ABSTRACT Jaganathan, Sudhakar. Characterization Methods and Physical Properties of Novelty yarn. (Under the guidance of Dr. William Oxenham) The purpose of this work is to find the characterization methods which quantitatively define the inherent properties of novelty yarn. The research was divided in to two parts. In the first part various instrumental methods and techniques were investigated to characterize the physical properties of the novelty yarns. Various structural properties of gimp and slub yarns were defined and characterized. Instrumental method included CTT Tester, Hairiness tester and a Traveling Microscope. An image analysis algorithm was proposed to measure the size distribution of novelty yarn structural effects. In the second part visual perception of novelty yarn texture was characterized. A texture nomenclature based on the theory of “Textons” was developed. A human psychological survey was conducted to get observers response on texture terms. We proposed various image analysis methods to quantitatively characterize the novelty yarn texture. The image analysis method had good correlation with human psychological response on the novelty yarn texture. CHARACTERIZATION METHODS AND PHYSICAL PROPERTIES OF NOVELTY YARN by SUDHAKAR JAGANATHAN A thesis submitted to the Graduate Faculty of North Carolina State University In partial fulfillment of the Requirement for the degree of Master of Science Textile Management and Technology COLLEGE OF TEXTILES Raleigh, NC 2005 Approved by: Dr.William Oxenham Chair of the Advisory Committee Dr.Nancy Powell Dr.Pamela Banks-Lee Committee Member Committee Member Dedicated to Amma, Appa, Anni and Anna for all the support and encouragement they have given ii Biography Sudhakar Jaganathan was born on June 29, 1979 in Coimbatore, India. He was awarded a gold medal in 1999 by PSG polytechnic, Coimbatore, for topping the diploma program in Textile Technology. His Diploma studies included intensive practical training in various spinning and weaving mills. Mr. Jaganathan later went on to complete his Bachelors in Textile Technology from SSM college of Engineering, Erode. Upon graduation he joined Golden home textiles, Chennai as a quality control in charge where he worked from 2002-2003. Sudhakar entered the graduate program in Textile Management Technology at North Carolina State University in fall 2003. During this time, he worked under Dr.Oxenham as a research assistant and lab manager for braiding and composite lab. His other accomplishments include the prestigious International Wool Textile Organization scholarship to do a internship in German Wool Research Institute, Aachen during summer 2005.After he receives his Master of Science degree in May 2005 Sudhakar plans to continue his education entering the Ph.D. program at North Carolina State University in Fiber and Polymer Science iii ACKNOWLEDGEMENT The author would like to express his sincere gratitude to the committee chair and the members Dr. William Oxenham, Prof. Nancy Powell and Dr. Pamela Banks-Lee, for their support which made this project successful. Dr.Oxenham, especially, whose motivation and suggestion provided deeper understanding of the subject. Appreciation is also extended to Dr.Behnam Pourdeyhimi for his guidance in texture analysis method. Dr. John M. Mackenzie, Director of the NCSU EM Center for his helpful comments on the image capturing techniques. C.Moses, of the Institute of Textile Technology for his time in teaching working principle of CTT tester. Timothy G.Pleasants for his guidance in novelty yarn production A special thanks to all graduate students who spent their invaluable time in taking the human psychophysical survey. iv TABLE OF CONTENTS: LIST OF TABLES ....................................................................................... ix LIST OF FIGURES...................................................................................xiii 1. Introduction............................................................................................... 1 1.1 Paradigm of Novelty Yarn Research..................................................................... 3 2 LITERATURE REVIEW …………………………………………….....6 2.1 Novelty Yarn Characterization Methods.............................................................. 6 2.2 Classification of Novelty Yarn ............................................................................... 8 2.2.1 Classification Based on Manufacturing Method................................................ 9 2.2.2 Classification Based on the Raw Material type ............................................... 10 2.2.3 Classification Based on Type of Components................................................. 10 2.2.4 Classification Based on the Morphological Structure ..................................... 10 2.3 Novelty Yarn Production Process........................................................................ 12 2.3.1 Production of Novelty Yarn Using Ring System............................................. 13 2.3.2 Snarl Yarn Production...................................................................................... 15 2.3.3 Hollow Spindle Process ................................................................................... 19 2.3.4 Rotor Spinning Machine.................................................................................. 20 2.3.5 Novelty Yarn by Texturising Machines........................................................... 21 2.4 Theory of Fancy Yarn Twisting........................................................................... 23 2.4.1 Theoretical Model of Novelty Yarn Structure................................................. 28 2.5 Testing Equipment Used for Novelty Yarn Characterization .......................... 31 2.5.1 Constant Tension Transport (CTT) Tester....................................................... 31 2.5.2 CTT EIB Software ........................................................................................... 42 2.6 Digital Image Processing ...................................................................................... 45 2.6.1 Introduction...................................................................................................... 45 2.6.2 Image Classification....................................................................................... 45 2.6.2.1Based on the number of colors................................................................... 45 v 2.6.2.2 Based on Image Representation ............................................................ 46 2.6.2.3 Based on imaging techniques.................................................................... 48 2.6.3 Digital Image Processing ............................................................................... 48 2.6.3.1 Digital Imaging ......................................................................................... 48 2.6.3.2 Image Enhancement and Preprocessing.................................................... 50 2.6.3.3 Image Analysis.......................................................................................... 51 2.6.4 Image Fundamentals and Operators ........................................................... 52 2.6.4.1 Image Acquisition using Multi Sensor-Array........................................... 52 2.6.4.2 Models of Image Formation...................................................................... 53 2.6.4.3 Image Sampling and Quantization............................................................ 53 2.6.4.4 Image Processing Operators ..................................................................... 54 2.6.4.5 Image Enhancement.................................................................................. 57 2.6.4.6 Histogram Equalization ............................................................................ 57 2.6.4.7 Image Segmentation.................................................................................. 61 2.6.4.8 Segmentation Based on the Discontinuity of Image................................. 61 2.6.5 Morphological Image Processing.................................................................. 69 2.6.5.1 Dilation of the Image ................................................................................ 69 2.6.5.2 Morphological Erosion ............................................................................. 73 2.6.5.3 Properties of Erosion and Dilation............................................................ 75 2.6.5.4 Morphological Opening and Closing........................................................ 76 2.6.5.5 Properties of Opening and Closing........................................................... 77 2.6.6 Image Descriptors .......................................................................................... 78 2.6.6.1 Size and Shape Measurement ................................................................... 79 2.6.6.2 Shape Description ..................................................................................... 82 2.6.7 Image Processing Application in Textile...................................................... 83 2.8 Texture Analysis of Novelty Yarn ....................................................................... 87 2.8.1 Introduction.................................................................................................... 87 2.8.2 Texture Models............................................................................................... 88 2.8.3 Texture Analysis Using Image Analysis System ........................................