<div><br></div><div><section class="_135editor" data-role="paragraph" style="font-size: medium; 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; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　答 造成筒子纱染色内、外层色差的原因是多方面的，现就其主要产生原因及防止方法分述如下。</span></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;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　①水质要求。筒子纱染色对水质要求较高，一般要求为：含游离氯&lt;0.05mg／L；硬度&lt; 25mg／kg；混浊度&lt;3°；含铁&lt;0.1mg／kg。水质含氯偏高，对氯敏感的活性染料就会发生色变，造成筒子纱外层与内层色差。水质浑浊表示水中含有一些悬浮物和其他微粒，在染色时，筒子纱如同一个“过滤器”，其杂质等在纱层中吸附，使之不能正常流通，能导致内、外层色差。水中含Fe2+、Fe3+量过多，会使漂白、浅色产品内层纱及筒纱之间两端接触紧密处产生铁绣黄圈，且在氧漂过程中起催化作用，造成筒子纱脆损。水质硬度过高，对绝大多数染料能产生凝聚而造成染色疵病。</span></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;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　②筒子纱预缩。如果是涤／棉纱，在络筒前必须经130℃汽蒸处理30min，将纱退捻到具有一定的回缩，而预缩工序往往被许多染厂所忽视：如涤／棉纱在煮练及高温染色时，就会产生严重收缩（5％～10％收缩率），而筒纱内层比外层收缩更快、更紧密，不易使染液均匀渗透。而纯棉筒子纱则不存在收缩。</span></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;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　③筒子纱卷绕密度。筒子纱卷绕方式及卷绕密度对造成内、外层色差有极大关系。筒子纱卷绕密度过低会使筒子纱外形变形或崩跨，若密度过大，筒纱紧硬，染液穿透困难，造成断路和色差。卷绕密度要根据染色机泵的扬程高低及外加压力情况而定，一般情况下卷绕密度为：未丝光棉纱0.3～0.4g／cm3（卷硬度30～20）；丝光棉纱0.35～0.25g／cm3（卷硬度25～15）；涤棉混纺纱0.3～0.4g／cm3（卷硬度30～20）；锦纶纱0.2～0.3g／cm3（卷硬度30～20）。筒子纱支数越高，相应卷绕密度应越小。筒子纱成形必须良好，松软均匀，每只筒子重量相同、直径相同，不可过硬、过软，不可以一头硬、一头软；不可有硬条凸起或硬边，要防止搬运时筒子受压变形等。</span></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;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　④泵的扬程流量，正反循环时间。筒子纱染色时染液要靠泵的扬程渗透到筒子纱内层，通过内外往复循环达到染色平衡。筒子纱染色时要求泵有足移的扬程流量，并可通过染液旁通阀来调节。如扬程流量过大，会使纱中部分短纤维脱出纱捻而浮出，起毛乃至断裂；如扬程过小，造成染液渗透不良，产生筒子纱中层比外层浅的现象。一般全棉纱的流量在35～50L／（min·kg）之间，T／C纱在30～40L／（min·kg）之间。筒子纱在染色过程中正反循环时间比应根据泵的扬程流量、纱线类别而定。一般筒子纱染色时，采用反循环（外一内）的时间大于正循环（内一外）的时间。筒子纱颜色内层浅、外层深，增加染液的正循环；筒子纱颜色内层深，外层浅，增加染液的反循环时间。筒子纱染色液流正反循环的调整，对色泽匀染有较大效果。因为正循环时染液从筒子中心向外喷射，压力大，这时筒子受正压，筒子内中心小，液流集中向筒子外层扩张，染液通过纱层产生阻力。这种阻力能使染液在纱层中间流通不畅、不匀，流速逐渐减慢，染液容易在筒子内分布不匀。因此正循环时间过长，更易产生内外色差。而反循环是染液从筒子四周流向中心，筒子受负压，虽然染液通过纱层仍有一定阻力，但筒子直径逐渐变小，对筒子中的流量、流速影响不大，染液在筒子中分布较均匀，纱层与染液接触浓度和时间上比较接近。因此多打反循环对改善色差较有利，同时反循环时由外向里吸，筒子不易变形。但是具体正反循环时问比如何确定，应根据各厂设备实际情况而定。</span></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;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　⑤染料的选择。染料选择好与坏是影响筒子纱染色的关键，由于筒子纱染色的特殊性，要求所有染料分子要细，染料的渗透性要好，移染性要好，拼色用染料相容性要好，扩散性等尽可能一致。有些染料还需通过研磨才能使用。</span></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;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　⑥制订合理染色工艺。如活性染料应掌握好食盐、元明粉的分次加入，控制升温。分散染料应控制染液pH值，90～130℃必须严格控温。还原染料染色后，立即升温、进水、去泡沫，避免筒子表面色点产生，要严格执行操作要求。</span></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></section><section class="_135editor" data-role="paragraph" id="autoparagraph" style="font-size: medium; 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%; 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