<div><section data-role="paragraph" class="_135editor" style="max-inline-size: 100%; margin: 0px; padding: 0px; border: 0px none; z-index: 0; overflow-wrap: break-word !important; outline: none 0px !important;"><section 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;"><section 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;">　　1．纱线的主要强力指标&nbsp; 主要包括断裂强力、断裂应力、断裂强度、断裂长度、断裂伸长、湿干强度比、10％定伸长负荷等，其与纤维的强力指标的表达意义和计算方法相同，详见第一章第三节，这里不再赘述。</p><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; overflow-wrap: break-word !important; outline: none 0px !important;"></p><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;">　　2．混纺纱的强力&nbsp; 混纺纱的强力并不像直观想象的那样，强力弱的加上强力大的就一定得到一个强力中等的。它不仅与纤维的强力有关，还与混纺纤维的伸长能力的差异密切相关。</p><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; overflow-wrap: break-word !important; outline: none 0px !important;"></p><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;">　　假设混纺纱中只有1、2两种纤维；纱线的断裂只是由于纤维的断裂而无滑脱；混纺纱中纤维混合均匀；两种纤维线密度相同。在此假设下，混纺纱的强力有三种情况：</p><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></p></section></section></section></div><div style="text-align: center; "><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/fzmlsj1416.png"></div><div style="text-align: center; "><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/fzmlsj1417.png"></div><div><section data-role="paragraph" class="_135editor" style="max-inline-size: 100%; margin: 0px; padding: 0px; border: 0px none; z-index: 0; overflow-wrap: break-word !important; outline: none 0px !important;"><section 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;"><section 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;"><br></p><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;">　　从式(2—22)可以看出，由于P2&gt;P1，所以随着n2的增加，纱线的强力增大，即随着混纺纱中强力大的纤维混纺比的增加，混纺纱的强力提高。</p><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; overflow-wrap: break-word !important; outline: none 0px !important;"></p><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;">　　(2)当混纺在一起的两种纤维断裂伸长率相差较大，且纤维1断裂时的强力大于纤维2在纱线中受到的拉伸力(P1&gt;P2)(如涤棉混纺纱)，两种纤维的拉仲曲线如图2—18(b)所示。这种情况下，纱线受拉伸后，纱线中的纤维明显地有两个断裂阶段。第一阶段是伸长能力小的纤维先断，第二阶段是伸长能力大的纤维断裂。当拉伸到伸长为纤维1的断裂伸长时，纤维1首先断裂，此时，混纺纱的承受的拉伸外力F1为：</p><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; overflow-wrap: break-word !important; outline: none 0px !important;"></p><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;">　　</p></section></section></section></div><div style="text-align: center; "><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/fzmlsj1418.png"></div><div style="text-align: center; "><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/fzmlsj1419.png"></div><div style="text-align: center; "><img src="http://dayaotex-img.gz.bcebos.com/article/fffspic/fzmlsj1420.png"></div><div style="text-align: center; "><br></div><div style="text-align: center; "><br></div>