Shanghai Daoqin Plastics Co., Ltd.

         screw is injection molding machine main/primary core parts, screw quality good bad products quality good bad.

         injection molding machine screw tool has 输送, melt, mixing/compounding, pressure shrink, amount and gas function, is effect/influence quality key/critical factors.

         lower small is large introduction lower injection molding machine screw classification, separation 段说明, parameters 说明, good bad evaluation standards, how to selection, use methods, Common issues and solution methods. can 够帮助 to large 家!

         injection molding machine screw 材质 classification

        1, HPT full hard powder alloy screw

         using/adopting using/adopting powder alloy tool 钢, 经特殊 process overall hard 化处理 molding, screw internal and external overall hardness same, to HRC65° left right. combined processing various transparent product, precision product and add fiber LCP, PPS, PES, PPA and other high temperature, high property plastics.

        2, di alloy screw

         using/adopting SACM645, 38CrMoAlA is 基材, rear or 者螺槽离子喷焊 carbon 化钨镍基 alloy, screw surface hardness in HRC60° left right. combined processing various transparent product and add fiber PA6, PA66 and other engineering material.

        3, electroplating screw

         using/adopting SACM645, 38CrMoAlA is 基材, molding rear outer surface electroplating hard 铬, 镍, titanium and other 元素. hardness in HRC60° left right. combined processing PC, PMMA, PET transparent material and property plastics U-PVC material.

        4, 不锈钢 screw

        材质 is 9Cr18MoV特殊不锈工 tool 钢, using/adopting overall 淬火+ overall hard 化处理, overall hardness in HRC55° left right

        5, SKD61 screw

         using/adopting day 立SKD61材 material, 经特殊 process molding, product tough property good, resistant force strong/high.

        6, nitrogen screw

         using/adopting SACM645, 38CrMoAlA is 基材经特殊 process molding, nitrogen deep degree 0.5-0.8mm, overall hardness HV980~1080°. combined processing plastics, 如PP, ABS, PS, AS, PVC and other plastics.

         injection molding machine screw separation 段说明

         injection molding machine screw generally lower can separation is add material 段, pressure shrink 段, 均化段(也称 is amount 段). (注: different screw 三段 占 ratio value 不一样, screw deep 不一样, screw 底径 渡形式不一样)

        1, injection molding machine screw add material 段

        此段螺沟 deep degree solid 定, its function is negative preheating and plastics solid 体输送 and 推挤. must ensure plastics in material 段结束时开始熔 melt.

        2, injection molding machine screw pressure shrink 段

        此区段 is shrink screw 螺沟牙 deep, its function is plastics raw materials melt, mixing/compounding, pressure shrink and add pressure gas. plastics in 此段会完 full solvent understanding, 体积会 shrink small, pressure shrink ratio design very important.

        3, injection molding machine screw 均化段

        此段 is screw solid deep, its main/primary function is mixing/compounding, 熔胶输送, amount, also must provide pressure, maintain uniform temperature degree and stability melt plastics amount.

         injection molding machine screw parameters 说明

        1, D—— screw 直径(more use Φ table/sheet 示)

         screw large small effect/influence can force large small, effect/influence injection large small.

        2, L/D—— screw long ratio

        L is screw 螺纹部 separation has long degree. screw 直径一定 front lower, L/D越 large, 说明螺纹 long degree long, effect/influence to material material in screw in hot 历程, effect/influence absorption can amount can force; if L/D太 small, effect/influence to material material 熔化效果 and melt quality; if L/D太 large, 则传递扭矩 add large, can amount consumption increase.

        3, L 1—— add material long degree

        L1 long degree ensure material material has 足够 输送空间, is short L1会导致 material material 早 熔 melt, from difficult ensure stability pressure conditions, difficult ensure screw rear 各段 塑化 quality and can force.

        4, h 1—— add material 段螺槽 deep degree

        h1 deep, nano material material more, improve/increase material amount and can force, effect/influence material material 塑化效果 and screw 根部 剪切 strong/high degree, generally h1≈(0.12~0.16)D.

        5, L3——熔 melt long degree

        L3 long degree has melt in in 波动, has stability pressure function, make material material uniform material amount from screw 头部排出, generally L3=(4~5)D.

        6, h 3——计 amount 段螺槽 deep degree

        h3 small, shallow, improve/increase plastics melt 塑化效果, has melt 均化, 但h3 small 会导致剪切 speed rate high, and hot large, separation degradation, effect/influence melt quality; if h3 large, due to 预塑时, screw back pressure generate function reinforcement, reduce can force.

        7, S—— 螺距

         its large small effect/influence 螺旋角, from effect/influence 螺槽 输送 efficiency, generally S≈D.

        8, ε—— pressure shrink ratio

        ε=h1/h3, add material 段螺槽 deep degree h1 and melt 段螺槽 deep degree h3之 ratio. ε large, reinforcement 剪切效果, decrease low can force.

         injection molding machine screw good bad evaluation standards

        1, quality

        一根 screw 首先必 must can production combined quality requirements products. combined quality requirements is production products combined below/following several requirements:

        (1) tool has combined requirements various property can. tool has combined 乎规定 material 理, chemical, force 学, electrical property can;

        (2) tool has combined requirements table/sheet quality. can to use for bubbles, 晶点, color dispersion uniform property requirements and other.

        (3) tool has combined requirements screw quality:

        ① screw extrusion melt temperature degree is uniform, toward 波动, toward temperature more large.

        ② is has molding most low melt temperature degree.

        ③ extrusion melt is has pressure 波动.

        ④染 color and its it add agent dispersion is uniform and other.

        2, output/production volume

         output/production volume is in ensure quality front lower, through to machine output/production volume or extrusion amount. front 述, output/production volume generally use 公斤/ small or 公斤/转 table/sheet 示. good screw, tool has relatively high can force (production can force).

        3, mono consumption

         mono consumption, is extrusion 一公斤 plastics (橡胶)消 consumption can amount, generally use N or table/sheet 示. its in N is rate (千瓦), Q is output/production volume (公斤/ small 时).

        (1) this value large, table/sheet 示塑化同样 weight plastics need can amount more, 即意味 consumption add hot rate more, electrical machine machine through and scratch hot 形式进入 material material more. 反之亦然.

        (2)一根 good screw, in ensure quality front lower, mono consumption can can low.

        4, property

        (1) screw property is screw for processing different plastics, different machine and different products can force. generally 说, property strong/high, 往往伴随 塑化 efficiency reduce.

        (2) therefore 我们总希望一根 good screw, its property and high efficiency 都应兼备.

        5, manufacturing difficult easy

        一根 good screw also must easy processing manufacturing, cost low.

         how to selection injection molding machine screw

        1, screw 直径（D）

         and requirements injection amount related, injection shot 容积=1/4×π×D↑2×S(injection shot 行程) ×0.85. and most high injection pressure formed ratio, and can force formed positive ratio;

        2, 输送段

         negative plastics 输送, and preheating, ensure preheating to melting point. crystallization property plastics long (ratio 如POM, PA); non property material 次之(ratio 如PS, PU, ABS); hot property most short (ratio 如PVC);

        3, pressure shrink 段

         negative plastics mixing/compounding, pressure shrink and add pressure gas, through raw materials full understanding, 但不一定会 uniform mixed combined. in 此区域, plastics 逐渐熔 melt, 螺槽体积必 must versus decline, for plastics 几何体积 decline, material pressure 不实, hot slow, gas defect. pressure shrink generally 占25% above screw as long degree, nylon screw 此段约占15%, high viscosity, resistant property, low property, high add material and other plastics screw 占40% left right, PVC screw can 占100% ratio/proportion, generate 激烈 剪切 hot.

        4, amount 段

         generally 占20%/25% screw as long degree, ensure plastics full melt and temperature degree uniform, mixing/compounding uniform. amount long mixing/compounding 效果佳, long easy make melt 停留 久而 generate hot separation understanding, short easy make temperature degree non-uniform. PVC and other hot property plastics 不宜停留 time long, hot separation understanding, can use relatively short amount or need amount 段.

        5, deep degree

        进 material deep degree deep, 则输送 amount large, 但需考虑 injection molding machine screw strong/high degree. amount deep degree shallow, 则塑化发 hot, mixed combined property can 指数越 high, amount deep degree shallow 则剪切 hot increase, hot increase, temperature rise high, formed plastics color or 烧焦, especially 不利于 hot property plastics.

        渐变 type screw —— pressure shrink relatively long, screw long 50%, 塑化时 can amount 转换缓 and, more used for PVC and other heat stabilized property plastics.

        突变 type screw —— pressure shrink relatively short, screw long 5%~15% left right, 塑化时 can amount relatively 剧烈, more used for polyolefin, PA and other crystallization type plastics.

         general purpose type screw —— can multiple plastics processing.

         injection molding machine screw use methods

        1, material 筒未达 to temperature degree 时, 切勿启动 machine. new electrical hot generally requirements temperature degree to setting value 30 separation rear again as screw.

        2, 每次停 machine ultra- semi small above, most good 关闭落 material 口并清扫 material inner material, 设置保 temperature.

        3, 避免异 material material material loss bad screw and material 筒. anti metal sheet/slice and material material 斗, processing recycling material, add upper magnetic property material anti iron and other material 筒.

        4, use anti need material inner plastics full melt, screw rear loss bad system parts.

        5, screw 空转, slip and other phenomenon.

        6, use new plastics 时, material 筒 余 material dry 净. use POM, PVC, PA+GF and other material amount decrease/reduce raw materials degradation, machine rear and use ABS and other water material dry 净.

        7, 避免POM and PVC meanwhile mixed material 筒, in melt temperature degree lower will 会发生 reaction formed heavy industrial 事故.

        8, melt plastics temperature degree positive also 不断发现熔 melt plastics black spots or color 时, 应检查 screw ring (胶圈, 介子) is loss bad.

         Common issues and solution methods

        1, slip

         in screw stage/phase, screw in machine inner 旋转沿 screw direction material material rear 退积累 material material lower one-time injection molding 时, screw 也会发生打 slip. if screw in stage/phase 开始打 slip, that in screw 继续旋转时, screw toward 运动会停止. injection molding machine screw slip causes main/primary is: add material generate pressure material difficult and machine long degree can formed viscous force, that screw 就发生 打 slip phenomenon.

         injection molding machine screw slip solutions has types:

        第一 types method: add a small amount of material material for machine 筒末端开始进行清洗, meanwhile 检査一 lower melt temperature degree, time short 会导致熔 melt temperature degree low machine temperature degree setting value.

        第二办 method, attention/notes molding products, if has black spots or strip/profile 纹, large 理石斑纹, that table/sheet material material in machine inner has to very good mixing/compounding.

        2, lower material

         injection molding production 时候, 经常会遇 to screw 转动却不 lower material 情况, 也就不 can formed positive production, injection molding machine screw lower material Common causes and solutions:

        (1) material lower material 口堵塞, 检查该处 is has plastics block adhesion.

        (2) temperature 控不准确, material rear temperature degree high, adjustment temperature degree setting, meanwhile can cooling water is 否堵塞.

        (3) screw overmolding phenomenon —— plastics screw 一起旋转.

        (4) plastics 里面添 add product more, formed screw slip.

        (5) plastics in material add more.

        (6) screw and material abrasion loss and abrasion loss can can injection molding machine screw lower material, formed plastics 漏流不往 material front 端输送.

        (7) plastics large, 会出现架桥 phenomenon, will plastics again powder 碎.

        (8) new screw if lower material, can can is material and screw lower material design 不恰当, for/regarding screw 方面就 is screw add material 段螺槽太 shallow, screw in 旋转 时候不 can belt/tape plastics front 输送, has can can is material amount very less and material 筒方面就 is lower material design.

        结语

        说 to this 里, large 家应该 for injection molding machine screw has understanding 吧! plastics as is 继钢材, 木材, water rear large 支柱材 material 之一, already widely used in 社会各 field/area, injection molding machine screw industry development therefore to 进一步 improves. future, technology 进步, screw 档次, degree and technology content will improve/increase, 求精, new, development combined market development trend product will is in the future screw product 主流.