Determination Of Fineness Of Ramie Fiber-Pneumatic Method

At present, the main method of testing ramie fiber fineness is cut-middles method. Thismethod has some shortcomings such as the little quantity of ramie samples, the deficiency ofrepresentativeness, the tedious operation and the results greatly influenced by subjective factors.This paper proposed a pneumatic method to measuring the fineness of ramie fibers.In this paper two constant pressure type air flow meters were chosen for experiment. Themetric count and linear density of samples were tested with cut-middles method and pneumaticmethod, respectively, therefore, athe regression relationship between the test results of pneumaticand cut-middle were established with SPSS software. Two types of pneumatic meters, the Y145Aair flow meter and the WIRA air flow meter were used in pneumatic testing. The NationalStandard “Determination of the fineness of ramie fiber---Pneumatic method”, which provides thebasis of using air flow meter to test the fineness of ramie fiber simply and quickly, was establishedon the base of these experiments.The main work of this paper is as follows:(1)Establishing the sample preparation method for the test. The degummed ramie fibers willbe cut into10cm at the middle section near the end, using the Carding machine to open and mix,then putting samples in standard atmospheric conditions, letting the samples reach equilibriumstate, taking fibers evenly with forceps and removing the unseparated fibers and impurities.(2)Determining the sample for the test. For the test using Y145A air flow meter and WIRAair flow meter, the weights of samples were3.5±0.05g and2.0±0.04g respectively. Each samplewere tested three times to get the average as the result. In the process of establishing the Standard,the same sample was used in both pneumatic method and cut-middles method.20mm length fibercutter was used in cut-middle to cut the fibers.(3) Establishing the regression equations. The regression equation testing the metric count ofY145A air flow meter is Y=-263.656X+2722.258. The regression equation testing the lineardensity is Y=0.995X+2.158. The regression equation testing the metric count of WIRA air flow meter is Y=-9.140X+3041.268. The regression equation testing the linear density isY=0.034X+0.982. At the significant level α=0.05, there is no significant difference between thecalculated values and the measured values.(4) Verifying the applicability of the Standard. The Standard not only suits for the fiberobtained from opened degummed ramie, but also suits for the fiber in combed slivers. It can beused to test the fineness of ramie fibers directly while the environment temperature and humiditydifferent from the standard condition, and figure out the fineness according to the moisture regain,if the environment humidity is not too high.