitious mission with the PAC2PAC project: to create an optimal recycling loop for PET packaging.

Partners in this project include Sesotec, Starlinger Viscotec, Krones, and PET-MAN. Each company has contributed its expertise and cutting-edge technology to a feasibility study aimed at delivering a forward-thinking, sustainable solution for mixed plastic collection in Switzerland.

Challenge in sorting PET packaging waste

Swiss plastic collection bag gathers various plastic packaging, including food-grade PET packaging and many non-food-grade items. Traditional sorting methods, such as NIR technology, color detection, or shape recognition, limit accurate distinguishing between food-grade and non-food-grade PET.

Solution: AI Sorting from Sesotec

The integration of AI in sensor-based sorting is revolutionizing the recycling industry, especially in distinguishing between food-grade and non-food-grade PET waste. In this project, Sesotec played a pivotal role in sensor-based sorting of food and non-food PET materials, with its sorting solution merging with AI.

After the material is separated through bale breaking, the plastic packaging enters the latest Sesotec sorting system, VARISORT+ UNITY. With the innovative OBJECT-AI technology, it becomes possible to reliably separate food-grade PET from other packaging.

VARISORT+ UNITY

OBJECT-AI is an AI-based evaluation method used for object recognition. It complements traditional sensor-based sorting, which enables material classification via NIR (near-infrared), color differentiation, or shape recognition. The existing shape and print of the bottle are also used as criteria to distinguish between food-grade and non-food-grade PET.

The VARISORT+ UNITY devices sort materials into two categories: the first contains “food-grade clear PET”, and the second “food-grade colored PET”. Simultaneously, analyses ensured compliance with food and non-food content limits throughout the project.

The new VARISORT+ devices (FLEX and UNITY) come equipped with advanced sensors and a high-performance evaluation unit, ready for AI analysis deployment.

The sorted packaging was then shredded into flakes, screened, and washed. The Sesotec sorting system, FLAKE PURIFIER+, ensured precise sorting of the plastic flake fractions. Each fraction underwent additional purification, reliably removing any remaining off-colors, metals, and incorrect plastics with the FLAKE PURIFIER+.

FLAKE PURIFIER+

To ensure the quality of recycled material, the Sesotec material analysis system FLAKE SCAN was utilized. It enables rapid and reliable sample analysis of material composition by plastic types, colors, and metal foreign bodies. Used for monitoring both input and output materials, it also ensures process safety. Additionally, the quick evaluation of material composition provides a solid basis for decisions regarding material usability.

FLAKE SCAN

The FLAKE SCAN analysis system excels in saving time and delivers precise and, most importantly, actionable results compared to the usual manual, visual, or thermal evaluations.

After successful sorting and reliable quality control, the pure flakes are extruded into mono-recycling films. These films are then thermoformed back into equivalent packaging. The PET cycle is complete: PAC2PAC.

Higher recycling rate with consistent quality

This forward-thinking recycling solution allows high-quality food-grade PET to be reintroduced into the cycle at a competitive price without compromising quality.

Additionally, non-food-grade, transparent PET and colored PET are reclaimed to further boost output from the yellow bag. The recycling loop is complete. Used packaging becomes new packaging. The project demonstrates a tripling of the recycling rate for the Swiss collection bag.