Study On The Fiber Contents Of Blended Cellulose Fiber Textiles Based On Computer Imaging Process

The cellulose fiber blended fabrics are the major produces in the teade of textile and garment. Every year, a large number of such products are exported to Japan, USA, Hong Kong and other regions and countries. Every country makes fiber content label as the compulsory requirements, as well as the blended ratio of the cellulose fiber blended fabrics. However due to differences of testing instruments and methods ,there are always big errors in the testing results of fiber content to cellulose fiber blended fabrics. How to get the accurate fiber content depends on the sampling method and minimum testing specimens.There are two methods of testing the blended ratio of cellulose fibers product: The one is to distinguish and count the fibers by the fiber lengthways characteristic after cutting the fibers into short segments. The another way is to distinguish and count the fibers by the characteristic of fibers' cross sections after making cross section slices. In this thesis, we focused on sampling method and confirming minimum testing times to test the blended ratio with above two methods.Sampling method in fiber cross section did not use the traditional collodium slicing method in the study, because the fiber were very tightly transfigured in the yarn cross section due to the squeezing. However, for the resin embedded method, it can keep the original shape of the fiber cross section in the yard, so it is very easy to get a clearer fibers cross section imaging than that of collodium method. Thereby, the investigated on the changes in blended ratio with resin embedded method was done.The conclusion is that the blended ratio varied more slightly in the short segment than that in the segment at random. Therefore, the ratio of blended product can be got in only one slice of one yarn which chosen from the different places at random. Comparised with the cross sections of cotton yarns in different mercerizing degrees with resin embedded method, the rotundity degree would be higher with higher mercerizing degree.In respect of sampling in lengthways direction, the standards such as FZ/T 30003-200, SN/T 0756-1999 and AATCC 20-2002 were compares in this dissertation. To solve the problems which occurred in the traditional methods, sampling method was improved based on AATCC 20-2002 sampling method. The length of slice was adjusted in order to observe the cross section characteristic and identify the fiber. The uniformity of the fiber segment was improved by increasing the blended ratio of the fiber section and mixing the fiber with boiled water. The accuracy and stability of testing results were improved obviously with the improved sampling method.Finally, the factors of the testing times were discussed based on the minimum sample volume statistical formula. From lengthways and sectional direction, the reasonable experiments were designed on different kinds of fiber blended products and different blend ratio products with the same fibers. The data showed that the blended ration of fibers and the kind of fibers only have a little impact on the value of the standard deviation of lengthways and sectional direction. The difference of standard deviation that came from different kinds of fibers and different blended ratio were also almost the same with the minimum sampling volume according to sampling theory. The minimum testing times is confirmed: more than 1900 fibers for lengthways and 18 cross sections for sectional directions.