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General Terms & Conditions and other service files
Buss AG
BUSS offers various service options and service packages. Different industries require different service levels - your choice, our service.
These General Terms and Conditions of Supply shall be binding if declared applicable in the quotation or in the order acknowledgement. Any conditions stipulated by the customer which are in contradiction to these General Terms and Conditions shall only apply if expressly acknowledged by BUSS in writing. BUSS means and refers to Buss AG, Pratteln, Switzerland, or, if Buss, Inc. USA, Buss Japan Ltd or another entity belonging to the Buss Group issued the quotation or order acknowledgement to the customer, such entity.
Form for Material Returns and Repair Requests for BUSS Machines.
LIST Technology AG
These Terms of Sale apply to studies and tests conducted at the LIST Test Center.
General Terms of Sale of LIST Technology AG.
BBA INNOVA AG
These general conditions of supply shall be binding if declared applicable in the tender or in the order acknowledgement. Any conditions stipulated by the customer which are in contradiction to these general conditions of supply shall only be valid if expressly acknowledged by the supplier in writing.
BUSS Co-Kneader Technology
Brochures & Flyers
Articles & Whitepapers
Gentle Compounding with High Mixing Effect and Good Scalability in the Co-Kneader | The patent on the operating principle of the co-kneader was applied for three quarters of a century ago. Compared to other extruder technologies, it features a clearly higher mixing effect while it processes the raw materials gently. Current applications for its further development range from reactive, shear-sensitive plastics to the compounding of high-performance engineering plastics.
Maximum Production Output from Compounding to Pelletizing | Compounding plastics requires precise control of parameters such as temperature and viscosity. The process becomes even more demanding when processing sensitive materials such as fillers that react to high temperatures or pressures. Buss co-kneader technology makes it possible to optimize compounding, pressure build-up and pelletizing independently of each other.
Co-Kneaders for Plastics Processing | Clearly, only those who really need a Co-Kneader will use one. It is usually more economical if an application can be modeled on a twin-screw extruder. But those who want to process shear-sensitice or high-performance engineering compounds quickly discover the added value of this technology. For our on-the-spot report, Plastic Insights spoke to Buss managing director Dr. Philip Nising about the company's history, applications and market developments.
LIST KneaderReactor Technology
Articles & Whitepapers
La parte principal del agua se atribuye al almacenamiento, pero también a su mezcla con el lodo para el transporte de éste. Solo una pequeña parte del agua podría considerarse como de reacción directa.
Language: Spanish / Year: 2000
The bulk free radical polymerization of methyl methacrylate (MMA) or the bulk free radical copolymerization of MMA based monomer recipes face a gel effect (Trommsdorff’s effect) and exothermicity. The kneader reactor offers a perfect combination of surface renewal and evaporative cooling to control temperature at high conversion (85 to 95%).
Language: English / Year: 2006
A new type of kneader reactor is proposed for the continuous radical (co-) polymerisation without solvent, based on the proven design of mature (kneader-) dryer technology. The reactor has been developed to satisfy all major aspects required for (co-) polymerisation while maintaining the safety and reliability of the previous mechanical design. The new kneader reactor offers a perfect combination of surface renewal and evaporative cooling to control temperature to high conversion (85 to 95%), even for bulk systems that have a strong gel effect (Trommsdorff’s effect) and high exothermicity.
Language: English / Year: 2006
A review of the existing polymerisation processes is proposed, with particular attention to the control of viscosity and heat removal. Up to the present time, different types of reactor have been developed in order to improve the stability of the polymerisation process. A review of these reactors is presented for the heterogeneous and homogeneous polymerisations. The production of solid polymer granules directly in a kneader reactor under evaporative cooling is seen as an efficient and reliable polymerisation technology.
Language: English / Year: 2001
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
In conventional spinning dope production, capacity is typically a function of the maximum processing viscosity the spinning plant can handle. Often the prior dissolving process step is limited by this fact. In a typical wet spinning operation, dope viscosity ranges from 500-2500 Pa ·s (zero shear viscosity at 95 °C) can be handled. For processors looking to meet rising demand with world-sca le plants, the limitations imposed by high viscosity dope sol utions are challenging and costly. List AG, Arisdorf/Switzerland, have now adapted the company’s high viscosity processing technology in order to meet the difficult processing challenges of today’s high-production fiber lines. The technology can easily handle 20,000-200,000 Pa·s (zero shear viscosity).
Language: English / Year: 2013
A new dissolution process for cellulose spinning solution was developed. As Basis for the new process served the classic cellulosic fiber production process. In the last 30 years or so the conventional viscose process became environmentally critical. Evaluated with regard to its environmental viability it was found to create considerable water and air pollution. This conclusion ignited the research and development of new technologies with less environmental impact.
Language: English / Year: 1999
Various types of reactor have been developed to date for improving the stability of the polymerisation process. This review describes a few examples of heterogeneous and homogeneous polymerisation, focusing particularly on viscosity control and heat removal. The production of solid polymer granules directly in a kneader-reactor with evaporative cooling is one efficient and reliable polymerisation technology.
Language: English / Year: 2003
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 most common application of sublimation is separation of volatile solids and purification of substances. This paper explains the p-T diagram of a pure substance, and discusses existing processes and their operation.
Language: English / Year: 1995
A dryer designed for pasty materials handles solvent Evaporation problems
Language: English / Year: 1996
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
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 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
How direct devolatisation of an elastomer solution can save time and money
Language: English / Year: 2006
The difference in the production of PA6 in comparison to that of other polymers is the downstream water extraction and drying after the granulation. During these process steps, the monomer and the oligomer contents in the final product are reduced in the 0.2 to 0.6 ww/w range. The installed units for extraction and drying of the final granulated product are characterized by their large energy consumption, which considerably influences manufacturing costs.
Language: English / Year: 2002
Reactors with indirect contact drying under vacuum conditions are often used for a large variety of different production processes. As a typical example for food processing the production of chocolate- or milk-crumb will be explained and discussed. Moreover, the potential for process optimization will be shown in this example.
Language: English / Year: 2004
Large volume kneaders are designed to handle highly viscous polymer processing. The unitary operations can be compounding, polymerizations, devolatilization or drying. Depending on the polymer viscosity in the kneader, the interaction of kneading elements induce a torque and force evolution on the shaft over one revolution.
Language: English / Year: 2006
The Lyocell fiber process is developed to transform cellulose to a man-made cotton-like fiber. The lyocell process includes a number of processing steps. The dissolving step is the most important one. It represents the heart of the lyocell technology. Kneaders developed by List AG, Arisdorf/Switzerland, are successfully applied for the continuous dissolving step whereby raw materials of different origin can be processed and transferred into a spinabie dope.
Language: English / Year: 2006
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
The increase in the amounts of paint and lacquer sludges from industrial processes combined with more stringent legislation, reduction in available land-fills, escalating costs, and the increasing pressure for residues to be processed at the point of origin has created a tremendous incentive for the development of new and economic concepts and techniques for their minimisation.
Language: English / Year: 2005
In the mid seventies, LIST developed and industrialized a continuous process for the recovery of toluene diisocyanate (further TDI) from distillation residue. The process, which will be highlighted in this document, ensures the Maximum recovery of TDI. The final residue is transformed into a non-toxic (neutral) and easy to handle solid/granular material.
Language: English / Year: 2000
Polymerization of lactide to polylactic acid (PLA) can be performed using conventional reactor technology such as stirred tank reactors, but the conversion and/or final molecular weight may have to be controlled to a lower level. At higher conversion and/or molecular weight, the reaction mass will become very viscous, which limits the ability of conventional reactor technology to provide adequate mixing, minimize mass transfer effects on reaction kinetics, remove exothermic heat of reaction and ensure proper heat transfer in order to eliminate hotspots/thermal degradation.
Language: English / Year: 2013
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
From Lab Testing to Industrialization, discover how LIST helps knead wood into textile with one of the most advanced, environment-friendly cellulose-based fiber production technologies.
Language: English / Year: 2019
LIST further optimized the cellulose dissolution technology, which was introduced in 1992. This succeeded the production of excellent spinning solution qualities, produced from a variety of low cost raw materials. The technology fulfils the current high safety standards.
Language: English / Year: 2001
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
Fiber, filament, flies and foil are the final products of a complex process of mixing, dissolving, spinning, washing and drying of raw material. Many specialists believe that the spinning part is the only relevant processing step for the final fiber quality. This belief falls short, as the fiber quality also depends on the dissolving step before the spinning step.
Language: English / Year: 2014
This paper elaborates on the constraints of the drying process of industrial sludges and distillation residues, such as, closed design and product containment, processing of sticky, crusting, or fouling intermediate phases, versatility, low energy demand, and single step drying. It then presents the mechanical, thermal and processing features as well as the operating principles of specialised single-shaft, DISCOTHERM B CONTI/BATCH, and twin-shaft, ORP (Opposite-Rotating Processor) CONTI, kneadersdryers.
Language: English / Year: 1998
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
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
As world consumption of textile fibers expands with the rapid growth of Asia and other developing countries, sources of fibers other than cotton and rayon must be developed and brought to market to meet demand. Cellulose fibers (Lyocell fibers) can meet these expanding needs because of the specific qualities and characteristics of the fiber, as well as the vast availability of the raw materials.
Language: English / Year: 2004
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
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
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
This lecture concisely reviews the development and evolution of specialised contact kneaders-dryers, presents the field of their application, defines the selection criteria, describes a basic design procedure, and closes with a list of parameters, that helps one to decide between the implementation of a batch or a continuous operating dryer.
Language: English / Year: 1998
Optimizing the recovery of residues in the production of polyurethane: learn how we process hazardous and toxic distillation residues and recover the valuable TDI monomer.
Language: English / Year: 2019
Consistent with the diversity of chemical-process-industries materials that undergo drying, a wide variety of contact dryers have been brought to the marketplace. However, there is a common set of principles for their process design, and for specifying them.
Language: English / Year: 2003
Large volume kneaders are designed to handle highly viscous polymer processing. The unitary operations can be compounding, polymerizations, devolatilization or drying. Depending on the polymer viscosity in the kneader, the interaction of kneading elements induce a torque and force evolution on the shaft over one revolution.
Language: English / Year: 2006
Over time, different types of reacotrs have been developed in order to improve the stability of the polymerization process. This article Reviews those reactors designed for heterogeneous and homogeneous polymerization. It then explorres the production of solid polymer granules directly in a kneader reactor under evaporative cooling, which is seen as an efficient and reliable polymerization Technology.
Language: English / Year: 2001
