Introduction to nine key eleme讀畫nts in the process 書商of plastic extruding

Today, in order to col友長or printing packaging 又低plastics extrusion laminating 村綠film manufacturers,知小 if you want to try to save 窗內the production cost, improve妹有 product quality and effectivel費明y and give full play to the pe你好rformance of the plastic e微件xtrusion equipment, must grasp the ke場姐y elements of the見答 extrusion process.

Key words: save the cost of production 我雪Improve the quality of produ公吃cts Master the ke什冷y elements

Each plastic pr是章oducts production and processing ente務姐rprises, especially given priority 聽技to with color printing plasti男間c extrusion composite packaging說都 film production of plastic factory鄉很, every senior technical management per到遠sonnel, must want to kno跳紙w your business very well products to 物市raw material properties, processing tec數很hnology, the performance of the 議著extrusion equipmen化用t, product quality 好家control, productivity,對飛 lower production costs and some other 術愛related factors, howeve藍都r, in the many factors, one thin吃很g is most important. Nam日計ely; Nine important 姐這element of extr吧做usion production proce對廠ss. This is every composite extrusion 電市plastic manufacturers, technic木快al management personnel at all le近農vels must firmly見照. For this, we groped山場 through years o空就f research, finally in the 鐵山extrusion production technology have so說紅me shallow knowledge, th答這e topic, for you行國r reference.

First, fully un做東derstand the de內靜sign requirements of extruder sc雨舞rew

Each extrusion laminat外水ing film manufacturers, in the us開草e of their own extrus友報ion machine, first to fu生工lly understand the important輛草 of screw all related to the舊問 number. We know extruder scr路技ew design is very importan會身t, even to buy a new screw, als照熱o want to be sure that t呢日he purchase of extruder screw design,慢外 whether to conform to 又很the shape you want, function, material,吧喝 and can speed the required screw. Suc服唱h as, need to buy a少她 used for the extrus女她ion of PE screw 窗坐extrusion film, you should民火 know that it's m放裡aterial, heat treatment, and screw the站麗 screw thread and must compl到劇ete some functions, for examp內短le, continuous adding resin現女, uniform melt resin林金, stable injection liquid h就海omogeneous mixed resin and workin通司g cycle, such as器快 amount of materi跳路al, material bolus geomet女子ry, back pressure and screw g知聽eometry. There mus紙錯t be a set of screw熱大 function used in the 看大display of data and parame湖舞ters. Because, in today's world,讀什 computer simulation te車低chnology is easy and should be used fo綠媽r simulating all the 弟靜screw, and unless you can get is suitab錢來le for the actual行子 situation of the related data of t船雪he same material.

Because each scr明河ew wear is related to t下讀he design of the screw, a街日 screw was wear is not necessa花時rily a bad screw, som朋信etimes wear even民要 good for cylinder mixture, or明和 when the pressure peak is beneficial信土 to increase product白她ion, it is good to d朋道etermine the position of the we歌站ar and tear, and the reason. Bu關電t the actual need of wear is i可姐n trouble, that f議得or a given input interface, is likel文窗y to mean that need higher me雪煙lt temperature.

At the same time, 明件we must grasp the deve匠器lopment situation o數農f the screw desig務媽n, because the curr線們ent by extrusion production factory is 窗鐵one of the most popular gener家他al screw, the manufacture刀那rs in the production of seve身動ral kinds of raw村視 materials for each, can be un飛也iversal. But must grasp說少, understand the general screw compress那熱ion screw is a kind o樂嗎f thread, a feeding拿去 section, a compression sect唱家ion and a metering sect跳愛ion, respectively acco離呢unted for 50% of the total le話空ngth of screw threa國聽d, 25% and 25%. Screw thread 醫人spacing is equal 拿區to its diameter, the scr懂道ew threads of the 報器tooth width is equal to 1/10 of its 是遠diameter. The taper machining of t微森he compression s白錢ection is gradually花劇 open, can produce comp他務ression ratio 2:1 to 3; 1, the 很科calculation method is to use the c費黑harging period div匠農ided by the measur知做ement of screw thread depth depth. Leng訊員th of screw thread, and the screw 校算diameter than the diameter L/器物D ratio is now ~ 24:1.

This kind of narrative without char票線ging depth and th公動e depth of measurement, i熱個t were not for the depth, compress些謝ion ratio is meaningless. From di音土fferent extruder manufac學黃turers provide the screw feeding 計劇depth range between 6 mm and 10線山 mm screw is easy房術 to see that the screw i門司s 60 mm, raging, L/D, GP (general 低坐screw). These influen但行ce depth value material fill化草ing and conveying, the文志 number of existing pla跳飛stic screw cavity, material through錢筆put, shear rate and the ove多也rall quality of the melt. Regardless火綠 of the screw of the exact depth, 謝物length, thread tooth width, by a sc子廠rew or brought in the effec作到tive value for industry. T北司he key is the gener女下al screw extruder風女 used, and two elastic features s年請et a direction for its future她村 application. Features a is u玩商nder the condition of wi得機thout destroying th村新e polymer performance, the民湖 function of the screw design, accordi和會ng to a variety購我 of cycle and quan的司tity of materials handling 就北all kinds of resin, characteristi日鐘cs of the two is the general scr銀西ew design manufac信地turing is the cheapest舞好 screw design.

The basic principl銀鄉e of extrusion plastic著醫 - each screw rotation of the cyl唱木inder and the plast照國ic to push forward. Screw is actu火新ally a inclined plane or 區快slope, wrapped a就去round the center layer. Its pu腦匠rpose is to increase the pr高廠essure, in order to ove數短rcome the resistance of the la木唱rger, because, for each o劇議f the extruder, with resistance will n樂為eed to overcome. Solid p答資articles of wall fric我兵tion laps before the screw rotation, t身嗎he friction between them, the screw is和農 not axial movement, while it ma訊用y turn to rapid ro們舊tation around the circumfere風文nce of a circle, bu少可t the axial force of the screw 美亮will be balanced. The single screw 她照extruder are rig那對ht hand thread, it has 化湖reverse rotation, when s什務een from behind because they try亮熱 to spin out the back cyl森樂inder, which can exert a從術 feeding tube of plastic melt in th跳友e big thrust forward, at th山個e same time, al謝美so for an object to a sam了花e direction thrust, this 友在power is ultimately fell b道我ehind the inlet of the thrust 師朋bearing.

Second, the operation stability

For various plasti如懂c manufacturers of co讀光nventional extruder, usually use will e子聽xist the following problems: 1習白, the improper 場亮control of techni知術cal conditions, and the moto笑北r load fluctuation will cause the 門跳fluctuation of extrusion t術城emperature and pressure, af書還fect the quality of extrusio道頻n products. 2, with the incr兵遠ease of extrusion pressure, 媽訊flow quantity and leakage綠商 flow rate will increa友新se, make the whole照門 extrusion flow rate dr要裡ops, screw driv村小e material at the same time, the c視的onsumed power is big, the she哥木ar stress of the material is big, a內技nd energy consumption will b知數e increased. 3, during the p呢吧olymer blending modificati輛明on, in order to mak友近e the extrudate with the dist男熱ribution of tempe睡土rature and pressure, inev新校itable requirement 妹筆to increase the leng還科th of the metering s北海ection, but this will increase 老站the screw processing difficulty 公這and cost, and make the material stay了了 time, go against processing東樂 of thermal sens動費itive material. How to solve校東 this problem, we through 女能our company imported日跳 equipment of large extrude術門r structure were analyze她湖d, and the best using a 為冷high temperature melt gear pump, 秒秒the purpose of the gear pump,弟花 main is to make the po微河lymer melt plasticization and me的說tering separate, independent o銀家f sending the melt計亮 to the nose. This pump is actual喝門ly a kind of is a tran器謝sfer device, the outlet pressure i西器s not affected by inlet pres南通sure change, volume efficiency and e學藍nergy efficienc他樹y is very high. It can吧睡 meet the operatio友些nal stability of the equipment, t慢妹hus improving the quality of products r的下equirements, and can meet the high e小看fficiency, low ener可秒gy consumption.

Extrusion machine is equip雜水ped with the melt pump at the same靜通 time, it is the biggest characteri公農stic is that a steady extrusion pre化紅ssure, can increase productio費術n, reduce wear and tear, increase th會務e flexibility of production li舊數ne and lower melt temperatur但街e, reduce the energy consumption. A視線s a conditional plastic extrusio鐵匠n products manufacturers in the 林雜extrusion machine of this enterprise, 對文can consider appropriately.

Three, heating elem計店ents

As we know, plastic extru外黃sion plastic is heat, it melt when 我通heated, and again when co民書oling solidification. Heat melt plasti窗做cs, mainly feed preheating and cylin很從der/mould heater. B見報ut the motor also can 長一input energy --, can overco服議me the resistance 靜姐of the viscous melt, the friction gener雜得ated in the cylinder body h路好eat when the screw is t村通he most important of讀亮 all plastic hea風信t source. For all other operations, sh河公ould know machine barrel hea相下ter. The chief source of heat in the 雜她operation, after the森高 barrel temperatur從內e remains perhaps the most im匠空portant, because it affects th錢請e tooth or the solid mater區什ial in the material c美分onveying speed, die and mould t北兒emperature should be ofte線微n melt temperature or close to the temp綠長erature. Therefore, we 快頻should bear in mind that 長做during extrusion plastic, the聽厭rmoplastics and its heating time is pr相暗oportional to the amount of thermal劇謝 degradation. Generally in plastics ex拍什trusion molding, in order to impr男算ove the quality of extru討間sion products, and should外友 try to prevent melt therm服謝al degradation, which should謝身 avoid melt in the die he現這ad for a long time.笑師

Fourth, feed zone element弟一s

Is known to all, each 水費input feed extruder than feeding ar書近ea of the cylinder and the光得 screw surface tempe這海rature is low, feeding area of the cyl他光inder surface, 哥到however, are almo南筆st always on plastic melt子科ing range, it is through人音 contact with the feed grain cooli文坐ng, heat from hot front科信-end backward heat 暗是transfer and controlled heati器光ng and maintain, or even the end by數去 the viscous friction heat, kee北睡p and do not need cylinder heat為海 input, the need to open 學離the heater. The feed tube, e關姐specially the general得他 groove dedicated t票吃o low pressure polyethylene機明, in order to make a single screw ext得頻ruder barrel smooth feeding t個算he thrift particles reach請市 maximum throughpu玩煙t, plastic pellet should be 購志on cylinder and slide 河要to the screw. If these m生遠aterial in the root of th哥都e screw, nothing to put it d從友own, the channe如爸l volume and will reduce the amount說近 of solid entry. Most plastic natural光遠ly slide in the root, therefore, when月呢 they entered the is cold爸和, and the friction f如木orce is not the root of hea黃用ting to and compared.刀畫in the same heat, for example, hig業司h plasticization of PVC a拍員nd some want to eventually us著東e of polyolefin copo身資lymer adhesive propertie討唱s.

For the machine barrel, plastic作廠 adhesive in the cylinder姐間 body, so that it be removed and the s身視crew thread to push 商是forward. At thi下愛s time between particles and wall 明聽should have a hi新水gh friction coefficient, an算暗d friction coefficient鐘科 to return to come o可花ver after the barrel temperature str又林ongly influenced. If the material does 照有not attach to, just on腦這 the rotation and小城 not push forwar舞話d, that is the reason資靜 why smooth feeding 空門is not good.

The surface friction 關謝is not the only fa會不ctor affecting the看著 feed. Many particles always do 關舊not contact with the cyl鐵哥inder body or th訊道e root of the screw, so th子習e friction inside the barrel must have報商 a chain and mechanical a站跳nd viscosity. So坐報me of the groov坐校ed in the barrel, of course, is an都個other story. The rest of the groove答人 in the feed zone with 事頻barrel is therma木行l insulation, and depth o低熱f water cooling. Threaded 白呢push particles into th要拿e slot, and in a considerable distan司歌ce to form a high pressure, which 湖看adds to the same output low amo雜可unt of bite allo見國w the screw rotation speed藍頻, so as to redu舞我ce friction heat generated 友件by the front end, the melt tempera地呢ture is lower. This 愛校may mean that accelerated cooling li樂資mit flow of film production花懂 line of flow. Therefore, in the但慢 cylinder slot is particularly suitable作笑 for PE.

Five, the screw elements at the 土兒ends of the pressure

The pressure at the ends of the scr人吧ew is very important 北朋in the extrusion, the downstream 西多pressure reflect多站s the screw all the objec算裡ts of resistance, filter and adap區高ter duct, and the mold itse了裡lf. It not only relies on the geometry大喝 of these components, also depen大自ds on the temperatur這火e in the system, which in商不 turn affect the resin viscosity and 金費movement speed.村刀 Although it does 聽外not rely on the screw design, except 飛店that it affects the temperature vis又計cosity and throughput. Se能師curity elements, for each of the extr工舞uder temperature measurem的明ent is very important了章, if it is too high, die 秒行and mold may burst科票 damage to the op美匠erators and the extruder. But the 化明pressure within the barrel on mixing 事她is good, especially in章遠 the screw measuring degrees. But too東分 much stress will mean 哥了motor output energy, th媽可us causing resin melt temperature拿購 is too high, but can 關數provide pressure limit.

Six, when the plastic melting bo購又dy stay within the die

All out of plastic,區湖 they melt in extrusion in ar子家riving at the nose, the residence 東爸time in the nose is plast城又ic is an important factor in the de熱時sign of the die. In the process o微有f extrusion, plastic material flo樂費w time should be多商 controlled wit道女hin the relaxation time and thermal st行章ability of time, time is too sh美相ort, the die swell is b道農igger, extrusion p務他roducts will have房你 a larger residual stress, i些個f time is too long, the 不道material will produce the快麗rmal degradation because of th知民e heat impact on the quality of extrus音樂ion plastic products.

Seven, main motor and extrus議下ion machine cylinder connected rela機村tions

All of the extruder, its 刀南main motor is the antithesis但了 of the barrel 服空body, barrel machine and main moto是門r is opposite. Why the barrel c空舊ontrol effect, and isn't always ex麗嗎pected, especially temperatur木紙e measurement zone. If the火商 barrel body heat, the makings are電費 compared.in the material viscos信道ity decreases, 工就the main motor in the mor什那e smooth barrel runtime ne師木eds less energy嗎服. Motor current down at th喝了is moment, on the contrary, if唱湖 the cylinder cooling, material are c小街ompared.in the melt v銀去iscosity increases, the motor mus船鄉t turn more power還中, the current also increases.

At this moment, through開花 the feeding tube to remove some o麗得f the main motor to 物業heat. Usually material bar校制rel adjuster does produce ef不我fect to melt, t場風his is what we expe從員cted. Anywhere but the effects are北務 not large area variables, the be街現st way is by measuring the melt朋鐵 temperature to really u可能nderstand the occurre鄉信nce of all kinds of situation, in白子 order to better take countermea化男sures.