LCM CC & TCC A member of the Possehl Group
LCM LONG CONTINUOUS MIXERS These continuous mixers compete with the quality level of products obtained by discontinuous internal mixers. They overcome both processing limitations of traditional short continuous mixers as well as mechanical limitations of twin screw extruders. The unique principle of operation allows continuous production of critical highly filled products with outstanding dispersion even at high capacity. Easy maintenance and long life of the equipment is in line with today requirements of Customers. Most part of the energy is given to the processed material by the variable speed / constant torque motor. The LCM operates at low pressure and continuously discharges the mixed and melted material to a second stage of process, usually performed by a single screw extruder. Rotors are 10 L/D long, tangential type, counter rotating at even speed. They are supported at both ends by lubricated bearings, and are bored for temperature control by water circulation. Rotors profile is continuous and is exactly the same for all kind of applications. The body has one single feed hopper, one heated discharge orifice with adjustable gate (PTFE-lined) and an atmospheric degassing venting section. Gas Barrier Seals and lubricated Self Sealing Visco-Seals are installed to prevent leakage at mixer inlet and discharge, respectively. The processing section is equipped with removable liners made by hardened materials for highest wear resistance; it has three zones with independent temperature control, by mean of electrical resistances for heating and water circulation in the drilled chamber for cooling. TECHNOLOGICAL ADVANTAGES LCM offers an additional mixing section and transport section compared to the rotors of traditional continuous mixers. In this added mixing section a unique and patented process is carried out before melting the polymer: different raw materials (separately fed to mixer hopper) are pre-blended, pre-heated and the energy of colliding polymer particles is transferred, directly and precisely, to the powder in order to efficiently break its agglomerates. This is the so-called Ball Mill Effect. In the second mixing section the material undergoes several mixing mechanisms as: Milling: intensive shear action between rotor tips and chamber wall Longitudinal cut-back: material is pushed forward and backward along rotors axes Kneading: rolling action between the two
CC COMPACT COMPOUNDERS Following their experience and success obtained by their LCM, POMINI Rubber & Plastics can offer a complete prepackaged unit for compounding called CC: Compact Compounder. The package includes the LCM and a single screw extruder with pelletizing or strand head, designed to have a unit both compact and versatile. Installation is simple and floor space is not greater when compared to a single stage machine. In addition to the vent port at the end of the mixing chamber, an additional vent port is available in the post-mixer extruder which can be fit to a vacuum pump to thoroughly complete degassing. rotors to enhance distribution Lateral overlap: interchange of material between rotor chambers Energy transfer in the LCM is so diluted over the whole processing section of the mixer and the amount of energy transferred in the final melting section is reduced. As a consequence, no geometry optimization is required: it remains exactly the same for different applications. Position of melting section in the mixer, temperature of discharged material as well as the quality of produced mixture are a function of operating variables: Throughput (kg/h), Screw speed (RPM), Orifice opening (%), Temperature set-up (T). Advantages offered by LCM when compared to traditional short mixer are: Higher filler amount combined with higher dispersion level Higher versatility Single rotor geometry instead of different styles for different formulations Comparable residence time in the melt state in the mixer (below 30 seconds avg.) Temperature of melt at discharge, at least, 10 C lower
TCC CONTINUOUS COMPOUNDER TCC is designed to combine the advantages of counter rotating, non intermeshing, two-stage continuous mixers with those of gear melt pump for pumping and pelletizing. TCC offers higher productivity and versatility, lower energy consumption and under vacuum degassing capabilities when compared to two stage mixers and heavier duty design and simplified construction when compared to the twin screw technology. The continuous mixer at its discharge end generate a pressure of only few bars. The melted and mixed product flows from a specifically designed orifice to a gear pump. The orifice is equipped with a diverter valve, hydraulically operated, that can be used to start-up and shut-down the line. The distance between mixer discharge and inlet of gear pump has been reduced to the limit and the resulting layout is extremely compact. As a consequence, the volume of melt and relevant residence times in the equipment are reduced. The comparison with conventional technologies gives an overall improved picture, able to fulfill the requirements of the highly sophisticated market of new plastic products. The TCC is based on a starved-feed tangential continuous mixer. Rotors are 8 L/D long and counter rotating at even speed, they have independent temperature control and are supported on lubricated bearings on both ends. Mixing chamber can be equipped with liners for highest wear resistance and has three zones with independent temperature control, (electrical resistances for heating and water circulation, in the drilled chamber, for cooling). Two valves have been introduced to modify the specific energy input and therefore to increase the possibilities for an optimal set-up for different formulation. The mixer has two hoppers, one in the main inlet and a secondary one after the first valve. The hopper for the secondary feeding is provided with an inspection window. Main feature of this second feeding section is that it can be used to feed raw materials directly to the melt while performing and atmospheric venting or as an under vacuum degassing section. MAIN FEATURES SEI REGULATION VALVES The mixing chamber is equipped with two SEI (specific energy input) regulation valves. The design of these valves guarantees the absence of dead volumes and self-cleaning capabilities. The set-up of such valves allows the process engineer to modify the specific energy transferred to the material up to ± 20%. GEAR PUMP SEI valves stabilize the filling factor in the process section of the mixer. The melt is fed to the inlet of a gear pump that acts as a booster increasing the pressure to screen the material and then to feed a pelletizing head. The gear pump inlet section has been optimised to accept low feed pressure. Main features are: low speed, high efficiency and low energetic requirements.
AUTOMATION POMINI Rubber & Plastics automation packages, based on the most advanced information technology tools, are customized in order to satisfy the specific needs of each Customer. They manage a single production unit (e.g. the Long Continuous Mixer) as well as complete line, from silo loading up to the discharge of finished products in the warehouse. The control manages process for automatic start-up, operation, shut-down. Main target is to guarantee repeatability, consistency, logging and analysis of the line operating condition data, in production of all different formulations processed by the line and set by technologists. LCM Each local unit is supervised by a PC and is connected through LAN (Local Area Network) to a central server that manages all the data. Data are available to production control, technologist, laboratory, etc. as soon as collected. POMINI Rubber & Plastics Supervision System provides, under windows user-friendly environment: Synoptics in real time Editing of recipes and production schedules Graphics in real time Reporting Historical data analysis TCC
POMINI Rubber & Plastics srl Via Leonardo da Vinci, 20 21053 Castellanza (VA) Italy Phone +39 0331 743111 Fax +39 0331 743204 info@pomini-rp.com www.pomini-rp.com That s why I choose Pomini A member of the Possehl Group