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1、,INJECTION MOLDING,注射模塑技术,Injection Molding Introduction,注塑之优点,Injection Molding Introduction,GOODPART,Material材料,Tooling 模具,Processing工艺,Design设计,好产品,Equipment设备,Injection Molding Equipment,MACHINE SHOT SIZE机器注射容量Part Weight=40-80%of Machine Shot Size制件重量=40-80%机器注射容量Optimal Part Weight=40 60%of Ma
2、chine Shot Size理想制件重量=40-60%机器注射容量,Injection Molding Equipment,材料选择投影面积产品设计(制件厚度,流动长度)注射压力,Injection Molding Clamping,Injection Molding Equipment,Screw Type Machines Are Recommended推荐采用的螺杆类型,Injection Molding Equipment,Metering计量,Feed进料,Screw and Cylinder Design螺杆和料筒设计,hf,hm,L/D长径比=20:1(18:124:1)Com
3、pression Ratio压缩比=2.5:1(2:12.5:1)Cylinder bi-metallic for Abrasion Resistance 双金属料筒,Transition过渡,L,D,Injection Molding Equipment,往复式reciprocating 螺杆头结构检查环类型:止回环,熔融树脂流过开放检查环,检查环关闭,防止在注塑过程中料的回流,建议采用止逆阀,Injection Molding Equipment,Standard Cylinder Nozzles标准料筒喷嘴,Heating Band加热环,CylinderBore料筒主体,To Mold
4、,Provides Mechanical and Thermal Connection FromHot Cylinder to Colder Mold提供从热的料筒到相对冷的模具的机械和热连接,到模具,Injection Molding,Sprue Bushing主流道衬套,Nozzle 喷嘴,Radius 半径,Orifice 主流道孔口,段道长度最大5mm射嘴开口:4.769.53 mm主流道衬套孔口要比喷嘴口径大0.81mm 尽可能地短,Tooling模具,Injection Molding tooling,Material flows only through the molten p
5、ortion of runner,Outer layer of material chills on contact with steel surface,Runners Flow,外层接触模具冷却固化熔体由内层向前流动,即实际有效流动面积要小于流道截面面积.,流道半径微小的增加就可以很大程度地增加流量,并相应地减小压力降,Q=流量 P=压力降R=浇口半径N=粘度L=流动距离,Q=,8n L,Q Proportional to R4,n R P,4,Runner,圆形 效率最好,梯形可接受的,半圆不好的,PL,Runners Design,Runner design recommended p
6、rofiles,RD,RD,RD W D3.24.83.24.86.44.86.48.06.48.011.08.09.512.79.5,Equivalent Round Runner,Design Alternative,Runners Design,Runner design trapezoidal profiles,W,D,W,Runners Design,Runner sizing recommendations:平衡的配置是最好的一级流道:圆形或梯形是最好的Length 250mm or longer:9.5mm diameter Length 75mm to 250mm:7.9mm
7、diameter Length under 75mm:6.5mm diameter二级流道:6.5mm diameter minimum,Sprue Puller,REVERSETAPERBEST,Z PULLERGOOD,GROOVETROUBLE-SOME,SUCKER PINNOTRECOMMENDED,Tooling Runners,RESTRICTIVE,PREFERRED,Tooling Runners,流动方向,冷料井,Tooling Runners,冷料井,流道直径:D,1.5 X D,Unbalanced System,A,A,A,A,B,B,B,B,Tooling Runn
8、ers,in,Balanced System,Tooling Runners,浇口定位要考虑的基本因素有：制件设计、流动和产品最终使用要求。应牢记下面的几点，以此作为一般指南。需要多浇口的大制件，应该有位置足够紧密的浇口，以减少压力损失。这样做可使树脂流动前缘交汇点的冷却最小化，从而提供较好的熔合线强度。应选择合适的浇口尺寸，以使树脂的充填有一个合理的压力和速度。浇口过渡段长度应保持尽可能的短。撞流浇口将有助于保证流入的流体直接对着模腔壁或型芯，从而可以避免漩纹。为避免夹气，来自浇口树脂流，应将空气导向排气槽。浇口位置应确定好，以便让树脂从厚壁部位流向薄壁部位；让熔合线最小化；并且远离冲击和应
9、力区。要使漩蚊、放射斑和浇口白晕减至最少，浇口应与流道有一个合适的角度(下图).直接浇注到装饰性表面，会引起表面缺陷。,Gate design,Gating,侧浇口的高度应为80100%的壁厚,宽度应为浇口深度的2倍,侧浇口,0.5mm Land Length,1.272.53mm,900,点浇口,Gating,Molded Part,Sprue,Parting Line,加设倒圆改善流动,Knock Out Pin,Tunnel Gate,Tooling Gating,300,450,1mm(min.),潜伏式,R1025,R,Gate,Cashew Gate,Tooling Gating,
10、25,2.5D,潜伏式,A Hot Runner System,Runners Heated Runners,Hot Runner Benefits Faster Cycles-15-20%Faster Eliminates Material Waste-No Sprues or Runners Improves Part Quality-Less Stress-Better Appearance,Runners Heated Runners,INTERNALLYHEATED,EXTERNALLYHEATED,Differences in Design Philosophy,Runners H
11、eated Runners,Runners Heated Runners,Smaller,Larger,Faster Colour ChangeShorter Residence Time,Lower ShearLower Pressure Drop,Melt Channel Sizing,Runners Heated Runners,Heating the Manifold,Runners Heated Runners,Parting Line,Depth 0.0350.075mm,Gate,2.5mm,Note Step,6mm(min.),0.40.75mm,Tooling Ventin
12、g,2550mm,Clearance Around Knockout,.0025,Ejector Pin,Tooling Venting,Molding Process 成型工艺,Injection Molding,使用合适的设备,正确的条件对材料进行预干燥,Dry Environment-30C dew point,Air Flow Rate1 cfm/hourly lb of resin used,Temperature 120C,Time 4 hrs+,Injection Molding Predry,Processing 工艺,Start-up:开机:,Purge with the C
13、orrect Material 用正确料清洗 Use Correct Processing Conditions 采用正确加工参数,Injection Molding Process,Recommended Purge Materials推荐清洗料,PolymerPurge Material聚合物 清洗料Cycolac/Cycoloy PMMA,PS,SANNoryl PS,PMMALexan PMMA,HDPEValox PS,HDPEUltem LEXAN,HDPE(Extrusion Grade)Supec HDPE,Injection Molding Process,Injection
14、 Molding Process,Important Process Variables重要加工参数,Melt Temperature 熔融温度Mold Temperature 模具温度Temperature Profiles 温度曲线Residence Time 停留时间Injection Speed 注射速度Injection Pressure 注射压力Pack Pressure 保压Clamp Tonnage 锁模力Cushion 缓冲料垫,Injection Molding Process,Model of Amorphous Polymers,Raise Temperature of
15、 Polymer,T,G,Locked 固态Entanglements,Stiff Flow难于流动,Easier Flow 较易流动,Injection Molding Variables,Melt Temperature熔融温度,Increased Melt Temperature yields increased Flow.提高熔融温度导致增加流动However,Too High a Melt Temperature May Cause Degradation.但,过高熔融温度造成降解,Injection Molding Material,Thermoplastics and Degra
16、dation热塑性塑料和降解,How is heat added to the polymer?外热如何作用于高分子材料,Electrical Heat:电加热Heater Bands 加热带Mechanical Heat 机械热Screw Speed 螺杆速度Back Pressure 背压Injection Pressure/Speed 注射速度/压力,ProductMelt Temperature(0 C)CYCOLAC 220-260LEXAN 270-320NORYL 240-320VALOX 235-275ULTEM 340-440CYCOLOY 240-280XENOY 240-
17、280SUPEC 305-330GELOY 195-220,Injection Molding Process,产品类别 熔体温度,Injection Molding,Barrel UnitThe Reciprocating Screw,Screw Rotation Feeds and ShearsMaterial Into a Melt.Melt Collects Into Front of Barrel,Forcing Screw Back,Shot,Rotation and Back Pressure,出量,通过螺杆回转，熔体聚集于料筒前部，反作用力使螺杆后退。,回转力矩和背压,150,
18、100,50,25,50,75,125,150,100,Screw Dia in mm,RPM,SCREW SPEED Suggestions,推荐螺杆转速,螺杆直径,转速,Injection Molding,建议的螺杆转速是根据直径而确定的。螺杆的最佳O.D.（外径）线速度为：每秒8英寸(202.4 mm).RPM=每秒8英寸（202.4mm）的最佳线速度60/螺杆直径3.14.例如：螺杆直径为3英寸（75.9mm）。那么，3(螺杆直径)3.1416=9.248,再被每秒8英寸（202.4mm）(最佳线速度)60 来除=51 RPM,即为螺杆转速。,Injection Molding,Inj
19、ection Molding Equipment,Barrel UnitThe Reciprocating Screw,Melt Required to Fill Mold Ready for Injection,Shot,Injection Pressure,注射压力,将要注入模具内的熔体,Injection Molding Equipment,Barrel UnitThe Reciprocating Screw,Screw Pushes Forward:Inject,Cushion,Packing Pressure,缓冲垫,保压,注射,Injection Molding Variables
20、,Injection Speed,100010010,Injection Speed affects the viscosity of the molten material.,注射速度,表观粘度,剪切速率,注射速度影响熔体粘度,Injection Molding Variables,注射压力曲线,注射压力峰值,液压压力,填充时间,Machine Downtime,停机2小时以下时,建议将料管温度降低56degC.停机28小时时,建议将料管温度降低至170degC.停机超过8小时的,建议将料管清洗干净,且停止加热.对于玻纤增强树脂,如果停机时间超过30分钟,应将料管清洗干净.,对于含PC的树脂
21、,不要将料管温度降至160degC以下,Downtime:停机,防降解,模温Mold Tempeature,Injection Molding Process,Injection Molding Process,Part Cooling and Solidification,Hot Melt,Cooled Mold,Solid Part,制件冷却和固化,热熔体,温度较低的模具,固化的制件,Mold Temperature,模温对制件的外观很重要模温一致对尺寸控制很重要均匀的模温可以减少翘曲合理的模温可以降低产品内应力合理的模温可以改善材料流动性,Injection Molding Coolin
22、g,模温,Cooling system,Mold Cooling Series Bubbler,IN,OUT,POOR,Pin,Blade,IN,OUT,30,Cooling System,Good,Cooling System,The Most Efficient Cooling Systems Are Those Which Operate Such That The Inlet and Outlet Coolant Temperatures Are Within 100 Of Each Other,Fluid Velocity Ft./Sec.,Turbulent Flow,Transi
23、tion Area,Heat Transfer EfficiencyWater Coolant,0.5,1.0,1.5,2.0,Laminar,Flow,Mold Temperature Control,冷却介质的通道应足以产生紊流,因为紊流带走的热量是层流的3倍.,REGRIND SUGGESTIONS Use Only Clean Non-degraded Uncontaminated Resin for Regrind Keep It As New Material Normally 20%of Regrind can be Used Screen Sizes should be 7 t
24、o 9 mm,Injection Molding Regrind,对材料回收使用的建议,只使用未降解材料回收料不能有污染要象保存新料一样 通常允许添加20%的回收料 过滤网应该在7至9MM,Injection Molding Closing,Ten Do for Molding Engineering Resins,Know Your Material 了解你所使用的材料Dry Properly 正确地干燥Use Recommended Processing Conditions 使用推荐的加工参数Use Properly Sized Equipment 选择恰当的设备Use Properly Designed Tooling 正确设计模具Use Adequate Runners 浇口尺寸充分Use Proper Venting 良好的排气 Use Nozzles with Proper Heat Controls 对喷嘴施以良好的温控Use Proper Screw Design 恰当的螺杆结构Schedule Annual or Bi-Annual Equipment Maintenance 正确维护保养设备,十大准则,
