Plastics Recycling

PET Recycling - Bottle-to-Fiber

Devolatilization of recycled PET bottles

First-Class Technology for the Recycling of PET Flakes

Thanks to its excellent devolatilization properties, Coperion's twin screw extrusion systems are ideally designed for the "bottle-to-fiber" process in which used PET bottles are recycled and turned directly into fibers.

PET bottle flakes, new PET product and masterbatch are fed into the Coperion ZSK extruder via high-accuracy Coperion K-Tron gravimetric feeders.

Processing shredded PET bottles with a single screw extruder requires a complex laborious drying process. By contrast, Coperion's ZSK twin screw extruder can process the PET while being essentially non-dried, and devolatilize the melt with a low energy expenditure in a vacuum of 1-5 mbar (absolute). Volatile contaminations and oligomers are extracted from the melt and separated from the exhaust gas flow in suitable separators upstream of the vacuum pump, before the melt is further processed into fibers.

Typical set-up for the bottle-to-fiber process

Comprehensive product range

Coperion ZSK 82 Mc18 Twin Screw Extruder

Twin screw extruders

Coperion's ZSK twin scew extruders are particularly suitable for PET recycling and the bottle-to-fiber process due to their excellent devolatilization properties. The ZSK twin screw extruder can process the PET flakes while being essentially non-dried, and devolatilize the melt with a low energy expenditure in a vacuum of 1-5 mbar (absolute).

ZSK Mc¹⁸ twin screw extruder
Coperion K-Tron SWB 300

Feeding Equipment

Coperion K-Tron offers a variety of feeding solutions for plastics processing. Each technology has its own advantages – what is decisive is the process know-how that brings operational requirements and processes together. Smart Weigh Belt Feeders can reliably feed large volumes of bulk material and materials with varying flow properties, since they weigh the bulk material prior to discharge and actively adapt belt speed. Vibratory Feeders are an ideal solution where smaller recyclates or flakes are being fed, or if glass fiber is added into compounding processes. Twin Screw Feeders are ideal for the precise feeding of finer bulk materials, and are therefore often used for additives.

Coperion K-Tron Feeder Refill

Material Handling

Coperion and Coperion K-Tron offer an extensive line of pneumatic conveying systems and components for the transfer of a wide range of bulk materials, such as additive powders, resin pellets, recyclates, stabilizers and colors. Our experienced global team can support you in designing, replacing, or modernizing the material handling system for your process line, taking the guesswork out of the process.

Coperion Inventory


We provide standardized and highly customized service packages for our machines and equipment. Our comprehensive range of services secures maximum plant reliability and lifetime.



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