The growth of the PET industry, particularly in Asia and Africa, is leading to a correspondingly high demand for recycling solutions for PET waste. “We offer the right systems for specific requirements, including for direct food contact,” says James Qiu, General Manager at EREMA Shanghai. The central element is the tried-and-tested VACUREMA® technology, which the international machine manufacturer launched 25 years ago and has been continuously developing ever since. About 400 PET systems for food grade in their various technological versions – such as VACUREMA® Basic, Advanced, Prime or MPR, and VACUNITE® – are in use worldwide and achieve a total capacity of more than four million tons per year. In the last three years alone, EREMA has delivered 100 systems for the “Bottle” sector. Almost 60 percent of these are bottle-to-bottle solutions. The remainder is divided between bottle-to-sheet, PET strapping and the ever-growing bottle-to-fiber segment.

Decontamination before extrusion

In order to produce food-safe, visually flawless rPET pellets from input material of varying quality, a reliable recycling performance is required. The key advantage of VACUREMA® systems is the SafeFlake technology in the vacuum reactor. It combines decontamination, drying and IV treatment. By pretreating the PET flakes under vacuum and at the correct temperature, moisture and migration substances are effectively removed before extrusion. This prevents hydrolytic and oxidative degradation of the melt in the extruder. The quality of the rPET pellets remains consistently high even if the parameters such as moisture, mixture or bulk density of the input material change.

In addition to the quality aspects, there are economic arguments in favor of the recycling process. This is because both the total costs of purchase and use (total cost of ownership) and the energy consumption are comparatively low. “The specific total energy consumption of a VACUREMA® Prime system, for example, is just 0.295 kWh/kg. This is a top energy efficiency value compared to the most common PET processing lines on the market,” says Christoph Wöss, Business Development Manager for the Bottle Division at EREMA. The VACUREMA® Prime is a variant of the process in which two crystallization dryers run in batch mode – also under vacuum – immediately upstream of the vacuum reactor and decontaminate alternately. The intrinsic viscosity (IV) is increased by solid state polycondensation (SSP) on the flake.

Double safety with VACUNITE®

Legal requirements and the public commitment of well-known brand owners are pointing the way towards a significant increase in the proportion of recycled material in products such as PET bottles. “Recycling plants have to produce better output material despite decreasing input quality,” explains Christoph Wöss. “VACUNITE® exists for these requirements.” Together with Polymetrix, EREMA has further developed the proven VACUREMA® process to include vacuum-assisted SSP in a nitrogen atmosphere. All thermal process steps take place with nitrogen and/or vacuum.

For users, decontamination at the beginning and end of the processing sequence means double safety. “With VACUNITE®, we offer our bottle-to-bottle customers an advanced technology that sets new standards at all levels, from technical performance to recyclate quality,” summarizes Christoph Wöss. The nitrogen used in the SSP is purified and then fed back into the upstream process steps, which reduces nitrogen consumption overall. Another advantage of VACUNITE® is the improved color values. “We can maintain transparency even after several recycling cycles and thus make bottle-to-bottle recycling fit for the future – for a truly functioning circular economy,” says Christoph Wöss.

Food-safe rPET on the rise – also in the textile industry

In addition to the food sector, food-compliant rPET is playing an increasingly important role in the textile industry. Well-known brands are increasingly relying on recycled PET as a raw material that meets the requirements for food grade in order to be able to offer their customers sustainable textiles that are harmless to health. A trend that is reflected at EREMA in the increasing sales of bottle-to-fiber applications. Asia is an important market in this segment. In general, the textile industry is becoming increasingly important for PET recycling. Around two thirds of the total amount of PET is used in the production of synthetic fibers. EREMA responded by setting up its own business application for fibers and textiles.

Gentle material preparation for fiber-to-fiber

The INTAREMA® FibrePro:IV machine was developed specifically for fiber-to-fiber recycling. By combining the proven INTAREMA® technology with the new IV optimizer, it is possible to process shredded PET fibre materials that have been heavily contaminated by spinning oils in such a way that the finest fibres can be produced from the recycled pellets. The system is characterized by targeted active surface renewal of the melt in a vacuum atmosphere, which removes spinning oils and other additives more efficiently than conventional PET recycling processes. After extrusion, the intrinsic viscosity is increased again in the IV optimizer by polycondensation of the PET melt to the level required for the respective fibre production. “With this recycling process, we achieve high-quality rPET granulate that is used for the production of the finest fibres up to 2 dtex – with an rPET content of 100%,” emphasizes James Qiu.

To drive forward developments in PET fiber recycling, the EREMA Group has set up its own fiber pilot plant at its headquarters in Ansfelden, Austria. Here, an interdisciplinary team operates an extensively equipped and variable recycling plant on an industrial scale. It is equipped with the necessary peripheral technology and is also available to customers for test runs.

Customer proximity thanks to local branch

Customer orientation has always been a declared goal for EREMA. In order to be quickly and personally available to customers in China, the company founded a branch in Shanghai in 2001. “Our experts in process engineering and commissioning are available to meet the special requirements of PET recycling and beyond,” says James Qiu. The EREMA experts also provide support in preparing for the approval procedures required for the production of food-grade rPET. In many other Asian regions, EREMA cooperates with local representatives and maintains local sales and service teams.

Cover photo: If you would like to visit EREMA in China, you will find the stand at Chinaplas in Hall 2.1 / C55 (Source: Erema)