Buehler Ag

Buhler Ag

Hans Geissbuehler

Filippo Terrasi

Camille Borer

Martin Mueller

Heinz Gasser

The invention relates to a method for treating plastic material, especially polyethylene terephthalate, wherein the relatively low temperature material is initially crystallized by heating before subjecting said material to heating or condensation in the solid phase. The material is then exposed to a hot treatment gas for at least 10 minutes in at least two chambers ( ) of an apparatus and crystallized at a temperature above 135&deg; C., e.g. 140-180&deg; C. The is subsequently heated in a preheating chamber ( ) having at least one to eight stages at a temperature of at least 185&deg; C., preferably at least 200&deg; C. and more preferably around 220&deg; C.

Device and method for treating plastic material

The invention relates to a drier-heat-exchanger for heat treating PET granulate and similar products. The drier has a channel which is delimited by air permeable sheets. This ensures that the product can pass through efficiently and evenly which in turn means that a higher gas speed can be used without the product being stirred up and therefore shorter heating times are possible.

Drier-heat-exchanger

An apparatus for the continuous crystallization of polyester material is described, which apparatus can likewise be used for the drying of granules. The apparatus operates to improve the residence behavior of the material and the process. This is achieved by a circular apparatus having a gas inlet and gas outlet and product entry and product outlet, The product entry and product outlet are arranged concentrically and parallel to the axis of the apparatus. A product outlet device is arranged so that it is axially displaceable.

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Zuzwil, Switzerland

Hans Geissbuehler