The Measurement Of The Fiber Diameter And Orientation Distribution Of The Nonwoven Fabrics Based On Image Processing

The nonwoven fabrics are made of fibers directly, so the properties of fibers have a direct influence on the properties of the nonwoven fabrics. The fiber diameter will affect the volume density, frictional property, intensity and hand. The fiber orientation distribution will affect physics and mechanism property of the nonwoven fabrics. Therefore, it is quite necessary to measure the fiber diameter and orientation distribution of nonwoven fabrics. The traditional methods to measure the fiber diameter are the microscope projection method and electricity lens method. However, both of them contain many human factors. There are many traditional methods to measure the fiber orientation distribution, but they all have some limitations and disadvantages. This thesis focuses on the measurement of the fiber diameter and orientation distribution by using image processing techniques. It is mainly about capturing the images, preprocessing the images, extracting the feature value, and comparing the results with the traditional methods.The brief of the thesis is introduced as follows.1. Capture the images. A series images are captured with CCD camera with the method of light transmitting on the sample of nonwoven fabrics. Amplify the fiber about 200 times to obtain the single fiber images for measuring the diameter of the fibers, and capture the image of the ruler to get the real size of the pixel. Amplify the fiber net about 100 times to obtain the images for measuring the orientation of the fibers.2. Measure the fiber diameter based on image processing. Firstly, process the image by medium filter to remove the noise; profile lines of the fiber are extracted by the 'Canny' edge detection, then the obliquity of the fiber is got by curve fit; the diameter of the fiber is obtained according to the relationship of the obliquity and the horizontal or vertical length of the fiber, so the diameter distribution of the nonwovens is got.3. Measure the fiber orientation distribution based on image processing. Remove the noise with medium filter at first; turn the image into binary image by Otus threshold, then dilate the image in order to fulfill the holes in the fiber; extract the image of the holes by image label, then obtain the orientation of the edge line of the holes' by curve fit, and the orientation equals to the fibers' orientation around the holes; finally, the orientation distribution is obtained.4. Compare the results of image processing method and traditional microscope projection method. As a result, image rocessing method is feasible. Comparing the two kinds of image processing methods which is used to get the fiber orientation distribution, it can be found that the obliquity of the fibers can be obtained by processing the image of a single fiber and the fiber orientation distribution can be obtained by extracting the line of the holes' edge from the digital image.