The Incidence of Cancer of the Bladder and Prostate in Certain Occupations

Total Page:16

File Type:pdf, Size:1020Kb

The Incidence of Cancer of the Bladder and Prostate in Certain Occupations VOLUME XXXI APRIL, 1931 No. 2 THE INCIDENCE OF CANCER OF THE BLADDER AND PROSTATE IN CERTAIN OCCUPATIONS. BY S. A. HENRY, H.M. Medical Inspector of Factories, N. M. KENNAWAY AND E. L. KENNAWAY. (From the Cancer Hospital Research Institute, London.) CONTENTS. PAGE I. Material examined 125 II. Sources of error 126 III. Method of calculation 128 IV. Incidence of cancer of the bladder 129 V. Occurrence of tumours of the skin, and of the bladder, in the same person 133 VI. The relations between cancers of the scrotum, of other parts of the skin, and of the bladder 134 VII. Incidence of cancer of the prostate . .135 VIII. Cancer of the bladder and prostate in chemical workers .... 136 IX. Summary 136 I. MATERIAL EXAMINED. THE results given below are derived from an examination of death certificates of cases of cancer and papilloma of the bladder in both sexes, and of cancer of the prostate, from England and Wales between 1921 and 1928. The total numbers of certificates examined are shown in Table I; from the whole series of 13,965 cases those relating to cancer of the bladder in males, and cancer of the prostate, Table I. Death certificates examined. Cancer of Papilloma of Cancer of bladder bladder prostate Males. 1921 589 86 — 1922 641 109 — 1923 647 114 — 1924 711 115 1022 1925 745 115 1116 1926 723 134 1145 1927 753 151 1172 1928 812 150 1353 5621* 974 5808* Females. 1924 350 — 1925 337 46 1926 340 51 1927 384 54 1411 151 * The difference between these totals and those given in Table II is due to the exclusion from the latter Table of seven cases of cancer of the bladder, and four cases of cancer of the prostate, occurring in persons under 20 years of age. Journ. of Hyg. xxxi 9 Downloaded from https://www.cambridge.org/core. IP address: 170.106.34.90, on 02 Oct 2021 at 10:53:12, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0022172400010731 126 Cancer and Occupation numbering 11,429, were chosen for study in detail, as in these classes the largest numbers and the best occupational data are available. The two classes which were not used for exact tabulation of the occupations, namely, papilloma of the bladder, and cancer of the bladder in females, were put aside for the following reasons: (a) The cases of papilloma, which amount to little more than one-sixth of those of cancer of the bladder, are insufficient in number; but data were obtained from this series, in regard to the chemical trades especially, which will be studied in future when more figures are avail- able. This class is valuable because the proportion of correct diagnoses is pro- bably high and the inclusion of any prostatic or rectal tumours is unlikely. (b) The death certificates of women did not yield a sufficient number in which any industrial occupation was recorded. Thus, in 1925, only 15 of the 337 death certificates for cancer of the bladder in women recorded any occupation not connected with domestic, nursing or teaching work. II. SOURCES OF ERROR. The analysis of such material as is afforded by the 11,429 certificates of cancer of the bladder in males, and of the prostate, encounters many difficulties, which may be classified under three headings. First, it is necessary to know the total number of persons following any given occupation. This is learned from the Census results (in this case the Census of 1921) but (1) the figure given by the Census cannot be relied upon throughout the 10 years until the next Census; (2) the utility of the Census figures in the present investigation depends upon the possibility of obtaining in the death entries such detailed information in regard to occupation and in- dustry as would enable the resultant figures to be related to the Census figures. It was not possible for example to ascertain a population at risk in regard to certain workers in chemicals and chemical manufactures in whom we were interested, and the corresponding death certificates, from which very inte- resting results might have been expected, could not be used statistically. Second, with regard to the smaller occupations. Some of the most inte- resting from the present standpoint (patent fuel manufacture, tar distilling, chimney sweeping) employ a few thousand men only, who will yield but very few cases of cancer of the bladder even if the incidence is high. Hence the sampling error will be large even over a period of 8 years. Three of the four deaths of tar distillers from cancer of the bladder recorded in Table III occurred in two of the eight years (1922 and 1923). Third, with regard to the individual entry in the death register. (1) This gives no information about the length of time during which the deceased followed the occupation named. (2) In some cases, especially in the case of deaths occurring in institutions, the information available to the Registrar at the time of registration is not so detailed as that supplied by the man him- self at the Census. (3) Incorrect diagnosis is of course a possible source of error which is unavoidable in all such material. Downloaded from https://www.cambridge.org/core. IP address: 170.106.34.90, on 02 Oct 2021 at 10:53:12, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0022172400010731 S. A. HENRY, N. M. KBNNAWAY AND E. L. KBNNAWAY 127 In the work recorded here, an attempt has been made to avoid these in- accuracies by special enquiry into individual cases in some occupations (patent- fuel labourers, gas-works engine and crane drivers, gas fitters, gas stokers, gas- works inspectors and foremen, gas workers and labourers (not stokers), gas- producer men, coke-oven workers, brick kiln and oven men, blast f urnacemen and labourers, dye mixers and dyers) where the smallness of the number employed made an error in a single death certificate most serious. Such enquiry was made in fifty cases of cancer of the bladder, chiefly of the more recent years (1924- 1928), from relatives, fellow-workmen and employers of the deceased, with re- ference especially to the exact nature of the occupation and the length of time for which it had been pursued. Of these fifty cases, forty-four could be traced. In forty-one the reliability for our purpose of the information given on the death certificate was confirmed. In one case the short time for which the occupation had been followed (5 to 6 months) caused it to be rejected as a factor, although the entry was of course perfectly correct. In two cases the industry rather than the occupation in that industry had been recorded. Thus an "alkali labourer" was found to have worked for 32 years at a gas-producer plant, and the case was transferred accordingly to the class of gas-producer men. The minimum duration of exposure necessary to produce an occupational cancer cannot be stated, and this question is a constant source of difficulty in such work as is presented here. In this series we have rejected the case of a gas- works labourer who had been employed in that work for not more than 5 or 6 months before death, and have retained the cases of a dyer with 2 years' and of a gas-producer man with 5 years' duration of employment before death. The objection may be raised that if special enquiry be made into any of the cases in Table III it should be made into all. But (1) to investigate, in places scattered all over England and Wales, the accuracy of over 1400 death certificates was not practicable for us. (2) The risk of serious error is greatest in the smaller groups. Thus, if the certificate relating to one of four patent-fuel labourers is incorrect, the error is serious; but it is extremely unlikely that 25 per cent, of the 160 farmers are described incorrectly. (3) The comparatively small number of occupational terms in some of the larger groups causes less classification difficulty in those groups than in some of the smaller ones. Thus, an agricultural labourer can hardly be misnamed, whereas a tar distiller may be described as a by-product worker, or a stillman in a chemical works. The occupational classification in use at the General Register Office was revised in 1921. The change was made in accordance with a resolution of the British Empire Statistical Conference of 1920 in favour of separate and inde- pendent tabulations by occupation and by industry. The classifications used in 1911 and earlier were only in part occupational, being largely industrial in nature. The change precludes the possibility of an exact comparison with previous Census results (see General Report, Census of England and Wales, 1921, p. 86), or with the data on the occupational incidence of cancer in England and 9-2 Downloaded from https://www.cambridge.org/core. IP address: 170.106.34.90, on 02 Oct 2021 at 10:53:12, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0022172400010731 128 Cancer and Occupation Wales in 1910, 1911 and 1912, published by the Medical Research Council (Young, Russell, Brownlee and Collis, 1926). In the last-named report the occupations associated with coal gas, tar and pitch, do not appear in the tables devoted to cancer of the bladder and prostate.
Recommended publications
  • Influence of Process Parameters on the Properties of Friction-Spun Yarns
    Indian Journal of Fibre & Textile Research Vol.18,March 1993,pp.14-l9 Influence of process parameters on the properties of friction-spun yarns A R Padmanabhan & N Ramakrishnan The South India Textile Research Association, Coimbatore 641 014, India Received 9 June 1992; revised received 23 October 1992; accepted 24 November 1992 The effects of spinning drum speed, yam delivery rate, core-wrapper ratio and number of wrapper slivers on the quality characteristics of yams spun on a laboratory model DREF-3 friction spinning ma- chine have been studied. It is observed that by and large, drum speed and per cent wrapper fibres deter- mine the yarn tenacity while the delivery rate and the per cent core fibre content influence the yam un- evenness. Keywords: Carding drum, Drum speed, Friction-spun yarn, Yarn tenacity, Unevenness, Wrapper fibres t Introduction drafting unit II with different core-to-wrapper ratios The quality of the yarn obtained from any spinn- and at different delivery rates. ing system depends on the quality of raw material In each count, 12 yarn samples, three for each of used as well as on the process parameters employed the four process variables, were produced by suit- during spinning. Friction spinning is no exception to ably altering the spinning parameters as listed in this. While many research workers have studied in Table 2. While varying the parameters, care was tak- detail the influence of process variables on yarn en to ensure that only one parameter was changed at quality in both ring and rotor spinning, such an in- a time, keeping the other three at the following opti- formation with regard to friction spinning appears mum level as suggested by the manufacturer.
    [Show full text]
  • Textile Industry Needs Christopher D
    The Journal of Cotton Science 21:210–219 (2017) 210 http://journal.cotton.org, © The Cotton Foundation 2017 ENGINEERING & GINNING Textile Industry Needs Christopher D. Delhom, Vikki B. Martin, and Martin K. Schreiner ABSTRACT lthough the immediate customer of the gin is Athe cotton producer, the end user of the ginned The immediate customers of cotton gins are lint is the textile mill, retailers, and eventually the the producers; however, the ultimate customers consumer. Thus, it is essential for the ginner to are textile mills and consumers. The ginner has satisfy both the producers and the textile industry. the challenging task to satisfy both producers and Consequently, the ginner needs to be aware of the the textile industry. Classing and grading systems needs of the textile industry. are intended to assign an economic value to the The intent of the cotton classing and grading bales that relates to textile mill demands and the system is to assign an economic value to the bale that quality of the end product. International textile documents its properties as it relates to the quality of mills currently are the primary consumers of U.S. the end product. Since the last edition of the Cotton cotton lint where it must compete against foreign Ginners Handbook in 1994, the customers of U.S. origins. International textile mills manufacture cotton have changed radically, shifting from primar- primarily ring-spun yarns, whereas domestic mills ily domestic to international mills. International mills manufacture predominantly rotor spun yarns. Pro- have been accustomed primarily to hand-harvested ducers and ginners must produce cottons to satisfy cotton that has been processed at slow ginning all segments of the industry, i.e., domestic and in- rates.
    [Show full text]
  • Start Spinning: Everything You Need to Know to Make Great Yarn Ebook
    START SPINNING: EVERYTHING YOU NEED TO KNOW TO MAKE GREAT YARN PDF, EPUB, EBOOK Maggie Casey | 120 pages | 01 Apr 2008 | Interweave Press Inc | 9781596680654 | English | Loveland, CO, United States Start Spinning: Everything You Need to Know to Make Great Yarn PDF Book To make two-ply yarn, take two singles strands or both ends of the same strand , attach them both to your spindle, and twist them around each other in the opposite direction from how you originally spun them. When you spin, you put twist into fibres so that they hold together to form a continuous thread. Navajo Plying - Making a three-ply yarn 8. Designed to appeal to the beginning spinner, tips and hints are provided that illustrate how easy, enjoyable, and relaxing spinning can be. When I was in Kenya, women spun Romney wool chiefly "in the grease," but it often locked in large amounts of dirt in the process. Spin spin spin! Covers fiber characteristics, preparation and spinning, choosing a wheel, and crafting the finished yarn into useful and attractive pieces. I Made It! Leave the original loop of fiber anchored on the spindle hook. Description If you are a knitter or crocheter looking to take the step from just using manufactured yarn to making your own this is a great book to get you started. A bunch of loose fibers will fall apart if you pull on their ends. Launching a Patreon! First and foremost, you want a balanced drop spindle that spins true. Either one will do just fine to learn on. It is also much easier to learn to spin wool than silk, or cotton and other vegetable fibres.
    [Show full text]
  • Dynamics of Rotating Superconducting Magnetic Bearings in Ring Spinning
    IEEE/CSC & ESAS SUPERCONDUCTIVITY NEWS FORUM (global edition), January 2016. EUCAS 2015 preprint 3A-LS-P-07.09. Submitted to IEEE Trans. Appl. Supercond. for possible publication. 3A-LS-P-07.09 1 Dynamics of rotating Superconducting Magnetic Bearings in Ring Spinning M. Sparing, A. Berger, F. Wall, V. Lux, S. Hameister, D. Berger, M. Hossain, A. Abdkader, G. Fuchs, C. Cherif, L. Schultz Abstract — A superconducting magnetic bearing (SMB) during spinning and winding. This procedure twists the fibers consisting of a stationary superconductor in a ring-shaped flow- thereby form sand strengthens the yarn. Details of the spinning through cryostat and a rotating permeant magnetic (PM) ring is process and various concepts to improve or replace the ring- investigated as potential twist element in the textile technological process of ring spinning. Since the dynamic behavior of the traveler system are described in the literature [5], [6]. The rotating PM influences the yarn as well as the stability of replacement of the ring-traveler system by an SMB eliminates spinning process, these factors are studied in this paper the problem of frictional heat in the existing system. A considering the acting forces of the yarn on the PM-ring, its detailed description of this process can be found in references vibration modes and the resulting oscillation amplitudes. [7]-[9]. For the assessment of a safe field cooling distance during the operation of the rotating SMB in a rings spinning machine, a II. RING SPINNING WITH AN SMB TWIST ELEMENT correct calculation of the resonance magnification is particularly important. Therefore, the decay constant δ of the damped A.
    [Show full text]
  • The Lancashire Cotton Textile Industry, 1918-1938
    This is a repository copy of Ownership, financial strategy and performance: the Lancashire cotton textile industry, 1918-1938. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/90410/ Version: Accepted Version Article: Higgins, D, Toms, JS and Filatotchev, I (2015) Ownership, financial strategy and performance: the Lancashire cotton textile industry, 1918-1938. Business History, 57 (1). 97 - 121. ISSN 0007-6791 https://doi.org/10.1080/00076791.2014.977873 Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Ownership, Financial Strategy and Performance: The Lancashire Cotton Textile Industry, 1918-19381 By David Higgins (University of Newcastle) Steven Toms* (University of Leeds) Igor Filatotchev
    [Show full text]
  • Results Vintage & Jewellery
    Results Vintage & Jewellery, No. Item Hammer price 1 A brilliant cut diamond ring, 1.35 ct. 35 000 SEK 2 A pair of 12 mm cultured South sea pearl, pink sapphire, peridote and diamond earrings. Unsold 3 A cultured pearl and brilliant-cut diamond brooch. 8 000 SEK 4 A brilliant-cut diamond necklace. Unsold 5 A brilliant-cut diamond, 1.01 cts, ring. Quality F/ VVS1 according to HRD certificate. Unsold 6 A brilliant-cut diamond, circa 1.74 cts, solitaire ring. Quality H/VVS2. Unsold 7 A diamond, circa 1.00 ct, and sapphire ring. Flexible parts. Unsold 8 A pair of Tahiti pearl, 13 mm, and diamond, circa 0.36 ct, earrings. 13 000 SEK 9 A brilliant-cut diamond brooch. Total carat weight circa 2.00 cts. Unsold 10 A South Sea pearl, circa 14.8 x 12.8 mm, and diamond, ca total 0.08 ct, pendant. Unsold 11 A tourmaline, total carat weight 16.20 cts, and diamond, total carat weight 2.99 cts. Unsold 12 A pair of cultured South sea pearl and brilliant-cut diamond earrings. Unsold 13 A NECKLACE, south sea pearls 14.3-17.0 mm. Clasp with multicolor sapphires c. 7.50 Unsold cts. Length 42 cm. 14 A pink sapphire, circa 1.55 cts, and diamond, total circa 0.7 ct, ring. 12 000 SEK 15 A pair of pearl and diamond earring. 12 000 SEK 16 A brilliant-cut diamond ring. Total gem weight 2.48 cts. Unsold 17 A pair of amethyst and diamond, circa 0.60 ct, earrings.
    [Show full text]
  • 7. Wool Combing
    7. Wool Combing Errol Wood Learning objectives On completion of this topic you should be able to: • Outline the objectives of wool combing • Describe the design of a typical rectilinear comb • Explain the steps in rectilinear combing – feeding, initial combing, final combing and drawing off, and sliver formation • Discuss the means by which noils are removed, and the balance required in setting the amount to be removed • Explain the purpose of re-combing • Calculate: tear ratio, noil(%), romaine, regain and combing production • Discuss the factors that affect the combing quality of fine wools Key terms and concepts Combing (Nobel and rectilinear), nips per minute, doublings, noils, finisher gilling, packaging, re- combing, tear, noil(%), romaine, percent fibres less than 30 mm, combing production. Introduction to the topic Wool combing is a comprehensive term when used in its widest sense, and it embraces all the operations carried out in a topmaking plant. It includes the processes of raw wool scouring, drying, carding, backwashing and preparer gilling. Then follows the actual combing operation and the sequence of topmaking processes concludes with two gilling steps called top finishing (or finisher gilling). Combing is not included in the semiworsted or woollen processing routes. Wool combing, the single process, is indispensable in the manufacture of a worsted yarn. The card has disentangled the fibres in the mass of scoured wool and has mixed them in a roughly parallel formation. However, during the carding process many fibres will have been broken, and the card sliver will consist of a variety of fibre lengths. Some vegetable matter will have been removed but fragments remain.
    [Show full text]
  • An Overview of Spinning Technologies: Possibilities, Applications and Limitations
    Indian Journal of Fibre & Textile Research Vol. 17 , December 1992, pp. 255-262 An overview of spinning technologies: Possibilities, applications and limitations K R Salhotra Department of Textile Technology. Indian Institute of Technology. Hauz Khas. New Delhi 110016. India Received 12 August 1992 The new spinning technologies such as rotor, air jet and friction spinning have tremendous potential for hi gher productivity. However. at present these technologies not o nl y suffer from the problem of imparting some undesirable properties to the fabric but a lso have limited applicability due to the restricted choice of fibres and counts which can be successfully spun on them. Ring-spinning system, though having lower productivity, does not have these drawbacks. This system, therefore, with the incorporation of some recent improvements is likely to occupy the centre stage for the next few years. Keywords: Air jet spinning, Fabric hand, Friction spinning, Jet spin-assembly wind, Open-end spinning, Ring spinning, Rotor spinning, Twin spinner, Wrap spinning, Yarn properties 1 Introduction 'moire' effect in the fabric despite many modifications The ring-spinning system had remained made to the original yarn. This situation was entirely unchallenged since its introduction in the middle of different from the earlier developments from hand last century till the late 1960s. However, the spinners spinning to ring spinning when the product were becoming increasingly aware of the fact that low characteristics did not undergo any basic change in its productivity was inherent to the basic principle of structure. The systems such as hand wheel, flyer ring spinning. The system had reached a plateau in spinning, cap spinning, spinning jenny, mule regard to maximum production speeds.
    [Show full text]
  • Cotton Mills for the Continent
    cotton mills_klartext.qxd 30.05.2005 9:11 Uhr Seite 1 Cotton mills for the continent Sidney Stott und der englische Spinnereibau in Münsterland und Twente Sidney Stott en de Engelse spinnerijen in Munsterland en Twente 1 cotton mills_klartext.qxd 30.05.2005 9:11 Uhr Seite 2 Cotton mills for the continent Bildnachweis/Verantwoording Sidney Stott und der englische Spinnereibau in afbeldingen Münsterland und Twente – Sidney Stott en de Engelse spinnerijen in Munsterland en Twente Andreas Oehlke, Rheine: 6, 47, 110, 138 Archiv Manz, Stuttgard: 130, 131, 132l Herausgegeben von/Uitgegeven door Axel Föhl, Rheinisches Amt für Denkmalpflege, Arnold Lassotta, Andreas Oehlke, Siebe Rossel, Brauweiler: 7, 8, 9 Axel Föhl und Manfred Hamm: Industriegeschichte Hermann Josef Stenkamp und Ronald Stenvert des Textils: 119 Westfälisches Industriemuseum, Beltman Architekten en Ingenieurs BV, Enschede: Dortmund 2005 111, 112, 127oben, 128 Fischer: Besteming Semarang: 23u, 25lo Redaktion/Redactie Duncan Gurr and Julian Hunt: The cotton mills of Oldham: 37, 81r Hermann Josef Stenkamp Eduard Westerhoff: 56, 57 Hans-Joachim Isecke, TECCON Ingenieurtechnik, Zugleich Begleitpublikation zur Ausstel- Stuhr: 86 lung/Tevens publicatie bij de tentoonstelling John A. Ledeboer: Spinnerij Oosterveld: 100 des Westfälischen Industriemuseums John Lang: Who was Sir Philip Stott?: 40 Museum Jannink, Enschede: 19, 98 – Textilmuseum Bocholt, Museum voor Industriële Acheologie en Textiel, des Museums Jannink in Enschede Gent: 16oben und des Textilmuseums Rheine Ortschronik (Stadtarchiv) Rüti: 110 Peter Heckhuis, Rheine: 67u, 137 Publikation und Ausstellung ermöglichten/ Privatbesitz: 15, 25u, 26u, 30, 31, 46, 65, 66, 67oben, 83oben, 87oben, 88u, 88r, 90, 92, 125l Publicatie en tentoonstelling werden Rheinisches Industriemuseum, Schauplatz Ratingen: mogelijk gemaakt door 11, 17 Europäische Union Ronald Stenvert: 26r, 39r, 97, 113oben, 113r, 114, 125r, Westfälisches Industriemuseum 126 Kulturforum Rheine Roger N.
    [Show full text]
  • Cotton and the Community: Exploring Changing Concepts of Identity and Community on Lancashire’S Cotton Frontier C.1890-1950
    Cotton and the Community: Exploring Changing Concepts of Identity and Community on Lancashire’s Cotton Frontier c.1890-1950 By Jack Southern A thesis submitted in partial fulfillment for the requirements for the degree of a PhD, at the University of Central Lancashire April 2016 1 i University of Central Lancashire STUDENT DECLARATION FORM I declare that whilst being registered as a candidate of the research degree, I have not been a registered candidate or enrolled student for another aware of the University or other academic or professional institution. I declare that no material contained in this thesis has been used for any other submission for an academic award and is solely my own work. Signature of Candidate ________________________________________________ Type of Award: Doctor of Philosophy School: Education and Social Sciences ii ABSTRACT This thesis explores the evolution of identity and community within north east Lancashire during a period when the area gained regional and national prominence through its involvement in the cotton industry. It examines how the overarching shared culture of the area could evolve under altering economic conditions, and how expressions of identity fluctuated through the cotton industry’s peak and decline. In effect, it explores how local populations could shape and be shaped by the cotton industry. By focusing on a compact area with diverse settlements, this thesis contributes to the wider understanding of what it was to live in an area dominated by a single industry. The complex legacy that the cotton industry’s decline has had is explored through a range of settlement types, from large town to small village.
    [Show full text]
  • Need for Lap Preparation
    Need for Lap preparation: The combers are fed with a small lap produced by combining several slivers. The raw material delivered by the card is unsuitable for combing as regards both form and fiber arrangement. If card slivers were just combined and fed to the comber, true nipping by the nipper plates would occur only on the high points, with the risk that the nippers could not retain the less firmly compressed edge zones of the slivers asshown in the below fig. This is because the slivers are not flattened. The fibres could then be pulled out as clumps by the circular combs during combing operation. A sheet with the greatest possible degree of evenness in cross section, with uniform thickness is therefore required as in-feed to the comber. Effect of fibre presentation: The fiber arrangement must also be taken into account, i.e. in this case the disposition of the hooks. If the comber is to straighten hooks, as it is intended to, then the fibers must be presented to it with leading hooks. The carded slivers have trailing hooks as the majority hooks (more than 50%) as the sliver emerges out of the calendar rollers in the carding machine. Each time the sliver is packed in a can and taken out, the majority hooks change. For example, as the sliver is withdrawn from the card can, the original trailing hooks (as the sliver went into the can) are now counted as the leading hooks as can be seen in Fig. Hence, at this stage majority hooks are the leading hooks.
    [Show full text]
  • Production of Shape Memory Alloy Core- Sheath Friction Yarns
    M. R. Ahmad, M. H. M. Yahya1), Production of Shape Memory Alloy Core- *M. R. Hassan, J. Salleh, Sheath Friction Yarns W. Y. W. Ahmad, Abstract N. Hassim This paper describes some studies on the development of shape memory alloy (SMA) core- sheath friction yarns. SMA wires for actuating purposes were utilised as a conductive ele- ment in the core-sheath friction yarn. A DREF 3000 friction spinning machine was used to produce the yarns. The conductive yarn was spun with the SMA actuator wire at the core and 100% cotton fibers in the second layer as the sheath producing a yarn called SMA Faculty of Applied Sciences, Universiti Teknologi MARA, core-sheath friction yarn (SMA CSFY). During spinning, the core-sheath ratio and spinning Shah Alam, Selangor, Malaysia drum speeds were varied. The main purposes of the study were to evaluate the SMA CSFY single yarn tensile strength and its actuating performance against changes in the spinning *Faculty of Engineering, process parameters. The results showed that SMA CSFY with the highest spinning drum Universiti Putra Malaysia, speed and 60% core gave the highest tensile strength and fastest actuation performance. Serdang, Malaysia 1)Corresponding author: [email protected] Key words: shape memory alloy, DREF 3000 spinning system, conductive yarn. natural and synthetic fibres from 32 to ity, increasing the yarn strength and im- 60 mm in length [8]. Technically fibres parting any functional fibre to the yarn n Introduction from a card sliver are opened into indi- produced. Figures 1.a and 1.b illustrate vidual fibres. The opened fibres (reduced the cross-sections and longitudinal view The growing development of smart tex- size fibres) are then transfered onto the of core-sheath friction yarns from the tiles is changing the point of view of spinning drums, which are rotating in the DREF 2000 and DREF 3000 spinning world textile fashion from traditional same direction with the assisstance of an systems.
    [Show full text]