<p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp; &nbsp; 有一种理论很注重工作箱内棉子的排出,认为要提高锯齿轧花机的生产率,首先应减少棉子在工作箱内的逗留时间。另外,一定要增加喂花量及棉子的排出量,以保持高产下的平衡。</p><p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; text-align: center; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;"><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/tu8-22.png" _src="http://dayaotex-img.gz.bcebos.com/article/fffspic/tu8-22.png" data-ratio="0.5717821782178217" data-w="404" style="margin: 0px; padding: 0px; max-inline-size: 100%; max-width: 100%; overflow-wrap: break-word !important; outline: none 0px !important; height: auto !important;"></p><section align="left" style="max-inline-size: 100%; margin: 0px; padding: 0px; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); overflow-wrap: break-word !important; outline: none 0px !important;"><p style="max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;</p></section><p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; overflow-wrap: break-word !important; outline: none 0px !important;"><br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;"></p><p><br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;"></p><p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 如图8-22所示,单粒子棉上的纤维是逐渐轧脱的;当单粒子棉初次接触锯齿时,由于棉子上带有最大量的纤维,故能被锯齿勾住的纤维相对较多。随着轧剥次数的增加,棉子上的长纤维越来越少,单粒子棉能被锯齿勾住的纤维也越来越少,即单粒子棉的轧剥机会越来越少。此外,单粒子棉的轧剥进度与其在工作箱内的逗留时间的曲线以横坐标为渐近线,即单粒子棉在工作箱内逗留时间无限长时,其上的长纤维才能被轧剥完。为保证高效的轧花生产率,适当控制棉子的毛头率,及时排出棉子是十分必要的。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; (一)棉子的排出过程<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 在工作箱内,子棉运动到丁区时几乎是沿着棉子梳的倾斜方向移动到锯齿上。带纤维的棉子能被锯齿带走,原因是锯齿直接勾住了其上的纤维,或其上纤维与被锯齿勾住的单粒子棉相粘连。稍带纤维或者仅有短绒的棉子既难于被锯齿勾住又失去了与其他子棉相粘连的条件,只能被挤入锯片间隙。这样,在棉子梳处,锯齿按照棉子带纤维的多少进行了一次分选。没被锯齿选上的、落入锯片间隙的棉子分为两种情况:<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 1.棉子与锯片侧面直接接触<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 与锯片侧面直接接触的这部分棉子与锯片之间产生摩擦力P,P的方向沿接触点锯片的切线方向。锯片侧面对棉子的摩擦作用转化为棉子受到的冲量,如图8-23所示。在锯片滚筒转速不变的条件下,冲量的大小取决于棉子与锯片接触的情况。当棉子含有较多的纤维时,摩擦力冲量较大,反之,较小。</p><p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; text-align: center; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;"><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/tu8-23.png" _src="http://dayaotex-img.gz.bcebos.com/article/fffspic/tu8-23.png" data-ratio="1.4236453201970443" data-w="203" style="margin: 0px; padding: 0px; max-inline-size: 100%; max-width: 100%; overflow-wrap: break-word !important; outline: none 0px !important; height: auto !important;"></p><section align="left" style="max-inline-size: 100%; margin: 0px; padding: 0px; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); overflow-wrap: break-word !important; outline: none 0px !important;"><p style="max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;</p></section><p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; overflow-wrap: break-word !important; outline: none 0px !important;"><br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;"></p><p><br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;"></p><p style="max-inline-size: 100%; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 设某一落入锯片间隙的棉子质量为m,它沿棉子梳移向锯齿的速度为v<sub style="max-inline-size: 100%; margin: 0px; padding: 0px; font-size: 12px; overflow-wrap: break-word !important; outline: none 0px !important;">0</sub>,接触锯片侧面后的速度为v,棉子与锯片之间接触的时间为t,由动量定理可得:<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; mv=mv<sub style="max-inline-size: 100%; margin: 0px; padding: 0px; font-size: 12px; overflow-wrap: break-word !important; outline: none 0px !important;">0</sub>+P<sub style="max-inline-size: 100%; margin: 0px; padding: 0px; font-size: 12px; overflow-wrap: break-word !important; outline: none 0px !important;">t</sub><br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 即棉子在棉子梳处与锯片侧面接触后的动量是Pt和mv<sub style="max-inline-size: 100%; margin: 0px; padding: 0px; font-size: 12px; overflow-wrap: break-word !important; outline: none 0px !important;">0</sub>的合成。mv<sub style="max-inline-size: 100%; margin: 0px; padding: 0px; font-size: 12px; overflow-wrap: break-word !important; outline: none 0px !important;">0</sub>近乎是常量,棉子上含纤维越多,mv受Pt的影响越大,棉子被抛得越远,最终落在离棉子梳较远的轧花肋条上部较平坦的部位。反之,棉子上含纤维越少,mv受Pt的影响越小,棉子被抛得越近,最终落在离棉子梳较近的轧花肋条下部较陡的部位。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 2.棉子未与锯片侧面直接接触<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 未直接接触的这部分棉子可能受到邻近被锯齿勾拉子棉的牵引,而棉子受单粒子棉牵引作用时间的长短取决于棉子和单粒子棉的联结程度。棉子上纤维越多,它与单粒子棉的联结越紧密,棉子受牵引作用的时间越长,当棉子脱离单粒子棉牵引后,最终落在轧花肋条上部较为平坦的地方。反之,棉子上纤维越少,棉子受单粒子棉牵引作用时间越短,最终落在轧花肋条下部较陡的地方。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 落在轧花肋条上的棉子受三个力的作用(由于轧花肋条表面很光滑,棉子与轧花肋条之间的摩擦力可不计),即棉子本身的重力、轧花肋条对棉子的支承力以及锯片侧面对棉子的摩擦力。棉子本身的重力使棉子沿轧花肋条表面向下滑落;锯片对棉子的摩擦力使棉子随锯片转动而沿着轧花肋条表面向上移动。当棉子落在轧花肋条上部平坦处时,棉子重力在轧花肋条表面的切向分力很小,锯片对棉子的摩擦力起主导作用,使棉子沿轧花肋条表面上移,重新回到子棉卷中。落在轧花肋条下部较陡处的棉子受重力作用影响很大,沿轧花肋条表面下滑,离开中箱而排出机外。这样,落入锯片间隙中的棉子再次受到锯片的分选,只有轧净长纤维的棉子被排出机外。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 以上叙述,即“二次分选论”是比较具有代表性的一种说法。还有一种说法认为:子棉卷运动到棉子梳处遇到快速旋转的锯片滚筒时,由于锯片滚筒表面线速度远大于子棉卷表面线速度,被锯齿从外到内撕开一条裂缝,子棉卷中的棉子在惯性离心力及自重作用下,沿裂缝通道排落。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; (二)影响棉子排出的因素<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 排出的棉子毛头率过大,会增大衣亏损失;排出的棉子毛头率过小,会影响皮棉质量及轧花、剥绒生产率,故应把棉子毛头率控制在适宜的范围内。国家标准《棉花细绒棉》<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; (GB1103—1999)中规定棉子毛头率为:加工1级、2级子棉时,不大于0.4%,加工3～5级子棉时,不大于0.6%。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 排出棉子通畅与否对于棉子毛头率及棉子光毛均匀程度影响很大。棉子排出不通畅、喂花速度在中挡以上时,子棉卷很紧实,喂花速度在高挡时,子棉卷就会停转。如果棉子排出通畅,喂花速度在中挡以上时,子棉卷不紧实;喂花速度在高挡时,子棉卷不停转。所以,棉子排出通畅与否非常重要。它主要受以下因素的影响:<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 1.工作箱几何形状<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 形状合理的工作箱能为轧净纤维的棉子及时排出工作箱创造较好的条件。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 2.子棉卷松紧程度<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 棉子在子棉卷疏松的情况下容易排落。因为子棉卷疏松,棉子与子棉卷的抱和作用较弱,棉子易脱离子棉卷而顺利排出。特别是子棉卷在棉子梳处与锯齿接触时,由于单粒子棉运动速度突然加快,子棉卷被锯齿撕开一条裂缝,使棉子能够顺利排出。子棉卷紧时,子棉卷遇到锯齿时就难以形成排子裂缝通道,而且,棉子与子棉卷的抱和作用强,很容易造成棉子排出不畅。为使棉子顺利排出,可调整工作箱抱和板的曲率半径到最大,子棉卷密度为最小,有利于棉子的排出。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 3.棉子梳的调节<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 调节棉子梳的倾斜度对于排子的通畅与否、对控制排出棉子的毛头率是至关重要的。棉子梳向上抬起,子棉卷在棉子梳处的局部密度增加,棉子不易排落;反之,棉子梳向下倾斜,棉子易于排落。所以,棉子梳的调节控制作用的程度与棉子梳的位置、结构有很大关系。新型锯齿轧花机的棉子梳除能进行倾斜度调节外,还能进行进退调节,以调节棉子梳与轧花肋条排的间隙。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 这种双向调节的棉子梳,加强和提高了棉子梳的调控作用,更有利于棉子的排出。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 4.排子道大小<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 排子道是轧花肋条排与阻壳肋条排之间的通道。轧花时,该通道在长度方向上被锯片滚筒分隔成许多“井”状通道。排子道的大小由“井”状通道的长、宽尺寸决定。而“井”状通道的长、宽尺寸由轧花肋条排与阻壳肋条排之间的间隙和锯片片距决定。在其他条件相同的情况下,轧花肋条排与阻壳肋条排的间隙大,棉子易抛射到肋条下部较陡位置,棉子易排落;反之,棉子易抛射到肋条上部平坦部位,棉子不易排落。轧花肋条排和阻壳肋条排可在小范围内调整,但应保证轧花肋条不与锯片滚筒隔圈相碰擦,并保证锯片伸出阻壳肋条的高度。在其他条件相同的情况下,锯片片距大,棉子易排落;反之,棉子不易排落,故锯片片距的缩小是有限度的。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 5.锯片片距及锯齿状态<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 锯片片距大,落于两锯片之间的棉子数量较多,与锯片侧面接触的棉子数量相对较少,即不受冲量作用的棉子多,大多数棉子受重力作用克服子棉卷的联结力和锯片摩擦力相对容易,棉子易于排落。锯片片距小,则与锯片接触的棉子多,棉子不易排出。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 锯齿不锋利,残缺过多,会严重影响锯齿在棉子梳处对带纤维棉子的勾拉,以至于造成排落棉子毛头率大,衣亏损失严重。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 6.轧花肋条的倾斜度<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 当轧花肋条向竖直方向调节时,排子道下部扩大,且肋条上部较平的部位趋于倾斜,增强了棉子重力对排子的作用,使排子通畅。当轧花肋条朝相反的方向调节时,则会影响排子。<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; (三)棉子在工作箱内的运动轨迹<br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;">&nbsp;&nbsp;&nbsp; 欲使符合毛头率要求的棉子及时排出机外,除了在现有的机型上采取合理的工艺参数及改进操作方法以外,另一种方法是对现有排子机构进行革新。</p><section class="_135editor" data-role="paragraph" id="autoparagraph" style="max-inline-size: 100%; margin: 0px; padding: 0px; border: 0px none; z-index: 0; overflow-wrap: break-word !important; outline: none 0px !important;"><p style="max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; overflow-wrap: break-word !important; outline: none 0px !important;"><br style="max-inline-size: 100%; margin: 0px; padding: 0px; font-family: 微软雅黑, &quot;Microsoft YaHei&quot;, sans-serif; font-size: 17px; caret-color: rgb(255, 0, 0); overflow-wrap: break-word !important; outline: none 0px !important;"></p></section>