Double-core single-wrapping structure auxetic composite yarn

The utility model discloses a double-core single wrapping structure auxetic composite yarn which comprises a first core layer, a second core layer and an outer wrapping layer, the outer wrapping layer is wrapped on the outer wall of the first core layer and the outer wall of the second core layer in a spiral line up and down alternating mode, the first core layer and the second core layer are both low-modulus high-elongation fiber filaments, and the first core layer and the second core layer are wrapped on the outer wall of the first core layer and the outer wall of the second core layer respectively. The outer wrapping layer is made of high-modulus low-elongation fiber filaments, the problem that the negative Poisson's ratio effect of a conventional auxetic yarn of a single-core single-wrapping structure is not obvious is solved, and the variety of the auxetic composite yarn is greatly enriched. 本实用新型公开了一种双芯单包缠结构拉胀复合纱，包括第一芯层、第二芯层和外包覆层，所述外包覆层呈螺旋线上下交替包缠在第一芯层和第二芯层外壁，所述第一芯层和第二芯层均为低模量高伸长的纤维长丝，所述外包覆层为高模量低伸长的纤维长丝，打