Screw extruder is the processing technique with plastic industry the widest application, nowadays, field application is entered directly after the plastic raw material of about 40% gives treatment through squeezing. 3 screw extruder is to be on the foundation of thorough to pushing a technology research, exploration accumulate via old technique accumulate the new model that moves toward field. Development and manufacturing practice make clear, the innovation that 3 screw push a technology makes the model of equipment is changed, mix the refine, effect that take off brandish to increase significantly, perspective of field development is wide. Screw kind the development course that extruder fettersed to already was experienced more than 100 years, had gone by arrive simply complex, arrive to develop a process efficiently by small effect, machine if pursue,planted development can be generalized 1. Among them, 3 screw extruder is in last few years the new model of ability face , include two kinds of type that form what the word arranges with the triangle. The model that the innovation on these technologies makes press a facility is changed, the ability that mix refine gets be strengtheninged further, energy-saving fall also have on bad news rise certainly. Press a facility and character, odd screw extruder does not have region of engagement, double screw extruder has a region of engagement, the 3 screw extruder that one word arranges has two region of engagement, trigonometry arranges the complete clench the teeth of form 3 screw extruder has 3 region of engagement, if pursue,2 are shown. The existence of 3 region of engagement, make stock endures cut frequency twice to rise, be in to stock undoubtedly the random of interface of the exchange of change of flow direction, velocity of flow and dimensional position, fuse-element changed a respect to produce beneficial effect. Trigonometry arranges the complete clench the teeth of form the simple combination that 3 screw extruder is not 3 odd screw absolutely. Learn to be told with kinematic angle from geometrical structure, between screw and the dimensional structure that forms between screw and machine canister is complex, once 3 screw of mutual clench the teeth run rise to be equal to be run at the same time at 3 pairs of double screw, the athletic contrail on 3 screw and its place endure stock cut action to compare its what what experience on double screw is complex much, form of going from place to place also has very big different, if the athletic contrail of imitate earning pursues,3 are shown. Graph the 3 individual particle showing trace that state 4 position of rest are different respectively (the red dot in the graph) has different motion contrail, advancing the final and located position after the axial of 30mm is apart from. The description of contrail of afore-mentioned motion of the typical particle that show trace explains, stock is given in 3 screw extruder there is motive of different field of force below hot condition, especially of 3 region of engagement cut, to be being machined the particle of each constituent in material is changed, the action result of leveling, odd screw and double screw squeeze a system to be able to not be offerred. Be the athletic contrail on much level of this kind of space, make stock is able to exchange adequately; Make the sheet that 3 screw extruder can grow diameter to compare greatly than obtaining with shorter long way, double screw crowded those who give conditional ability to obtain good distributing dispersedly mixture effect. The research transmission system of special transmission system and axial force allocate the crucial skill that trigonometry ranks research and development of 3 screw extruder to need to solve the research design of box is the technical key that trigonometry arranges the 3 screw extruder of form, it is the premise condition that realizes 3 screw to stabilize movement. Compare with double screw extruder, or the 3 screw extruder that arranges with one word is compared, trigonometry arranges the construction of system of transmission of 3 screw extruder of form to go up more complex, design difficulty is greater; The triangle of 3 screw arranges demarcate the design space of gear and bearing, formed a space to the structure is designed and run life of two respects restrict and contradict. The research of double screw extruder, design, make, use there already was 20-30 in China year the history. If say, the limitation that the research and development of double screw extruder is apart from by screw center, make installation deserves to compared gear and thrust bearing to get the confine on dimensional size, this kind of confine and difficulty are behaved more outstandingly on 3 screw extruder, if pursue,4 are shown. If why undertake inside limited space the structure is designed optimizing, make 3 screw synchronism runs, and rotate speed is stable, even, assure to bear the weight of force and service life, on exterior dimension unapt too giant, become the main problem that this technical stress captures. Study group of comprehensive and Baconian, analysises at present the structure of system of transmission of extruder of foreign double screw, if German Leistritz company is mixed,what the output level of the double screw extruder of Bandera company uses is inside transmission; What the double screw extruder of Japanese Toshiba company and German Berstorff company uses is drive of double clench the teeth. Project group will outside tine drive, inside in the design that the design concept of tine drive and union of photograph of drive of double clench the teeth uses at system of transmission of 3 screw extruder, break through a center to be apart from definitive space on one hand, assure the bear the weight of and delivers torque capacity of system of transmission of 3 screw extruder effectively on one hand; Make whole designs better land give attention to two or morethings bear the weight of, the technology such as torque allocation and service life is characteristic. Screw geometry studies geometry discharges cloth geometry is the science of cloth of platoon of position of research component space, appearance, size and interaction, a kind of machine should realize regular job, must satisfy certain geometrical requirement. To 3 screw extruder, besides wanting to satisfy specific geometrical requirement, still need to consider the degree of clench the teeth of screw and direction of rotation; The formation that this decided final whorl curve again mechanism of principle, action and character. According to geometrical structure, the form discharging cloth of 3 screw can be like a graph 5 show: One word is arranged, V glyph is arranged or be the triangle is arranged. Among them, the one word of 3 screw is arranged and V word is arranged (graph the A of 5, B, C and D) , it is OK also that screw can turn with Xiang Xuan different Xiang Xuan turns, but have two region of engagement only. Because be the same as to with curve of grain of different Xiang Luo generate a principle to differ, trigonometry arranges the different Xiang Xuan of form to turn 3 screw extruder, among them a pair of screw can tangent cannot clench the teeth (graph 5e) , realize complete clench the teeth impossibly. From geometry for, trigonometry is arranged 3 screw extruder can make the complete clench the teeth of form turn with Xiang Xuan only (graph 5f) . Whorl head number, phasic the complete clench the teeth that should realize 3 screw with hands-off movement condition is hands-off movement, whorl head number is not aleatoric. Number of this technical whorl head is 3 or only head, and phasic difference is two screw end panel 0 ° . 3 screw cannot satisfy whorl of Nextpage double head hands-off movement condition. According to the principle of clench the teeth of double screw extruder, component of double head whorl should realize hands-off movement, difference of two screw starting phase is 90 ° . The 3 screw extruder that uses this one requirement at the triangle to arrange is unworkable, the reason has 2: 3 screw that are double head whorl each other cannot at the same time mutual and perpendicular, 2 it is the metropolis below any phasic conditions has interference, if pursue 6. Should avoid double head whorl the interference of 3 screw, need to adjust screw center to be apart from, make upside two screw are tangent it is one of plan, if pursue 5 (E) , but can form two region of engagement only. When the correction that waits for clearance clench the teeth should realize 3 screw synchronism to run on real significance wait for clearance clench the teeth, theoretic must set out from geometry of dimensional curved surface, to the outside face edge of screw each choose a magic art to undertake correction, what this task uses is curved surface law to correction law, acquisition clearance is like graph 7b. In actual production, after the syncretic of whorl component group with different lead rises, although screw clearance is even, but the end panel figure that joint face manages however cannot complete be identical, if pursue 8. The method of commonly used burnish in the project will make up for, but this insoluble basic problem, because change,this is planted after combination abhorrent appear possibly still again. The means that research group offerred to adjust curve of snail chamfer flank will reduce error of end panel joint, this one process calls error of end panel joint to amend, its effect is apparent. To different screw parameter, can reduce this one error 30% less than commonly. Graph structure of characteristic of correction technology of error of union of 8 end panel is unusual 3 screw of the combined-type machine canister that the 3 screw extruder that this technology develops a note of the ancient Chinese five-tone scale wears by follow in a continuous line of gearing, 3 opening, complete clench the teeth and nose composition, its structure is unusual a note of the ancient Chinese five-tone scale is: 3 screw show 1) the triangle is arranged; 2) the diameter such as 3 screw, wait for long, complete clench the teeth; 3) 3 screw are completely active, turn with Xiang Xuan; System of 4) special transmission. 5) screw is building blocks combined-type, whorl component includes, retrorse whorl component and mediate dish component, change screw combination can get used to a variety of material and craft. Specifications is special after 3 screw arrange the action with peculiar area of center of a note of the ancient Chinese five-tone scale triangularly, formed 3 region of engagement and division of a center. Central area is trigonometry forms the area with the 3 screw particular extruder of form, looking in axes direction is the area that a sectional area changes circularly. Research is earlier, to its action has bigger doubt, think to form bigger circumfluence and sluggish to flow likely. The behaviour that studies the group is potential to central area undertook imitate is analysed. By the speed vectorgraph of central area 9 can see, when the area is the largest, central area existence is circumfluent, area most the hour is done not have such circumfluent. Imitate computation is knowable, the particle of 95% can pour out of model area inside 5 seconds. (The existence when A) area is the largest is circumfluent (B) area most the hour is nonexistent circumfluent graph the periodic change of area of area of center of vectorgraph of rate of 9 centers region, formed those who be similar to pump to suck close, take in and send out in large quantities action. The experiment makes clear, below the circumstance that opens wide nose, the fuse-element of central area with " a string of beads " the form is carried ahead continuously, if pursue 10. Actual measurement makes clear, this one flow of central area occupies the 8%-10% of total sendout. This to fuse-element to carry, voltage build-up has clear active sense. Graph the extruding pump of area of center of extruder of 10 3 screw sends however, just come out as a result of 3 screw extruder before long, research returns the accepted theory about central division function to was not formed at present, carry to fuse-element, mechanism of action of melt, compound still needs thorough research. Nextpage is cut with cut a number by the graph 11 can see, what 3 screw extruder sheds the of 92% particle in field to endure is the biggest cut rate to be centered inside 0-1250; And what double screw extruder sheds the of 90% particle in field to endure is the biggest cut rate to be centered inside 0-750. Can see by the analysis above, the stock in 3 screw extruder is endured the biggest the range that cuts rate to distributing is wide extruder of Yu Shuang screw, the dispersive mixture ability of the 3 screw extruder that this shows identical screw parameter likewise is good extruder of Yu Shuang screw. Realize expensive stuff to be with the preparation of bead of carbon black mother easily exemple, the accretion of the carbon black when at present extruder of groovy double screw squeezes a bead of preparation black female is measured normally under 35% , prep above this scale often passes because of instantaneous torque big and occurrence blame is normal stop machine. Of craft of pump of fuse-element of ＋ of reciprocating type odd screw highest add a capacity for 44% . Industry thinks consistently to add the technology with higher volume to adopt tall mix after be being mixed first, by refine of close refine secret, cool stock again broken join double screw extruder to undertake building bead, some still needs to go out via be being squeezed twice build bead, additive carbon black content is highest for 50% . Apparent, use lubricious mother of high concentration of preparation of this kind of craft to expect, what require equipment much, working procedure is much, time-consuming long, cost can be high, efficiency is low, cost is high. Use this technology, after be being mixed at the beginning of mixer of classics high speed, squeeze directly piece build bead, realized the preparation of bead of mother of carbon black of 55% high concentration conveniently, what use device little, working procedure is simple, specific power consumption is low, efficiency is tall, cost is low. Take off extruder of the sheet with advanced brandish, double screw to distribute system of stock vacuum exhaust about exhaust, in order to takes off brandish, exhaust, dehumidify, ensure product quality. However this has to craft condition strict slashing even requirement, if screw structure dimension is designed (namely pump compares a design) strict requirement, exhaust paragraph the reasonable adjusting control of around craft temperature, otherwise vent is risked easily makings, need to often clear; If Shu Yuqing manages, can block dead gas district up, make vacuum exhaust system cannot produce effect. Trial production makes clear, use 3 screw to push a technology, can prevent vent effectively to risk makings, raise exhaust to take off brandish effect, and do not have afore-mentioned strict requirement to craft condition, this brought huge advantage to treatment production, the makings cost that avoided craft to feel index to rise greatly, specific power consumption, man-hour, manpower and maintenance are measured. Dispersive, distributing those who mix the carbon black in the preparation that evaluates mother bead is the most difficult dispersedly, carbon black concentration is higher, disperse harder even, to carbon black itself be changed imperceptibly and can disperse sexual demand is higher. Use 3 screw extruder, right with carbon black (brand: 326) fill spends the ZSK Φ 25/40 that is in the 3 screw extruder of Φ 60/20 and Φ 65/24 and WP company respectively for the LLDPE data system of 55% squeeze on double screw extruder piece build bead, again right afore-mentioned mother bead section, have lens of TEM transmission report, use image of German IBAS I/II again (granuality) analyzer undertakes granuality is analysed. By the graph the transmission photograph of 12 is mixed the picture looks on 13 particle size distribution, appearance of the particle in photograph of transmission of 3 screw sample and photograph of transmission of double screw sample and granuality size, distributing dispersedly namely mixture result is almost same. Than specific power consumption about comparing specific power consumption, according to document statistic, 80 time metaphase compares the century on homebred model machine specific power consumption is about 1. 8-2.
4KWh/kg, 90 time fall for 1.
2-1.
4KWh/kg, be equivalent to international the corresponding period the 2-3 of advanced level times. Foreign traditional engine, 90 time are about than specific power consumption 0.
4-0.
53KWh/kg, average 0.
464KWh/kg. We contrasted below same technology condition 3 screw of 65/24 of extruder and double screw extruder than specific power consumption, adoption double screw extruder is ZSK 25/40 model. In preparation polypropylene (F401, MI=2.
5) when mother bead, screw rotate speed by 50 ～ 220rpm, of 3 screw extruder it is than specific power consumption 0.
23 ～ 0.
26KWh/kg, of comparative machine it is than specific power consumption 0.
25 ～ 0.
27KWh/kg, former those who compare latter is lower than specific power consumption 5% . Comparative data explains, 3 screw extruder is more apparent than specific power consumption under level of traditional engine of 90 time abroad. Analytic reason: Because the screw of 3 screw extruder grows diameter to compare,be on one hand short, the double screw extruder with length groovy comparing about short 1/3 to 1/2, this to specific power consumption reducing is remarkable; Be attributed to the geometrical structure with 3 screw peculiar extruder even on the other hand, put in 3 region of engagement and central area namely, the space that stock flows freely in machine canister interior increases, conduce to the torque that reduces screw, reduce specific power consumption thereby. The sense of 3 lever extruder that this task group develops and university of foreground Beijing chemical industry began research and development 2000 3 screw extruder, mix to August 2005 Φ 60/20 was mixed in December 2005 Φ 65/24 the two industry prototype of two kinds of norms comes out, be debugged successfully and trial production. In the research practice that goes 7 years, below the joint efforts of cooperative unit, finished by " new conception, screw geometry studies, dynamic imitate, the design is developed, circulate an analysis, industrial chance " research process, produce can, had more comprehensive research than specific power consumption, mixture character. On August 11, 2006, this technology passed the appraisal of achievement of science and technology that Ministry of Education is organized and chairs, appraisal conclusion is " domestic and international initiate " , the technology is " international is advanced " . The innovation that is based on trigonometry to arrange the 3 screw extruder of form to go up in theory and practice, and advantage of brings a lot of technology, the personage inside course of study and expert very value this one project, a when consider as pair of existing polymer treatment equipment and technology great complement and development, hopeful is Chinese plastic treatment domain of a lot of heat is offerred be badly in need of equiping, drive China to be changed in general and plastic function greatly, the project is plastic high-powered change, the research of the high-end domain such as bead of mother of material of electric high polymer, expensive stuff and industrialization. By afore-mentioned is opposite 3 screw extruder is peculiar the analysis that squeezes a character, can win following verdict: 1, compare with the double screw extruder of identical screw parameter, the many region of engagement of 3 screw extruder, fuse-element endures cut frequency twice to rise, 3 screw extruder is the biggest cut rate to distributing range is wider, mix ability dispersedly from what cut dispersive angle to tell 3 screw to compare double screw strong; 2, because stock is on 3 screw,complex athletic contrail and space are exchanged, be helpful for obtaining filler in data system distributing equably; 3, 3 screw extruder pushs a performance peculiarly, make its can achieve favorable plasticate result with be being compared relative to short long way, and whole function bad news is inferior; 4, the particular function of the interact of 3 screw and central area makes 3 screw extruder has better adaptability to expensive stuff craft, can satisfy efficient ask with what turn production continuously. CNC Milling
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