DOCSLIB.ORG

Mechanical Behavior Characterization of Knitted Textiles a Thesis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mechanical Behavior Characterization of Knitted Textiles a Thesis Mechanical Behavior Characterization of Knitted Textiles A Thesis Submitted to the Faculty of Drexel University by Mustafa Oncul in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering December 2017 © Copyright 2017 Mustafa Oncul. All Rights Reserved. ii In the Name of Allah, the Entirely Merciful, the Especially Merciful iii TABLE OF CONTENTS LIST OF TABLES .......................................................................................................... v LIST OF FIGURES ........................................................................................................ vi ABSTRACT .................................................................................................................... x CHAPTER 1: INTRODUCTION ................................................................................... 1 1.1 An Overview ............................................................................................................. 1 1.1.1 Knitted Textiles .................................................................................................. 3 1.2 Testing and Characterization of Textiles .................................................................. 7 1.3 Nonlinear Mechanics of Knitted Textiles ................................................................. 9 1.4 Thesis Structure ....................................................................................................... 12 CHAPTER 2: BACKGROUND AND STATE-OF-THE-ART IN MECHANICAL BEHAVIOR CHARACTERIZATION AND TESTING OF KNITTED TEXTILES . 14 2.1 Bulk Measurements ................................................................................................. 14 2.2 Local Level Measurements ..................................................................................... 18 2.3 Textile Testing Standards ........................................................................................ 22 2.4 Three-dimensional Geometry Extraction ................................................................ 25 2.5 Modeling ................................................................................................................. 26 CHAPTER 3: THESIS OBJECTIVE AND APPROACH ............................................ 31 3.1 Research Motivation ............................................................................................... 31 3.2 Hypothesis and Objective ........................................................................................ 33 3.3 Proposed Approach ................................................................................................. 34 CHAPTER 4: EXPERIMENTAL SETUP AND PROCEDURE ................................. 37 4.1 Manufacturing of Specimens .................................................................................. 37 4.2 Mechanical Testing Setups ...................................................................................... 41 4.2.1 Micro-scale ....................................................................................................... 42 4.2.2 Lab-scale........................................................................................................... 43 4.3 Strain and Apparent Stiffness Calculations ............................................................. 45 4.3.1 Strain Calculation ............................................................................................. 45 4.3.2 Apparent Stiffness Calculation ......................................................................... 46 4.4 Speckle Pattern Creation for Digital Image Correlation ......................................... 47 4.5 Image Acquisition Setup ......................................................................................... 50 iv CHAPTER 5: MECHANICAL BEHAVIOR CHARACTERIZATION OF KNITTED TEXTILES .................................................................................................................... 52 5.1 Global Measurements .............................................................................................. 52 5.1.1 Deformation ...................................................................................................... 52 5.1.2 Anisotropy ........................................................................................................ 55 5.1.3 Cyclic Loading ................................................................................................. 61 5.1.3 Stress Relaxation .............................................................................................. 63 5.2 Local Measurements ............................................................................................... 65 5.2.1 Yarn-level measurement results ....................................................................... 69 5.3 Correlation of Global and Local Measurements ..................................................... 72 CHAPTER 6: 3D GEOMETRY EXTRACTION ......................................................... 77 6.1 Material Geometry Characterization ....................................................................... 77 6.2 Data Extraction and Connection to Modeling ......................................................... 78 CHAPTER 7: CONCLUDING REMARKS AND FUTURE PROSPECTS ................ 82 LIST OF REFERENCES .............................................................................................. 83 v LIST OF TABLES Table 1: Deformation mechanisms of fabrics: a) Knitted, b) Woven, c) Nonwoven [14] ......................................................................................................................................... 8 Table 2: Measurement types and ASTM Standards ...................................................... 23 Table 3: Geometrical parameters and gauges of the manufactured specimens ............. 39 Table 4: GATAN load stage characteristics .................................................................. 42 Table 5: Mark-10 tensile tester characteristics .............................................................. 44 Table 6: Average speckle length values ........................................................................ 50 Table 7: Facet field characteristics ................................................................................ 51 Table 8: Average apparent stiffness values (N/mm) ..................................................... 58 Table 9: Areas of the load-strain curves ........................................................................ 62 vi LIST OF FIGURES Figure 1: Common textile structures: a) Knitted, b) Woven, c) Nonwoven, and d) Braided [2, 3] ................................................................................................................... 2 Figure 2: Various knitting patterns: a) Plain weft knit (Single Jersey), b) Rib knit, c) Plain warp knit, d) Single Tuck stitch F, e) Single Tuck stitch G, f) Interlock E, g) Full tricot, h) three-needle queens cord, i) Three-needle sharkskin [4-6] .............................. 3 Figure 3: Schematic representation of the hierarchical knit architecture; a) knitted loop, b) knit patterns, c) grid pattern, d) restructured grid [11] ............................................... 4 Figure 4: a) plain weft knit, b) weft knitting process, c) warp knit, d) warp knitting process [4, 5] ................................................................................................................... 5 Figure 5: The mechanism of a latch needle; a) running, b) clearing, c) feeding, d) loop pulling, e) knock over [8] ................................................................................................ 6 Figure 6: Some of the textile testing and characterization methods [1] .......................... 9 Figure 7: Load-displacement curves for woven and knitted fabrics [16]...................... 10 Figure 8: Structure of the thesis .................................................................................... 13 Figure 9: Macro-level deformation modes: a) transverse compression, b) in-plane tension, c) in-plane shear, d) out-of-plane bending [16] ............................................... 14 Figure 10: (a) Structure of the co-woven-knitted fabric, (b) Tension stress-strain and (c) tear displacement-load curves, along various directions ............................................... 16 Figure 11: Tensile test setup with non-crimp fabric structure....................................... 17 Figure 12: Stress-strain curves of the spacer fabrics: a) not glued, and b) glued to platens surfaces ............................................................................................................. 18 Figure 13: Micro-level deformation modes: a) inter-yarn slip, b) inter-yarn shear, c) yarn bending, d) yarn buckling, e) intra-yarn slip (inter-fiber friction), f) yarn stretching, g) yarn compression, h) yarn twist [16] ....................................................... 19 Figure 14: Displacement fields; a) at macroscale, b) at mesoscale (within the yarn) ... 21 Figure 15: a) Test apparatus; tensile tester and image acquisition, b) Displacement field within a woven yarn with 1.92 mm warp width and 2.21 mm weft width ................... 21 Figure 16: Picture frame test: (a) ‘Small Square’ setup in the reference state (ROI and subset window is indicated), (b) Fabric deformation for the ‘Small Square’ setup, (c) Fabric deformation for the ‘Large Cross’ setup ............................................................ 22 Figure 17: a)
Load more

Recommended publications
  • Here. the Whispered
    Apprentice Writer Vo The Lempuyang Gates of Heaven Chantel Kardous Lincoln, RI l u 38 m e Apprentice Writer www.apprenticewriter.com PRIZES HIGH SCHOOL WRITERS ARE INVITED TO SUBMIT $200 THEIR POETRY, CHOREOPOETRY, SPOKEN WORD to Outstanding Writer POETRY, GRAPHIC FICTION AND NONFICTION, PROSE in fiction, nonfiction, FICTION AND NONFICTION, AND PHOTOGRAPHY and poetry SUBMISSIONS FOR PUBLICATION & PRIZES. CALL FOR SUBMISSIONS: September 15 to March 15 In addition to being published in the 2021 edition, a published author $50 will award selected writers the prize of Outstanding Writer in fiction, to Runners-Up in nonfiction, and poetry as well as Runners-Up in each genre. fiction, nonfiction, and SUBMISSIONS: poetry HTTP://TINYURL.COM/APPRENTICEWRITER2021 Questions? Contact Ashley Houtz at The Writers Institute, Susquehanna University, at [email protected]. Spend a week immersed in writing with Susquehanna’s nationally recognized authors! JULY 18—24, 2021 Live the life of a practicing writer through intensive writing workshops and one-on-one conferences. Concentrate on fiction, poetry, or memoir. The $1025 fee (discount given for early applications submitted by April 15) covers all costs, including room and board. Scholarships are available. APPLY ONLINE AT: WWW.SUSQU.EDU/ WRITERSWORKSHOP The Gates of Heaven been taught better than that), but we didn’t play the be, but I liked the process anyway. game anymore. Instead, I stood on the stump alone, I carried a different name, different are White (Among sometimes with a notebook, sometimes just with the story—a different spoon-fed lie or Other Things) ants. I’d occasionally try to lean back on my own, partial truth, depending on how you Emily Bach but I wouldn’t get very far without falling.
    [Show full text]
  • Woven Fabrics
    Fabric – Woven Fabrics WOVEN FABRICS Fabrics are made of yarns by weaving them in different combinations. It is mostly done by interlacing two sets of yarn or thread made of fibers called the warp and weft of the loom. It only stretches in the bias directions, between the warp and weft directions, unless the threads are elastic. Lengthwise stronger vertical yarns with more twist are Warp or Picks while widthwise filling yarns are termed as weft or ends. Sidewise edge of fabric is termed as Selvedge. THREE BASIC WEAVES There are three main types of weave: Plain, Twill and Satin Plain weave is a basic weave which is made when the thread is woven on one up and one down principle, some plain weave fabrics are Chambray, Chiffon, Gingham, and Organza etc. Twill weave is made when the thread is placed by varying the order of interlacing the yarns so that diagonal parallel lines are produced across the fabric. Satin Weave is a weave made when each warp yarn floats over four filling yarns and interlaces with fifth filling yarn. Plain weave Twill weave Satin weave Fabric – Weft Knit Fabrics Knitted Fabrics Knitting is the process of construction of a fabric by interlocking loops of yarn by means of hooked needles. Knitted fabric consists of horizontal rows known as courses and vertical columns of loops known as Wales. Knitted fabrics are porous having insulated air pockets giving warmth when worn. Knitted fabrics are very absorbent, wrinkle resistant and lightweight. They shrink more than woven fabrics unless shrink- proofing techniques are used.
    [Show full text]
  • Sew Any Fabric Provides Practical, Clear Information for Novices and Inspiration for More Experienced Sewers Who Are Looking for New Ideas and Techniques
    SAFBCOV.qxd 10/23/03 3:34 PM Page 1 S Fabric Basics at Your Fingertips EW A ave you ever wished you could call an expert and ask for a five-minute explanation on the particulars of a fabric you are sewing? Claire Shaeffer provides this key information for 88 of today’s most NY SEW ANY popular fabrics. In this handy, easy-to-follow reference, she guides you through all the basics while providing hints, tips, and suggestions based on her 20-plus years as a college instructor, pattern F designer, and author. ABRIC H In each concise chapter, Claire shares fabric facts, design ideas, workroom secrets, and her sewing checklist, as well as her sewability classification to advise you on the difficulty of sewing each ABRIC fabric. Color photographs offer further ideas. The succeeding sections offer sewing techniques and ForewordForeword byby advice on needles, threads, stabilizers, and interfacings. Claire’s unique fabric/fiber dictionary cross- NancyNancy ZiemanZieman references over 600 additional fabrics. An invaluable reference for anyone who F sews, Sew Any Fabric provides practical, clear information for novices and inspiration for more experienced sewers who are looking for new ideas and techniques. About the Author Shaeffer Claire Shaeffer is a well-known and well- respected designer, teacher, and author of 15 books, including Claire Shaeffer’s Fabric Sewing Guide. She has traveled the world over sharing her sewing secrets with novice, experienced, and professional sewers alike. Claire was recently awarded the prestigious Lifetime Achievement Award by the Professional Association of Custom Clothiers (PACC). Claire and her husband reside in Palm Springs, California.
    [Show full text]
  • Checklist for Textiles U.S.A
    THE MUSEUM OF MODERN ART 11 WEST 53 STREET, NEW YORK 19, N. Y. TELEPHONE: CIRCLE 5-8900 No. &• TENTATIVE AND CONFIDENTIAL CHECKLIST FOR TEXTILES U.S.A. Home Furnishings Category Anderson Studio of Handweaving - East Gloucester, Massachusetts. Drapery material. Cotton, viscose and Jute. Designed by Beatrice Anderson, 1951*. Thelma Becherer - West Franklin, New Hampshire. Tapestry. Handwoven of green, yellow and clear "velon" plastic, with dried horsetails and cattails. Plain weave. 1956. Monica Bella Broner, Tapestry. "Fur Weave." Wool, cotton and fur strips, 195^• Bill Carter and Dodie Childs - Chicago, Illinois. Roll Shade, Handwoven matchstick bamboo across multicolored and textured cotton, wool and metallic yarn warp, 1955* Arundell Clarke Drapery fabric. "Strocm Draden". Handscreened white print on trans­ parent white silk. Designed by Pierre Kleykamp, 1955. Drapery fabric, "Primitive Forms." Handscreened black print on brown cotton. Designed by Baldwin-Machado, 1950, Drapery fabric. "10,000 B.C." Cotton jacquard, charcoal on white. Designed by Naomi Raymond, 1952. Cohn-Hall-Marx Co, (For Colvin, see Bertha Schaefer Callery - Page 3.) Upholstery fabric, Saran and metal, novelty weave. Brown, 1955. Fazakas Fabrics, Inc. Drapery fabric, "Hit & Miss," Black spray on white cotton batiste, Designed by DoneIda Fazakas, 1950, Qeraldine Punk - Lancaster, Pennsylvania, Window ahade, Handwoven red and rust cotton and rayon warp. Banana bark and coconut cord weft. 1950, Screen, Handwoven in Puerto Rico, White string warp,, white jnaguey and coconut sliver weft, 19^8, % Ginstrom - Cedar Falls, Iowa. Screen. "Scallops." Handwoven, handtied openwork; all linen panel. 1955. folding Decorative Fabrics. Drapery fabric. "Torero-Vermilion 33." Silk screened cotton sateen. Designed by Otto and Grete Wollner,1955» LiUy E.
    [Show full text]
  • SHARKSKIN SUITS Karl Schrag, Irving Maranu
    Paintings On Display In Stores / 'or the Better Things in Life. Original nil paintings hy a group of distinguished Amer­ WHITE ican artists have inspired U. S. Rubber Co., new "Ked- ettes Collection of Brilliant ('anvases." FRONT The exhibition currently is being shown by the May Co. Wilshire, with reproductions of the collection being shown in the shoe departments at all other May Co. stores Artists represented in the collection of ten paintings in­ clude Maurice Freedman, SHARKSKIN Karl Schrag, Irving MaranU. SUITS Mans Moller. Joseph De Mar­ Where else but White Front does so tini, Walter Meigs, Ben Benn, little money buy so much? Yet every lason Schoener, Victor Can- boy looks like a million in our tradi­ ilell, and .lulien Binford. tional ivy suits of 2 ply rayon shark- The manufacturer also is Skin, which retain fit and shed sponsoring a nationwide con­ wrinkles. Lustrous rayon linings test in havi which each of ten top inside pockets. winners will receive the orig Belt loop trousers inal painting of her choice as are smoothly unpleated. Black, olive, part of the prize. Customers blue and burgundy In sizes 8 to 16. only need select the pointing which they would like to own and fill in the entry form. Forms are available at all May Co. stores. There is no obligation of any kind and winners will be selected by drawing. Ten first-place winners also 'STOCK THE VAULT . Officials f Imperial Rank Rot a helping hand from will receive an all-rxpense- city officials nnd the new Miss Tor inrr RS they stocked the vault prior lo l H st paid weekend Thursday's in New York! opening of the Tnrraiu-c 1 rniu-h at 21151 Hnwthorne Blvd.
    [Show full text]
  • Textiles U.S.A
    THE MUSEUM OF MODERN ART 11 WIST S3 STREET, NEW YORK 19, N. Y. TILIPHONEi CIRCLE 5-8900 FOR RELEASE: TUESDAY, AUGUST 28, 19^6 PRESS PREVIEW: DAILY NEWCPATERS, MONDAY, AUGUST 27 MAGAZINES, TUESDAY, AUGUST 28 No. 80 11 am - h pm both days TEXTILES U.S.A. OPENS AT MUSEUM OF MODERN ART A delicate-looking mesh fabric used in radar targets, an opulent rayon "cloak" that is actually from the inside of a tire, brilliantly striped cotton and wool upholstery, faded blue denim and regulation Army twill, acetate jersey coated with 2k karat gold, handwoven tapestries and light dacrons, printed dress silks and combed cottons are among the 185 examples of American fabric designs on view at the Museum of Modern Art, 11 West 53 Street, from August 29 through November k in an exhibition, TEXTILES U.S.A. The show, the first at the Museum devoted entirely to American textile design, was selected by a seven-member jury from more than 3500 entries. Aesthetic qualities of construction, color and design were the criteria by which fabrics were chosen in three categories: home furnishings, apparel and industrial uses. Arthur Drexler, Director of the Museum's Department of Architecture and Design, organized the exhibition. Greta Daniel, Associate Curator, was project di­ rector and Bernard Rudofsky, well-known architect, designed the installation in the Museum's first floor galleries and on the garden terrace. Many of the labels carry swatches and the legend "please touch." Entrance to the exhibition is through screens of yellow and black polyethy­ lene ropes strung from floor to ceiling.
    [Show full text]
  • Master of Textile Design (Choice Based Credit System)
    RASHTRASANT TUKADOJI MAHARAJ NAGPUR UNIVERSITY NAGPUR (Established by Government of Central Provinces Education Department by Notification No. 513 dated the 1st of August, 1923 & presently a State University governed by Maharashtra Universities Act, 1994) FACULTY OF HOME SCIENCE DIRECTION NO. 79 OF 2016 DIRECTION GOVERNING THE EXAMINATION LEADING TO THE DEGREE OF MASTER OF TEXTILE DESIGN (CHOICE BASED CREDIT SYSTEM) (Issued under section 14(8) of the Maharashtra University Act 1994) Whereas the Maharashtra Universities act No. XXXV of 1994 has come into force with effect from 22nd July, 1994 and was amended from time to time. AND WHEREAS, the University Grants Commission, New Delhi vide letter No.D.O.No.F-2/2008/(XI Plan), dated 31st January 2008 regarding new initiatives under the XI Plan – Academic reforms in the University has suggested for improving quality of higher education and to initiate the academic reform at the earliest, AND Whereas the Task Force in BFD/BTS/BPD in the Faculty of Home Science at its meeting held on 25/08/2016, have recommended for starting of semester pattern and prepared the syllabus and scheme of examination for Master of Textile Design, commensurate with the governing guidelines. AND Whereas the Coordinator, Faculty of Home Science concurred with the recommendations of the Task Force in BFD/BTS/BPD in the Faculty of Home science vide his observations dated 25/08/2016 AND 1 Whereas, the new draft direction and scheme of examination as per semester pattern is to be implemented from the academic session 2016-2017 for Master of Textile Design which is to be regulated by this direction and as such there is no existence and framing of an ordinance for the above examination, AND WHEREAS the Hon‘ble Vice-Chancellor has accepted the syllabus along with draft direction on the behalf of Academic Council on 7-10- 2016 under section 14(7) of Maharashtra University Act 1994.
    [Show full text]
  • Global Material Sourcing for the Clothing Industry
    International Trade Centre UNCTAD/WTO Source-it Global material sourcing for the clothing industry Source it English copyright.pdf 1 2/17/2014 5:07:03 PM Source it English copyright.pdf 2 2/17/2014 5:07:18 PM International Trade Centre UNCTAD/WTO Source-it Global material sourcing for the clothing industry Geneva 2005 Source it English copyright.pdf 3 2/17/2014 5:07:18 PM ii ABSTRACT FOR TRADE INFORMATION SERVICES 2005 SITC 84 SOU INTERNATIONAL TRADE CENTRE UNCTAD/WTO Source-it – Global material sourcing for the clothing industry Geneva: ITC, 2005. xvi, 201 p. Guide dealing with dynamics of the global textiles and clothing supply chain, and why and how garment manufacturers need to develop alternative sourcing and supply management approaches – reviews historical background; discusses Chinese advantage in the international garment industry; explains different stages involved in material sourcing process; deals with fabric and trim sourcing; discusses politics of trade; includes case studies; appendices cover preferential access to the EU, summary of United States rules of origin, measures and conversions, and shipping terms/Incoterms; also includes glossary of related terms. Descriptors: Clothing, Textiles, Textile fabrics, Supply chain, Supply management, Value chain, Agreement on Textiles and Clothing English, French, Spanish (separate editions) ITC, Palais des Nations, 1211 Geneva 10, Switzerland The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the International Trade Centre UNCTAD/WTO concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
    [Show full text]
  • Taking Advantage of the Design Potential of Digital Printing Technology for Apparel
    Volume 4, Issue 3, Spring2005 TAKING ADVANTAGE OF THE DESIGN POTENTIAL OF DIGITAL PRINTING TECHNOLOGY FOR APPAREL J.R. Campbell, Associate Professor, Iowa State University 1073 Lebaron Hall Ames, IA 50011 515-294-0945 Jean Parsons, Assistant Professor, Iowa State University 1071a Lebaron Hall Ames, IA 50011 515-294-4022 ABSTRACT The integration of digital technologies into apparel forms allows designers to explore and visualize new creative possibilities. How the technology is used and how design concepts are perceived in the industry are areas of crucial importance to the technology’s longevity. Our goal, as collaborative artists, focuses on integrating technology into the creative process to create both art and industry-oriented apparel. The applications of digital textile and apparel design have implications for many areas of the industry, but we have focused on three: art-to -wear, custom design, and mass customizable products. The body of research and artwork that we have developed suggests that a systematic approach to integrating new technologies into the textile and apparel design process can be developed, recorded and employed in future design explorations to inspire the most rapid technology integration with the greatest potential for new product conceptualization. Keywords: Digital textile printing, apparel design, design process, art-to -wear The integration of digital technologies into creative process to create both art and industry- apparel forms allows designers to explore and oriented apparel. visualize new creative possibilities. How the technology is used and how design concepts are When we began our collaborative process, the perceived in the industry are areas of crucial use of digital printing for apparel was at a importance to the technology’s longevity.
    [Show full text]
  • Effects of Lignin Type and Total Polymer Concentration
    polymers Article Fabrication and Characterization of Electrospun Poly(acrylonitrile-co-Methyl Acrylate)/Lignin Nanofibers: Effects of Lignin Type and Total Polymer Concentration Suchitha Devadas 1 , Saja M. Nabat Al-Ajrash 1 , Donald A. Klosterman 1 , Kenya M. Crosson 2,3, Garry S. Crosson 4 and Erick S. Vasquez 1,3,* 1 Department of Chemical and Materials Engineering, University of Dayton, Dayton, OH 45469, USA; [email protected] (S.D.); [email protected] (S.M.N.A.-A.); [email protected] (D.A.K.) 2 Department of Civil and Environmental Engineering and Engineering Mechanics, University of Dayton, Dayton, OH 45469, USA; [email protected] 3 Integrative Science and Engineering Center, University of Dayton, Dayton, OH 45469, USA 4 Department of Chemistry, University of Dayton, Dayton, OH 45469, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-(937)-229-2627 Abstract: Lignin macromolecules are potential precursor materials for producing electrospun nanofibers for composite applications. However, little is known about the effect of lignin type and blend ratios with synthetic polymers. This study analyzed blends of poly(acrylonitrile-co-methyl acrylate) (PAN-MA) with two types of commercially available lignin, low sulfonate (LSL) and alkali, Citation: Devadas, S.; kraft lignin (AL), in DMF solvent. The electrospinning and polymer blend solution conditions were Al-Ajrash, S.M.N.; Klosterman, D.A.; optimized to produce thermally stable, smooth lignin-based nanofibers with total polymer content Crosson, K.M.; Crosson, G.S.; of up to 20 wt % in solution and a 50/50 blend weight ratio. Microscopy studies revealed that AL Vasquez, E.S. Fabrication and blends possess good solubility, miscibility, and dispersibility compared to LSL blends.
    [Show full text]
  • Effect of Padder Roller Speed and Pressure During Pre-Treatment on Color Characteristics of Digitally Printed Cotton Knit Fabric Grace Wasike Namwamba and Devona L
    Effect of Padder Roller Speed and Pressure during Pre-treatment on Color Characteristics of Digitally Printed Cotton Knit Fabric Grace Wasike Namwamba and Devona L. Dixon, Textile Technology Southern University Agricultural Research and Extension Center, Baton Rouge, LA 70813 ABSTRACT The purpose of this study was to determine the effect of padder roller speed (RPM) and pressure (PSI) on the color of digitally printed cotton fabrics. Single layers of double-knit cotton fabric were padded at speeds of 20, 40, and 60 rpm and pressure levels of 5, 15, 40, 60, and 70 psi using a 36” wide padder. The padding solution consisted of alginate, soda ash, urea, and distilled water. Color readings were taken using a spectrophotometer. Results indicated that roller speed and roller pressure both had an effect on the shade depth of the fabric. The deepest color depth was obtained at a roller speed of 40 rpm and roller pressure of 20 psi. INTRODUCTION Printing directly onto a substrate requires the fabric be chemically pre-treated to ensure optimum dye penetration and color vibrancy. The padding solution or chemical pre-treatment may vary according to fiber chemistry and end-use requirements. Common pre-treatment solutions for digital textile printing of cotton (cellulosic) fibers include a mixture of alginate, soda ash, urea, and distilled water where alginate and urea are the thickeners for the pre- treatment solution. In this formulation, alginate is mixed with urea to control the temporary containment of droplets spreading toward the fabric (Baffoun, Viallier, Dupuis, & Haidara, 2005). The chemical pre-treatment is best applied using a padder (Namwamba, 2005) consisting of rollers.
    [Show full text]
  • Proper Processing of 100% Cotton Knit Fabrics
    TECHNICAL BULLETIN 6399 Weston Parkway, Cary, North Carolina, 27513 • Telephone (919) 678-2220 ───────────────────────────────────────────────────────────────────── TRI 3011 WET PROCESSING OF 100% COTTON KNITTED FABRICS © 1999 Cotton Incorporated. All rights reserved; America’s Cotton Producers and Importers. INTRODUCTION It is well established that knitted fabrics of all constructions and fiber blends are inherently more prone to shrinkage as compared to wovens. Because of the inability of a knitter to form a knitted fabric with no shrinkage, it is important for the dyer and finisher to make an effort to remove as much shrinkage from the product as possible. However, the ease with which a cotton knitted fabric is distorted during processing makes it especially difficult to deliver fabrics with no shrinkage. This bulletin will discuss in some detail the aspects of knitted fabric construction and wet processing and how they are related in terms of shrinkage. The factors that influence the level of dimensional stability can be summarized as follows: © knitting parameters, © processing tensions after knitting, © relaxation techniques in finishing, and © mechanical and chemical finishes. Each of these areas can be broken down into fundamental aspects. KNITTING As published in literature, the amount of shrinkage for any given knit fabric is primarily dependent upon the product specifications and the knitting parameters used to meet those specifications. The predominant fabric specifications that determine the shrinkage of a knitted fabric are the weight, stitch counts, and width at which the fabric is sold for cut-and-sew. The knitter uses those specifications to establish another set of specifications for knitting. Whether or not these knitting specifications are achievable is determined by the knitting machinery available to the knitter.
    [Show full text]