Collections Edited By Fondazione Acimit ″STRATEGIES OF INDUSTRIAL ECONOMY″ THE TEXTILE MACHINERY INDUSTRY IN ITALY: STRATEGIC, COMMERCIAL, FINANCIAL BEHAVIOURS (April 1997) THE TEXTILE MACHINERY INDUSTRY IN THE 2000’s: HYPOTHESIS, SIMULATION GAMES, TREND OF THE RELATED SCENARIOS (November 1997) THE CRISIS OF THE ASIAN TEXTILE SECTOR ON THE VERGE OF THE 2000’S (November 1998) TEXTILE MACHINES: THE COMPETITION OF THE EMERGING COUNTRIES (December 1999) THE TECHNOLOGICAL EVOLUTION OF THE CHINESE TEXTILE MACHINERY INDUSTRY (February 2001) THE ITALIAN TEXTILE MACHINERY INDUSTRY: COMPETITIVE STRATEGIES, INTERNATIONAL POSITION AND ECONOMIC PERFORMANCES (December 2001) THE WORLD TEXTILE MACHINERY INDUSTRY: COMMERCIAL FLOWS AND MARKET SHARES. +39 024693611, fax +39 0248008342 e-mail: info@acimit.it, http//www.it First edition: November 2001 Third revised edition: November 2006 Any reproduction, even partial and by whichever means, infringes copyright and is liable to prosecution by law in accordance with international conventions. Foreword I am pleased to present the third edition, extensively revised and updated by the Authors, of the fifth “Notebook” on textile machine technologies in the textile finishing sector, which Fondazione ACIMIT decided to prepare for the use of the Italian textile technical institutes and of the universities with degree courses in textile engineering. The exigence of working out these Notebooks emerged in 1999 from a series of meetings which Fondazione ACIMIT started with the headmasters of various technical Institutes and with their teachers within several initiatives aimed at intensifying the relations of this Foundation with the school world.
In fact we were informed that the text-books available at that time were no more abreast of the steady and rapid technological development which had characterized the textile sector in these years. In order to publish Notebooks which respond as much as possible to students’ learning needs, Fondazione ACIMIT decided, in accordance with the schools’ headmasters, to entrust a group of teachers of their Institutes with the realization of these Notebooks, a demanding task which they accepted with great enthusiasm. The success of this initiative – the total run exceeded 16.000 copies - convinced us also of the opportunity to translate the Notebooks into English, Chinese and Arab in order to ensure their circulation also with the leading foreign textile institutes and universities, in particular in the countries with high textile vocation. We shall highly welcome any suggestion and correction presented by teachers, company technicians, etc,.
which can permit us to improve these publications and to enhance their efficacy. October 2006 Paolo Banfi, President of Fondazione ACIMIT Acknowledgements The ACIMIT Foundation wishes to thank the headmasters and the teachers of following Institutes: • ITIS Buzzi – Prato • ITIS Leonardo da Vinci – Napoli • ITIS Carcano – Como • ITIS Marzotto – Valdagno (Vicenza) • ITIS Casale – Torino • ITIS Paleocapa – Bergamo • ITIS Facchinetti – Busto Arsizio (Varese) • ITIS Q. Sella – Biella • ITIS Leonardo da Vinci – Carpi (Modena) • ITIS Varese – Varese Without the prompt and active co-operation of headmasters and teachers of these Institutes, the publication of these Noteboooks would have been never possible. *** In particular, the “Finishing” Notebook was written by following teachers: • Prof.
Pietro Bellini Graduate in 1974 in Chemistry at the Università Statale di Milano; from 1977 teacher of Textile Chemistry and Fabric Finishing at the technical institute ITIS Carcano in Como and since 1994 teacher at this institute of Dyeing Chemistry; contributor to the association “Tessile di Como”. Ferruccio Bonetti Graduated in 1975 in Chemical Engineering at Politecnico di Milano. Since 1983 teacher of Dyeing Technologies and Textile Finishing at the technical institute Paleocapa in Bergamo. Since 1999teacher of “Textile and Dyeing Chemistry”within the curriculum for Textile Engineering degree at the Università di Bergamo.
Ester Franzetti Graduated in Chemistry and Pharmaceutical Technologies at theUniversità di Milano; since 1985 teacher of Chemistry, Textile Chemistry and Textile Finishing at the technical instituteITIS Varese in Varese. Giuseppe Rosace Graduated in 1991 in Chemistry at the Università di Messina; in 1995 doctor’s degree in Chemical Sciences at the Università di Bologna. Since 1996 teacher of Textile Chemistry at the technical institute ITIS Paleocapa in Bergamo. Since 2001 teacher of “Finishing technologies for textile materials” within the curriculum for Textile Engineering at the Università di Bergamo.
Sergio Vago Graduated in 1976 in Chemical Engineering at the Politecnico di Milano. From 1978 to 1991 teacher at the technical institute ITIS Carcano in Como, where he teaches Dyeing Chemistry since 1998. ACIMIT Foundation wish to thank all above mentioned eminent personalities for their extensive and enthusiastic contribution. Table of Contents INTRODUCTION .page 1 The textile finishing cycle .“ 2 Wool finishing cycles .“ 3 Cotton finishing cycles.“ 5 Silk finishing cycles .“ 6 Man-made fibres finishing cycles .“ 7 PRE-DYEING TREATMENTS.“ 17 Fulling and washing-milling .“ 24 Treatments on elastane-blended fabrics.
“ 43 Colour matching cycle .“ 56 Pre-dyeing and dyeing machines.“ 78 Air jet machines .“ 85 Beam dyeing machines .“ 86 Garment dyeing machines .“ 89 Pad dyeing machines.“ 108 Washing machines for printed fabrics .“ 111 Developments in screen/ cylinder engraving and textile printing techniques .“ 117 Ink jet printing. “132 Mechanical finishing treatments .“ 166 Crease-proof finishing.“ 173 Hydrophobic, oil-proof and water-proof finishing .“ 176 Soil-repellent finishing.“ 180 Anti-static treatment.“ 195 Finishing of ready-made denim garments .203 Influence of finishing treatments on dyed goods. “212 AUTOMATION IN TEXTILE FINISHING .“ 218 Colour analysis and control.“ 222 Production managing systems.“ 223 Automated dye kitchens .“ 231 Handling and robotisation systems .“ 232 Machine monitoring systems. “241 NOTICES ON LABORATORY TECHNIQUES.
“243 INTRODUCTION The aim of this book is to supply the most comprehensive and global insight into textile finishing processes. Since the subject is exceptionally extensive and complex, this book may appear limited to the experts working in this sector. As far as students are concerned, we hope that this book will offer them an essential background, a basis to be extended by further studies. Textile finishing usually includes treatments such as scouring, bleaching, dyeing and/or printing, the final mechanical or chemical finishing operations, that during this stage are carried out on textile products (staple, sliver or top, yarns or filaments, woven or knitted fabrics) to enhance their basic characteristics like dye penetration, printability, wettability, colour, hand, and appearance.
By textile finishing, we also mean all the processing operations that, though included in the so- called finishing stage, are generally applied to the fabrics to improve their appearance, hand and properties, at times in accordance with their field of application. The finishing stage plays a fundamental role in the excellency of the commercial results of textiles, which strictly depend on market requirements that are becoming increasingly stringent and unpredictable, permitting very short response times for textile manufacturers. The latest machines on the market used for finishing operations generally offer multi-purpose applications; the flexibility and versatility features of these machines are uninterruptedly evolving to grant excellent consistency of results. Finishing operations can be carried out by means of discontinuous, continuous and semi-continuous systems.
- Discontinuous or batch-type systems: all the operations are carried out on a single machine; it is therefore necessary to load the machine, carry out the treatments following a predetermined cycle, unload the machine and finally wash it thoroughly before starting a new cycle. This working process is extremely flexible and is suitable for processing small lots: for example, it is possible to carry out a scouring treatment on a single machine, then a bleaching treatment followed by a dyeing process. For the production of large lots, the discontinuous process is labour-intensive, i. it requires many operators to load and unload the material; it also entails long processing times and results that can vary from one batch to the other.
- Continuous systems: the operations are carried out by means of a series of machines; every machine carries out always and solely the same process. Every machine is assembled according to specific production requirements. A system like this entails high start-up costs and a complex setup but, once the system has started, requires a smaller staff and grants excellent repeatability and high output rates; continuous systems are therefore suitable for manufacturing large lots of products with the highest cost-efficiency. - Semi-continuous systems: in these mixed systems, several operations are carried out with both continuous and discontinuous machines.
For example, a continuous pad-batch machine is used to wet the fabric and a discontinuous system is successively used for other treatments. These mixed systems are suitable for processing small and medium lots; they require reasonable start-up costs and grant quite good reproducibility. 1 The textile finishing cycle: Staple, tow Preparation and and top dyeing of staple, tow, sliver Production of yarn Preparation and and ply yarn on dyeing of cone, cone, warp beam beam or hank or hank Large diameter Flat and small diameter Weaving circular knits circular knits Inspection and Eventual rolling garment dyeing Pre-treatment (cotton-, wool- or silk-type) Piece dyeing and/or printing Wet or dry finishing Final inspection, (cotton- and wool- rolling and packing 2 Wool finishing cycles The sequence of the treatments undergone by wool fibres in various forms (staple, sliver, yarn, woven and knitted fabric) varies according to the modification process of the fibre structure, according to the type of processing system used and according to the experience of the operator (these criteria are valid for all fibres). Therefore the wool processing cycle can vary according to several schemes.
An example is shown in the following. Worsted finishing cycle: Greasy wool Scouring Oiling Sliver pre- Carding dyeing Drawing treatments Combing Staple dyeing Dyeing Vigoureux Recombing Printing Drawing Spinning Weaving, Yarn pre-dyeing knitting operations Dyeing and/or Printing Finishing and inspection 3 Woollen finishing cycle: Staple washing Short staple wool Carbonising and dyeing Oiling Carding Drawing Weaving Weaving, Yarn pre-dyeing knitting operations Dyeing and/or printing Finishing and final inspection 4 Cotton finishing cycle Staple Yarn Fabric Possible Possible Singeing Singeing and Mercerising Desizing (not for knitted Scouring fabrics) Bleaching Possible Yarn Mercerising Dyeing Scouring Bleaching Possible Desizing (not on ply and knitting yarns) Dyeing and/or Printing Steaming (after printing) Washing after dyeing and/or printing Crabbing and inspection 5 Silk finishing cycle Yarn Fabric Scouring or Degumming (eventual weighting) Scouring or Degumming Yarn dyeing on cone or in hank Bleaching Dyeing and/or Printing Finishing and inspection 6 Man-made fibres finishing cycles Woven or Filament Yarn knitted fabric Texturising Scouring and Bleaching Scouring and/or dyeing Heatsetting Decortication (only PES) Dyeing and/or Printing Finishing and inspection 7 PRE-DYEING TREATMENTS The pre-dyeing stage includes a series of operations that prepare the textile product for subsequent finishing treatments such as dyeing, printing and finishing. These operations vary according to the type of fibre on which they have to be carried out, to the structure of the textile product (staple, top, sliver, yarn, fabric) and also depend on the subsequent treatments to be carried out, which may change according to various factors such as market demands, customer requirements, staff experience and availability of machines. The pre-dyeing stage includes for example singeing, desizing, mercerizing, scouring and bleaching.
Each process varies according to the processing conditions and to the above-mentioned specific situations. Some of these processes (for example bleaching and mercerizing) can be considered either preliminary operations or finishing treatments; this depends on the type of the downstream processes to be carried out on yarns or fabrics. Singeing This treatment has the purpose of eliminating the fluff protruding from the fabric, in order to make more evident and visible the fabric weave and to yield a smooth surface, besides ensuring higher soil-resistance and lower tendency to pilling. This operation is generally carried out on loomstate (grey) fabric pieces and its residues are removed through a subsequent scouring process.
Singeing is seldom carried out on knitted fabrics, but quite frequently on woven fabrics. A preventive brushing prepares the fabric to singeing, by eliminating fluff and impurities. The singeing tool is an oxidizing flame which does not leave any sooty residue on the fibre.