The Hosokawa Alpine TFG Toner Fluidised Bed Opposed Jet Mill is a very specialist multi-tasking impact mill and air classifier combination purposely engineered for the effective fine comminution of materials used to create premium-quality printer toner, coloured pigments and hard-wearing powder coatings.
The robust and efficient TFG jet mill is closely related to Hosokawa’s pioneering AFG Fluidised Bed Opposed Jet Mill, which transformed powder processing by jet milling when it was launched in 1981.
Using our patented Megajet® nozzles and high-speed jets of air to cause rapid and intense interparticle collision of fluidised materials in the grinding chamber, the TFG range produces free-flowing, dry and superfine powder from approximately 3.7µm to 80µm with the assistance of its patented, integrated ultrafine classifier, which ensures a consistently high precision cut and an exact top-size limitation.
The TFG Toner Fluidised Bed Opposed Jet Mill has a number of technologic and ergonomic advantages that assist precision batch processing operations for coloured powders and coatings, not least a hydraulic mechanism for the wear-protected classifier wheel, making it easy for the operator to swing the classifier through 180° to facilitate excellent accessibility for quick cleaning and maintenance of the equipment and faster product changes, monitored load cells and classifier to check product levels, excellent product loading capabilities to improve performance and product quality and a flat grinding chamber, ensuring only minimal amounts of unground material remain in the equipment.
The specialist Hosokawa Alpine TFG Toner Fluidised Bed Opposed Jet Mill is the perfect solution for finely grinding materials, such as temperature-sensitive resin blends and polymers, in order to manufacture the highest-quality toner cartridge powder for laser printers and other complex fine powders used for coatings and colourisation.
Currently available in five standard sizes, the TFG jet mill models, between them, feature either three or four grinding nozzles and a size appropriate patented TTSP ultrafine classifier wheel. The range offers comminution between approximately 3µm to 80µm (depending on the model chosen). The smallest standard model in the range (TFG 400) can typically process powder between approximately 3µm and 30µm, while the largest TFG 1000 model typically handles material between around 6µm and 80µm.
The polished stainless-steel TFG jet mill is very closely based on the innovative technology of Hosokawa Alpine’s original AFG Fluidised Bed Opposed Jet Mill, which revolutionised the powder processing industries when it was launched in the early 1980s.
Ideal for processing powder that demands an exact top size limitation and as few out-of-spec fines as possible, one of the TFG’s many plus points is the capability to process heat-sensitive materials into fine powder with a low melting point, which, in the case of toner, permits faster and more energy-efficient laser printing and a better-quality print.
Perhaps the TFG’s best engineering feature, though, is its incredibly practical design and, in particular, the extremely efficient classifier wheel, which can be hydraulically lifted and moved through 180° to permit the quickest and most efficient cleaning and maintenance of the milling chamber between colour changes.
Special Design Features
The TFG Toner Fluidised Bed Opposed Jet Mill has been specifically engineered to process dry, free-flowing printer toner, hard-wearing powder coatings and a wide variety of premium-quality pigments and dyes more practically and effectively.
The TFG combines jet milling and classifying technology to manufacture incredibly fine powder compounds with a very narrow particle size distribution from a wide range of raw materials, including minerals, metals, wax, resins, ceramics, carbon, rare earths, metallic compounds and salts.
Resins and other heat-sensitive materials used to make high-quality laser printer toner, in particular, demand very specialist equipment design and engineering to produce a super-fine, consistent powder with the necessary lower melting point. These characteristics greatly contribute to the excellent performance and speed of laser printers.
End products that also benefit from the highly specialist processing capabilities of the TFG include ceramic pigments for making coloured tiles, sanitaryware, tableware, glazes and glass, as well as deeply coloured pigments and dyes for use in thousands upon thousands of everyday products such as paints and printing inks, primers, plastics, powder coatings, food packaging, toys, kitchen appliances, oil, gas and water pipes, lighting fixtures, electrical cabinets, automotive parts, aluminium doors and windows, road signs, ski poles, exercise equipment, radiators, patio furniture, glass, garden tools and durable, protective car finishes.
The high-performance Hosokawa Alpine TFG Toner Fluidised Bed Opposed Jet Mill is used for batch processing materials used to manufacture premium-quality printer toner, pigments and powder coatings. The super-fine, free-flowing dry powder is in the range of between approximately 3µm to 80µm, depending on which of the five models is used, and requires a very specialist piece of equipment and a highly complex process system to achieve the best result.
The jet milling concept deployed by the TFG is based on a combination of product fluidisation, high-speed impaction, pressure and temperature and the use of compressed gas exiting the three or four, equally spaced, Megajet® nozzles at an accelerated rate. The compressed air expands as it exits the special Laval nozzles at more than the speed of sound and creates kinetic energy from the heat generated, which is used to comminute the feed material in the grinding chamber.
Laval nozzles have a very specific hourglass shape, whose divergent part can be lengthened to suit the operating pressure. Gas and material are extremely rapidly drawn from the grinding chamber’s fluidised bed. Milling occurs as our patented, evenly and closely configured Megajet® nozzles create an under-pressure in their core area. Material particles collide together in the jets of air and the core area where the jets of air intersect.
Typically, the compressed air used in the TFG is around 20°C and 6 bar overpressure is frequently used for the grinding gas. Nozzle exit speeds of around 500 metres a second are normal for the compressed gas, while the equipment is designed to be pressure and shockproof to 10 bar overpressure.
To increase the performance of the TFG, the nozzle jets have a very high loading capacity, meaning that an optimum amount of particles can be processed at one time. The high concentration of particles results in more efficient, stronger impact probabilities. Better interparticle collision causes a higher concentration of finer powder.
Hosokawa’s jet mills are a kind of impact mill and require the addition of a dynamic, deflector-style, air classifier wheel with support to achieve the maximum levels of powder fineness our jet mills are renowned for. The wheel speed is easily adjustable so the fineness level required can be accurately set with an exact top-size limitation and minimal out-of-spec material.
Any rejected particles that remain too large to continue in the process are transported back to the fluidised bed, where they will go through a regrinding process, while particles that are fine enough are separated from the grinding gas by a dust filter or separator.
The specialist TTSP Toner Classifier has been developed especially to double-classify and dedust toners and pigments and is the air classifier of choice to complement the TFG. Replete with a stabilising support, the patented TTSP Toner Classifier classifies material in a two-stage process and discharges the in-spec material for further processing, while any remaining out-of-spec material is conveyed to the coarse material discharge. Three-fraction classification is available for special toner applications, with a special second stage classifying wheel and a system configured for the collection of the toner powder, dust and coarse particles.
Product levels in the TFG mill are monitored and controlled by load cells and the monitoring of the incredibly efficient TTSP classifier wheel as it processes.
As with the jet mill itself, the TTSP ultrafine classifier has been configured to be easy to access for cleaning and maintenance, further reducing the machine downtime generated by the overall milling and classification process.
Subsequently (depending on the type of powder being produced), dedusting, coating and sieving processes might be required, while mixing and pre-grinding of material may also be needed prior to the TFG’s fine grinding step. Additional equipment, ancillaries and complex system designs to achieve all of these processes can be designed, engineered, manufactured and supplied by Hosokawa Micron Group.
For further information, please see the Process System Solutions section. Alternatively, feel free to get in touch with us on +44 (0)1928 755100 or complete our short enquiry form – we would be delighted to help you choose the perfect fluidised bed opposed jet mill equipment or jet milling process system for your needs.
The high-performance Hosokawa Alpine TFG Toner Fluidised Bed Opposed Jet Mill can be supplied as an individual high-impact jet mill but may also be supplied as part of a complex, tailor-made process system for specialist multi-process manufacturing of end products such as ground toner, as well as for the manufacturing of the finest powder coatings and pigments.
Chosen by a wide variety of global manufacturing industries – including the printing, automotive, construction and household goods sectors – the quality of the powder produced by the TFG Toner Fluidised Bed Opposed Jet Mil and complementary process system helps to contribute to the processing performance, wearability and visual quality of many thousands of everyday products, including laser printers, cars, tableware and exercise equipment.
The TFG Toner Fluidised Bed Opposed Jet Mill has been specifically adapted from the classic Hosokawa Alpine AFG Fluidised Bed Opposed Jet Mill to very finely process the raw materials needed to produce the highest-quality coloured toner powders for use in laser printers.
Hosokawa Micron Group has extensive experience of pioneering innovative powder processing techniques and equipment – in fact, we introduced fluidised bed opposed jet mills to the market as long ago as 1981. We can supply every piece of specialist equipment required to build a high-performance, technically very complex, process system for the specialised printer toner market.
Complex multi-process systems for challenging ground toner
Superfine powders required for printer toners are made with polymer powder, which are compounded with cyan, black, yellow and magenta colourant, charge control agents and wax. The mixture is then cooled and solidified so that it can be milled and a flow control agent added. For a 1200dpi print, you would be looking at achieving a powder fineness of around 5µm.
Because of the nature of the printing process, the printer toner particle levels need to be uniformly precise to successfully overlap and create a clear, high-quality image. To achieve excellent printing quality throughout the entire printing process, other key printer toner characteristics required include a very small particle size, low melting point, roundish shape, excellent flowability and sharp particle size distribution.
Milled printer toner goes through four processes – mixing and pre-grinding, fine grinding, dedusting, coating and sieving – and combines around fourteen pieces of equipment to create the process system, which can be tailor-made specifically for your requirements. Components might include a Cyclomix, cooling belt, compressor, blower, the TFG Toner Fluidised Bed Opposed Jet Mill, an Optisizer, Cyclone, TTSP Toner Classifier, sieve, a filling and weighing system and bulk container handling equipment, all of which can be supplied by Hosokawa Micron Group.
The TFG Toner Fluidised Bed Opposed Jet Mill is involved in the second, fine grinding process and its innovative technology has become more and more important to the toner industry as printers have become faster, more energy-efficient and require even better colour reproduction performance. The addition of an integrated classifier removes the need for a separate course classification step downstream and contributes hugely to the overall quality of the final laser printer toner product.
Hosokawa Micron Group – Complete lifecycle solutions for manufacturing high-quality powder
Trusted across the globe by world-leading manufacturing companies, Hosokawa Micron Group is best known for its pioneering equipment innovations and game-changing powder processing techniques. These innovations are complemented by a first-class in-house project management and engineering service – from feasibility studies, product testing and initial design conception to equipment delivery, commissioning and maintenance.
Our powder processing equipment portfolio is underpinned by extensive lifecycle management services and friendly, efficient customer care to support you during the decades of service you can expect to enjoy from Hosokawa Micron Group equipment and process systems.
The exit velocity of the compressed gas used by Hosokawa Alpine’s TFG Toner Fluidised Bed Opposed Jet Mill Megajet® Laval nozzles is greater the speed of sound.
Used to communise toner materials, our specially designed, patented Laval nozzles have an hourglass shape, which widen downstream of the narrowest cross-sectional point. The length of the divergent part can be adapted to suit the operating pressure and, typically, the exit velocity of 20°C compressed air is around 500 metres a second.
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