What safety precautions should be paid attention to during the processing of alumina board?

The processing flow (such as cutting, stamping, anodizing, grinding, etc.) of aluminum oxide plate (usually aluminum plate treated by anodic oxidation process or aluminum plate treated by oxidation during processing) involves mechanical operation, chemicals and high temperature environment, so it is necessary to strictly abide by safety regulations to avoid mechanical injury, chemical corrosion and health risks. The following are the safety matters that need to be paid attention to in each processing link, which are classified according to the three dimensions of "mechanical processing", "chemical treatment" and "general operation":

First, the mechanical processing link safety: to prevent physical injury.

Mechanical processing is the basic process of alumina plate (such as cutting, stamping, bending and polishing), and the core risks are "equipment accidental injury" and "debris splash", which need to be paid attention to:

Inspection and protection before equipment operation

Before starting the equipment (such as CNC cutting machine, punching machine and bending machine), it is necessary to check the status of the equipment: confirm whether the emergency stop button and safety fence/cover are in good condition, the transmission parts (gears and conveyor belts) are not loose, the sharpness of the tool/mold and the firmness of installation (to avoid the tool cracking and the mold falling off during processing).

Operators shall wear personal protective equipment (PPE) as required:

Hand: wear cut-proof gloves (to avoid scratches during cutting/stamping, and do not wear loose gloves to prevent being involved in transmission parts);

Eyes: wear impact goggles (to prevent metal chips and dust from splashing into eyes, especially when grinding and cutting);

Head: Wear safety helmet (beside heavy equipment such as stamping and bending to prevent the workpiece from falling or the tool from being injured);

Foot: Wear anti-smashing safety shoes (to prevent the workpiece from falling and hurting toes or slipping on the ground).

Operating specifications in the process of machining

Illegal operation is prohibited: if the aluminum plate is pushed directly under the tool by hand (a special pusher is required), any part of the body will extend into the closed area of the die during stamping (strictly observe the operation of the "two-hand start" button to avoid triggering with one hand), and when cutting, the aluminum plate will go beyond the range of the equipment workbench (to prevent the workpiece from shaking and causing cutting deviation or falling).

Control processing parameters: adjust the rotating speed and pressure of the equipment according to the thickness of the alumina plate (usually the hardness of the plate is slightly improved after anodic oxidation) (for example, if the cutting speed is too high, the plate will be overheated and deformed, or the debris splashing will be intensified; Excessive stamping pressure may lead to mold rupture), it is forbidden to overload the equipment.

Stop the machine immediately if it is abnormal: if there are abnormal noises, stuck plates, broken tools, etc. during processing, you need to press the emergency stop button immediately, and then troubleshoot after cutting off the power supply. It is forbidden to clean up debris or adjust components by hand during equipment operation.

Second, the safety of chemical treatment: to prevent corrosion and poisoning.

The core characteristics of alumina plate depend on "anodic oxidation" process (oxide film is formed by acidic/alkaline electrolyte), which involves strong acid (such as sulfuric acid and oxalic acid), strong alkali (such as sodium hydroxide) and electrolyte, so it is necessary to focus on preventing "chemical corrosion", "toxic gas" and "electric shock risk";

Storage and access of chemical agents

Storage specification: Strong acids and alkalis should be classified and stored in corrosion-resistant special reagent cabinets (such as PP materials), away from fire sources, heat sources and food, and clear warning signs of "corrosiveness" and "toxicity" should be posted outside the cabinets; It is forbidden to store different types of chemicals together (for example, mixing acid with alkali will produce a violent reaction, releasing a lot of heat and causing splashing).

Access operation: wear acid alkali resistant gloves (such as nitrile gloves, latex gloves are forbidden, and strong acid will corrode latex), chemical protective clothing (to prevent the medicine from splashing on clothes or skin) and protective mask (to prevent the medicine from volatilizing gas to irritate respiratory tract or liquid from splashing on face); Use a special pipette or pump when taking liquid medicine. It is forbidden to pour it directly (to prevent spilling). If it is accidentally spilled, it needs to be cleaned with corresponding neutralizer (such as covering the spilled acid with baking soda powder and neutralizing the spilled alkali with dilute boric acid solution). It is forbidden to wash it directly with water (strong acid may aggravate corrosion when it meets water).

Safety control of anodic oxidation process

Anti-electric shock: Anodizing equipment needs to be connected with a reliable grounding device, and the electrolyte is a conductive liquid. It is forbidden to touch the electrode or equipment switch with wet hands, and regularly check whether the insulation layer of the line is damaged (to avoid leakage); Wear insulating shoes and stand on insulating mats during operation (to reduce the risk of electric shock).

Gas hazard prevention: During anodic oxidation, electrolyte (such as sulfuric acid solution) will volatilize acid gas (such as sulfur dioxide), which will irritate respiratory tract and even lead to chemical pneumonia for a long time. Therefore, the processing area needs to be equipped with a strong ventilation system (such as an exhaust hood), and the operator needs to wear a gas mask (such as N95 or above, or a special filter box for acid gas); If it is necessary to operate in a confined space, it is necessary to detect the gas concentration first to ensure that it meets the safety standards (for example, the concentration of sulfuric acid mist in the air of the workshop is ≤ 1 mg/m, refer to occupational exposure limits on Hazardous Factors in the Workplace).

Prevention of high-temperature scalding: Some oxidation processes need to heat the electrolyte (for example, the temperature of hard anodic oxidation is about 10-20℃, but the temperature of the electrolyte should be controlled during the heating process to avoid overheating and boiling). It is forbidden to directly touch the electrolyte tank or heating device with hands. If sampling and testing are needed, special high-temperature resistant tools (such as Shi Ying test tubes) should be used to prevent high-temperature liquid from splashing on the skin and causing scalding.

III. General safety matters: covering the whole process risks.

Working environment management

Keep the site clean and tidy: irrelevant sundries (such as tools and packaging materials) should be cleaned in the processing area, and the ground should be free of oil and water stains (to prevent slipping). Metal chips (such as aluminium scrap produced by cutting and polishing) should be collected with special tools (such as magnetic vacuum cleaner and waste bin) in time, and accumulation is prohibited (aluminium scrap should be kept away from fire sources if it may cause dust explosion in case of open fire for a long time).

Ventilation and lighting: In addition to the special ventilation in the chemical treatment area, air circulation should be ensured in the mechanical processing area (reducing the concentration of metal dust), and adequate lighting should be provided in the workshop (avoiding operation errors caused by unclear vision, especially in fine processing such as punching and polishing).

Personnel health and emergency treatment

No violation: Smoking is prohibited during processing (aluminium scrap and chemicals are flammable/explosive/corrosive substances, and open flames may cause accidents), and eating and drinking in the working area are prohibited (to prevent chemicals from polluting food and causing accidental poisoning); Operators need pre-job training (familiar with equipment operation and emergency procedures), and unlicensed personnel are forbidden to operate heavy equipment independently or contact with chemicals.

Emergency response plan:

Mechanical injury: In case of finger cutting and workpiece smashing, it is necessary to stop the operation immediately, press with clean gauze to stop bleeding, and send it to a doctor in severe cases (to avoid wound infection, aluminium scrap needs professional debridement if it is embedded in the skin);

Chemical corrosion: If strong acid/alkali splashes on the skin, immediately rinse it with plenty of flowing water (at least 15 minutes), and then apply corresponding neutralizer (such as 5% sodium bicarbonate solution for acid corrosion and 2% boric acid solution for alkali corrosion). If it splashes on the eyes, immediately open the eyelids and rinse it with normal saline, and do not rub it, and seek medical attention in time;

Electric shock accident: immediately cut off the power supply (or open the wires with insulating tools), and move the electric shock victim to a ventilated place. In case of coma and respiratory arrest, cardiopulmonary resuscitation (CPR) should be performed immediately and emergency calls should be made.

Equipment and consumables maintenance

Regular maintenance of equipment: the safety protection devices (such as fences and photoelectric sensors) of mechanical processing equipment should be checked weekly to avoid damage or unauthorized removal; Electrolyte tanks and pipelines for chemical treatment should be regularly checked for leakage (to prevent chemicals from seeping out to corrode the ground or pollute the environment), and waste liquid should be treated according to environmental protection standards (direct discharge is prohibited and should be recycled by qualified units).

Standardize the use of consumables: the sandpaper and grinding wheel used for grinding should meet the equipment specifications (to avoid the bursting caused by the mismatch of grinding wheel speed). When replacing the tool, it is necessary to confirm that the equipment is powered off, and it is forbidden to replace the accessories when the tool rotates.

summary

The safety core of alumina plate processing is "prevention first"-by standardizing equipment operation, doing personal protection, controlling chemical risks and keeping the environment clean and tidy, mechanical injuries, chemical corrosion and health hazards can be effectively reduced. At the same time, enterprises need to establish a sound safety training system (to ensure that operators are familiar with the process) and an emergency mechanism (to deal with unexpected accidents) to ensure that the processing process meets the requirements of laws and regulations such as Safety Regulations for Metal Cutting and Safety Management Regulations for Hazardous Chemicals.