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Verfahren zur Herstellung von thermoplastischen Polymerschaumpartikeln

Production of foam particle from thermoplastic polymer for interior parts of vehicles, comprises supplying the polymer to extruder, plasticizing and subjecting the polymer with propellant, and cutting the polymer to form the foam particles
 
: Kauffmann, A.; Diemert, J.; Klein, O.; Bosch, E.; Lieb, B.

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Frontpage ()

DE 102007048369 A: 20071009
DE 102007048369 A: 20071009
B29B0009
B29C0044
C08J0009
German
Patent
Fraunhofer ICT ()

Abstract
(A1) Es werden Verfahren und eine Vorrichtung zur Herstellung von Schaumpartikel aus thermoplastischen Polymeren vorgeschlagen, indem das Polymer einem Extruder aufgegeben und plastifiziert und mit einem Treibmittel beaufschlagt wird, wonach das plastifizierte Polymer ueber eine Duese oder ein Duesenaggregat auf dem Extruder ausgebracht und infolge Expansion des Treibmittels aufgeschaeumt und mittels einer stromab der Extruderduese angeordneten Schneideinrichtung zu den Schaumpartikeln zerkleinert wird. Um fuer eine einfache und kostenguenstige Erzeugung der Schaumpartikel in einem einzigen Verfahrensschritt zu sorgen, sieht die Erfindung vor, dass das aus der Extruderduese austretende Polymer mittels einer Schneideinrichtung zerkleinert wird, welche ein um eine in Bezug auf die Extruderduese im wesentlichen senkrechte Achse rotierendes Schneidwerkzeug aufweist, wodurch die Schaumpartikel mit einer im wesentlichen senkrecht zur Extruderduese gerichteten Geschwindigkeit beaufschlagt und dadurch von der Extruderduese seitlich, insbesondere im wesentlichen senkrecht, fort gefoerdert werden.

 

DE 102007048369 A1 UPAB: 20090507 NOVELTY - The method for producing foam particle from a thermoplastic polymer for interior parts of vehicles, comprises supplying the polymer to an extruder (1), plasticizing and subjecting the polymer with a propellant, removing the plasticized polymer from extruder over a nozzle and foaming due to expansion of the propellant, and cutting the polymer by a cutter (2) to form the foam particles. The cutter is arranged downstream to the extruder nozzle and comprises a cutting tool rotating around a cutting axis (3) with respect to the extruder nozzle. The foam particles are subjected with a velocity. DETAILED DESCRIPTION - The method for producing foam particle from a thermoplastic polymer for interior parts of vehicles, comprises supplying the polymer to an extruder (1), plasticizing and subjecting the polymer with a propellant, removing the plasticized polymer from extruder over a nozzle and foaming due to expansion of the propellant, and cutting the polymer by a cutter (2) to form the foam particles. The cutter is arranged downstream to the extruder nozzle and comprises a cutting tool rotating around a cutting axis (3) with respect to the extruder nozzle. The foam particles are subjected with a velocity directed to the extruder nozzle. The foam particle in a partial plastic condition is cut by the cutting tool to the foam particles. The removed polymer is immediately cut by the cutting tool. A distance between the free end of the extruder nozzle and the outer circumference of the cutting tool is adjusted to 1 mm. The rotation axis is positioned in such a manner that the distance of the axis is half of the radius of the cutting tool. The foam particles are subjected with a speed impulse directed in a gravitation direction by the cutting tool and are promoted by a gas flow of the extruder nozzle, whose flow direction is chosen parallel to the direction of the speed impulse on the foam particles. The gas flow is produced by a negative pressure downstream of the extruder nozzle. The cutting tool is cooled with air and has the shape of a circular cylinder or -ring, and is intended at parallelly arranged edges, which have an extension direction component running in an axial direction. The edges of the cutting tool diagonally run under an angle of 0-60 degrees regarding the axial direction of the cutting tool. An INDEPENDENT CLAIM is included for a device for producing foam particle from the thermoplastic polymer. USE - Method of producing foam particle for producing polymer mold parts for packaging and for interior parts of vehicles. ADVANTAGE - The method ensures cost-effective production of foam particles with improved particle shape and stabilized fine-pored foam structure having closed surface and spherical shape.

: http://publica.fraunhofer.de/documents/N-95838.html