8-涂布技术与设备.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,涂布技术与设备,1,Introduction,前言,We will review paper coating equipment,the basic concepts will be discussed along with:,我们将回顾一下涂布的设备，并依次讨论一下其基本概念,-advantages in paper quality,对纸张的优点,-disadvantages,对纸张的缺点,-operational issues,纸机操作的影响,These things are important to your ability to problem solve and provide detailed feed back to principle and internal customers like TMC.,这些方面对于提高解决问题的能力，并提高反馈问题的能力都是很有帮助的。,2,Fundamentals,基本原理,Almost all coaters consist of two functions:,所有的涂布机都具有两种功能：,Application,上料装置,metering,计量装置,3,4,Application,consists of applying more material than is needed in the final product,上料,是指将过量的涂料涂到纸张表面,Metering,methods remove the excess in a way which leaves the desired coating quality at the desired production rate,计量,是指将过量的涂料从纸层移除，达到需要的涂布量,5,1,、典型的涂层厚度为,5-20,微米,2,、典型的单面涂布量,5-20,克,/,平方米,6,涂布纸的分类,Lightweight coated:5-10 g/m2 per side,Single-coated,medium weight 8-16 g/m2 per side,Double-coated 14-26 g/m 2 per side,Triplecoated 24-40 g/m 2 per side.,7,固含量要高，以达到节省能量的目的,印刷纸典型的固含量,50-70%,某些功能性的颜料涂布纸固含量,10-30%,随着纸机车速的提高，防止涂层里面出现空气是非常关键的,8,目前涂布技术的发展,上料装置,保证纸张上每个点被涂料覆盖,计量装置,精确对纸张进行涂布,9,涂布上料和计量分类,10,上料系统,11,上料装置应该具备的特征,使涂料盘外形与上涂辊一致，消除死角，浆系统内的涂料降低到最低限度,用水冷壁冷却表面促使结露水，以防止溢出物与喷溅物结垢硬化，从而方便清洗,支持刮刀架的横梁要有较大的截面以防止下弯，用水循环控制温度,有一组空气管操纵的夹紧装置,12,辊式涂布,APLICATION ROLL,13,使用于大多数纸张涂布,从车速小于,500,米,/,分钟,1500,米,/,分钟都能适应,14,组成,-,上涂辊 背辊 涂料盘和刮刀片,由两个不同直径的辊子组成，辊子表面被橡胶覆盖，均是主动,背辊（,BACK ROLL,）直径大，速度,=,纸机车速,上涂辊,(APPLICATOR ROLL),直径是背辊的,30-40%,，速度是纸机速度的,15-25%,典型的辊间距离是,0.5-1.5mm,15,16,两辊之间的距离,上料辊的速度,涂料的粘度,关键参数,17,涂布过程的三个阶段,18,1,、上料阶段,-,涂料和纸张接触,2,、驻留阶段,-,上料至计量之间,3,、计量阶段,-,有刮刀、棒式和气刀计量,19,在接触阶段,2-5ms,，压区内的涂料承受了压力脉冲，最大压力在,05-4BARS,，主要依靠于车速、压区宽度和涂料粘度,由于压力存在，涂料滤饼开始形成；涂料中的液体渗透到纸张内部,当上料辊与纸张分离后，压力下降；压力甚至低于大气压，形成气穴,驻留期大约持续,20-50ms,，依靠于车速和辊的直径；在驻留期主要依靠纸张的吸水脱除涂料中的水分。,20,在计量阶段，纸张上的涂料组成分两个部分：,1,、几微米厚的涂料滤饼,2,、在滤饼表面的液体层,滤饼层的厚度为,2-4,微米，相当于,3-5,克,/,平方米涂料；大约,3-6,层颜料积层！,21,所以，辊式上料也称为,-,长驻留上料涂布,22,随着纸机车速的增加，进入压区、通过压区或回流到涂料盘的,涂料增加，容易导致飞溅,SPLASH,和漏涂现象的发生！,23,涂层分离,SPLIT,，不能形成完全均匀的表面，取决于涂料的粘度和表面张力,SPLIT,容易形成,RIBBED PATTERN,在纸张表面和涂布辊表面,纸机车速越高，,RIBBED,又导致,DROPLETSD,的形成，最终涂布纸质量发生变化解决,RIBBED,的方法：采用,JET APPLICATION,喷射上料装置,24,短驻留涂布,SDTA,25,26,短驻留上料装置,27,对纸张强度要求没有长驻留高,刮刀承受的负荷小,纸张断头少,28,SDTA,的脱水,压力,时间,原纸的吸受,一定温度下，涂料对脱水的抵抗力,温度,29,由于短驻留脱水时间，在驻留区承受的压力小，所以不会导致涂料的强烈脱水,短驻留回流压区与计量刮刀之间的距离为,30-50mm,当纸机车速为,1000-1500m/min,时，驻留时间为,1.2-3,毫秒；与,600mm,长驻留相比，驻留时间只有其,1/10,30,短驻留原纸回湿现象少,在涂布头处纸张的强度损失少,31,两种驻留上料的比较,32,由于短驻留上料涂料失水不严重，涂层滤饼不容易形成,如果形成涂布滤饼，则在刮刀处涂料的固含量比泵送过来的新鲜涂料要高，结果导致涂料头的压力上升，结果导致过多的涂布缺陷产生和纸张断头。,33,短驻留对纸张质量的影响,短驻留主要用于低、中量涂布,6-11,克,/,平方米,涂料固含量为,59-64%,34,短驻留为什么产生比较平滑的涂层表面？,fiber roughening,35,短驻留条痕,short dwell streaks,36,37,短驻留涂布量为,15,克,/,平方米；长驻留涂布和喷射涂布要高,20,克,/,平方米,38,消除短驻留涂布条痕的措施,39,喷射上料,JET APPLICATOR,40,Voith Dynamic Jetflow C,41,辊式涂布的取代产品,两把刮刀，使得控制困难；纸张张力不容易控制,42,Valmet Opticoat Duo,43,Valmet Opticoat,44,上述几种喷射上料涂布难以在实际生产中应用。,45,Another example of premetered jet applicator(Valmet Opticoat).,46,Free jet applicators,47,FREE JET APPLICATOR,的工作原理,48,Backing roll,Nozzle gap 0.61.2 mm,Premetered colour,150-200.ml/m,Colour supply,Paper,20-40,49,50,51,52,53,消除了,FILM SPLIT,和溢流，喷出的层状涂料均匀一致,影响因素主要包括：,流动速率,堰板宽度,喷射角,喷射距离,54,55,56,57,计量装置,58,Fundamentals,page 2,基本原理,第二页,We will consider the four most popular coating methods:,Blade coating both bent and stiff,刮刀涂布，硬刮刀和软刮刀,Air Knife Coating,气刀式涂布,Rod Coating,棒刀式涂布,Metering Size Press/Roll,计量式施胶涂布,/,辊式,59,Blade vs Airknife vs Rod/Metering Size Press,刮刀式涂布和棒式,/,计量式施胶涂布的比较,60,影响涂布机运转的因素,61,刮刀式涂布,Blade coaters are the most commonly used metering device in the paper&board industry,在造纸工业的涂布应用中刮刀式涂布是最,常见的方式,ridged blade,硬刮刀,bent blade,软刮刀,62,63,64,65,Typical Operational Conditions for Blade Coaters,刮刀涂布的典型工作条件,Head angle,0,刮刀角,35 to 50,15 to 25,Coating solids,涂料固含量,45 to 70,45 to 70,Coater Speed,涂布车速,To 2000 m/min,200 to 1200 m/min,Coating Visc.,涂料粘度,800-3000,800-1500,Best suited for,最适合于,LWC,pre-coats and low coat weight,Board and high coat weights,Biggest concern,最关系到,Blade streaks,刮刀条纹,Blade streaks,刮刀条纹,Stiff Blade,硬刮刀,Bent Blade,软刮刀,66,Blade Coaters-Ridged,刮刀涂布机,硬刮刀,Ridged blade coater advantages,硬刮刀涂布的优点,平整的纸面,-,优异的凹版和胶版印刷性能,高速或高固含量下的良好的涂布量控制,当用短留着型涂布设备时，非常适合轻涂纸,LWC,67,Stiff Blade,Bent Blade,Immobilized,coating,layer,Coating colour,Paper,P 5.28-BLAD-TE-0152e,Blade Operation Modus,68,68,blade angle,adjustment,blade load,adjustment,DynaBlade C,Coat weight control,69,69,Ridged blade disadvantages,硬刮刀涂布的缺点,在低速时很难达到高的涂布量,刮刀压力越大，保水性越差,erational issues,操作方面,blade lines/streaks,刮刀条痕,blade wear can be high,刮刀磨损严重,70,Blade Coaters-Bent,刮刀涂布机,软刮刀,Bent blade coater advantages,软刮刀涂布的优点,same smooth coating as stiff blade,像硬刮刀一样的平整纸面,ability to obtain high coat weight at low speed or solids,在较低的车速或固含量下，得到较高的涂布量,can apply high coat weight on smooth substrates with few blade lines,在光滑的底面上得到高的涂布量，刮刀条痕较少,less problems with streaks than stiff blade,刮刀条痕较硬刮刀少,71,Bent blade disadvantages,软刮刀涂布的缺点,poor ability to achieve low coat weight at high speeds,在高速下较难达到高的涂布量,high coating dewatering at high blade angle/pressure,在大的刮刀角度或加压时保水性能差,Operational issues,blade lines/streaks,刮刀条痕,blade wear can be high,刮刀磨损严重,72,Influence Factors Coat Weight g/m,Raw paper parameters:,Absorbancy(Cobb test),furnish,porosity,Coating colour parameters:,Viscosity mPa.s,solids content%,binders,Pre-metering parameter:,Colour pump rate m/h,Metering element parameters:,Metering blade angle,Blade load through spacer unit setting mm,Blade thickness,73,73,Air Knife Coaters,气刀式涂布机,AK coater advantages,气刀式涂布机的优点,uniform thickness coat important for optical uniformity,均一的涂层厚度，对保持均一的光学性能非常重要,versatile in coat weight and the uniform thickness is important for many functional coatings,涂布量的灵活性和均一的涂层厚度可以适应多种涂布的需求,74,AK coater disadvantages,气刀式涂布机的缺点,requires low viscosity/solids&thus high drying load,需要较低的粘度,/,固含量，因为干燥的需求比较大,can have patterns,会形成花斑,entrained air and porous coatings,空气会进入涂层形成中空的涂层,75,Operational issues,操作方面,lips become plugged,especially at higher speed,喷嘴会堵赛，尤其是在高速时,can only be used on low speed&coaters under 500 m/min,只能应用于低于,500m/min,的涂布机,76,Airknife Coater,气刀式涂布机,77,Airknife Coater double knife w/blowoff pan,气刀式涂布机,-,带吹气面板的双刀型,78,Rod Coaters,棒式涂布机,79,Rod coater advantages,棒刀式涂布机的优点,free of blade lines,没有刮刀条痕,rugged/excellent for base coats,适合于底涂,80,Rod coater disadvantages,棒式涂布机的缺点,coatings can have patterns,涂层易形成花斑solids or viscosity change coat weight,固含量或粘度直接影响涂布量,81,Operational issues,操作方面,rod life is long compared to blade,棒刀的寿命高于刮刀,coat weight control is difficult.especially at high speed,涂布量的控制比较难,-,尤其在高速纸机上,82,Elements of Rod Coater,Jagenberg type,棒刀涂布机的组成,83,Rod Affect on Coating Smoothness,棒刀对涂层平滑度的影响,84,Metering Size Press Coaters,计量式施胶涂布,85,Speedsizer:,Principle arrangement and components,Applicator,Metering,element,Return flow,Rest film,(10-40%),Web tension,50-500 N/m,Airturn,Applicator,roll 800-,1600 mm,FL,Roll nip,15-45 mm,Line load(N/m),Roll cover(P&J),15-20 mm,Premetered film,5-50 ml/m,2,(=100%),FL,86,86,87,87,SpeedSizer AT web run,88,88,89,90,施胶棒计量,施胶棒转动,液压马达,施胶棒从两边转动,施胶棒与施胶辊转动方向相反,转动速度,-50-100 rpm 表面施胶,-150-200 rpm 涂涂料,91,用于涂布和表面施胶的施胶棒,-平滑的施胶棒直径12-35mm,-带槽的施胶棒直径9.83-15mm and 16-25mm,膜施胶工作原理：,1 预计量施胶辊表面的湿膜量,2 将湿膜传递到纸幅上,3 不固定的膜层分离,4 固定的膜层的水准测量,92,膜在施胶辊上的传递,93,带槽的施胶棒：施胶量测量,表面施胶（沟纹棒施胶量每面0.5-4 g/m,2,固含量3-15%,涂料（光滑棒）,涂布量范围 2-12 g/m/side,固含量 40-68%,车速 200 2000 m/min,94,膜传递涂布，,难达到,高涂布量,95,MSP coater advantages,计量式施胶涂布,free of blade lines,没有刮刀条痕,rugged/excellent for base coats or LWC,适合于底涂,can run at speeds over 2000 m/min,运转车速可以超过,2000m/min,can coat two sides simultaneously,同时两面涂布,low capital cost,成本低,96,Rod coater disadvantages,CD profile can be difficult,CD,向的横幅控制比较难,coat weight control limited&sensitive to coating vis.,涂布量控制较难，对涂料粘度比较敏感,Operational issues,applicator roll condition critical to good surface quality,上料辊的工作状况对纸张表面质量有很大影响,97,Metering Size Press Coater,计量式施胶涂布,98,Metering Size Press Coater,计量式施胶涂布,99,Metering Size Press Coater,计量式施胶涂布,100,Metering Size Press Coater,计量式施胶涂布,101,MSP,容易导致的问题,运行性问题：,淀粉在计量棒分离,不可控制的纸幅从施胶辊分离,在压区出口处纸幅转移,计量棒上散开的薄雾,：,计量棒压力高易产生薄雾,辊壳硬更容易产生薄雾,增加计量棒的转速可减少薄雾,计量棒喷蒸汽可减少薄雾,计量棒运转中保持清洁，不容易产生薄雾,102,103,104,总 结,105,Selection of coating equipment is a critical step in making the right product for the market,在生产市场上需要的涂布纸时第一步就是选择好涂布机的类型,Understanding the fundamental principles of each are necessary to gaining advance knowledge,为了获得先进的涂布技术，了解每一种涂布机的基本工作原理是必需的,106,One must weight the advantages and disadvantages of our choices,no piece of equipment is without problems,我们必须衡量每一种涂布机的优点和缺点，没有一种涂布机是完美无缺的,107,谢 谢！,108,