The Research Of Yarn Hairiness Testing Method Based On The Loss Of Microtubule-Based Air Pressure And The Device Based On This Method Of Yarn Hairiness Testing

Yarn hairiness is an important index of yarn quality.Yarn hairiness not only affects the appearance of yarns and the smooth of fabrics,but also brings the reduction of productivity during the weaving progress because the yarn hairiness creates the unclearness of open.When it has little yarn hairiness,it will turn out the smooth surface of fabrics,the quite clearness of lines and the softness of feelings.Excessive yarn hairiness will affect yarn lease after sizing progress,twist the adjacent yarns during the weaving progress,and make the opening of loom unclear.Uneven yarn hairiness leads to unevenness of dyeing which shows that the more yarn hairiness,the deeper color and the less hairiness,the lighter color.According to that,the testing of yarn hairiness is one of the most crucial testing projects. Generally speaking,the main yarn hairiness testing methods includes:visual method,gravimetric method,electrometric method,air osmose process method,electrostatic method,digital image processing method,projection counting method, all-optics hairiness testing method and so on.In this thesis,it develops a brand-new testing method -based on the loss of microtubule-based air pressure.This method depends on the surface yarn hairiness that will change the values of air pressure in the microtubule and according to that,the loss values of the air pressure in the microtubule manifests the surface yarn hairiness.Meanwhile,this thesis develops the testing device based on this principle.This thesis analyses the factors of affecting testing principle and related hydrodynamics formula and it concludes that there are three main affecting factors,such as basic air pressure in the microtubule(air flow),yarn speed,yarn tension.And through the each single-factor experiments,it will validate the impact degree of final testing results according to each affecting factor.After the experiments of all affecting factors,it concludes that750Pa is the better basic air pressure,and the uneven diameter yarns have a little affect on the testing result,even negligibly.Yarn speed and yarn tension also have a bit affect on the testing result within the range of existing parameters.According to the results of experiment,the basic conditions of contrast experiment are basic air pressure 750Pa,yarn speed V=5m/min,yarn tension F=10cN.This thesis makes the contrast experiment on the microtubule-based yarn hairiness testing device and YG172 yarn hairiness testing device and analyses the linear correlation of results,after that it validate the principle feasibility and rationality of this device.In the experimental verification,yarn were sized with a certain rate of sizing,then the yarn go through a type of loaded weaving simulation by three different frequency,after that it progresses three same conditions yarn samples except amount of yarn hairiness.After three yarn samples testing of YG172 yarn hairiness testing clevice and this microtubule-based yarn hairiness testing device,it gains the number of 3mm length yarn hairiness and the loss value of air pressure.It concludes the correlation of two testing device results through the contrast of results of two kinds of devices.Through the experimental verification,the correlation coefficients are above 0.9,which means that the principle of this microtubule-based yarn testing device is feasible and this microtubule-based device is reasonable.