Measures to prevent fire in the hottest gravure pr

2022-08-15
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Measures to prevent fire in gravure printing workshop

all fire accidents are the result of the simultaneous occurrence of these three necessary conditions. Preventive measures are nothing more than to avoid the simultaneous occurrence of three necessary conditions. Because the oxygen in the air is generally sufficient, it is normal to avoid the occurrence of the first two conditions at the same time, and it is best not to occur at all

what are the places with high VOC concentration in gravure coating workshop

1. Inside and top of ink bucket or plastic bucket. Therefore, if you use an electric ink pump, you must use an explosion-proof motor or an air pump

2, near the applicator. Due to the continuous stirring of the coating roller, the concentration around the ink glue tank in contact with the plate roller is high. If there is electrostatic discharge, it is easy to catch fire. (1) this will infringe the machine and affect your work. Turn on the experimental motor to burn

3、 ink "> inside the oven close to the feed inlet of the printing coater. Especially now, most of the solvents are fast drying solvents, and the heating temperature is high. Most of the solvents evaporate in the oven close to the feed inlet, where the concentration is the highest. If the air volume is insufficient, the coating is thick, and the amount of solvent is large, it may exceed the lower explosion limit.

preventive measures

1. Eliminate the fire source. The printing factory does not allow smoking and other actions with open flames in the workshop 。 The most likely ones are sparks caused by static electricity and sparks caused by mutual collision or friction. Especially in the above three places, there can be no sparks, so the ink bucket or plastic bucket, near the coating head, printing coating 2. Because the jaw of the hydraulic universal experimental machine often uses the cloth machine, the interior of the oven close to the feed inlet must do a good job of electrostatic elimination

electrostatic elimination is to eliminate the local high voltage on the surface of the material. At present, there are methods of grounding through conductors and electrostatic generator elimination. The electrostatic generator elimination method is to neutralize the voltage on the material by generating positive and negative ions through the generator. The electrostatic generator itself is a discharge process, so it cannot be too close to the place with high VOC concentration, which has hidden dangers and is not recommended. The method of grounding through conductors is economical and practical. Generally, copper wire, copper wire and aluminum foil are used close to the material, or electrostatic brush is added, and then the copper wire or electrostatic brush is grounded. The problem that is easy to occur is that the copper wire or electrostatic brush is connected to the ground wire through the frame or guide roller, and the insulation may be caused by rust and oil on the contact surface of the frame, or the ground wire of the machine itself is broken and the joint falls off, resulting in failure. It is recommended to directly connect copper wire or electrostatic brush with ground wire with special wiring

friction fire is caused by sparks caused by mutual collision or friction. Previously, there have been accidents in which the upper metal fell off and touched the ink tank to produce sparks and ignited the solvent fire, which should be paid attention to

when the air humidity is high, the static electricity on the film or paper is easy to leak through the air, so maintaining the appropriate humidity in the workshop also plays a role in eliminating static electricity

in recent years, Chinese plastic machinery enterprises have expanded their opening up of emerging markets for extruders. 2. VOC concentration alarms are installed in ovens. Once the concentration is too high, the VOC concentration alarm will automatically alarm

3. Install carbon dioxide fire extinguishing device, which will automatically spray carbon dioxide in case of fire

4. Don't put glue, solvent and ink near the gravure machine, and it's best to isolate them from the machine, so as to prevent the surrounding solvent from igniting and exploding in case of a fire, causing a major accident. Spare materials should be kept away from dangerous places, and the quantity should not be too large

5. Ensure that the inlet air volume of the oven cannot be lower than a minimum value, and ensure that the VOC concentration is less than 25% of LEL at this minimum air volume. The drying oven of gravure printing machine, coater and laminating machine will not catch fire and explode under normal circumstances due to the large inlet and exhaust air volume. Fire and explosion often occur because the oven temperature is not enough, the operator closes the air inlet and exhaust valves too small, or the exhaust fan does not work due to circuit failure or belt breakage, and the VOC content on the material is large

6. There is a pressure relief port on the oven. Once the oven pressure rises to a certain extent, the pressure relief port will automatically open, so that the oven will not explode

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