Flax Production

Flax Production, all processes of processing flax from removing fibers from the plant to obtaining finished fabrics. To extract flax fibers from the stem, it is necessary to destroy the pectin substances that bind them to the bark and wood. This is achieved by a bacteriological method: under favorable conditions, bacteria or fungi present in the stem multiply, which for their nutrition primarily destroy the pectin substances. This process, called retting, is most often carried out in rural conditions by spreading flax straw on meadows (dew retting), where it is alternately exposed to rain and sun for 3-6 weeks, or by immersing the straw in water (in pits) at a temperature of about 19° for 14 days; in factory conditions, the straw is immersed in tanks with water at a temperature of about 33-35°, and here the process completes in 3-4 days. Retting of flax and a number of subsequent processes—until obtaining flax fiber freed from all impurities—is called primary processing of flax. Until recently, these were carried out in extremely unsanitary rural conditions, and only in recent years in the USSR a number of enterprises for primary processing of flax have emerged. The latter consists of the following processes: retting, drying, scutching, and hackling. Flax straw that has undergone the retting process (straw) goes for drying—in the summer in the sun, in winter in special dryers where it is exposed to hot air; the dried straw goes to a scutching machine, which consists of three parts: a breaker where the shive is broken, a scutching drum where the woody part is scraped from the bast, and a shaker where the tow is shaken and cleaned of impurities. The cleaned flax fiber goes to flax spinning mills. Here it undergoes the following operations: hand combing (straightening of fibers—holding); machine combing, which is performed on heckling machines; spreading and drafting on a spreading machine; further drafting and parallelization of the fiber on 2-4 band machines; drafting and initial twisting on roving frames; final drafting and twisting on water frames, and for low counts of yarn, spinning on dry water frames; however, to obtain high counts of yarn, wet spinning is required, which represents considerable interest from a sanitary-hygienic point of view. Noils from heckling machines, tow from scutching machines, and short fibers from band machines are also used, for which they are first shaken on shaking machines. Noils from tow, obtained when extracting long-fiber flax from raw flax, go to carding machines, where tangled fibers are straightened; then follows combing, processing on band machines, etc. From yarn, fabric is obtained at linen weaving mills. The process of linen weaving compared to paper weaving presents nothing original (see Weaving). Grey linen fabric goes to linen finishing mills. Here it goes to the bleaching department, where it undergoes a very complex processing consisting of multiple passes through a solution of bleaching lime, through a solution of sulfuric acid with bisulfite, through a solution of soda, boiling in vats with soda, washing more than 15 times—in general about 40 operations; then the fabric moves to the finishing department. Here it undergoes final finishing, and some fabrics are first dyed, mainly with sulfur dyes. Production hazards. 1. Dust. From scutching to weaving, the flax processing process is accompanied by the release of dust in quantities significantly exceeding those in cotton production. The dustiest processes are scutching and processing on carding machines. Even despite the installation of machines of the latest design (in primary processing) and the presence of local ventilation at carding machines and other places, the amount of dust released is extremely large. To illustrate the latter, data from recent studies of the Smolensk linen finishing plant and a number of spinning mills are provided. Smolensk linen finishing plant: in the scutching machine room in different places, dust was found in 1 m³ from 18 to 144 mg, at tow preparation machines—125-260 mg, at the funnel of the firebox in the boiler room—406 mg, at the shive collector—700 mg, etc.—Linen spinning mill 'Zarya sotsializma' (Yaroslavl): in the carding room in 1 m³ when ventilation is not working—30-90 mg, when it is working—10-60 mg; at band machines—30-70 mg and 20-45 mg. At the Kokhma factory at heckling machines when ventilation is not working—60 mg, when it is working—19 mg; in the carding room—50-135 mg and 16-28 mg; at roving frames—11-21 mg and 6-9 mg.—At the Nerekhta factory: at carding machines—18-200 mg, at band machines—13-15 mg, at dry water frames—13 mg, in the weaving department—21-26 mg, etc. It should be taken into account that the composition of flax dust also includes silica. When burning pure flax, 0.41% SiO₂ is obtained; in the initial processing stages, the amount of silica contained in flax and dust is undoubtedly much greater (according to Gliber, in 1 m³ of air there are 75-980 thousand plant particles, 17-23 million mineral particles). 2. Meteorological factors—abnormal temperature and humidity. To varying degrees, this factor plays a decisive role in all operations. In primary processing, some departments (retting, pressing) have high relative humidity (75-90%) at normal or reduced temperature (in winter 12-15°); in spinning, weaving, and finishing mills, the air temperature is almost everywhere elevated. On West European spinning and weaving mills, very high humidity (75-90%) is maintained for successful spinning; in USSR mills, such high relative humidity is not found in most departments; except for the wet water frame department, it does not rise above 60-65%. Temperature in different departments of different factories fluctuates within rather wide limits: in the carding machine department it reaches 23-25° in winter, in band machine departments—24-26°, in dry water frames—26-28°, in the weaving department—24-25°, etc. In summer, these conditions are of course worse. Of particular interest is the wet water frame department, where the yarn coming from bobbins (roving) passes through a trough filled with hot water (60-90°). This department appears most unfavorable from a sanitary-hygienic point of view: due to the evaporation of hot water, the relative humidity reaches 80-90% here, the temperature reaches 25-30° in winter and 30-35° in summer; the floor is constantly flooded with water; the workers' clothes are also soaked with water, their hands are constantly moistened with water, etc. In the room there is a specific unpleasant smell of decaying organic substances. In the bleaching department due to the abundance of boiling, washing, etc. processes, temperature and relative humidity are always elevated: humidity in different parts of the department ranges from 65% to 100%, temperature from 24° to 30° and higher. The same is true in dyeing: sulfur dyeing is carried out at a water temperature close to boiling point, and temperature and humidity in the room are always elevated. 3. Poisonous gases are released during bleaching and dyeing processes. In bleaching departments, chlorine is released and in some processes (due to treating the fabric with a bisulfite solution) sulfur dioxide; on Kostroma factories, Razgulyaeva determined in 1 liter of air from 0.002 to 0.0137 mg of chlorine, 0.028-0.2 mg of sulfur dioxide. When dyeing with sulfur dyes, hydrogen sulfide is released (in the same factory it was found from 0.0034 to 0.0145 mg in 1 liter of air). Regarding other specific hazards of spinning (constant standing on feet, walking, noise, tension of attention), weaving (noise, vibration, tension of attention and vision, etc.)—see Weaving, Bleaching, Dyeing. The effect of these hazards on the health of workers in flax mills has almost not been studied yet. Undoubtedly, such factors as the huge amount of dust containing silica, high temperature and humidity, and other specific hazards of spinning and weaving must have an adverse effect on the health of workers in flax production. Arkhangel'sky, who examined more than 3,000 workers of the 'Zarya sotsializma' mill, found that compared to auxiliary workers, actual linen textile workers have poorer development, with the worst condition noted in workers of the weaving department (especially women). Akim, having studied the morbidity from tuberculosis among Kostroma linen textile workers, comes to a definite conclusion that among them tuberculosis is more widespread than among workers in the cotton industry, with the largest number of persons with active tuberculosis found among linen weavers (4% of their total composition). Some idea of the effect of similar dust (hemp and jute) is given by studies conducted at the First State Rope Factory in 1922 and at the Odessa Jute Mill in 1928. In the first case, 1,192 workers were examined; despite the rather superficial nature of the examination, it was revealed that among them diseases of the respiratory tract are especially widespread (in some departments up to 50%) and active tuberculosis (in different departments from 4% to 20%).

Among 657 workers in a jute factory, a high percentage of those affected by active tbc (from 3.2% to 6.5%) was also found; radiologically, changes in the glandular apparatus were found, which the author considers corresponding to the first stage of pneumoconiosis.--Old authors describe the so-called fever of hacklers ('Hechler-fieber'); in those working in the breaking, scutching, and hackling of flax and hemp, an attack of the disease developed, somewhat resembling the picture of foundry fever (feeling of fatigue, cough with mucus secretion, elevation of body temperature, swelling of the skin of the face and hands, etc.). The cause of the disease was sought in the action of foreign protein substances. In the USSR, cases of such diseases--at least for recent years--have not been described.--Contaminated water from the troughs of wet waterers; it is a frequent cause of chronic eczema developing on the hands of waterers; when this water contaminates the face, eczema also develops here. The fight against professional hazards in flax production appears to be a rather difficult matter, especially in the USSR, where almost all flax factories, built in the pre-revolutionary period, do not meet sanitary requirements at all and do not make it possible to carry out radical health-improving measures on them. In the fight against dust in enterprises for the primary processing of flax and in flax spinning factories, the basic measure is powerful, properly equipped local exhaust ventilation from a number of machines (hackling, carding) and general supply ventilation with a large number of air changes per hour. The latter has primary importance also for fighting high temperature and humidity. In wet spinning in the USSR in recent years, a radical improvement has taken place: factories have switched to cold spinning--instead of hot water, a solution of aromatic sulfonic acids is used (temperature 25--30°); technologically the result was very good, and from a hygienic point of view, as a special study by the Institute of Labor Protection showed, a change for the better also occurred: temperature and humidity decreased (instead of temperature 25-30° and 82-90% relative humidity it became: temperature 16-27° and 80% relative humidity), the amount of organic substances in the air decreased; no harmful effect of the sulfonic acids on the skin of the workers was noted.--In bleaching and dyeing, the same health-improving measures are required as in paper bleaching and dyeing: powerful supply-exhaust ventilation, covering of alcohol and acid machines, isolation of boiling vats, elimination of work with bisulfite, which prevents the release of sulfur dioxide (on the Kostroma factories this has already been done), etc.