D. A. Hargrave *
* Adapted from 3rd edition, Encyclopaedia of Occupational Health and Safety.
The origins of the wool industry are lost in antiquity. Sheep were easily domesticated by our remote ancestors and were important in satisfying their basic needs for food and clothing. Early human societies rubbed together the fibres collected from the sheep to form a yarn, and from this basic principle the processes of manipulating the fibre have increased in complexity. The wool textile industry has been in the forefront in developing and adapting mechanical methods and was therefore one of the early industries in the development of the factory system of production.
The length of fibre when taken from the animal is the dominant, but not the only, factor determining how it is processed. The type of wool available may be broadly classified into (a) merino or botany, (b) crossbreds-fine, medium or coarse and (c) carpet wools. Within each group, however, there are various grades. Merino usually has the finest diameter and a short length, while the carpet wools are long-fibred, with a coarser diameter. Today, increasing quantities of synthetic fibres simulating wool are blended with the natural fibre and are processed in the same manner. Hair from other animals-for example, mohair (goat), alpaca (llama), cashmere (goat, camel), angora (goat) and vicuсa (wild llama)-also plays an important, although subsidiary, role in the industry; it is relatively expensive and is usually processed by specialized firms.
The industry has two distinctive processing systems-woollen and the worsted. The machinery is in many ways similar, but the purposes are distinct. In essence, the worsted system uses the longer stapled wools and in the carding, preparing, gilling and combing processes the fibres are kept parallel and the shorter fibres are rejected. Spinning produces a strong yarn of fine diameter, which then is woven to yield a light fabric with the familiar smooth and firm appearance of men’s suits. In the woollen system, the aim is to intermingle and intertwine the fibres to form a soft and fluffy yarn, which is woven to give a cloth of full and bulky character with a “woolly” surface-for example, tweeds, blankets and heavy overcoatings. Since uniformity of fibre is not necessary in the woollen system, the manufacturer can blend together new wool, shorter fibres rejected by the worsted process, wools recovered from tearing up old wool garments and so on; “shoddy” is obtained from soft, and “mungo” from hard waste material.
It should be borne in mind, however, that the industry is particularly complex and that the condition and type of the raw material used and the specification for the finished cloth will influence the method of processing at each stage and the sequence of those stages. For example, wool may be dyed before processing, at the yarn stage or towards the end of the process when in the woven piece. Moreover, some of the processes may be carried on in separate establishments.
Hazards and Their Prevention
As in every section of the textile industry, large machines with rapidly moving parts pose both noise and mechanical injury hazards. Dust can also be a problem. The highest practicable form of guarding or enclosure should be provided for such generic parts of the equipment as spur gear wheels, chains and sprockets, revolving shafting, belts and pulleys, and for the following parts of machinery used specifically in the wool textile trade:
· feed rollers and swifts of various types of preparatory opening machines (e.g., teasers, willeys, garnetts, rag-grinding machines and so on)
· licker-in or taker-in and adjacent rollers of scribbling and carding machines
· intake between swift and doffer cylinders of scribbling, carding and garnetting machines
· rollers and fallers of gill-boxes
· back shafts of drawing and roving frames
· traps between the carriage and headstock of mules
· projecting pins, bolts and other securing devices used on the beaming-off motion of warping machines
· squeeze rollers of scouring, milling and cloth-wringing machines
· intake between cloth and wrapper and roller of blowing machines
· revolving-knife cylinder of cropping machines
· blades of fans in pneumatic conveying systems (any inspection panel in the ducting of such a system should be at a safe distance from the fan, and the worker should have indelibly impressed on his or her memory the length of time it takes for the machine to slow and come to a stop after the power has been cut off; this is particularly important since the worker clearing a blockage in the system usually cannot see the moving blades)
· the flying shuttle, which presents a special problem (looms should be provided with well-designed guards to prevent the shuttle from flying out of the shed and to limit the distance it might travel should it fly).
The guarding of such dangerous parts presents practical problems. The design of the guard should take into account the working practices connected with the particular process and particularly should preclude possible removal of the guard when the operator is at the greatest risk (e.g., lockout arrangements). Special training and close supervision are required to prevent waste removal and cleaning while machinery is in motion. Much of the responsibility devolves on machinery manufacturers, who should ensure that such safety features are incorporated into new machines at the design stage, and on supervisory personnel, who should ensure that workers are adequately trained in safe handling of equipment.
Spacing of machinery
The risk of accidents is increased if insufficient space is allowed between the machines. Many older premises squeezed the maximum number of machines into the available floor area, thereby reducing the space available for aisles and passageways and for the temporary storage of raw and finished materials within the workroom. In some old mills, the gangways between the carding machines are so narrow that enclosure of the driving belts within a guard is impracticable and recourse has to be made to “wedge” guarding between the belt and the pulley at the in-running point; a well-made and smooth belt fastener is particularly important in these circumstances. Minimum spacing standards, as recommended by a British Government committee for certain wool textile machinery, are required.
When modern mechanical load-handling methods are not employed, there remains the risk of injury from the lifting of heavy loads. Materials handling should be mechanized to the fullest extent possible. Where this is not available, the precautions discussed elsewhere in this Encyclopaedia should be employed. Proper lifting technique is particularly important for workers who manipulate heavy beams into and out of looms or who handle heavy and cumbersome bales of wool in the early preparatory processes. Wherever possible, hand-trucks and movable carts or skids should be used to move such bulky and heavy loads.
Fire is a serious hazard, especially in old multistorey mills. The mill structure and layout should conform to local regulations governing unobstructed gangways and exits, fire-alarm systems, fire extinguishers and hoses, emergency lights and so on. Cleanliness and good housekeeping will prevent accumulations of dust and fluff, which encourage the spread of fire. No repairs involving the use of flame cutting or flame-burning equipment should be carried on during working hours. Training of all staff in procedures in case of fire are necessary; fire drills, conducted if possible in concert with local fire, police and emergency medical services, should be practised at appropriate intervals.
Emphasis has been placed on those accident situations which are especially to be found in the wool textile industry. However, it should be noted that the majority of accidents in mills occur in circumstances that are common to all factories-for example, falls of persons and objects, handling of goods, use of hand tools and so on-and that the relevant fundamental safety principles to be followed apply no less in the wool industry than in most other industries.
The industrial disease usually associated with wool textiles is anthrax. It was at one time a great danger, particularly to wool sorters, but has been almost completely controlled in the wool textile industry as a result of:
· improvements in production methods in exporting countries where anthrax is endemic
· disinfection of materials liable to be carrying anthrax spores
· improvements in handling the possibly infected material under exhaust ventilation in the preparatory processes
· microwaving the wool bale sufficiently long to a temperature that will kill any fungi. This treatment also assists in the recovery of lanolin associated with the wool.
· significant advances in medical treatment, including immunization of workers in high-risk situations
· education and training of workers and the provision of washing facilities and, when necessary, personal protective equipment.
Besides anthrax fungal spores, it is known that spores of the fungus Coccidiodes immitis can be found in wool, especially from the southwestern United States. This fungus can cause the disease known as coccidioidomycosis, which, along with the respiratory disease from anthrax, usually has a poor prognosis. Anthrax has the added hazard of causing a malignant ulcer or carbuncle with a black centre when entering the body through a break in the skin barrier.
Various chemicals are used-for example, for degreasing (diethylene dioxide, synthetic detergents, trichloroethylene and, in the past, carbon tetrachloride), disinfection (formaldehyde), bleaching (sulphur dioxide, chlorine) and dyeing (potassium chlorate, anilines). The risks include gassing, poisoning, irritation of the eyes, mucous membranes and lungs, and skin conditions. In general, prevention relies on:
· substitution of a less dangerous chemical
· local exhaust ventilation
· care in labelling, storage and transport of corrosive or noxious liquids
· personal protective equipment
· good washing facilities (including shower baths where practicable)
· strict personal hygiene.
Noise, inadequate lighting, and the high temperatures and humidity levels required for wool processing may have a deleterious effect on general health unless they are strictly controlled. In many countries, standards are prescribed. Steam and condensation may be difficult to control effectively in dyeing sheds, and expert engineering advice is often needed. In weaving sheds, noise control presents a serious problem on which much work remains to be done. A high standard of lighting is necessary everywhere, particularly where dark fabrics are being manufactured.
As well as the specific risk of anthrax spores in the dust produced in the earlier processes, dust in high quantities sufficient to induce irritation of the respiratory tract mucosae is produced at many machines, especially those with a tearing or carding action, and should be removed by effective LEV.
With all the moving parts in the machinery, particularly the looms, woollen mills are often very noisy places. While attenuation can be achieved by proper lubrication, the introduction of sound baffles and other engineering approaches should be considered as well. By and large, prevention of occupational hearing loss depends on the workers’ use of ear plugs or muffs. It is essential that workers be trained in the proper use of such protective equipment and supervised to verify that they are using it. A hearing conservation programme with periodic audiograms is required in many countries. As equipment is replaced or repaired, appropriate noise-reduction steps should be taken.
Work stress, with its attendant effects on workers’ health and well-being, is a common problem in this industry. Since many of the mills operate around the clock, shift work is frequently required. To meet the production quotas, the machines operate continuously, with each worker being “tied” to one or more pieces of equipment and unable to leave it for bathroom or rest breaks until a “floater” has taken his or her place. Coupled with the ambient noise and use of noise protectors, their heavily routinized, repetitive activity makes for de facto isolation of the workers and a lack of social interaction that many find stressful. The quality of supervision and the availability of workplace amenities have a great influence on workers’ job stress levels.
While larger enterprises are able to invest in new technological developments, many smaller and older mills continue to operate in old plants with out-dated but still functioning equipment. Economic imperatives dictate less rather than greater attention to workers’ safety and health. Indeed, in many developed areas, mills are being abandoned in favour of new plants in developing countries and areas where cheaper labour is readily available and where health and safety regulations are either non-existent or are generally ignored. Worldwide, this is an important labour-intensive industry in which reasonable investments to workers’ health and well-being can bring significant dividends to both the enterprise and its workforce.