1、TRAININGTRAININGTRAININGTRAINING意大利SIPA二步法吹瓶机 TRAININGTRAININGSTRETCH&BLOW STRETCH&BLOW MOULDINGMOULDING拉伸拉伸吹制吹制1.THEORETICAL PART原理原理部分部分TRAININGTRAININGThermoplastic polymers聚合聚合体的热塑性体的热塑性General characteristics of PET一般一般特性特性SBM process explanation拉伸拉伸吹制过程解释吹制过程解释Heating and conditioning process加
2、热加热调整过程调整过程Stretch/blowing process拉伸拉伸吹制过程吹制过程12345TRAININGTRAININGCH2=CH2Ethylene乙烯基Polyethylene 聚乙烯-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-例如:Polymer chains聚合体链:a high molecular mass substance characterized by the repetition of one or more types of monomeric units由由一种或多种单体副本组合而成的高分子化合物一种或多种单体副本组合而成的高分子化合
3、物Monomer单体:a simple compound whose molecules can join together to form polymers 分子分子组合在一起可形成组合在一起可形成聚合体的一种简单化合物聚合体的一种简单化合物()nMonomer单体Polymer聚合体Polymerization聚合聚合n 1001TRAININGTRAININGPET(PolyEthylene Terephthalate聚对苯二甲酸乙二醇酯聚对苯二甲酸乙二醇酯),是由Purified Terephthalic Acid纯对苯二酸(PTA)和Ethylene Glycol 乙烯乙二醇(EG)
4、两种原料化合形成的聚脂,这两种石油加工物在反应器内形成聚脂1“POLYESTER”聚脂POLY=MANY许多ESTER=joining of an ACID and a GLYCOL酸和乙二醇的连接物EGPTAEGPTAEGPTAEGPTAEGPTATRAININGTRAININGThe chain structure depending from the monomer链结构由单体的泛函性组成决定 functionality(2 or 3)1Monomer单体直线状(PET,HDPE)树枝状(LDPE)网状(PU)F 平均泛函性:F=2 线性F 2.8 网状2 F 2.8 树枝状TRAINI
5、NGTRAINING1直线状和树枝状连接聚合体链结构如何能影响材料性质链结构如何能影响材料性质?链间相互之间可以滑动 热塑性热塑性加热变软,冷却变硬,在软化状态(温度高于Tg)通过吹制成型聚合体举例:PE,PP,PET,Nylon,PVC,PC典型工艺:挤压,注塑,吹制.TRAININGTRAINING网状连接聚合体链间相互之间不能滑动 因为它们之间有非常坚固的化学连接 聚合体举例:Epoxy resin环氧树脂,silicon resin硅有机树脂典型工艺:铸造,注射,挤出,压缩(聚合作用在成型后发生)热硬化性热硬化性通过加热或其它处理(化学,光学)不能通过加热软化,不可熔融和溶解1TRAI
6、NINGTRAININGOmopolymer:polymer where all the repetitive units are of the same kindCopolymer:polymer where the repetitive units are of two different kinds.In many cases,a small quantity(24%)of different moleculas(i.e.isophtalic acid)are added to ethylene glycol and terephthalic acid in order to impro
7、ve processability of the resin.Monomer“A”Omopolimer“A”Copolimer“A+B”Monomer“B”2TRAININGTRAININGMonomer“A”Monomer“B”AlternatedA blocchiRandomGraftThe order and distribution of the B monomers in the chain change the material behaviour.2TRAININGTRAININGThe polymer mechanical behaviour depends on the ch
8、ains average lenght.聚合体的机械特性由链平均长度决定链越长则链与链之间的可滑动量越小IV=Intrinsic Viscosity固有粘度Quantity proportionalto chains length.Its the measure of the mobility of the polymer chains.链长度所占比例反映了聚合物的滑动性能短链IV低,链滑动性高,机械强度低 长链IV高,链滑动性差,机械强度高2TRAININGTRAININGFiber grade纤维等级纤维等级Specifications:短链结构(平均长度 100 units)Intrin
9、sic Viscosity 固有粘度=0,5 0,7 dl/g acetaldeyde content乙醛含量高(AA)Applications:films and fibers胶片和纤维PET 可有两种状态存在:(fiber)纤维等级和瓶子等级挤压机挤压机Flakes切片切片切割机切割机单体单体Reactor反应器反应器冷却器冷却器Production process:Fuse state polycondensation2TRAININGTRAINING瓶子等级瓶子等级Specifications:长链结构(平均长度 130 units)Intrinsic Viscosity固有粘度=0,
10、74 0,86 acetaldeyde content乙醛和水含量低 用途:瓶子Production process生产工艺:polycondensation固态缩聚颗粒料颗粒料N2N2 or vacuumPET 纤维等级纤维等级1st Crystallization结晶结晶150C200C2nd 结晶结晶150C200C固态缩聚固态缩聚220C冷却冷却N2 or vacuumN2 or vacuumAA and H2OAA and H2OAA and H2O2TRAININGTRAINING瓶子等级PET是一种高IV,低AA的树脂 2机械强度差机械强度差气体渗透性高气体渗透性高结晶率高结晶率
11、高熔点低熔点低低低 IV机械性能好机械性能好气体阻隔性好气体阻隔性好结晶率低结晶率低高高 IV熔点非常高熔点非常高有热降解的危险有热降解的危险非常高非常高 IV加工性能加工性能 0.74-0.84机械性能和气阻性能机械性能和气阻性能TRAININGTRAININGPET 的链之间怎么排列和组织的链之间怎么排列和组织?(颗粒)(瓶坯)熔融熔融+冷却冷却(瓶子)拉伸拉伸+吹制吹制2TRAININGTRAININGCrystalline state结晶态固态Tm250C 310C降解态熔融态2gasgasgasgasAligned chain segments按链段排列:Opaque不透明 机械性能
12、和热阻性好 易脆裂 气阻性好 熔化过程没有软化阶段温度在Tm以下不能变形TRAININGTRAININGAmorphous state无定型态聚合体链没有特殊的排列:Transparent透明的 Poor chemical resistance低化学阻抗 Elastic有弹性 High gas permeability高气体渗透性 Softens before melting熔融前有软化阶段gasgas玻璃态Tg70C160C弹性态结晶态250C降解态320C粘弹性态温度在Tg之上可变形Tm熔融态2TRAININGTRAINING定形态(strain induced crystallizati
13、on应变结晶)容器生产的理想需求Transparent透明high mechanical property高机械特性high barrier property高气阻性无定形态PET少量结晶态被无定形态随机环绕如何适应这种结构形态如何适应这种结构形态?加热到高于 Tg塑性变形定形态PET 定形态和无定形态2Biaxial oriented双轴向的双轴向的单轴向的单轴向的TRAININGTRAININGPET 是一种吸湿的树脂,有从外界吸收水分的倾向。很多因素决定水分的吸收量,如:保存时间,温度,环境露点,树脂的结晶率。PET在无定形态要比结晶态吸水速度快。The amount of water
14、absorbed depends on various factors that is storage time,temperature,environment dew point,crystallization%of the resin.PET in the amorphous state absorbs moisture more quickly than in crystalline state.2TRAININGTRAININGThe water moleculars trapped between the polymers molecular chains behaves as a
15、lubricant.聚合体分子链之间的水分子表现为润滑作用。So it becomes easier to stretch the material but this also has a negative effect on bottle shrinkage through the NSR rise.所以它使拉伸变的容易，但同时因为自然拉伸率的上升对瓶子的收缩有负面影响325 Kgf 1 mm 伸长10 Kgf 1 mm 伸长TRAININGTRAINING3If an amorphous PET sample is subjected to a tensile stress importa
16、nt consequences can be obtained on its molecular structure.They basically depends on the temperature at which stresses are applied to the material.Elastic Strain弹性应变弹性应变:Oriented被导向被导向Plastic Strain塑性应变塑性应变:Stretched拉伸拉伸TRAININGTRAINING3How the plastic sample modifies during the elongation steps塑料样本
17、在延长过程中如何变形 ELONGATION延长延长STRESS压力压力TRAININGTRAINING拉伸是自我限制的为什么为什么PET能被拉伸能被拉伸?延长延长NSR自然自然拉伸率拉伸率STRESS压力压力STEEL钢钢CRACKING断裂断裂PETFOR HAVING FURTHER DEFORMATION IS NECESSARY STRESS INCREASING如果需要更大如果需要更大的变形需要增加压力的变形需要增加压力3TRAININGTRAINING哪种情况是最好的拉伸哪种情况是最好的拉伸?延长延长NSR自然自然拉伸率拉伸率STRESS压力压力UNSTABLE不稳定拉伸不稳定拉伸
18、过度拉伸过度拉伸最适宜的拉伸最适宜的拉伸3TRAININGTRAININGThe stretching can be adjusted by working on the thermal profile拉伸的调整可通过改变加热曲线来完成拉伸的调整可通过改变加热曲线来完成ELONGATION伸长伸长STRESS压力压力1.拉伸度越高需要的温度拉伸度越高需要的温度越高越高2.厚度是由加热曲线控制厚度是由加热曲线控制的的TT2 T1e e2 e e13.拉伸速度越快，需要的拉伸速度越快，需要的温度越高温度越高V3TRAININGTRAININGThe stretching ratio depends
19、 on preform and bottle design实际拉伸率由瓶坯和瓶实际拉伸率由瓶坯和瓶子的设计决定子的设计决定(几何形状几何形状)LBOTTLPREFFBOTTFPREFrad =FbottFpref_avrgax =LbottLpreftot =ax x rad 2.4ax3.53rad57tot 只在必要时!TRAININGTRAINING纵向温度曲线纵向温度曲线To be choosed in 2 steps分两步选择:1.瓶坯的统一加热 2.(因瓶坯底部和支撑环下部边缘影响的结果)2.根据瓶子的料分布定制(由外形决定)由以下参数控制:灯管加热功率输出百分比4TRAINING
20、TRAINING细节细节 1 在瓶坯底部和瓶颈下部有边界效应在瓶坯底部和瓶颈下部有边界效应细节细节 2瓶颈下部区域厚度小瓶颈下部区域厚度小,不需要很长的热转换时间瓶坯底部厚度大，需要的加热量大，甚至可能使用超出瓶坯范围瓶坯底部厚度大，需要的加热量大，甚至可能使用超出瓶坯范围的加热灯管（如底部下方）的加热灯管（如底部下方）有热分配问题的危险!4瓶坯瓶坯底部和瓶颈下部的加热底部和瓶颈下部的加热TRAININGTRAINING内侧内侧 外侧温度曲线外侧温度曲线内侧需要比外侧高的温度烘箱外一段时间的调整是必要的由以下参数控制:1.功率和加热灯管的数量(如：5 个灯管100%加热比10个灯管50%加热温
21、差要高)2.风扇(=冷却外侧)3.烘箱进出口加热功率的平衡 4.烘箱外调整的时间热转换热转换 4瓶坯内侧的拉伸比外侧要多TRAININGTRAINING4105C95C理想的调整时间TRAININGTRAINING厚瓶坯 如：CSD瓶坯厚部位 如：瓶身和瓶底出烘箱后有更多的时间烘箱进口一侧更多的加热更多的排风灯管更高的功率更多的热转换更多的热转换薄瓶坯 如：纯净水瓶坯薄部位如：瓶颈下部较少的热转换较少的热转换4出烘箱后有较少的时间烘箱两侧同样的加热 较少的排风灯管较少的功率一般都没有问题!TRAININGTRAINING1.The time at disposal for heating pe
22、netration加热处理的时间2.The conditioning time after the exit from the ovens出烘箱后的调整时间 灯管加热和排风 烘箱进口一侧加热功率 烘箱出口一侧加热功率 SFL 系列系列生产量变化改变了什么生产量变化改变了什么?产量产量不充分的热转换 产量产量过度热转换 烘箱进口一侧加热功率(甚至关闭烘箱进口的第一组灯管)4怎么解决怎么解决?TRAININGTRAINING5一次气一次气(10bar)二次气二次气(40bar)减压减压TRAININGTRAINING拉伸杆下降拉伸杆下降速度一次气进入一次气进入压力,流量,延时5气泡的形成Omoge
23、neous stretchVolume 60-70%No uncentered二次气进入二次气进入压力,延时减压排气减压排气时间一次气吹制时间二次气吹制时间TRAININGTRAININGSTRETCH&BLOW-STRETCH&BLOW-MOULDINGMOULDING 2.PRACTICAL TRAININGTRAININGTRAININGTopics:Recipe setting工艺参数设定:Find a thermal profile寻找适合的温度曲线Primary air blow一次气吹制Secondary air blow 二次气吹制Optimization in continu
24、ous production连续生产的优化Long period variations长时期后的变化12345TRAININGTRAINING需要使用多少个灯管参与加热?在瓶坯上标记每个灯管的位置 (作为最终模板eventually use a template)1设定灯管和风扇的参数Decision taken according to the productivity,preform characteristics(thickness,color.)Es.lamps 60%ventilation 70%Modify heatingparametersGlobal temperatureis
25、 correct?Should be from 90C and 100C(pirometer or other kind of sensor)Thermal profilesettingNOYESTRAININGTRAININGMark the position of thelamps in preform1HeatingsFree blowp=2.5-3.5 barIt depends of thepreform thicknessThermal profile is OK?Preform should be stretched with uniformityPower lamps adju
26、stment until the uniformity of stretch hasbeen reachedNOYESPrimary airblowingTRAININGTRAINING1Practical exampleHeating of L3 and L4 not enoughOptimum profileHeating of L1and L2 not enoughTRAININGTRAININGSettings of primary/secondary air blowingprimary:when the stretch rod touches the preform bottom
27、secondary:when the stretch rod reaches the lowest position 2Primary air blowingdescription:without the secondary air,blow a batch of preforms only with primary airAir and stretch rod should be syncronized.Adjustments to carry out in the following order:1.Setting of the best primary air pressure and
28、the best stretch rod speed2.Setting of the primary air delay/advance3.Adjustment of primary air flow regulator in each blow cavityTRAININGTRAINING2Check the conformation of the bubbles target:the bubbles should be stretched with uniformity,with a good disposition of thickness and centeredTRAININGTRA
29、ININGSecondary air enabled:When:stretch rod reaches the lowest positionHow much time:all the remaining time before decompressionwith 30bar of pressure for natural water,light bottle 40bar for CSD 3Blow a batch of preforms with secondary airThe following defects can happen:White area in the bottom lo
30、w temperature of preformchange the lamps power set,set T of ovensair,adjust the fans speedSchretched logosexcess of formation in primary airdelay the primary air,reduce the air pressure,advance the secondary airMaterial bad distributionthermal profile or primary air delay not optimizedoptimize the h
31、eating and the primary air delayTRAININGTRAINING4Found the best recipe loading little preform batches,set the pyrometer with the read value,switch on the feedback and start the production for at least 3 minutes.Defects due to the temperature variation of ovens air can appear(too much material in the
32、 bottom,craters).What can I do?Follow the suggestions:Increase the set T of air andventilationAttention:if T air is too high the risk is:overheating the ovens and stabilization time too longTmax=85CMore power to the lampand more ventilation reduction of air temperature gap between start up and conti
33、nuous productionReduction of preform set T(max 3C)Balancing the effect due to the different temperature of the airIn continuous production the feedback should work around-4%TRAININGTRAINING4set Tair 空气设定温度空气设定温度set Tpreform 瓶坯设定温度瓶坯设定温度Tair 空气实际温度空气实际温度Tpreform 瓶坯实际温度瓶坯实际温度时间温度之后时间温度以前1st.解决方法Increa
34、se Tair set and ventilation增加空气设定温度和排风TRAININGTRAINING4TairTpreformset Tairset TpreformtimetemperatureAfter2nd.解决方法Increasing lamp and ventilation power增加灯管加热功率和排风timetemperatureBeforeTRAININGTRAINING4TairTpreformset Tairset Tpreform3rd.SOLUTIONPreform temperature set reduction降低瓶坯设定温度timetemperatur
35、eBeforetimetemperatureAfterTRAININGTRAINING5What can change in the long period?1.Environment temperature环境温度2.Temperature of preforms in stock瓶坯库存温度What should I do?Optimize again the process:find the new set of the total power for the ovens,ventilation and modify the set temperature of air and pref
36、orm.The ideal thermal profile doesnt change!TRAININGTRAININGProductivity changeWhich are the settings need to be changed in case of higher productivity?1.Heatings:the preform temperature and the thermal profile need to remain the same 2.Thermal inversion:it is needed to guarantee the same difference
37、 of temperature between internal and external(the inversion must be increased)3.Primary pressure:increasing the speed of the stretching rod,the primary air pressure must be increased(the bubble in primary has to remain the same)4.Air inlet set:it could be necessary re-adjust the settings for primary
38、 and secondary air entry 5TRAININGTRAININGProductivity change:high productivity Which are the productivity limits?1.Ovens:To guarantee the sufficient heating power and a higher thermal inversion it should need increase the percentages of the lamps and increase the ventilation.Beyond a limit,the lamp
39、s will arrive to the saturation.For being able to heat ulteriorly the preform,the ventilation needs to be decreased.This will involve a minor thermal inversion and an overheating of the air of the oven(possible problem of overheating of the neck).2.Air inlet:Higher is the speed of the stretching rod
40、s,greater must be the precision of the valves.3.High pressure time:Decreasing the permanence time in cavity,the time available to cool the possible hot zone not stretched(bottle bottom)decreases.5TRAININGTRAININGProductivity change:low productivityWhich are the productivity limits?1.Oven:for too low
41、 speeds there could be a very high thermal inversion or even a thermal preform degradation.In order to decrease the inversion it is possible to switch off the first lamps or all the inlet side oven.No other particular problems need to be note,except to remember the PT100.2.Air inlet:lower is the str
42、etching rod speed,lower must be the air pressure.It cannot be adjusted lower than 6.5-7 bar and this can be a problem.3.Stretching speed:decreasing the strecthing speed it can result a not good uniformity and obtain bottles with low mechanical proprties.Practically,decreasing the stretching speed it is equivalent to have low stretching ratio.5
