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高分子知识专题培训,内容摘要,1.熔融挤出； 2.高弹态拉伸；,聚丙烯塑料的特性,结晶型塑料，最快结晶温度为135度左右 吸湿性小，可能发生熔体破裂，长期与热金属接触易发生分解 流动性极好 冷却速度快 90以上时易发生变形,何谓塑化,何为塑化?塑化与熔化有何区别? 答：成型物料在挤出机料筒内经过加热、压实以及混合等作用以后，由松散的粉状或粒状固体转变成连续的均化熔体的过程称为塑化。 塑化包含四方面的内容：熔体内组分均匀、密度均匀、黏度均匀和温度分布均匀。而熔化只是将固态原料变为连续熔体，并不一定熔体组分、密度、黏度、温度均匀。,何为熔体破裂,熔体破裂：聚合物熔体在失稳状态下通过模内的流道后，将会变得粗细不均，没有光泽，表面出现粗糙的鲨鱼皮状。在这种情况下，如果继续增大切应力或剪切速率，熔体将呈现波浪、竹节形或周期螺旋形，更严重时将互相断裂成不规则的碎片或小圆柱块，这种现象称为熔体破裂。 失稳流动：大分子链会在极高的剪切速率(106s1)作用下完全被拉直，继续变形就会呈现很大的弹性性质，导致流动无法保持稳定的层流，熔体陷入一种弹性紊乱状态，各点的流速会互相干扰，通常将此现象称为聚合物熔体失稳流动。,克服办法： 提高温度，使熔体引起流动失稳时的极限应力和极限剪切速率提高； 在大截面向小截面流道的过渡处，减小流道的收敛角，使过渡的表壁呈现流线状时，可提高失稳流动时的极限剪切速率。,熔融挤出,1.挤出机 粒料从料斗进入到挤出机的机筒，在热压作用下发生物理变化，并向前推进。由于滤板、机头和机筒的阻力，使粒料压实，排气；与此同时外部热源和物料摩擦热使粒料受热塑化，变成融融粘流态，凭借螺杆推力，定量地从机头挤出,螺杆的结构,螺杆的形式,加料段：对加入的料进行压实和输送，对挤出机的产量影响较大 压缩段：压实、软化，同时将夹带的空气压回到加料口排出。 压缩比：螺杆在加料口的螺槽容积与均化段最后一个螺槽容积之比 均化段：把压缩段送来的熔融物料进一步塑化均匀，使其能定量、定压挤出。,挤出机螺杆的主要参数 1.螺杆直径； 2.长径比； 3.螺槽深度； 4.螺纹厚度。,评价挤出机，从两个方面考虑 1.生产能力的高低，适用范围是否广泛；2.应有较完善的控制系统。,BM型螺杆,分离型螺与普通螺的本质差别在于熔融段有一条起屏障作用的副螺纹把固态塑胶和熔融的塑胶分开。 其特点是剪切强，塑化好。,挤出机机筒,塑料挤出过程,计量泵,模头,塑料熔体在模头流道中的实际分布，由熔体的流动性质、流道的几何形状、通过模头的流动速率以及模头中的温度分布决定。模头设计的一般要求是：流道中无死角，整个出口处熔体流速均匀一致，组装和拆卸容易，模口定型段长度约为模口间隙的10倍，流道几何形状不宜骤然变化和采用小的渐近角。自动调节模头可以在生产过程中逐步优化产品厚度的均匀性。,铸片,2.高弹态拉伸,塑料拉伸变形分为高弹形变和粘性形变。高弹形变增加有限，粘性形变发展却很快，有利于聚合物取向。 （1）在高于粘流温度Tf或熔点（Tm）温度拉伸时，聚合物的大分子活动能力很强，在很小的外应力作用下就会引起分子链解缠、滑移和取向，然而在高温作用下，其分子的解取向速率也会加快，使有效取向度降低。 （2）当温度逐渐升高到Tg以上时，聚合物具有弹性，热运动的能量克服了某些物理交联点的牵制，使链段产生运动，但整个分子链尚不能移动。 （3）当在Tg以下拉伸时，外力只能引起分子链伸缩、振动和键角的微小改变。塑料薄膜的拉伸温度一般在TgTm(或Tf)之间，具体温度根据聚合物的性能决定。,BOPP薄膜生产过程中的取向主要发生在纵向拉伸和横向拉伸过程中，在经过纵向拉伸后，高分子链呈单轴纵向取向，大大提高了铸片的纵向力学性能，进一步横向拉伸后，高分子链呈双轴取向状态。 随着分子链取向度的提高，薄膜中伸直链段数目增多，折叠链段数目相应减少，晶片之间的连接链段逐渐增加，材料的密度和强度都相应提高,纵向拉伸,结晶聚合物结晶速度最快的某个温度，就是最大结晶温度(Tmax)。一般来说，结晶聚合物的最大结晶温度(Tmax)和熔点温度(Tm)存在以下关系：Tmax (0.800.85 )Tm也就是说，晶体生长最大速率大约在熔点温度的0 .80.85倍处。聚合物在Tmax范围，结晶速度快，结晶度急剧增加。,高聚物结晶度高，在拉伸过时容易破膜，所以在拉伸过程中要尽量降低高聚物的结晶速度，控制较低的结晶度，保证拉伸的顺利进行。通过避免在Tmax范围拉伸可以有效的降低结晶速度，保证结晶速度较慢，以利于分子链段的取向；,纵拉,横拉,净化线,横向拉伸,由于片材在拉伸之前已经经历了纵向拉伸，分子在纵向得到了取向，所以在横向拉伸区的温度应该比纵向拉伸区高1525左右。横向拉伸各区温度是影响薄膜机械强度、成膜性、厚度均匀等性能的关键因素 。而温度过高会因起厚度公差大，薄膜雾度大，严重时引起破膜。当然，温度过低也会引起破膜、脱夹等问题。,横向拉伸区整个温度 的分布也是很重要的，各区温度要稳定、均匀。虽然聚合物在拉伸时会产生热量，但在伸长过程中，粘度也会增大，要实现连续拉伸，一般横向拉伸区的温度是递增的。,拉伸破膜的原因及解决办法,在生产过程中，物料从铸片到收卷，整个过程中都有可能破膜。通常，根据破膜位置把破膜分为横拉前破膜、横拉破膜、横拉后破膜。,横拉前破膜,在铸片或纵拉过程中生产条件发生了明显变化、薄膜纵向厚度变化很大或铸片出现很大缺陷时，使得铸片在拉伸过程中局部拉伸应力超过了材料的允许承受应力，导致横向破膜。不过横拉前破膜在正常生产过程中很少见。,横拉破膜,横拉破膜在生产过程中最为常见。薄膜被高速横向拉伸时最容易破裂。一般把横拉破膜分为横向破膜、纵向破膜和脱夹破膜3种类型。,（1）横向破膜 横向破膜原因很多，具体可分为： 原料中含有性能差异较大的杂质(低分子物、油污等)。 铸片上有明显的横向条纹、气泡。 各种不明显的横拉前破膜因素进一步扩大(纵向厚度波动等)，使局部区域应变过大。 铸片的结晶、取向状况偏差过大。,过滤器损坏，片铸片杂质含量高。 机头漏料。 辊面压伤。 废料、设备划伤薄膜。 挤出、纵向拉伸温度设定不当。 烘箱顶部及风管上聚集的各种挥发物落到薄膜上。 另外，链夹损坏也是其中一个重要原因。,纵向破膜,如果出现纵向破膜，可以从以下几个方面分析： 薄膜横向厚度偏差过大。 纵、横向拉伸比过大。 纵向拉伸时边缘温度过高。 纵向拉伸定型温度过高，铸片结晶取向不好。 链夹温度过高。 横拉烘箱内有废料划伤薄膜。,脱夹破膜,脱夹主要从膜片、夹具和工艺3方面分析:： 首先，如果铸片边缘不好或者厚度偏差大，就容易造成脱夹。此时要及时调整铸片工艺，把铸片的缺陷消除。 其次，如果在正常生产中出现脱夹，经人工复位后仍然脱夹，此时就要考虑设备原因，可能是有链夹损坏无法闭合，也可能是有废膜挂在链夹上，或者可能是入口导边器失灵。出现此种情况，要立即停机，并认真检查。 另外，薄膜横向拉伸时预热、拉伸温度过低，入口张力不适宜等也会造成脱夹。,收卷分切,关于收卷和分切，有几篇文献总结了一些经验，会对我们今后的弧度翘边有所帮助。,几种隔膜材料的制造工艺流程,目前市场化的锂离子电池隔膜主要是以聚乙烯、聚丙烯为主的聚烯烃隔膜，包括单层PE,单层PP，三层PP/PE/PP复合膜。现有的聚烯烃隔膜生产工艺可按照干法和湿法分为两大类，同时干法又可细分为单向拉伸工艺和双向拉伸工艺。 干法单向拉伸工艺是通过生产硬弹性纤维的方法，制备出低结晶度的高取向聚丙烯或聚乙烯薄膜，在高温退火获得高结晶度的取向薄膜。这种薄膜先在低温下进行拉伸形成银纹等微缺陷，然后高温下使缺陷拉开，形成微孔。这种方法最早见于美国Celanse公司1970年专利,USPatent3426754，用于生产单层的聚丙烯多孔膜。该工艺经过几十年的发展在美国、日本已经非常成熟，现在美国Celgard公司、日本UBE公司采用此种工艺生产单层PP、PE以及三层PP/PE/PP复合膜。用这种方法生产的隔膜具有扁长的微孔结构，由于只进行单向拉伸，隔膜的横向强度比较差,但正是由于没有进行横向拉伸,横向几乎没有热收缩。 由于受国外专利保护及知识产权方面的制约，国内采用单向拉伸方法制备隔膜的工业化进展很慢。国内2004年已经开始有这方面工艺的专利，和国外专利的不同之处在于，在聚丙烯中加入具有结晶促进作用的成核剂以及油类添加剂剂，加速了退火过程中的结晶速率。,多层膜的生产工艺示意图,湿法又称相分离法或热致相分离法，将高沸点小分子作为致孔剂添加到聚烯烃中，加热熔融成均匀体系，然后降温发生相分离，拉伸后用有机溶剂萃取出小分子，可制备出相互贯通的微孔膜材料，适用的材料广。采用该法的具有代表性的公司有日本旭化成、东燃及美国Entek等，目前主要用于单层的PE隔膜。用湿法双向拉伸方法生产的隔膜由于经过了双向拉伸具有较高的纵向和横向强度。国内佛山塑料集团在2004年建立了一条采用湿法工艺生产PE隔膜的双向拉伸生产线，2005年底开始有产品在市场上销售。,Definition of defect,Anything that dissatisfies your Customer,Defect are good!,“Associates need to feel comfortable in identifying and reporting defects.”,The effects of defects,Every occurrence of a defect within the process requires time to inspect,fix,and re-inspect. Average cycle time is directly proportional to the total number of defects in the process.,Welcome to Motorolas Quality Story,Culture,Culture guides the enterprises Day-To-Day behavior,The nature of culture,Culture provides its members with guidelines for dealing with just about everything Much of every culture is cvert and implicit largely submerged like an iceberg Cultures are constantly changing and evolving. When culture and strategy clash,invariably culture wins out. If the organizational culture does not embrac initiatives related to change,overall change efforts will fail,There is no such thing as “Were different”,WERE DIFFERENT,Functions in a typical organization,Accounting Advertising Distribution Energy management Environmental affairs External affairs Facilities Finance Health & safety Human resources legal,Manufacturing Marketing Profuct/service development Payroll Purchasing Sales Scheduling Training Transportation Travel,The evolution of motorolas quality culuture,1979 “Our quality stinks”,1980 corporate quality officer named,1981 motorola training & education center(Mtec) established,communications sector begins total defects per unit measurement(TDU) - july manufactured products - november sales orders,chairman changes agenda of customer visits created “the card”,Evolution continues!,Corporation adipts six sigma 2 year- 10x; 4 year- 100x uality improvement Six sigma by 1992 goal is set,1988 Malcolm baldrige nation quality award Mapped ISO 9001 into quality system review(QSR),1992 10x redustion in defect eveery 2 years customer satisfaction metrics 10x times improvement in cycle time in 5 years Changed measurement base to parts per billion,Evolution continues!,How many objectives are there in your organization?,Key beliefs how we will always act Constant respect for people Uncompromising integrity KEY GOALS what we must accomplish Best in class People Markting Technology Products:softwarehardware and systems Manufaction Service Increased global market share Superior finacical results KEY INITATIVES how we will do it Six sigma quality total cycle time reduction product manufaction and environmental leadership Prfit improvement Empowerment for all in a participative Cooperative and creatice workplace,Our fundamental objective (Everyones overriding responsibility) Total customer satifaction,Our fundamental objective,Total customer satisfaction Key beilfes How we will always act Key goals What we must accomplish Key initiatives How we will do it,Everyones overriding responsibility,KEY INITATIVES how we will do it, Six sigma quality total cycle time reduction product manufaction and environmental leadership Prfit improvement Empowerment for all in a participative Cooperative and creatice workplace,Consistent focus,Card created & adopted 1986 Five minor changes in1992 No significant changes during five different chairman Bob Galvin George Fisher Bill Wiese Gary Tooker Chris Galvin,Creating and managing the Six Sigma quality culture,Sis sigma quality,One of the two key drivers of increased Total customer satisfation and reduced cost,Product/Service is delivered when promised,Every occurrence of a defect within the process requires time to inspect,fix,and re-inspect Average cycle time is directly proportional to the total number of defects in the process.,Product/service is delivered with no defects,No test/inspection is 100% effective in finding defects. Delovered defects escape test/inspection within the process. Delivered defects are directly proportional to the total number of defects in the entire process,Six sigma quality impoves customer satisfaction,Reducing the total defects in the enire process reduces: Delivery delinquencies; Delivery defects; Early life failure rate;and therefore Increases customer satisfaction and Decreases warranty cost!,Process cost and defects,Reducing the total defects in the entire process: Reduces the cycle time per unit Reducing WIP(Work in process) Reducing inventory carrying costs Resuces defect inspection,analysis,and repair cost;therefore Decreases “Manufacturing” cost,Cost/Quality,Six sigma has shown that The highest quality producer is The lowest Cost producer,TDU is the best measure of the over all quality of the process TDU is the independent variable Process yields are dependent upon TDU,The common metric: Total defects per unit(TDU),Defining a unit,A “unit” may be as diverse as a: Piece of equipment Line of software Order Technical manual Medical claim Wire transfer Hour of labor Customer contact Anything that is measurable & understandable by the person who is trying to reduce defects,Sigma,a figure of merit,TDUcould be expected to be proportional to the complexity of the unit Complexity is directly proporttional to the number of opportunities to creat a defect To normalize processes of different complexity, we use:,Total defects Opportunities From which we can calculate sigma,DPMO =,x 1,000,000,Improvement,7,Sigma(+1.5 sigma shift),1,10,100,1K,10K,100K,2,3,4,5,6,(66810 ppm),(6210 ppm),(233 ppm),(3.4 ppm),30x Improvement,10x Improvement,70x Improvement,6,5,3,4,Defects per Million opportunities,Benchmarking,Best in class,internal + external Repair costs, 10%,Average company, 1%,Defects per Million opportunities,Sigma(+1.5 sigma shift),2,3,4,5,6,7,Restauant bills,Doctor prescription writing,Payroll processing,Order write-up,Journal vouchers,Wire transfer,Airline baggage handing,Purchased material lot reject rate,Benchmarking,Best in class,Average company,Sigma(+1.5 sigma shift),Defects per Million opportunities,Process quality levels may vary widely within a company,(0.25 PPM),1,10,100,1K,10K,100K,2,3,4,5,6,7,Airline baggage handling,Domestic airline flight fatality raate,Best in class,Average company,Sigma(+1.5 sigma shift),Defects per Million opportunities,Implementation of the six sigma culture,Total sustomer satisfaction,Six steps to six sigma & design for manufacturability,Cycle time reduction,Motorolas black belt,Problem-solving tools,驅動力來自評量指標以及合理 且具挑戰性的目標,The six-steps design process,Manufactued product Identify physical and functional requirements of customer Determine characteristics of product critical to each Determine for each characteristic,whether controlled by part,process,or both Determine maximum range of each characteristics If CP2 redesign material,profuct,and process as required.,Administrative/office Identify the work you do(your product) Identify who your work is for(your customer) Identify what you need to do your work,and from whom(your supplier) Map the process. Mistake-proof the process and eliminate delays. Estableish quality and cycle time measurement and improvement goals.,Cycle time reduction,Will be coverd in detail afer lunch,Problem solving identification tool,All member of the organization should have trining in problem solving indentification tools Flow charts Brain storming Pareto charts Cause & effect diagram,Black belt tools,Process characterization Process improvements Graphical data analysis Distribution analysis(graphical and numberical) Comparative methods(graphical and numberical) Process sources of variation Measurement system analysis,Process control(SPC) Process capability(Cp and Cpk) Confidence intervals Design of experiments Linear regression Screening experiments Optimization using response surface methodology,Black belt tool(cont),Maanagement of the quality/continuous improvement process,Methodology to continuoisly reduce defects Regular review of DPMO performance Quality system review Corporate quality council,Institutionalize solutions,Process step 1,Process step 2,Process step 3,supplier,customer,Record defects,Trend chart / Goal,Record defects,Record defects,Record defects,Record defects,Continuous improvement meyhodology,Results & institutionalize,Problem splve,Defect analysis is done by the appropriate organization: Marketing Engineering Manufacturing Materials service etc,Process step 1,Process step 2,Process step 3,Record defects,Trend chart/Goal,Record defects,Record defects,Record defects,Record defects,supplier,customer,Institutionalize solutions,Continuous improvement meyhodology,Results & institutionalize,Problem splve,Defect analysis is done by the appropriate organization: Marketing Engineering Manufacturing Materials service etc,Process step 1,Process step 2,Process step 3,Record defects,Trend chart/Goal,Record defects,Record defects,Record defects,Record defects,supplier,customer,Institutionalize solutions,procedure,DPMO Enables regular review of continuous improvement performance,Corporate level review Business level review Group or division review Product line review Production line review Operator level review Same measurement same improvement goal,Spectrum CVD,100,50,20,10,5,2,1,0.5,0.2,0.1,Total defects per unit,Vision only,TDU,1989,1990,1991,1992,1993,1994,Years,4 = 188,5,5,6,Guidelines,1996年7月,品質評鑑系統,QSR：assessment vehicle for the total organization,Sets a common goal of perfection Drives progress to world class standards Provides an awardreness of quality process requirments Cross-fertilization of ideas(knowledge sharing) Teaching tool(auditors and auditees) Information source for registrars,This id the “enngine” of a self sustaining contibuous improvement process Without it “virtually” all well-meaning quality initiatives FAIL,This is important Unfortunately this is where Many organization start and End-in FAILURE.,Best practices Documentation Conformance Compliance Audit,Motorola “QSR” Quality system review,Institutionalize Solutions,Process Step 1,Process Step 2,Process Step 3,SUPPLIER,Record Defects,Record Defects,Record Defects,Record Defects,Record Defects,Continuous Improvement Methodology,Results & Institutionalize,Problem Solve,Defect Analysis is done by the Appropriate Organization: Marketing Engineering Manufacturing Materials Service Etc.,Corporate quality council,Quality managers of all major operations Corporate-wide programs Quality system reviews of all major operations,Quality council,CQO,Bussiness units,Management board,QSR process,cusomers,suppliers,Motorola University courseware,assess,Quality reviews Short-term results,教育,Recommendations on vision and direction,The role of quality management at motorola Internal customer advocate Lead Teach audit,Culture change is driven by measurements & rewards,Measurements and rewards must be consistent with change objectives;what you measure is what you get Processes must be changed to achieve the measured operational goals,Six sigma provides.,A method to drive quality improvement A common language-defects,continuous improvement,six sigma A method of measurement A method of comparison A method of providing common reach out goals,Paradigm shifts,Start counting defects .27% bad vs. 99.73% good Change unit of measure 2,700 PPM vs. .27% bad,What is six sigma,It is a culture change for a complete organization Thats: Individually driven but involves everyone Continuous process Consistent throughout the organization Measurement driven Based on the premise “Everyone wants to do the best job they can“ It is not a numbers game,Was the meeting necessary? Was ther an objective communicated in advance? Was time used effectively? Was there adequate advance information to help me understand and contribute to the objective? Did I contributen to the objective? Was the objective accomplished?,meeting: _ Date: _,yes,no,Was the meeting necessary? Was ther an objective communicated in advance? Was time used effectively? Was there adequate advance information to help me understand and contribute to the objective? Did I contributen to the objective? Was the objective accomplished?,meeting: _ Date: _,yes,no,Requirements for culture change,Top-down commitment and involvement Set the example,be active in the audit process Measurement system to track progress At both macro and micro level Common well-understood set of metrics Tough goal setting(reach out!) Provide the required education Spread the success story Shared the rewards with those that that contributed,10 year journey 1990 through 2000,Quality Through defect elimination -we have eliminated 99.7% of in proces defects (5.60) COPQ (cost of poor quality) - reduced 84% on a per unit basis Manufacturing cost saving - cumulative saving over $18.0 billion Product reliability - MTBF . . . increased 5-10 fold,Financial Sales up 2.9x，$37.6 billion - anaverage compounded growth rate of 13.2% per year Employee productivity -increased 408%, Motorola University,years,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,0,50,100,150,200,250,97,98,99,300,00,Sales per employee (thousands),sales,Question & answers,
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