core yarn

基本解释

The tensile strength of the core yarn is the highest, the second is the folded yarn, and the lowest is the wrapped yarn.
包芯纱具有较高的断裂强力，其次是平行纱，而包缠纱的最低；
The protection that wrapped yarn gives to the high performance core yarn improves the weaving performance of core spun yarn.
外层编织纱对高性能芯纱的保护使复合后的纱线的织造性能得到很大改善，可直接在二维或三维织机上进行织造。
When the core yarn is led into the slab catcher, the presence of the core is explicated more than in a time after the winding of the core yarn (10) is started by the winding device (12).
在该导入时，与开始上述卷绕装置（12）的包芯纱（10）的卷绕后的期间相比使芯线的存在明显化。
ip.com

Baker tells me he can make a sock core just as cheaply as anyone in China or Honduras - the machine costs the same, so does the yarn, there's hardly any labor.
NPR: Alabama Town Questions an Economy of Socks