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Weaving and Knitting

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Weaving and knitting are the two primary textile processes for manufacturing fabrics. In the modern textile industry, these processes take place on electrically powered automated machines, and the resulting fabrics find their way into a wide range of end-uses, including wearing apparel, home furnishings and industrial applications.

Weaving

The weaving process consists of interlacing straight yarns at right angles to one another. It is the oldest technology of manufacturing fabric: hand-powered looms were used in pre-Biblical times. The basic concept of interlacing the yarns is still followed today.

Warp yarns are supplied from a large reel, called a warp beam, mounted at the back of the weaving machine. Each warp yarn end is threaded through a heddles harness. The harness is used to lift or depress the warp yarns to allow the weaving to be done. The simplest weaving requires two harnesses, and more intricate woven fabrics require as many as six harnesses. Jacquard weaving equipment is used to manufacture the most decorative fabrics and has features to enable each individual warp yarn to be lifted or depressed. Each yarn end then is threaded through a reed of closely spaced thin parallel metal pieces mounted on the machine’s lay, or sley. The lay is designed to move in a reciprocating arc around a pivotal anchor point. The yarn ends are attached to the take-up roll. The woven fabric is wound on this roll.

The oldest technology for feeding the filling yarn across the width of the warp yarns is the shuttle, which is propelled in a free-flight fashion from one side of the warp yarn to the other side and pays out the filling yarn from a small bobbin mounted in it. New and faster technology, shown in figure 1, called shuttleless weaving, uses air jets, water jets, small projectiles that ride in a guidetrack, or small, sword-like devices called rapiers to carry the filling yarn.

Figure 1. Air-jet weaving machines

TEX055F2

Tsudakoma Corp

Employees in weaving are typically grouped into one of four job functions:

  1. machine operators, commonly called weavers, who patrol their assigned production area to check on fabric production, correct some basic machine malfunctions such as yarn breaks and restart stopped machines
  2. machine technicians, sometimes called fixers, who adjust and repair the weaving machines
  3. direct production service workers, who transport and load raw materials (warp and filling yarn) onto the weaving machines and who unload and transport finished products (fabric rolls)
  4. indirect production service workers, who perform cleaning, machine lubrication and so on.

 

Safety risks

Weaving presents only a moderate worker safety risk. However, there are a number of typical safety hazards and minimization measures.

Falls

Objects on the floor that cause worker falls include machine parts and oil, grease and water spots. Good housekeeping is particularly important in weaving, since many of the process workers spend most of their workday patrolling the area with eyes directed to the production process rather than toward objects on the floor.

Machinery

Power transmission devices and most other pinch points are typically guarded. The machine lay, harnesses and other parts that must be frequently accessed by weavers, however, are only partially enclosed. Ample walking and working space must be provided around the machines, and good work procedures help workers avoid these exposures. In shuttle weaving, guards mounted on the lay are needed to prevent the shuttle from being thrown out, or to deflect it in a downward direction. Lockouts, mechanical blocks and so on are also required in order to prevent the introduction of hazardous energy into areas when technicians or others are performing job duties on stopped machines.

Materials handling

These can include lifting and moving heavy cloth rolls, warp beams and so on. Hand-trucks to help unload, or doff, and transport small cloth rolls from take-ups on the weaving machine reduce the risk of worker strain injuries by alleviating the need to lift the full weight of the roll. Powered industrial trucks can be used to doff and transport large cloth rolls from bulk take-ups placed at the front of the weaving machine. Wheeled trucks with powered or manual hydraulic assists can be used to handle warp beams, which usually weigh several hundred kg. Warp-handling workers should wear safety shoes.

Fires and ignition

Weaving creates a fair amount of lint, dust and fibre flyings which can represent fire hazards if the fibres are combustible. Controls include dust-collection systems (located under the machines in modern facilities), regular machine cleanings by service workers and use of electrical equipment designed to prevent sparking (e.g., Class III, Division 1, Hazardous Locations).

Health risks

Health risks in modern weaving are generally limited to noise-induced hearing loss and to pulmonary disorders associated with some types of fibres used in the yarn.

Noise

Most weaving machines, operating in the numbers found in a typical production facility, produce noise levels that generally exceed 90 dBA. In some shuttle and high-speed shuttleless weaving, levels may even exceed 100 dBA. Appropriate hearing protectors and a hearing conservation programme are nearly always necessary for weaving workers.

Fibre dust

Pulmonary disorders (byssinosis) have long been linked with dusts associated with the processing of raw cotton and flax fibres, and are discussed elsewhere in this chapter and this Encyclopaedia. Generally, ventilation and room air filtration cleaning systems with dust collection points under the weaving machines and at other points in the weaving area maintain dusts at or below required maximum levels (e.g., 750 mg/m3 of air in the OSHA cotton dust standard) in modern facilities. Additionally, dust respirators are needed for temporary protection during cleaning activities. A worker medical surveillance programme should be in place to identify workers who might be especially sensitive to the effects of these dusts.

Machine Knitting

There is a major cottage industry for the production of hand-knitted items. There are inadequate data on numbers of workers, generally women, thus engaged. The reader is referred to the chapter Entertainment and the arts for an overview of likely hazards. Editor.

The mechanical knitting process consists of interconnecting loops of yarn on powered automated machines (see figure 2). The machines are equipped with rows of small, hooked needles to draw formed yarn loops through previously formed loops. The hooked needles have a unique latch feature that closes the hook to easily allow the loop drawing and then opens to allow the yarn loop to slide off the needle.

Figure 2. Circular-knitting machine

TEX055F3

Sulzer Morat

Circular-knitting machines have needles arranged in a circle, and the fabric produced on them comes off the machine in the shape of a large tube that is wound onto a take-up roll. Flat-knitting machines and warp-knitting machines, on the other hand, have needles arranged in a straight row, and fabric comes off the machine in a flat sheet for roll take-up. Circular- and flat-knitting machines are generally fed from yarn cones, and warp-knitting machines are generally fed from warp beams that are smaller but similar to those used in weaving.

Employees in knitting are grouped into job functions with duties similar to those in weaving. Job titles appropriately parallel the process name.

Safety risks

Safety risks in knitting are similar to those in weaving though generally of a lesser degree. Oil on the floor often is a little more prevalent in knitting due to the high lubrication needs of the knitting needles. Machine entrapment risks are less in knitting since there are fewer pinch points on the machines than those found in weaving, and much of the machinery lends itself well to enclosure guarding. Energy-control lockout procedures remain a must.

Cloth roll handling still presents a worker strain injury risk, but the heavy warp-beam handling risks are not present except in warp knitting. Risk control measures are similar to those in weaving. Knitting does not produce the levels of lint, flyings and dust that are found in weaving, but the oil from the process helps keep the fire fuel load at a level that needs attention. Controls are similar to those in weaving.

Health risks

Health risks in knitting are also generally lower than those in weaving. Noise levels range in the mid-80-dBA to low-90-dBA levels. Respiratory disorders for knitting workers processing raw cotton and flax do not appear to be especially prevalent, and regulatory standards for these materials are often not applicable in knitting.

 

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Contents

Preface
Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Clothing and Finished Textile Products
Leather, Fur and Footwear
Textile Goods Industry
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides

Textile Goods Industry References

American Textile Reporter. 1969. (10 July).

Anthony, HM and GM Thomas. 1970. Tumors of the urinary bladder. J Natl Cancer Inst 45:879–95.

Arlidge, JT. 1892. The Hygiene, Diseases and Mortality of Occupations. London: Percival and Co.

Beck, GJ, CA Doyle, and EN Schachter. 1981. Smoking and lung function. Am Rev Resp Dis 123:149–155.

—. 1982. A longitudinal study of respiratory health in a rural community. Am Rev Resp Dis 125:375–381.

Beck, GJ, LR Maunder, and EN Schachter. 1984. Cotton dust and smoking effects on lung function in cotton textile workers. Am J Epidemiol 119:33–43.

Beck, GJ, EN Schachter, L Maunder, and A Bouhuys. 1981. The relation of lung function to subsequent employment and mortality in cotton textile workers. Chest suppl 79:26S–29S.

Bouhuys, A. 1974. Breathing. New York: Grune & Stratton.

Bouhuys, A, GJ Beck, and J Schoenberg. 1979. Epidemiology of environmental lung disease. Yale J Biol Med 52:191–210.

Bouhuys, A, CA Mitchell, RSF Schilling, and E Zuskin. 1973. A physiological study of byssinosis in colonial America. Trans New York Acad Sciences 35:537–546.

Bouhuys, A, JB Schoenberg, GJ Beck, and RSF Schilling. 1977. Epidemiology of chronic lung disease in a cotton mill community. Lung 154:167–186.

Britten, RH, JJ Bloomfield, and JC Goddard. 1933. Health of Workers in Textile Plants. Bulletin No. 207. Washington, DC: US Public Health Service.

Buiatti, E, A Barchielli, M Geddes, L Natasi, D Kriebel, M Franchini, and G Scarselli. 1984. Risk factors in male infertility. Arch Environ Health 39:266–270.

Doig, AT. 1949. Other lung diseases due to dust. Postgrad Med J 25:639–649.

Department of Labor (DOL). 1945. Special Bulletin No. 18. Washington, DC: DOL, Labor Standards Division.

Dubrow, R and DM Gute. 1988. Cause-specific mortality among male textile workers in Rhode Island. Am J Ind Med 13: 439–454.

Edwards, C, J Macartney, G Rooke, and F Ward. 1975. The pathology of the lung in byssinotics. Thorax 30:612–623.

Estlander, T. 1988. Allergic dermatoses and respiratory diseases from reactive dyes. Contact Dermat 18:290–297.

Eyeland, GM, GA Burkhart, TM Schnorr, FW Hornung, JM Fajen, and ST Lee. 1992. Effects of exposure to carbon disulphide on low density lipoprotein cholesterol concentration and diastolic blood pressure. Brit J Ind Med 49:287–293.

Fishwick, D, AM Fletcher, AC Pickering, R McNiven, and EB Faragher. 1996. Lung function in Lancashire cotton and man-made fibre spinning mill operatives. Occup Environ Med 53:46–50.

Forst, L and D Hryhorczuk. 1988. Occupational tarsal tunnel syndrome. Brit J Ind Med 45:277–278.

Fox, AJ, JBL Tombleson, A Watt, and AG Wilkie. 1973a. A survey of respiratory disease in cotton operatives: Part I. Symptoms and ventilation test results. Brit J Ind Med 30:42-47.

—. 1973b. A survey of respiratory disease in cotton operatives: Part II. Symptoms, dust estimation, and the effect of smoking habit. Brit J Ind Med 30:48-53.

Glindmeyer, HW, JJ Lefante, RN Jones, RJ Rando, HMA Kader, and H Weill. 1991. Exposure-related declines in the lung function of cotton textile workers. Am Rev Respir Dis 144:675–683.

Glindmeyer, HW, JJ Lefante, RN Jones, RJ Rando, and H Weill. 1994. Cotton dust and across-shift change in FEV1 Am J Respir Crit Care Med 149:584–590.

Goldberg, MS and G Theriault. 1994a. Retrospective cohort study of workers of a synthetic textiles plant in Quebec II. Am J Ind Med 25:909–922.

—. 1994b. Retrospective cohort study of workers of a synthetic textiles plant in Quebec I. Am J Ind Med 25:889–907.

Grund, N. 1995. Environmental considerations for textile printing products. Journal of the Society of Dyers and Colourists 111 (1/2):7–10.

Harris, TR, JA Merchant, KH Kilburn, and JD Hamilton. 1972. Byssinosis and respiratory diseases in cotton mill workers. J Occup Med 14: 199–206.

Henderson, V and PE Enterline. 1973. An unusual mortality experience in cotton textile workers. J Occup Med 15: 717–719.

Hernberg, S, T Partanen, and CH Nordman. 1970. Coronary heart disease among workers exposed to carbon disulphide. Brit J Ind Med 27:313–325.

McKerrow, CB and RSF Schilling. 1961. A pilot enquiry into byssinosis in two cotton mills in the United States. JAMA 177:850–853.

McKerrow, CB, SA Roach, JC Gilson, and RSF Schilling. 1962. The size of cotton dust particles causing byssinosis: An environmental and physiological study. Brit J Ind Med 19:1–8.

Merchant, JA and C Ortmeyer. 1981. Mortality of employees of two cotton mills in North Carolina. Chest suppl 79: 6S–11S.

Merchant, JA, JC Lumsdun, KH Kilburn, WM O’Fallon, JR Ujda, VH Germino, and JD Hamilton. 1973. Dose-response studies in cotton textile workers. J Occup Med 15:222–230.

Ministry of International Trade and Industry (Japan). 1996. Asia-Pacific Textile and Clothing Industry Form, June 3-4, 1996. Tokyo: Ministry of International Trade and Industry.

Molyneux, MKB and JBL Tombleson. 1970. An epidemiological study of respiratory symptoms in Lancashire mills, 1963–1966. Brit J Ind Med 27:225–234.

Moran, TJ. 1983. Emphysema and other chronic lung disease in textile workers: An 18-year autopsy study. Arch Environ Health 38:267–276.

Murray, R, J Dingwall-Fordyce, and RE Lane. 1957. An outbreak of weaver’s cough associated with tamarind seed powder. Brit J Ind Med 14:105–110.

Mustafa, KY, W Bos, and AS Lakha. 1979. Byssinosis in Tanzanian textile workers. Lung 157:39–44.

Myles, SM and AH Roberts. 1985. Hand injuries in the textile industry. J Hand Surg 10:293–296.

Neal, PA, R Schneiter, and BH Caminita. 1942. Report on acute illness among rural mattress makers using low grade, stained cotton. JAMA 119:1074–1082.

Occupational Safety and Health Administration (OSHA). 1985. Final Rule for Occupational Exposure to Cotton Dust. Federal Register 50, 51120-51179 (13 Dec. 1985). 29 CFR 1910.1043. Washington, DC: OSHA.

Parikh, JR. 1992. Byssinosis in developing countries. Brit J Ind Med 49:217–219.
Rachootin, P and J Olsen. 1983. The risk of infertility and delayed conception associated with exposures in the Danish workplace. J Occup Med 25:394–402.

Ramazzini, B. 1964. Diseases of Workers [De morbis artificum, 1713], translated by WC Wright. New York: Hafner Publishing Co.

Redlich, CA, WS Beckett, J Sparer, KW Barwick, CA Riely, H Miller, SL Sigal, SL Shalat, and MR Cullen. 1988. Liver disease associated with occupational exposure to the solvent dimethylformamide. Ann Int Med 108:680–686.

Riihimaki, V, H Kivisto, K Peltonen, E Helpio, and A Aitio. 1992. Assessment of exposures to carbon disulfide in viscose production workers from urinary 2-thiothiazolidine-4-carboxylic acid determinations. Am J Ind Med 22:85–97.

Roach, SA and RSF Schilling. 1960. A clinical and environmental study of byssinosis in the Lancashire cotton industry. Brit J Ind Med 17:1–9.

Rooke, GB. 1981a. The pathology of byssinosis. Chest suppl 79:67S–71S.

—. 1981b. Compensation for byssinosis in Great Britain. Chest suppl 79:124S–127S.

Sadhro, S, P Duhra, and IS Foulds. 1989. Occupational dermatitis from Synocril Red 3b liquid (CI Basic Red 22). Contact Dermat 21:316–320.

Schachter, EN, MC Kapp, GJ Beck, LR Maunder, and TJ Witek. 1989. Smoking and cotton dust effects in cotton textile workers. Chest 95: 997–1003.

Schilling, RSF. 1956. Byssinosis in cotton and other textile workers. Lancet 1:261–267, 319–324.

—. 1981. Worldwide problems of byssinosis. Chest suppl 79:3S–5S.

Schilling, RSF and N Goodman. 1951. Cardiovascular disease in cotton workers. Brit J Ind Med 8:77–87.

Seidenari, S, BM Mauzini, and P Danese. 1991. Contact sensitization to textile dyes: Description of 100 subjects. Contact Dermat 24:253–258.

Siemiatycki, J, R Dewar, L Nadon, and M Gerin. 1994. Occupational risk factors for bladder cancer. Am J Epidemiol 140:1061–1080.

Silverman, DJ, LI Levin, RN Hoover, and P Hartge. 1989. Occupational risks of bladder cancer in the United States. I. White men. J Natl Cancer Inst 81:1472–1480.

Steenland, K, C Burnett, and AM Osorio. 1987. A case control study of bladder cancer using city directories as a source of occupational data. Am J Epidemiol 126:247–257.

Sweetnam, PM, SWS Taylor, and PC Elwood. 1986. Exposure to carbon disulphide and ischemic heart disease in a viscose rayon factory. Brit J Ind Med 44:220–227.

Thomas, RE. 1991. Report on a multidisciplinary conference on control and prevention of cumulative trauma disorders (CDT) or repetitive motion trauma (RMT) in the textile, apparel and fiber industries. Am Ind Hyg Assoc J 52:A562.

Uragoda, CG. 1977. An investigation into the health of kapok workers. Brit J Ind Med 34:181–185.
Vigliani, EC, L Parmeggiani, and C Sassi. 1954. Studio de un epidemio di bronchite asmatica fra gli operi di una tessiture di cotone. Med Lau 45:349–378.

Vobecky, J, G Devroede, and J Caro. 1984. Risk of large-bowel cancer in synthetic fiber manufacture. Cancer 54:2537–2542.

Vobecky, J, G Devroede, J La Caille, and A Waiter. 1979. An occupational group with a high risk of large bowel cancer. Gastroenterology 76:657.

Wood, CH and SA Roach. 1964. Dust in cardrooms: A continuing problem in the cotton spinning industry. Brit J Ind Med 21:180–186.

Zuskin, E, D Ivankovic, EN Schachter, and TJ Witek. 1991. A ten year follow-up study of cotton textile workers. Am Rev Respir Dis 143:301–305.