1、PET簡介,I.C Kuo 2002/12/11,分子量192*n+62n为聚合度,一般为100160,聚酯的性质,聚对苯二甲酸乙二酯,英文名称,中文名称,Polyethylene terephthalate,简称,PET,玻璃化温度Tg,无定形 67 结晶 81 高顺向(取向态)结晶 125 ,熔点Tm,般 240265 纯结晶 271 ,密度 g/cm3 无定形 1.334结 晶 1.455熔 体 270 1.220295 1.117,吸水率,温度25 ,相对湿度65% 一星期含水0.4%温度25 ,浸水中 一星期含水0.50.8%,折射率,2 2.4825 1.64,干燥不良对制品的影响
2、,IV 下降 强度下降、破裂 黄颗 未熔物 气泡 白雾 拉丝,PET CHIPS 干燥,风温(进口、出口、冷却后) 风量 露点 干燥时间 死角 均匀性 漏气,桶槽 堆积密度 860Kg/m3,冷却,过滤,风机,加热,分子筛,分子筛,加热,TI,TI,D.P,FI,除湿,PET干燥图,PET 注塑成型 瓶 胚 成 型 的 过 程加料 熔融 射出 保压 冷却 成型,挤出机,挤出机螺杆,瓶胚注射,Co- Injection Process Optimization,BARRIER LAYER VELOCITY PROFILE,Cavity,Core,What Do Converters Want?,
3、Operating efficiency equal to monolayer Cycle time equal to monolayer Machine size and mold size equal to monolayer Ease of operation and process control Economical use of barrier materials as low as 2% Uniform distribution around leading edge of barrier Preforms with Barrier PCR PCR and barrier,200
4、2/11/12,第1页 共47页,What is Multi-Layer?,Monolayer PET Bottle,Multilayer PET Bottle,Short shelf life,Extended shelf life,ThreeLayers,PET Barrier PET,One Layer,PET Only,MULTI-LAYER 2 Material, 3 Layers,Turnkey PET Co-Injection Systems,Other Technology,3-LAYER FLOW,Other Technology,3-LAYER FLOW,Other Tec
5、hnology,3-LAYER FLOW,Other Technology,3-LAYER FLOW,Kortec Technology,3-LAYER FLOW,Kortec Technology,3-LAYER FLOW,Kortec Technology,3-LAYER FLOW,Kortec Technology,3-LAYER FLOW,SIMPLE BARRIER LAYER ADJUSTMENTS,Simultaneous injection Three parameters adjust barrier layer distribution1.) Leading edge2.)
6、 Trailing edge 3.) Layer thickness,Co- Injection Process Optimization,KORTEC OTHER,Combine layers remote from gateStandard mold sizeStandard machine size,Combine layers close to cavityNon-standard mold sizeNon-standard machine size,Nozzle Technology,Three-Layer Injection Profile,TIME POSITION “A”,In
7、ject PET only,A,Simultaneously inject PET & barrier,TIME POSITION “B”,B,Three-Layer Injection Profile,Complete injection of barrier Continue PET injection,TIME POSITION “C”,C,Three-Layer Injection Profile,TIME POSITION “D”,D,Finish PET injection ensuring gate is sealed with PET only and nozzle is co
8、mpletely purged Ready for next shot,Three-Layer Injection Profile,如何减少应力,熔体温度 模具温度 注塑压力 保压压力 瓶子瓶胚设计 测试方法:双折光法,如何减少白化(料口),原料 干燥 背压 转速 熔融温度 模具设计、温度 冷却速率 料门开关,注塑速率与压力之关系,注塑速率,压力损失,料流长度,收缩率,充模压力,因,素,温 度 的 设 定,T 290 280EX1 EX6 N/A,TRANSFER BACK,N/A,M,BH,BHE,EX1,EX3,EX2,EX4,EX5,EX6,DIS,SPH,SCREW,BARREL,SP
9、2,SP1,一步法与二步法的比较,在一台机内完成注、拉、吹工序的工艺叫一步法。 一步法是在瓶坯注塑后冷却后做拉吹动作。省电生产率高不经人手减少污染,两步法将注及拉吹分离,在两台机器上分时进行。第一步用注塑机注出瓶坯。第二步将室温的瓶坯再加热后,拉吹成为瓶子,,购买瓶坯吹塑成型。可以减少投资(人材及设备)。瓶坯的体积远小于瓶子,方便运输及储存。淡季生产的瓶坯可在旺季吹成瓶子。,250,200,150,50,100,RT,300,Cooling,Cooling,Bottle,Preform,PET Chips,Glass Temp,A,Reheat,Stretch Blow Range,PET d
10、rying In hopper,PET Melting in barrel,RT=Room temp,MT=Melting Temp,B,Injection,比 较,内外温差比较 厚度差异 瓶胚设计限制 个别注塑速率差异造成厚薄不均,稳定性差,AA 的 产 生,原料(Free AA 、Potential AA)干燥 (Air flow,Temp, Stay time)注塑条件(Temp,Press,Speed,Stay time,Chips Temp)注塑设备(Screw,Hotruner,Model,MeltTemp),IV 下降,强度抗张强度(摔落易破)色泽变异,厚 薄 不 均,瓶胚设计瓶子设计IV 下降吹瓶温度(一步法,二步法)吹气时间与延伸之关系PET 延伸倍率,耐 热 性,原料瓶胚,瓶子设计(吹胀品,耐真空设计,重量)设备定型温度,时间吹瓶温度(瓶胚)及温度均一性(内,外,中差异)瓶子厚薄分布存放条件,摔 落 破 裂,瓶子,瓶底设计底部肉厚分布IV 下降或太低,爆 瓶,原料干燥瓶子,瓶胚设计关系瓶肉厚分布吹瓶时瓶胚温度吹瓶冷却-底部温度充填压力润滑液存放条件,