Safety design template of blackboard newspaper in primary school

People gave up cars, a warmth and an order; Cars make people, giving up a safety and an understanding. The following is what I bring to you: the blackboard of primary school safety:

Safety information of primary school blackboard newspaper: why can fire retardant coatings prevent fire?

Compared with ordinary coatings, the physical properties of fire-retardant coatings are basically the same, except that after drying, the paint film itself is not easy to burn, and once a fire occurs, it can delay the spread of flame to the combustible materials coated, which has certain fire-retardant properties. According to the test, the common paint and fire retardant paint were coated on the wood board respectively, dried and baked with the same flame, and the wood board coated with the common paint burned with the paint in less than 2 minutes; However, the wood coated with non-expansive fire retardant coating only appears smoldering after 2 minutes, and then goes out immediately after standing for 30 seconds; Even after baking 15 minutes, the wood board coated with intumescent inert gas fire retardant coating did not even appear smoldering phenomenon. It can be seen that once a fire breaks out, it can really stop the fire from spreading and protect the surface of the object within a certain period of time, thus winning valuable time for fire fighting. Why can fire retardant coatings prevent the fire from spreading in a certain period of time? According to the analysis of the existing three kinds of fire retardant coatings, the reasons are as follows:

Expansion type: The resin in this kind of fire retardant coating adopts foaming substance sodium silicate or foaming agent boric acid, which will change when heated, so that the paint film will expand and bubble, form a hard shell, and increase the distance between the fire source and the surface of the object.

Primary school blackboard school safety picture:

Safety pictures of primary school blackboard opening

The safety picture at the beginning of the blackboard newspaper in primary school II

Non-intumescent: This fire retardant coating uses perchloroethylene, chlorinated rubber, ethyl acetate and vinyl chloride polymer as resin. When they encounter a flame, they will be decomposed by heat, producing non-combustible gases, such as chlorine and carbon dioxide, which dilute the surrounding combustible gases and weaken the fire. Sometimes, chemicals such as ammonium carbonate, ammonium chloride and ammonium phosphate will be added to the paint, and these chemicals will also produce nonflammable gases when heated, but the addition of these chemicals will often have a certain impact on the physical properties of the paint film, so it must be used reasonably.

Expanded inert gas type: the fire retardant coating is made of phthalic anhydride resin. When heated, it can not only make the paint film expand and bubble, but also produce non-combustible gases such as chlorine, which has the above two functions, so the effect is better and the fire resistance time is longer.

In addition, pigments used in fire retardant coatings should also be mainly used to block and isolate heat sources, such as asbestos powder, antimony white powder, mica powder, titanium dioxide and so on. Among them, antimony white powder has strong infrared reflection ability and can reflect heat when it meets flame, so it is widely used in fire retardant coatings.

As a new type of coating, fire retardant coating still has some shortcomings, such as high cost and unsatisfactory physical properties of some fire retardant coatings. However, these shortcomings will be overcome through practice to meet the needs of fire prevention.