"Manuscripts don't burn!" - wrote the famous Russian prose writer and playwright M. Bulgakov. In fact, the legendary quote has nothing to do with real facts. Fire easily reduces fibrous material to ash, and the ignition temperature of paper depends on the type of paper, air humidity, oxygen level in the atmosphere and the power of the heat source.
The essence of the process
From the point of view of science, combustion is a chemical oxidation reaction, which releases heat, carbon monoxide, hydrogen and other gaseous substances. We observe combustion products in the form of smoke with a sharp, specific smell. Usually paper ignites in the presence of an oxidizing agent and an ignition source, but self-ignition is also possible. Oxygen acts as an oxidizing agent, it must be at least 14% in air.
Dry paper sheets or rolls can be set on fire from an open flame, a spark of electrical or mechanical origin, an incandescent object. The absorption of paper by fire begins with an exothermic reaction, if nothing is done in time, then the initiatedignition, the process does not die out and soon turns into a stable combustion.
Features
As you know, for the industrial production of paper, wood, cotton fibers, flax, hay or recycled materials (waste paper) are used. At the primary stage of processing, boiled wood pulp, which is destined to become a material for writing, drawing and other human needs, contains up to 95% of water. After drying, the paper becomes thick, smooth and sensitive to fire.
Different printing methods have their own requirements for sheets in terms of density, texture, color, so the ignition temperature of paper differs slightly depending on its type. For a photograph to light up, the Celsius degrees must exceed 365°C. To obtain a glossy material, resin is added to the composition, which helps to accelerate the thermochemical reaction.
If the hostess in the kitchen is dealing with a material made of oily pulp, which does not have to be pre-oiled, then the ignition temperature of baking paper will be 170 ° C. But, as a rule, the coefficient of heat resistance of "professional" baking films with silicone impregnation is much higher (up to 250-300 °C). Special refractory paper almost does not support combustion, has good mechanical strength, heat-resistant fiber can withstand temperatures above 1,000 ° C.
Paper flash point in Celsius
In Russia and a number of other countries, including European ones, to measure temperatureuse degrees Celsius, which are also used in the International System of Units (SI) along with the kelvin. Anders Celsius defined 0 °C as the melting point of ice, and at 100 °C water boils. As for the ignition temperature of paper, remember the famous epigraph to Ray Bradbury's novel?
"Fahrenheit 451 is the temperature at which paper ignites and burns."
Already after the publication of the book "451 degrees Fahrenheit" it turned out that a mistake was made in the title: fire on the surface of paper pages occurs at a temperature of 451 degrees Celsius, and not on the Fahrenheit scale. Later, the best-selling author admitted that after consulting with a familiar firefighter, he simply confused the temperature equivalents.
Paper Flash Point Fahrenheit
Inhabitants of England and the United States are more accustomed to using the Fahrenheit scale, which is named after the physicist Gabriel Fahrenheit, where zero degrees Celsius is 32 °F. For a long time, the scale of the German scientist was used in all English-speaking countries, but at the end of the 70s of the last century, it was almost completely replaced by the Celsius scale. The freezing point of water in Fahrenheit became + 32 °, and the boiling point + 212 °. By simple calculations, it can be determined that the process of burning paper or cardboard starts if the dry material is heated to 843 degrees Fahrenheit.
Combustion vs Ignition: What's the difference
Ignition is considered the beginning of burning paper under the influenceignition source. In fact, this is the starting mechanism, after which a chain reaction begins. If you have time to respond in time, you can eliminate the fire without outside help.
Ignition is always accompanied by a sustained flame, releasing the light and heat needed to sustain the fire. The greatest danger is loosened paper: it is sufficiently saturated with oxygen to be ignited by a spark or the heat of local heating. A few degrees can be added or subtracted from the average fire temperature of paper, depending on fiber quality and burning conditions.
High temperature measurement method
Measurement of flame temperature has its own specifics and difficulties. To determine the ignition temperature of paper or any other combustible material, you need a pyrometer. It is also called an infrared thermometer or a thermodetector. There are optical, radiation and spectral pyrometers. An electronic device is indispensable in cases where the fire is not close to get close.
Pyrometer is a precision engineering device designed to measure the power of thermal radiation in a non-contact way. The device serves as an excellent alternative to contact means, they can remotely calculate the temperature of hot objects or use them as heat detectors in various industrial areas. You can determine at what temperature the paper ignites using a low-temperature pyrometer.
Is it possibleself-ignition
Sharp self-acceleration of exothermic reactions without external influence of a flame or hot body leads to self-ignition. The auto-ignition temperature of paper is around 450 °C. When determining the indicator, the degree of moisture content of the material, its composition, the presence or absence of pigment dyes are taken into account. Simply put, a "bonfire" made of waste paper is able to ignite on its own when the ambient temperature reaches a critical level.
Reducing air humidity and increasing the concentration of oxygen in the combustion chamber, affect the auto-ignition temperature, reducing it. Oiled sheets of paper after drying are prone to thermal spontaneous combustion, but tapes in rolls are reluctant to burn. If heat and smoke are released, but there is no flame, the process is called smoldering.
By the way, illusionists often use self-igniting paper in their performances. For example, a sheet impregnated with sodium peroxide ignites quickly and brightly when in contact with a small amount of water. The spectacle is very spectacular, but quite dangerous, so it is not recommended to perform the "trick" at home without certain technical skills.
Don't mess with fire
Paper is a serious fire hazard, it quickly ignites, actively interacts with vapors and gaseous products contained in the air, and burns intensely. In residential apartments and houses, a gas stove, overheated or faultyelectrical appliance, not extinguished match, cigarette. The main cause of household fires is human negligence, failure to follow basic safety rules.
Do not leave paper near heaters, do not overload the power grid. Do not put cardboard sheets under the TV, computer, lighted candles. To prevent paper from becoming a source of fire, never smoke in bed, keep a fire extinguisher and thick cloth in the house - with their help, the flame will not have time to spread to neighboring objects. Workwear and 100% cotton denim are not flammable.
Even if the paper is on fire, act sensibly and don't panic. If possible, eliminate drafts - access to fresh air adds strength to the fire, cover your face from acrid smoke with a damp handkerchief, turn off all electrical appliances from the sockets and, having grabbed important documents, leave the room. Knowing and strictly observing the rules of safe behavior, you can prevent the spread of fire without risk to life.
Summarize
It is almost impossible to imagine the daily life of mankind without books, magazines, notebooks, calendars and other printed matter. Paper, which was so highly valued in the ancient world, played an exceptional role in the development of literature and painting, education. Its irrational use threatens not only the destruction of millions of trees, but will inevitably lead to a humanitarian catastrophe in the future. Be careful with paper, be vigilant and careful with fire- so we will preserve the beauty of our planet, make the world a better place!
