干网知识培训

1、By Werner Thommen Product manager dryers Andy Zhou Technical service,Dryer Fabrics干网,Types of yarns and materials (原材料种类) Dryend operation, (干燥工艺) Definitions (定义) Dryer Fabric Requirements, (干网要求) Designs & Features (设计与特性) Installation, Tension & Guiding (安装, 张力 与定位) Summary & Questions (总结和问题),Dr

2、yer Fabric Course Outline提纲,Australia(澳大利亚) Bangladesh(孟加拉国) China (中国) India (印度) Indonesia (印尼) Japan (日本) Korea (韩国) Malaysia (马来西亚) New Zealand(新西兰) Pakistan (巴基斯坦) Philippines (菲律宾) Taiwan (台湾) Thailand (泰国) Vietnam (越南),Locations:位置 North America:北美 USA: 7 plants 美国: 7个工厂 Canada: 3 plants 加拿大:

3、 3个工厂 Belgium Czech Republic Asia:亚洲 China 中国 AstenJohnson sales office Singapore,Types of yarns and materials原材料种类,Yarn Types 线的种类,Spun Yarn 细纱 Monofilament 单丝 Round Monofilament 圆形单丝 Shaped Monofilament 其他形状单丝,Regular Round Monofilament常用圆形单丝,Shaped Monofilament 其他形状单丝,Ribbon Shaped Monofilament 带

4、状单丝,Yarn Materials 线的材料,Polyester 聚脂 Polyamides 聚酰胺 PPS 抗磨损聚脂 PEEK 耐高温聚脂,Polyester 聚脂,Key Properties:主要特性 Excellent dimensional stability 尺寸稳定 Excellent tensile strength 良好的抗张强度 Excellent resistance to abrasion 良好的抗磨损性 Chemically resistant to acids 耐酸性 Fair resistance to alkalis 抗碱性 Moderate resista

5、nce to hydrolysis 中等耐水解性,DRY-END OPERATION干燥工艺,Functions of a Dryer Fabric干网的功能,Supports sheet through dryer section(纸张的支撑) full support through Uno-run & Single Tier sections Improves heat & mass transfer(提高热与质量传递) better sheet contact on dryer can,Some Definitions定义,Definition:定义 Volume of air per

6、 unit area that passes through a fabric under a pressure differential of 1/2” of water column. 在1/2”水柱压力差异下通过网的空气数量单位.,Permeability 透气性,Hydrolysis Definition水解,A double decomposition reaction involving the addition of the elements of water and the formation of an acid and a base, an acid and an alco

7、hol, or an acid and phenol, resulting in major tensile loss. 一种包含了水分子的酸合物,或酸和酒精, 或酸和苯酚的复分解反应, 其结果是伸长性的丢失.,Hydrolysis 水解,Yarn degradation caused by a combination of high heat and moisture both heat & moisture must be present.(水解导致线的退化是由高温与湿气引起) Fabric gets “rotten” usually starting on the edges.( 网的腐

8、化往往是从边上开始),Must be dimensionally stable. 尺寸稳定 Provide good runnability 提供良好的运转性 Must have a smooth surface and seam 光滑的表面和接缝 Must be of adequate strength 足够的拉力 Contamination resistant and easy cleaning 抗污及易清洁 Have an even perm-profile 透气性的一致性,Dryer Fabric Requirements干网要求,Dryer Fabric Requirements,H

9、ave the right air-permeability 正确的透气值 Air-perm in relation with:透气性与以下相关 Drying capacity 干燥能力 Sheet stability 纸张稳定性,Dryer Fabric Requirements,Achieve a reasonable life time.达到合理的寿命 Factors affecting the life time:影响寿命的因素 Contamination(污染) Hydrolysis(水解) Chemical degradation(化学退化) Abrasion(磨损),Dryer

10、Fabric Designs & Features设计与特性,MonoTier Concept: Features and BenefitsMonoTier 概念: 特性与优点,Contact Area,MonoTier,Balanced Weave,Same Contact area as fabric Exceptional Strength Non-marking,MonoTier Concept: Pin Seam,Fabric strength comparison,Pin seam,Product Management 18.10.2006,MonoTier,Streamline

11、Coil Seam,Seam Designs 接缝设计,Spiral fabric,Extrafine Spiral design For high speed machines For single tier, Uno Run and conventional positions Low caliper 1.6 mm High contact area 30 % Easy to clean Perm steps 110 - 150 - 200 - 250 cfm,Bi-colored seam spiral,SpiralFine,The MonoTIer advantage of 2 ind

12、ependent warp systems,Abrasion,FABRIC INSTALLATION网的安装,INSTALLING NEW FABRICWITH OLD FABRIC 用旧网安装新网,USING LEAD-ON HARNESS,TYING GUIDE PADDLE,Fabric Installation,The important steps:重要步骤,Ensure all Isolations are in place 隔离装置到位 Center the guide roll 导向居中 Secure guide palm 安全 Align fabric 调整 .,Fabric

13、 Installation,The important steps (contd) : 6. Seaming接缝 Start at guide palm side.从导向端开始 Align Marks调整标记 Pass the pintle trough the seam channel.穿连接线 Use the Seaming assist to minimize tension用接缝辅助使张力最小化 When pulling the wire, do it slowly to avoid friction heat.慢拉以防止摩擦热量的产生 Finish both ends as demo

14、nstrated. 7. Bring Fabric up to Tension Gradually 慢慢加大张力 A new fabric should start with low tension(say 1.0 kN/m)in order to align it on the machine. Increase gradually when the fabric runs straight,Fabric Tension张力,Advantages:优点 Improves drying efficiency by squeezing air out between the web and th

15、e dryer. Forces paper into close and constant contact with steam heated cylinders increasing heat transfer. Machine speed can be increased, steam consumption decreased resulting in reduced operating costs.,Fabric Tension,Disadvantages:缺点 Shortened fabric life due to: Wear from pitted rolls, overstre

16、tching & weakening Bearing wear & drive load increase. Roll deflection: fabric distortion, CMD permeability variation. speed variation between center and edges. Sheet marks from fabric weave pattern.,Recommended:推荐 3 4 kN/m on new machines Follow manufacturers specifications,Fabric Tension,Fabric Cl

17、eaning网的清洁,Shower types冲淋方式 Low pressure chemical shower. roll side of fabric, into nip of first return roll. Low pressure rinse shower. paper side of fabric, end of return run. HP cleaning/rinsing shower. paper side of fabric, perpendicular to fabric. end of return run.,Fabric Cleaning,Cleaning Pro

18、cedure:清洁步骤 Ensure cans are cooled to avoid thermal shock. 确保已经冷却 Crawl speed.爬行速度 Warm water on showers.喷淋水升温 Dilute cleaning solution.稀释清洁剂 Keep fabrics wet.使网湿润 Follow recommended cleaning time.根据建议清洁时间,Thoroughly rinse fabric with fresh water. 用清水彻底冲洗网面,Fabric Cleaning,Advantages:优点 Consistent d

19、ryer performance.网的可靠性 Improved sheet profile.提高纸张质量 Better pocket ventilation. Better fabric life.延长使用寿命 Reduced steam usage. 降低蒸汽用量 Lower energy cost.降低能源成本,Change in Permeability透气性的改变,Fabric Cleaning,There is no quick and easy answer to this question, dryer fabrics should be inspected at regular intervals, both:这里没有直接的回答, 干网需要经常性的定期检查: During Shuts, and 关机时和 While Running 运转时,Fabric Inspection/Removal网的检查/取下,