基于光谱特征的粘胶纤维混色纺纱过程呈色机理分析

Color Mechanism Analysis During Blended Spinning of Viscose Fibers Based on Spectral Characteristics

针对现有色纺纱配色模型对纤维集合体呈色机理解释上表述模糊的问题,对原液着色粘胶纤维集合体在纺纱过程中的颜色变化机理进行了探究。实验纺制了36组不同混色比条纱样品,利用欧式距离和光谱角距离分别量化各组不同状态纤维集合体间的光谱幅值差异和形状差异,并以基于CMC(2∶1)公式的色差评价为对照,结合基于类别可分比(CSR)公式的差异性判别准则对量化的光谱差、色差大小作以横向比较,分析了纺纱过程中纤维集合体形态改变对反射光量与单色光成分的影响,其中,在生条与熟条间,样品CSRED和CSREcmc均值分别为2.87、 2.17,表现近似,且有30组样品对应CSRED>1, 23组样品对应CSREcmc>1,光谱的辐射差异较色差表现更稳定,在熟条与纱线间,dED和ΔEcmc有相同趋势的更大幅度改变,全部样品CSRED和CSREcmc均大于1;以上过程中,样品光谱的形状差异均保持较小的尺度,并条与纺纱前后,分别有20组、 22组样品对应CSRSAD>1,且其均值分别为1.69、 1.60,并不随加工进行而发生显著变化。由此得出,在纺纱过程中,因纤维排列和聚集态的重塑,反射光的量(明度)呈减小趋势,且气流纺阶段是发生变化的主要阶段,而光质(色相)并不在此过程发生显著变化。进一步地,依据纤维的光反射理论,即纤维的反射光的量主要受外反射光影响,而色度主要受内反射光的影响,可以得出纺纱加工主要影响了纤维的外反射光,而对内反射光不具有解释力。另一方面,还验证了综合光谱幅值和形状特征的SAD-ED公式对色纺纱颜色差异的表征能力,CSRSAD-ED可分辨31组生条熟条样本,可分辨全部条纱样本,该方案较CMC(2∶1)公式更具敏感性和稳定性,为色纺纱的颜色评价提供了新思路。

Aiming at the ambiguity in explaining the color mechanism of fiber aggregates by the existing color-spinning color matching models,the color change mechanism of dope dyed viscose fiber aggregates during spinning was explored.In the experiment,36 groups of sliver andyarn samples with different color mixing ratios were spun,and the Euclidean distance and spectral angular distance were used to quantify the spectral amplitude difference and shape difference between the fiber aggregates of different states in each group.The chromatic aberration,which was calculated based on the CMC(2:1)formula was evaluated as a control,and the quantified spectral difference and chromatic aberration were compared horizontally based on the discrepancy criterion based on the category separable ratio(CSR)formula.Among them,between the raw sliver and the drawn sliver,the mean values of CSReD and CSReeme of the samples were 2.87 and 2.17,the dED of the sample is similar to the performance of Ecmc,and the spectral radiation difference is more stable than the color difference.Between the sliver and the yarn,the dED and Ecmc have the same trend of greater changes,and all the samples CSReD and CSREcmc are greater than l;in the above process,the shape difference of the sample spectrum keeps a small scale,before and after drawing and spinning,there are 20 and 22 samples corresponding to CSRsaD>1,and their mean values are 1.69 and 1.60,respectively,which did not change significantly with processing.It can be concluded that during the spinning process,due to the remodeling of fiber arrangement and aggregation state,the amount of reflected light(brightness)tends to decrease,and the spinning stage is the main stage of change,while the light quality(hue)not significantly changed during this process.Further,according to the light reflection theory of the fiber,that is,the amount of the reflected light of the fiber is mainly affected by the externally reflected light,and the chromaticity is mainly affected by the internally reflected light.It can be concluded that the spinning process mainly affects the external reflected light of the fiber.However,it has little explanatory power for internally reflected light.On the other hand,it also verified the ability of the SAD-ED formula,which integrates spectral amplitude and shape features,to characterize the color difference of colored yarns.CSRsADED can distinguish 3l groups of sliver and drawn sliver samples and can distinguish all drawn sliver and yarn samples,this formula shows more sensitive and stable than the CMC(2:1)formula,which is the color difference.,This scheme also provides a new idea for the color evaluation of colored yarns.