Overview of fire and explosion prevention in the p

Overview of fire and explosion prevention in match production

matches can be divided into daily matches and special matches according to their uses. Daily matches are divided into sulfur phosphorus matches and safety matches. Phosphorus sulfide matches have stopped production in China. Safety matches need to be scratched on the phosphorus side of the box to get angry, which is safer. Special matches include windproof matches, high-temperature matches, signal matches, waterproof matches, etc. At present, pressing the "input 11/5" key in China is still in the trial production stage. （1） Composition and performance of matches 1. Structure of matches daily safety matches are composed of four parts: match stems, match heads, match boxes, and match phosphors. Match stems are made of wood or paper soaked in wax and processed. 2. Composition of drug head match drug head is made of chemical raw materials such as oxidant, reductant and filler. The ignition point of paraffin is reached through the ignition of the medicine head, and then the match stalk is ignited. See Table 1 for the formula of safety match medicine head. Table 1 name of raw materials of safe match medicine head formula main function proportion (%). Potassium chlorate oxidant 52 leather glue (absolutely dry) adhesive 8.75 potassium dichromate tanning agent 1 rosin reductant 2.5 sulfur reductant 10.5 quartz powder filler chitosan is an ideal material in the utilization of food technology 21 manganese dioxide filler, Colorant - zinc oxide acidity stabilizer 2 antimony trisulfide reductant - color colorant appropriate amount of white emulsion adhesive 2.253. Matchbox is the packaging material of matches. On the one hand, it separates the combustible match heads into a certain number (20-78 pieces/small box), so as to reduce the danger of matches in the process of storage and transportation. On the other hand, it is easy to sell and use, and it is used as the substrate for painting phosphorus surface. Match phosphorous surface is composed of igniting agent, filler, adhesive, acidity neutralizer and other raw materials. The phosphorus surface of the match is painted on one or both sides of the match box. Its main function is to ignite the red phosphorus by the heat generated by the friction of the medicine head on the phosphorus surface. The formula of match phosphorus noodles is shown in Table 2. Table 2 match phosphorus surface formula raw material name main function proportion (%) formula red phosphorus luminescent agent 32:58 antimony trisulfide filler 36:64 carbon black colorant 1:21 calcium carbonate acidity neutralizer appropriate amount of white emulsion adhesive 29:574. Risk of match ① the spontaneous combustion point of match is generally 160-200 ℃. When the ambient temperature exceeds the above temperature, the match can burn by itself. ② It is easy to burn and explode during friction or impact. Especially when the drug head rubs with the phosphorus surface, it is easier to burn. The national standard gb393-80 stipulates that the friction sensitivity of matches on phosphorus surface is 10-30g. The explosive head is easy to explode when it is hammered. ③ Matches themselves can burn, and their packaging materials are also easy to catch fire. 5. Combustion of matches when the match tip rubs with the phosphorus surface, heat is generated to oxidize red phosphorus into phosphorus pentoxide: 4P + 5o2 - 2p2o5 + 2101.6kj the basic combustion process of the match tip is the oxidation-reduction reaction caused by the interaction between potassium chlorate and sulfur. The heat released when sulfur reacts with oxygen: 2kco3+3s → 2kcl+3 will directly transition to the flame temperature of 811 so2+890.3kj match tip, which can reach 1400-1500 ℃. However, due to its small volume and short combustion time, the heat emitted is not enough to make the match stem reach the ignition point (above 300 ℃), so the substance with low ignition point and high calorific value must be used as the ignition agent as the combustion medium between the match tip and the match stem. At present, the commonly used igniter is paraffin. When the drug head is burned, it can cause the paraffin to burn, and the heat released by the paraffin burning can ignite the match stick. （2） The production process of daily-use safety matches in China can be divided into wood stick matches and paper stick matches. The semi mechanized production of most enterprises has been replaced by match continuous machines. The technological process of match production is shown in the figure below. There is a risk of combustion and explosion in the process of match stem preparation, match head preparation, single yarn tensile test, match slurry preparation, phosphorus preparation, match packaging and storage of raw materials, finished products and semi-finished products. Figure match production process flow