Patent EP-1844917-A2 (EP)
Inventor: RUST HARALD
IPC: B29C48/44
Filed: 2006-07-13
Abstract: The procedure for operating planet roller extruder for degassing and drying thermoplastics, comprises cogging planet roller spindles together with a central spindle toothing with housing teeth, utilizing the single-part or multi-part planet roller spindles and/or central spindles and/or housing teeth, at which 2-4 teeth are totally or partly worked out, with remaining teeth circumference of the planet roller spindles and/or central spindles and/or housing teeth, and producing the toothing after a fixed tooth contour at the planet roller spindles and/or central spindles and/or housing teeth. The procedure for operating planet roller extruder for degassing and drying thermoplastics, comprises cogging planet roller spindles together with a central spindle toothing with housing teeth, utilizing the single-part or multi-part planet roller spindles and/or central spindles and/or housing teeth, at which 2-4 teeth are totally or partly worked out, with remaining teeth circumference of the planet roller spindles and/or central spindles and/or housing teeth, and producing the toothing after a fixed tooth contour at the planet roller spindles and/or central spindles and/or housing teeth. The tooth contour is fixed, so that it is similar to teeth with totally or partially processed teeth. The teeth are helical teeth, so that the individual tooth runs as screw threads at the toothed surfaces corresponding to the gradient of the teeth for extruder longitudinal axis. The planet roller extruder has an external toothed central spindle, planet roller spindles rotating on the central spindle, an internal toothed rotating housing and evolvent toothing for degassing and/or drying thermoplastics. The planet roller spindles and/or central spindles and/or housing teeth have an even number of teeth in the region of the reduced teeth edges during the teeth have an odd number of teeth at the corresponding planet roller part or have an odd number of teeth in the region of the reduced teeth edges during the teeth have an even number of teeth at the corresponding planet roller part and/or are combined with unprocessed planet roller spindles and/or are combined with differently processed planet roller spindles. The teeth are spaced in irregular distances. The planet roller spindles and/or central spindles and/or housing teeth have a full tooth edge and/or knob teeth or other teeth in the remaining region. A manufactured part of the planet roller spindles and supply habit of the manufactured part of the planet roller spindles are used, so that the manufacturing are continued without reducing the entire tooth edges or by reducing the entire tooth edges. The single-part and multi-part planet roller spindles and/or central spindles and/or housing teeth having a part with reduced tooth edge and a part with all teeth edges are used. The tooth gap developed by reducing the tooth edge runs out at the passage between both parts. The both parts are separately produced, are connected together, are provided with holes, and are braced against each other with an anchor arranged in the holes. The part with a planet roller spindle diameter of less than 160 mm in the spindle longitudinal direction has a length of 800 mm, and with a planet roller spindle diameter of greater than 160 mm in the spindle longitudinal direction has a length of 2500 mm. The planet roller spindles are used with reduced tooth edges for drying process and/or degassing of the treatment products. Plastic particles are dried, where the particles have an internal temperature below the melting point. The treatment procedure and/or the treatment temperature and or the feeding effect are modified by combination of the planet roller spindles with reduced tooth edges, with planet roller spindles, with normal teeth or other teeth. After the reduction of the tooth edges at the planet spindles, the reduced flow rate is partly balanced by increasing the number of the planet spindles. A variation of the teeth is produced over the length of the planet roller spindle and/or central spindles and/or housing teeth. The tooth gap on a plant roller spindle and/or a central spindle and/or two teeth between housing teeth in the area of the reduced tooth edges is greater than an adjacent tooth.