Shanghai Daoqin Plastics Co., Ltd.

1. machine 械原则 extrusion basic mechanism very simple ——一 screw in in 转动并 plastics toward front 推动. screw upper is 一 斜面 or 者斜坡, in in upper. its is increase pressure 以便克服 relatively large retardant force. 就一台 extrusion machine 而言, has 3 types retardant force need 克服: solid pellets （进 material ） for 筒壁 摩 scratch force and screw front 几圈时（进 material 区） it between versus scratch force; melt in upper force; melt by toward front 推动时 its internal material retardant force. 牛顿曾 understanding 释说, if material has toward to direction 运动, that this material upper force in this direction in balanced. screw is toward 运动, although in 圆周附近 it can can toward fast speed 转动. therefore, screw upper toward force by balanced, but also if it to plastics melt add very large toward front force that it meanwhile to certain material add same toward rear force. in this 里, it add force is function in material rear bearings ——止推 bearings upper. more mono screw is right 旋螺纹, 像木工 and machine in use screw and 螺栓. if from rear 面看, it is toward 转动, is it need force toward rear 旋出筒体. in di screw extrusion machine in, screw in 两 筒体 in toward 转动并 versus 互交叉, therefore 一 必 must is right toward, 另一 必 must is left toward. in its it combined di screw in, screw same direction 转动因而必 must has same orientation. however, tube/pipe is types 情况都 has absorption toward rear force bearings, principle suitable. 2. hot can extrusion plastics is hot plastics —— it in add hot 时熔化并 in cooling again solid. plastics hot amount from 何而? material preheating and 筒体/ injection molding parts mold add hot device can can function but also in 启动时 non important, is, electrical machine can amount —— electrical machine viscous melt retardant force screw formed 于筒体 inner scratch hot amount —— is has plastics most important hot 源, small system, low speed screw, high melt temperature degree plastics and extrusion coating application remove outer. for/regarding has other as, to add hot device is as in main/primary hot is very important, for extrusion function ratio expected can can need small （见第11 strip/profile 原则）. rear temperature degree can can important, is it effect/influence combined or material in solid material speed degree. and injection molding parts mold temperature degree usually is need melt temperature degree or 者接近于 this temperature degree, remove non it used for certain specific 目 像 upper light, separation or pressure control. 3. decrease speed in more extrusion machine in, screw speed degree through adjustment electrical machine speed degree achieve. electrical machine usually large 约1750rpm full speed 转动, is this for extrusion machine screw fast. if 以如此 fast speed degree 转动, generate more scratch hot amount but also plastics time short can made uniform, very good melt. type decrease speed ratio rate in 10: 1 to 20: 1 between. stage/phase can use gears can slip 轮组, is stage/phase use gears but also screw in most rear large gears in 心. in slow speed machine in （ ratio used for UPVC di screw ）, can can has 3 decrease speed stage/phase and most large speed degree can can low to 30rpm or more low （ ratio rate 达60: 1）. 另一 极端 is, used for very long di screw can 以600rpm or more fast speed degree 运行, therefore need non low decrease speed rate and very more deep cooling. has decrease speed rate and 任务匹配 has 误——会 has more can amount can use —— but also has can can in electrical machine and most large speed degree decrease speed stage/phase between increase slip 轮组. this need make screw speed degree increase to ultra- 先 front or reduce most large speed degree 允许该 system most large speed degree more large percentage 运行. this will increase can obtain can amount, decrease/reduce 安培数并避免 electrical machine issues. in types in, according to material and its cooling need, can can increase. 4.进 material cooling agent extrusion is electrical machine can amount —— has is add hot device ——传送 to cold plastics upper, from it from solid 体转换 formed melt. 输入进 material ratio to material in and screw surface temperature degree low. however, to material in surface 几乎总 is in plastics scope/range upper. it through and material pellets 接触而 cooling, hot amount hot front toward rear hot amount and can control add hot maintain. currently hot amount viscous property scratch maintain and need hot amount 输入时, can can need rear add hot device. most important outer is type material 筒, 几乎专 used for HDPE. screw surface by material cooling by plastics material pellets （ and pellets between gas ） from upper hot. if screw 突然停止, material 也停止, and is hot amount from more hot front toward rear 移动, screw surface in material more hot. this can can pellets in viscous or 搭桥. 5. in material inner, viscous to upper slip to screw upper is make mono screw extrusion machine light slip 筒体进 material solid pellets amount to most large, pellets viscous in upper slip to screw upper. if pellets viscous in screw 根部, has what can it lower; 通道体积 and solid 体 入口 amount decrease/reduce. in viscous good causes is plastics can can in hot generate and similar pellets, or 者随输出 speed degree 变化间歇 viscous in 断. more plastics very in sliding, is it 们进入时 is cold, but also scratch force also has add hot to and 筒壁一样 hot. 一 材 material ratio 另一 材 material more can can viscous 附: high degree 塑化PVC, non 晶体PET, and certain most use in need has viscous features polyolefin type polymer. for/regarding 筒体, plastics has necessary viscous in this 里以便 it by 刮掉并 by screw toward front 推动. pellets and between has high friction coefficient, friction coefficient 反 也受 rear temperature degree strong/high effect/influence. if pellets viscous 附, it is 就 转动而不 toward front 移动—— this is is what light slip material good causes. surface scratch non effect/influence material factors. very more pellets 永远都不接触筒体 or screw 根部, therefore in pellets material internal must has scratch and machine and viscosity 连锁. belt/tape 槽筒体 is types 特殊情况. in material 区, material and its separation is hot insulation is deep degree water cold. pellets 推入槽 inner in versus short inner formed very high pressure. this increase same relatively low screw speed combined amount, from front generate scratch hot amount decrease/reduce, melt temperature degree more low. this can can cooling made made film production in more fast production. especially combined 于HDPE, it is remove fluorine plastics outer most slip plastics. 6.材 material most large in certain lower, material cost can to cost 80%—— more other has factors and —— remove less quality and packaging especially important product ratio medical grade tube/pipe. this 原则自然引出两 结论: processing 商应该尽 can can more heavy use material and waste product Raw Materials, can can 严格 遵守容差以免背离 target/goal thick degree and product issues. 7. can cost versus for 说并不 important tube/pipe 一 工 injection molding parts processing force and true positive issues and upper rise can cost in water upper, 运行一台 extrusion machine can still is production cost in very less separation. 情况总 is this 样 因 is material cost non high, extrusion machine is has system, if more can amount that plastics very fast non hot 以致于无 method positive processing. 8. screw pressure very important this pressure screw lower has material retardant force: and 污染扎碎 machine sheet/plate, device tube/pipe, solid 定搅拌 device （ if has ）以 and injection molding parts mold 自身. it 不但依赖于 this parts 几何图形 also 依赖于 system in temperature degree, this also effect/influence resin viscosity and through speed degree. it 不依赖于 screw design, it effect/influence temperature degree, viscosity and through amount remove outer. safety causes 说, amount temperature degree is very important —— if it high, and injection molding parts mold can can 爆炸并伤害附近人员 or machine. pressure for/regarding is has 利, especially in mono screw system most rear 区域（计 amount 区）. however, high pressure 也意味 electrical machine need more more can amount ——因而 melt temperature degree more high —— this can pressure 极限. in di screw in, screw versus combined is types more add has 效 搅拌 device, therefore used for this type of 目 时不 need pressure. in manufacturing 空心部 parts 时, ratio use for core 定位 蜘蛛 injection molding parts mold manufacturing tube/pipe 子, must in injection molding parts mold inner generate very high pressure separation material heavy new combined. 否则, welding product can can relatively low and in use can can issues. 9.输出= most rear 一 螺纹 位移+/- pressure material and most rear 一 螺纹 位移叫做 positive 流, 依赖于 screw 几何形状, screw speed degree and melt density. it pressure material adjustment, upper decrease/reduce amount retardant force 效果（由 most high pressure table/sheet 示） and increase amount material in 任何 咬 combined 效果. upper can can is direction in 任意一 direction. 计算每 rpm（转） 输出 amount is has use, is this table/sheet certain time screw can force decline. another related is use force or 千瓦 输出 amount. this table/sheet efficiency can 够估计一台 to electrical machine and device production can force. 10.剪切 rate in viscosity in main/primary function has plastics has force decline features, is in plastics 运动 越 越 fast viscosity low. plastics this table/sheet especially obvious. 例如一 PVCs in force increase 一倍时流 speed increase 10倍 or more more. versus 反, LLDPE剪 force decline is more, increase 一倍时 its speed increase 3 to 4倍. decrease/reduce force reduce 效果意味 extrusion conditions lower high viscosity, this also need more more electrical machine rate. this can understanding is what LLDPE运行时 temperature degree ratio LDPE high. amount 以剪切 rate table/sheet 示, in screw in large is 100s-1, in more injection molding parts mold type in is 100 and 100s-1 between, in and 筒壁间隙 and small injection molding parts mold in large 于100s-1. melt is viscosity commonly used amount methods is 颠倒 （ ratio is amount /推 force is force /流 amount ）. can 惜, its amount is in rate in 10s-1 or more small but also in melt speed very fast extrusion machine in can can is true 实 测 amount value. 11. electrical machine and for 立, and electrical machine for is what control 效果并 non is and 期望 一样, especially is in amount inner? if for add hot, 筒壁处 材 material viscosity small, electrical machine in this more add light slip inner need can amount more less. electrical machine electrical 流（安培数） decline. versus 反, if cooling, 筒壁处 melt viscosity increase large, electrical machine must more add use force 转动, 安培数 increase, through 筒体时 remove hot amount also by electrical machine 送回. usually, adjustment device for melt generate 效果, this is 我们 期望, is 任何 方 效果都没 has 区域变 amount large. most good is amount melt temperature degree true positive understanding what 情况.