| For a glass fiber yarn product,the delay time,sound velocity,degree of orientation,orientation angle and sound modulus of and the instrument and fiber samples are calculated by drawing extrapolation method by using the principle of sound speed orientation instrument and multi-point method.The results of calculation based on the known glass fiber density and random orientation sound velocity of glass show that under different pretension,the curve of distance-sonic wave propagation time is similar to the regular change.After fitting straight line with least square method and extrapolating to zero,the results of multi-point method are obtained;for the same sample and instrument environment conditions,the sample pretension and transducer spacing are obtained.The measurement length/sonic wave propagation distance of the sample has an effect on the measurement results of sound velocity,but the pre tension has little influence and no obvious rule is found,and the measurement distance can significantly change the delay time.This information can provide a reference for the instrument setting optimization of the measurement of glass fiber sound velocity and orientation parameters quickly and easily by using the more common method of doubling length.Based on the multi-point measurement data of glass fiber,the instrument delay time,sonic velocity,orientation degree and orientation angle of sound velocity method,sonic modulus and other parameters are calculated by using the principle of multiple length method.The results show that the data measured by the double length method when the sample length(measuring distance)is 150 mm-300 mm is the closest to that measured by the multi-point method,and the rule has nothing to do with the pretension,when compared under the same pretension.According to the initial characteristics of each sample,it is found that the glass fiber with starch type sizing agent has higher sound velocity,higher modulus,higher degree of orientation,smaller orientation angle,and better flexibility;the sound velocity and sonic modulus of twisted glass fiber are slightly higher than those of untwisted glass fiber,and the influence of pretension is significant in the process of measurement,which easily leads to the mutual slip of glass fiber filaments;The linear density of four kinds of glass fiber is very different.It is consistent with the conclusion that the sound velocity has nothing to do with the cross section of the specimen.In order to solve the problems of loose yarn,flying yarn and hairiness increase of glass fiber yarn,coating a layer of "glue" before warping can improve the glass fiber clustering,reduce hairiness and flying yarn,and prevent loose yarn.The changes of acoustic modulus,tensile strength,elongation at break and micro morphology of glass fiber yarn before and after rubber treatment were measured.It was found that the acoustic modulus of twisted glass fiber yarn was higher than that of untwisted glass fiber yarn;the acoustic modulus of starch type sizing agent glass fiber decreased significantly after rubber treatment,which indicated that starch type sizing agent glass fiber was more suitable for rubber treatment to improve softness;the acoustic modulus of glass fiber yarn after rubber treatment was higher than that of untwisted glass fiber yarn The surface regularity of the fibers decreased or even cracked in varying degrees,which confirmed that the tensile strength and elongation at break decreased.It is necessary to consider the performance changes and specific conditions,and consider the cost to comprehensively judge that the fiber still has enough performance to meet the needs of subsequent processing and use while improving the clustering. |
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