1、Combing,The second step in the cotton system is to begin to align the fibers and form a continuous strand. To accomplish this task, the fibers must be separated almost to a single-fiber state so they can be reassembled. This very complete separation also results in very efficient cleaning. The proce
2、ss of fiber-to-fiber separation is called carding.,Carding involves passing the picker lap through hundreds of fine wires on a card machine. One set of wires is usually mounted on revolving surface flats. The picker lap is pulled through a small gap (0.01 inches or o.25 millimeters) between these tw
3、o surfaces by the rotation of the cylinder. The teasing action of the wires completes fiber separation, removes extremely short fibers and more debris, and mixes fibers while aligning them roughly parallel to each other.,A thin web of fiber is formed. Because a web is difficult to handle in further
4、processing, it is shaped into a rope-like strand of partially aligned fibers. Cotton webs move through a funnel-shaped device. The rope-like strand formed is the card sliver, “a continuous strand of loosely assembled fibers that is approximately uniform in cross-sectional area and without twist.” It
5、 is about the size of a persons thumb and is not very uniform in diameter.,The third step (necessary only when combed yarns are being manufactured) is to extract the shorter fibers and continue to align the longer fibers. The card sliver is formed into a combed sliver. In this process, 10-15% of the
6、 shortest fibers in the card sliver may be removed; this portion becomes waste. In combing, the card sliver is drawn and formed into a lap, which is then combed.,The lap is literally torn to pieces in successive tufts. Both ends of each tuft are combed with metal combs, and the tufts are subsequentl
7、y reassembled into a combed sliver. The combing operation may be used to enable the ultimate yarn to be smoother, finer, stronger, and more uniform. It is used in the production of combed cotton yarns, worsted yarns, some flax yarns, and spun silk yarns.,第六章 精梳,6.1 概述 一、目的与任务 1、排除短纤维，提高纤维长度整齐度 2、清除棉
8、结、杂质和疵点 3、使纤维进一步伸直、平行、分离 4、制成符合要求的精梳条,The basic objectives of combing are:,Removal of the short fibers; Removal of non-fibrous impurities which may be called trash, and imperfections such as neps and slubs; Straightening and parallelization of the long fibers which are retained.,二、精梳机的种类,1、直型精梳机 特点：
9、 从喂入到输出的工艺路线为直线。 梳理作用是间歇式周期进行的。,分类： 前摆式：分离（拔取）罗拉作前后摆动，而钳板部分固定，用于毛、麻、绢及化纤的精梳 后摆式：钳板和喂入机构作前后摆动，而拔取（分离）罗拉固定，用于棉纺的精梳 前后摆动式（意大利PSD）：钳板部分和分离部分都摆动,2、圆型精梳机（圆梳机）：从喂入到输出的工艺路线呈圆周形运行，包括绢纺的圆形梳绵机、亚麻纺的栉梳机。,圆行梳绵机,亚麻栉梳机,1、圆梳工艺绢纺原料初加工精干绵选别给湿配绵开绵切绵圆梳梳绵排绵精梳绵延展制条并条(道)粗纱细纱后加工 2、直型精梳工艺绢纺原料初加工精干绵选别给湿配绵开松罗拉梳绵理条(2道)直型精梳针梳4道粗
10、纱细纱后加工,三、精梳准备,1、任务： 改善条子内的纤维排列结构，提高纤维伸直平行度，减少精梳机加工时可纺纤维的损失，同时减少加工时纤维和梳针的损伤。 根据喂入精梳机的需要，制成均匀的小卷（棉纺）或条子（毛、麻、绢纺）。,2、棉精梳准备 （1）精梳准备机器 预并条机 条卷机 并卷机 条并卷联合机,条卷机,并卷机,条并卷联合机,（2）精梳准备工艺 梳棉预并条条卷精梳特点：国内使用较多，设备结构简单，但制成的小卷横向均匀度差。 梳棉条卷并卷精梳特点：此工序制成的小卷，横向均匀度好，有利于精梳时钳板的握持，使每排梳针作用的纤维数均匀，且落棉均匀。,梳棉预并条并卷联合精梳特点：由于牵伸倍数和并合数较大
11、，纤维伸直度和小卷均匀度好，但条并卷联合机占地面积大，且小卷易粘连，对车间温湿度要求高。,3、长纤维精梳准备,毛精梳准备采用三道针梳 麻、绢精梳前准备采用二道针梳,针梳机,4、精梳准备的工艺道数 喂入精梳机的纤维应尽量伸直平行，如喂入纤维呈弯钩状态，也应以前弯钩喂入较好。 梳理机输出的生条中以后弯钩居多 精梳准备工艺道数为偶数道,5.2 精梳机的工艺过程及运动配合,一、棉精梳机（后摆式）,1、机构组成,（1）喂入机构给棉罗拉 （2）钳持机构上、下钳板 （3）梳理机构锡林、顶梳 （4）拔取分离机构分离罗拉、分离 皮辊 （5）出条机构车面集合器、车面压辊、牵伸罗拉、圈条压辊、圈条器 （6）清洁机构毛刷、尘笼,
