Polymer & Rubber
In the Polymer and Rubber industry the use of LIST Process Solutions is a matter of course and an integral part of the production of a large variety of polymers and elastomers for different applications. LIST KneaderReactors are used in virtually all processes of polymer and elastomer production.
No other conventional process equipment can master the demanding and complex processes parameters and requirements. Only the use of LIST KneaderReactors allows the development and production of new, pioneering polymers and elastomers using process steps such as bulk polymerization, polycondensation, main evaporation and devolatilization.
These processes might interest you
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The synthesis of most elastomers is carried out either by Solution or emulsion polymerization. After the polymcrization step, the polymer is separated from the solvent or emulsifying agents. This separation requires several process steps including coagulation, Stripping, various mechanical separation stages, and finally diying. Beyond that, the existing technologies are energy consuming, waste solvent must be incinerated, and the installation of main and ancillaiy equipment occupies large spaces.
Lamguage: English / Year: 2007
For decades, conventional polymerization in the production of elastomers has been the norm. The time and cost involved in removing and treating solvents in the final stages of production, for example, were acceptable. But as pressure builds on manufacturers to reduce operating costs, there is greater urgency to develop processes that can help streamline cost and production. One such effort by List AG has yielded promising results.
Language: English / Year: 2014
Energieeinsparung und Qualitätsverbesserung durch indirekte Eindampfung von Polymerlösungen oder direkte Polymerisation und Polykondensation
Language: German / Year: 2004
Devolatilization of solvents from viscous polymer cement is realized through stripping of solvent with steam in stirred vessels or directly by evaporating the solvent from the polymer. The later so-called direct desolventizing is realized in extruders or high volume kneaders. All 3 methods involve additional energy to drive out solvent either by partial pressure through additional steam (steam stripping), building and releasing pressure in order to explode the polymer bulk (extruder) or dynamic surface renewal (kneader).
Language: English / Year: 2005
A concentrated rubber solution (less than 20 % solvent) is fed to a high volume kneader in order to remove the solvent down to ppm level. A simulation program has been developed to describe this devolatilization step. The program predicts final solvent content, the filling level and the mechanical torque build-up. The program can be used to refine process control and the scale-up of this type of process.
Language: English / Year 2005
Das Fraunhofer-Pilotanlagenzentrum für Polymersynthese und -verarbeitung
Language: German / Year: 2005
Eine konzentrierte Elastomerlösung (weniger als 20 % Lösungsmittel) wird einem großvolumigen Knetreaktor zugeführt, um das Lösungsmittel bis auf ppm-Gehalte zu entfernen. Um diesen Entgasungsschritt zu beschreiben, wurde ein Simulationsprogramm entwickelt. Das Programm errechnet den Restlösungsmittelgehalt, den Füllgrad und das Drehmoment des Reaktors. Es kann sowohl der Feineinstellung sowie auch dem Scale-up des Prozesses dienen.
Language: 2005 / Year: 2005
Polymerprozesse – Aufbereitung und Finishing von Polymeren – Knetertechnologie in der Polymeraufbereitung – Wirtschaftlichkeit
Language: German / Year: 2006
Die bestehenden Technologien für die Aufbereitung von Polymeren nach der Polymerisation können in ein-, zwei- und mehrstufige Verfahren unterteilt werden. Dem entsprechend kommen Stripptechnologien mit nachgeschalteter mechanischer und thermischer Entfernung der Hilfsmittel, Extruder in verschiedenen Bauarten und großvolumige Kneter zum Einsatz. Die Knetertechnologie ist vor allem für temperatur- und scherempfindliche Polymermassen geeignet, bei denen die Entgasung diffusionsbestimmt ist.
Language: German / Year: 2006
Batch trials were performed on a kneader reactor where a bulk co-polymerization was carried out. Polymerization conversion, viscosity build, reaction kinetics, and heat transfer calculations were performed using the experimental data from the batch trials. A continuous process was proposed for this bulk copolymerization and the models and results from the batch trials were used in designing the continuous process. Predictions of the continuous process using the batch trial data are compared to the actual continuous process, with a focus on polymer conversion, heat transfer, and torque prediction.
Language: English / Year: 2007
Die Synthese von Kautschuk ist ein wichtiger Prozess: Hersteller von Gummiprodukten – ganz gleich ob Autoreifen oder Kondome – benötigen hochwertigen Kautschuk als Ausgangswerkstoff. Doch die Kautschukerzeugung ist teuer und verschlingt große Mengen an Energie. Forschern des Fraunhofer-Instituts für Angewandte Polymerforschung IAP in Potsdam ist es gemeinsam mit ihren Entwicklungspartnern LIST AG und Dow Olefinverbund GmbH gelungen, den Energiebedarf der Kautschuksynthese um 76 Prozent zu senken.
Language: German / Year: 2007
Synthetic elastomers have been produced for over 50 years. Advances in catalyst systems and polymer formulations have been somewhat diminished by the continued use of the same processing technology. In particular, the use of coagulation, steam stripping, mechanical dewatering, and convective drying for the devolatilization of temperature sensitive elastomeric solutions can be replaced with direct devolatilization using kneader technology. A two-step, direct devolatilization process has demonstrated energy savings and advantages in environmental emissions and process/product flexibility when compared to the conventional steam stripping process.
Language: English / Year: 2008
Kneader reactors are used for combined unitary processing in the polymer industry for devolatilization, compounding or polymerization. In the past, mass transport prediction for devolatilization operations in kneader reactors did not match experimental results, when diffusion was assumed as sole driving force. It was detected that there is an additional concentration and temperature dependent driving force that triggers enhanced transport at finite solvent concentrations by orders of magnitude. The author suggests that the underlying root cause is likely micro bubble formation within the polymer melt. An attempt to model this additional mass transport mechanism is presented.
Language: English / Year: 2008
Are you looking for a solvent-free, safe, eco-friendly and energy-efficient way of producing new types of products with new levels of quality? New technology is available to help you do exactly that.
Language: English / Year: 2009
Sie suchen ein lösungsmittelfreies, sicheres, umweltfreundliches und energieeffizientes Herstellungsverfahren, das neue Produkttypen mit neuen Qualitätsmerkmalen hervorbringt? Eine neue Technologie macht’s möglich.
Language: German / Year: 2009
Mit lösemittelfreier Prozessführung, dem sogenannten Dry Processing, lassen sich zwei entscheidende Ziele erreichen: umweltfreundliche Prozesse und eine deutliche Senkung der Investitions- und Betriebskosten. Die Schweizer Firma List konzentriert sich dabei nicht auf einzelne Verfahrensschritte, sondern auf den Prozess als Einheit, um eine ganzheitliche verfahrenstechnische und wirtschaftliche Optimierung zu erreichen.
Language: German / Year: 2009
Der Einsatz von großen Lösungsmittelmengen in Polymerisationsprozessen mit den damit verbundenen Nachteilen muss nicht sein. Ein neues Verfahren beschreitet neue Wege: Kneten statt strippen lautet die Devise.
Language: German / Year: 2010
Der Einsatz von großen Lösemittelmengen in Polymerisationsprozessen mit den damit verbundenen Nachteilen muss nicht sein. Ein optimiertes Verfahren ermöglicht die direkte Entgasung von Lösemitteln, ohne dabei Strippmittel einsetzen zu müssen. Aufwendige Trennschritte werden so vermieden und höhere Produktqualitäten können erreicht werden.
Language: German / Year: 2010
The achievable final volatile content within kneader devolatilization processes is highly dependent on the final melt temperature. For thermosensitive polymers the state of the art process performs poorly. The amount of dissipated energy leads to a heat up of the polymer, limiting the maximal kneader shaft speed and therefore volatile removal rate. This new process uses a suitable additional volatile compound to cool off the dissipated energy by evaporation using the off gas to strip and boost the mass transfer coefficient. A complex multi-parameter study is presented, to predict performance of industrial equipment from pilot scale data.
Language: English / Year: 2011
The achievable final volatile content within kneader devolatilization processes is highly dependent on the final melt temperature. For thermosensitive polymers the state of the art process performs poorly. The amount of dissipated energy leads to a heat up of the polymer, limiting the maximal kneader shaft speed and therefore volatile removal rate. This new process uses a suitable additional volatile compound to cool off the dissipated energy by evaporation using the off gas to strip and boost the mass transfer coefficient. A complex multi-parameter study is presented, to predict performance of industrial equipment from pilot scale data.
Language: English / Year: 2011
Converting the polymer industry to solvent-free polymerisation processes and avoiding unnecessary recirculation decreases energy consumption and reduces waste production. This can be achieved with the horizontal large-volume Kneader Reactor with superior mixing and homogenisation performance. The casing, shafts and mixing elements are indirectly heated by heat transfer fluids and dynamically self-cleaning.
Language: English / Year: 2012
Conventional polymerisation in the production of elastomers has been the norm for decades. The time and cost involved in removing and treating solvents in th e final stages of production , for example, were acceptable, but as pressure builds on manufacturers to reduce operating costs, there is greater urgency to develop processes that can help streamline cost and production. One such effort has yielded extremely promising results.
Language: English / Year: 2013
For decades, conventional polymerisation has been the norm in the production of elastomers. The time and cost involved in removing and treating solvents in the final stages of production were acceptable. Yet as pressure builds on manufacturers to reduce operating costs, there is greater urgency to develop processes that can help streamline costs and production techniques. One such effort has yielded extremely promising results.
Language: English / Year: 2015
Der zunehmende Kostendruck macht keinen Halt vor der Produktion von Elastomeren. Gefragt sind intensivierte Prozesse, die unnötige Verfahrensschritte ersparen und sowohl Zeitaufwand wie auch Kosten senken. Nun liefert ein innovativer Ansatz aus der Schweiz, die sogenannte Direct Devolatilization (direkte Entgasung) von Polymerlösungen, vielversprechende Ergebnisse.
Language: German / Year: 2015
