Occupational hazards and protection of common industries

Common industries refer to machinery manufacturing, welding, electroplating, plastic industry, shoe industry, printing and dyeing industry, paper industry, furniture industry, cement industry, battery industry, etc. there are more or less occupational hazard factors in these industries. This paper analyzes the occupational hazard factors in these industries, and puts forward preventive measures< The production process of machinery manufacturing industry generally includes casting, forging, heat treatment, mechanical gold processing, assembly and other processes, in addition to cold work, welding, cutting, electroplating and painting (1) harmful factors in the production process (1) dust. Casting workshop will melt the metal pouring in the sand mold prepared in advance, after cooling into the casting, this process is called casting. The raw materials used in foundry, such as sand, clay, clay and coal powder, contain a certain amount of free silica, and dust is produced in varying degrees in the process of sand making, molding, box beating and sand cleaning. The dust can also be dissipated in the machining workshop by using grinding wheels and tools. The grinding wheel is mainly made of corundum and emery, which contains less free silica. There is also a certain amount of dust in the welding process. The main component of the dust is iron oxide. Other components vary according to the type of electrode used. For example, when using manganese electrode, manganese oxide can be contained in the air. Workers exposed to one of the above dust for a long time may have pneumoconiosis, such as foundry worker’s pneumoconiosis, grinder’s pneumoconiosis, welder’s pneumoconiosis, etc< (2) high temperature and thermal radiation. The basic production process of the forging workshop is to first put the billet or ingot into the heating furnace, heat it to 800-1200 ℃, take it out, and then forge the large parts with steam hammer, air hammer or hydraulic press, while the small parts can be hammered with hand hammer. The heating furnace, drying furnace, molten metal and hot castings in the forging workshop, the heating furnace and salt bath in the heat treatment workshop are all heat sources. 1n summer, they work at high temperature, and a large amount of heat radiation is produced in the forging process. Smelting furnace in foundry production is also high temperature operation< (3) carbon monoxide and sulfur dioxide. Carbon monoxide and sulfur dioxide are mainly produced in foundry. Carbon monoxide and sulfur dioxide can be produced in the process of iron melting, pouring, mold baking and drying; Forging furnaces also produce large amounts of carbon monoxide and sulfur dioxide< (4) zinc oxide and lead oxide. When casting copper, the dust of zinc oxide and lead oxide is produced in the process of copper melting because of the lead and zinc contained in copper alloy< (5) formaldehyde and ammonia. Formaldehyde and ammonia can be produced when urea formaldehyde resin is used as core binder< (6) benzene, toluene and xylene. The painting methods include painting, dipping and spraying. Spray painting is to put the paint and diluent into the spray gun tank and spray it to the surface of the parts with 2-4 atmospheres of compressed air to prevent the metal surface from rusting. The paint, especially the benzene or toluene or xylene in the paint thinner, can be contacted during the painting process; Sometimes the concentration of benzene compounds in the air is quite high when many spray guns spray the same part at the same time under the condition of poor ventilation in the workshop. Benzene poisoning may occur in this kind of working environment for a long time< (7) noise and vibration. When molding and tamping machines are used for pressure molding in foundry workshop, pneumatic tools are used in sand cleaning, and electric saws are used in wood mold workshop when rollers, grinding wheels, air compressors and hammers are used in forging< (8) ultraviolet and strong light. Welding can produce a lot of ultraviolet and strong light, welders in the protection is not at the time can cause electro-optic ophthalmia< (9) chromium, acid mist and hydrogen cyanide. Chromium acid mist can be produced in the electroplating process, and hydrogen cyanide can also be produced in the cyanide electroplating process if it is not handled properly. The nasal mucosa of electroplating workers exposed to chromium salt for a long time was damaged, and even perforation of nasal septum was caused. 1n some cases, dermatitis and ulcer of hands could be seen< (10) high frequency. Heat treatment is mainly to change the performance of parts through heat treatment, but does not change their shape. Quenching using high-frequency furnace, workers exposed to high-frequency electromagnetic field, high frequency can have a certain impact on the human body< (2) protective measures the dust prevention work in machinery industry should focus on the foundry. For the preparation of molding sand, the mixture should be stirred in the airtight exhaust device, and the molding sand should be transported by air force. The sand cleaning of castings should use wet operation such as hydraulic sand cleaning and water blasting sand cleaning. Shot blasting and sand cleaning should be carried out in the closed exhaust chamber for cleaning castings. Roller sand cleaner can be used for cleaning small castings. Vibrating Sand shaker can be used for box beating. Sealing and ventilation device should be installed in order to prevent chromium poisoning in electroplating, it should be installed in the electroplating tank and pickling tank installation side of the ventilation device, or in the electroplating bath using acid mist inhibitor, also can be covered with foam plastic fragments. Electroplating workers should wear rubber gloves heatstroke prevention measures should be taken for high temperature and thermal radiation. 1n addition, measures should be taken to prevent harmful gases, noise and vibration< Welding is one of the most widely used processes in industry. Almost all industrial sectors are involved, especially in shipbuilding, boiler, machinery manufacturing, bridge, chemical industry, construction, vehicle manufacturing and other industries. There are many kinds of welding processes, and their harmful factors are also different. Not only physical harmful factors, but also toxic smoke and dust can seriously affect the health of welders< (1) harmful factors in the production process. During arc welding, the welding core, coating and base metal of the electrode are melted at high temperature of the arc, and a large amount of metal oxide and other material dust can be produced by intense overheating, evaporation and oxidation, which will escape in the air in the form of aerosol. The composition of welding fume varies with welding conditions, base metal and coating composition. 1ts main chemical components are iron oxide, manganese oxide, fluoride and amorphous silica. Long term inhalation of high concentration welding fume can cause welder pneumoconiosis< (2) manganese oxide and fluoride. Manganese oxide is an important poison in electric welding. 1ts content depends on the content of manganese in electrode coating. Long term inhalation of high concentration manganese oxide can cause manganese poisoning. Fluoride mainly exists in the dust of low hydrogen type electrode, especially soluble sodium fluoride and potassium fluoride. 1t can cause respiratory tract irritation and digestive tract symptoms, even mild chronic fluorosis< (3) ozone, nitrogen oxides and carbon monoxide. Under the high temperature of welding arc, harmful gases such as ozone, nitrogen oxide and carbon monoxide can be produced. 1t can cause neurosis such as dizziness, headache, fatigue and weakness, pharyngodynia, cough, chest tightness and other chronic inflammation of respiratory tract. Acute carbon monoxide poisoning can be caused in narrow and poorly ventilated places< (4) ultraviolet and strong light. The ultraviolet radiation produced during welding can cause electro-optic ophthalmia< (5) noise. 1n the process of plasma spray welding, thermal spraying and cutting, due to the fluctuation of pressure in different airflow directions, vibration and friction will produce noise, which can cause certain harm to human body< (6) high frequency electromagnetic field. High frequency oscillators are used to start and stabilize the arc in non M1G and isoelectric arc welding. The electric field strength can reach 100 V / m when starting the arc. However, since each time of starting the arc is only 2-3 seconds, the cumulative time of starting the arc in a working day is generally only about 10 minutes, so the high frequency has little effect< (7) slag and metal particles. Hot metal particles and slag splashing during welding can cause skin burns< (2) protective measures in order to avoid the harm of harmful factors in welding and cutting operation to human body, semi-automatic and automatic welding can be used instead of manual welding. The welding rod with low dust and low toxicity shall be used. The fixed or mobile local ventilation and dust removal device shall be installed for welding operation. The air supply mask or dust cover can also be used. 1n addition to airtight, ventilating and purifying the arc area, and removing radioactive substances and smoke, wet cleaning and washing hands with soap before meals should be adhered to in argon arc welding and plasma welding workplaces. High frequency electromagnetic field can be protected by high frequency shielding method. When welding and cutting workers are working, they must use corresponding protective glasses, wear white protective clothing and insulating rubber shoes< 1n order to prevent metal products from rusting, enhance metal hardness and beauty, electroplating is often used to plate one metal on another metal surface by electrolysis. Electroplating includes nickel plating, chromium plating, zinc plating, copper plating, gold plating, silver plating, etc< (1) harmful factors in the process of production electroplating generally includes pretreatment, metal plating and post plating. The harmful factors in the production process are as follows: (1) gasoline, kerosene, ethanol, sodium hydroxide, sulfuric acid, hydrochloric acid, nitric acid, etc. Gasoline, kerosene, ethanol, sodium hydroxide, sulfuric acid, hydrochloric acid, nitric acid and other chemical substances are commonly used in the process of degreasing and derusting before plating. These substances cause damage to the skin, mucous membrane and respiratory tract of workers< (2) chromium, cyanide, acid mist, nickel, etc. During electroplating, the air around the electrolytic cell is easily polluted by various components of electrolyte, especially when the current density, electrolyte concentration and temperature are increased, it can promote the damage of various toxic substances to skin and mucous membrane. Some can cause oral mucosa congestion, pharyngeal wall dry, severe can appear ulcer. Chromium nasal disease (perforation of nasal septum) can be caused by exposure to chromate in chromium plating workers. Nickel sulfate is often exposed to nickel plating workers, which can cause contact dermatitis, allergic eczema and even nickel sores. 1n addition, the toxic substances mentioned above can also cause pathological changes of nerves, blood and digestive system< (3) dust. The light comes out in the treatment after plating. 1n order to make the parts more beautiful, the surface of the parts after plating is often polished, which can produce a lot of metal dust in the polishing process< (2) protective measures
in order to prevent the harmful factors of electroplating operation from harming workers, protective measures should be taken, and cyanide electroplating should be changed to non cyanide electroplating; The closed electroplating should be used instead of the open electroplating as far as possible. The electroplating tank should adopt the double side ventilation device and strengthen the natural ventilation

in order to reduce the acid mist escaping, the electroplating tank can be treated with acid mist inhibitor or foam pellet, liquid paraffin and so on. 1n order to reduce the escape of acid mist, workers should wear rubber gloves, work clothes and aprons with cuff ligation, and wear protective masks, glasses and rubber shoes. Wash hands with hot water and soap after work, and avoid contact with cyanide in case of skin damage. 1n case of respiratory disease, transfer from electroplating operation as soon as possible< There are two kinds of plastics in plastics industry: one is thermosetting plastics, that is, they can't be dissolved after "curing", such as amino, epoxy, phenolic, polyester, polyurethane and so on; The other is thermoplastics, which can be repeatedly dissolved and reshaped, such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylon, organic fluorine and other plastics. The production process of plastics is divided into two steps. The first step is to make monomer from chemical raw materials, and the monomer is polymerized to polymer; The second step is to process the polymer into plastic products. 1n the production process before monomer polymerization, workers had more chances to contact poisons< (1) production process

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