Kunststofffolie Entwässerungsmaschinen Lieferanten

Centrifugal dryers vs squeeze-roll dewatering — choosing the right technology

Centrifugal dryers (spin dryers) use a high-speed rotating basket or drum to throw surface water off plastic flakes or film by centrifugal force. They are well-suited to rigid plastic flake and shorter-cut film pieces where the material flows freely in the rotating drum. A well-designed centrifugal dryer reduces moisture content from approximately 30–50% (after washing) to below 3–5% (surface moisture) in a single pass. A subsequent thermal dryer then reduces moisture to below 0.5% or less for pelletising. Centrifugal dryers are the most common mechanical dewatering stage in plastic recycling lines. Squeeze-roll dewatering machines (screw press or compaction dryers) mechanically compress wet plastic film between rollers or in a screw press to expel water — rather than spinning it off. They are particularly effective for long, tangled film pieces that do not flow well in a centrifugal dryer. Squeeze-type dewatering is used in lines handling whole agricultural mulch film, long shrink film strips, or other materials that present feeding challenges for centrifugal dryers. Some plant designs combine a squeeze dewatering stage with a centrifugal dryer to achieve lower final moisture content more efficiently.