英语大三总结.doc

简答题 1、when making a blended yarn , in which processing step different fibers may be mixed ?（20课、第3题） In the manufacture of a blend yarn , the fibers may be intimately（紧密地） mixed before yarn manufacturing starts or during the finishing-drawing operation . For nonwovens the fibers must be blended before the fiber mat（垫子） is formed . Unless a thorough blending occurs ,the end product will not be uniform. 2、How to remove the remained moisture in the wool after scouring ?（23、4） In the more primitive(原始的) days of woolen manufacture when wool was washed in rivers and stream, it was presumably（大概地） dried by hand –wringing（湿透的） or by the action of the wind and sun in the open air . Drying by hot air is popular today and is based on the fact that moisture can be transferred（转移） from the wet wool if brought in contact with heated air . Anyway ,hot air in the presence（出席，存在） of wet wool is not sufficient . Before it becomes saturated （饱和的）with moisture the air must be removed , or condensation（浓缩） of water may occur . Adequate（足够的） pressure is necessary to force the air to do more than simply impinge（撞击） on the surface of the wool staples under treatment ; it must be sufficient to ensure that the interior（内部的） of the staples is dried . 3、Describe the work principle of the yarn detector（探测器） ? (26、3） Upon leaving the tension device ,the yarn passes through a detector whose purpose is to detect thick spots. This detector may be as simple as a frame which contains an adjustable（可调整的） blade（叶片） which can be set to allow only predetermined yarn diameters to pass through . This device is often called a snick blade. The detector ,however ,may contain sophisticated（老练的） electronics which continuously monitor the yarn to detect thick or thin portions . 4、What is the purpose of warping ?(27、4） If the fabric forming system is weaving or warp knitting ,some or all of the yarns forming the fabric are presented in sheet form . It is necessary therefore to remove the yarn from the winding