"Manuscripts do not 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 turns fibrous material into ash, and the ignition temperature of paper depends on its grade, 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 reaction of oxidation, as a result of which heat, carbon monoxide, hydrogen and other gaseous substances are released. We observe combustion products in the form of smoke with a pungent, specific odor. Typically, 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 should 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 process initiated by ignition does not die out and soon turns into stable combustion.
Characteristics
As is known, wood, cotton, flax, hay or recyclable materials (waste paper) are used for industrial paper production. At the initial stage of processing in boiled wood pulp, which is destined to become material for writing, drawing and other human needs, is up to 95% of the water. After drying, the paper becomes thick, smooth and sensitive to fire.
Different printing methods have their own requirements for sheets by density, texture, color, so the ignition temperature of the paper is slightly different depending on its type. So that the photograph lights up, the degrees Celsius 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 greasy pulp material that does not need to be pre-oiled, then the ignition temperature of the 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 ° С). Special refractory paper almost does not support combustion, has good mechanical strength, and heat-resistant fiber is able to withstand temperatures above 1, 000 ° C.
Celsius Paper Flash Point
In Russia and a number of other countries, including European ones, degrees Celsius are used to measure temperature, which are also used in the International System of Units (SI) along with kelvin. Anders Celsius defined 0 ° C as the melting point of ice, and at 100 ° C water boils. Regarding the ignition temperature of the paper, remember the famous epigraph to Ray Bradbury’s novel?
"451 degrees Fahrenheit is the temperature at which paper ignites and burns."
Even 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 firefighter friend, he simply confused the temperature equivalents.
Fahrenheit Paper Ignition Temperature
Residents of England and the United States are 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 German scientist’s scale was used in all English-speaking countries, but at the end of the 70s of the last century, the Celsius scale almost completely replaced it. The freezing temperature of water in Fahrenheit became + 32 °, and the boiling point + 212 °. Using simple calculations, you can determine that the burning process of paper or cardboard is started if the dry material is heated to 843 degrees Fahrenheit.
Ignition or fire: what is the difference
Ignition is considered to be the beginning of burning paper under the influence of an ignition source. In fact, this is the starting mechanism, after which the chain reaction begins. If you have time to respond in time, then you can eliminate the fire without assistance.
Ignition is always accompanied by a steady flame, while the light and heat necessary to maintain the fire are released. Loose paper is the most dangerous: it is saturated with oxygen enough to ignite from a spark or the heat of local heating. A few degrees can be added or subtracted to the average paper ignition temperature, depending on the quality of the fiber and the burning conditions.
High Temperature Measurement Method
The measurement of flame temperature has its own specific features 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 thermal detector. Distinguish between optical, radiation and spectral pyrometers. An electronic device is indispensable in cases where you can’t get close to the fire.
A pyrometer is an accurate engineering device that is designed to measure the power of thermal radiation in a non-contact way. The device serves as an excellent alternative to contact means, they remotely calculate the temperature of incandescent objects or use as heat radars in various industrial fields. You can determine at what temperature the paper ignites using a low-temperature pyrometer.
Is spontaneous combustion possible
Abrupt self-acceleration of exothermic reactions without external influence of a flame or a hot body leads to self-ignition. The autoignition temperature of the paper is in the region of 450 ° C. When determining the indicator take into account the degree of moisture of the material, its composition, the presence or absence of pigment dyes. Simply put, a “bonfire” from waste paper can ignite on its own when the ambient temperature reaches a critical level.
A decrease in air humidity and an increase in oxygen concentration in the combustion zone affect the auto-ignition temperature, reducing it. Oiled sheets of paper are prone to thermal spontaneous combustion after drying, but ribbons 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 in their ideas often use self-igniting paper. For example, a sheet saturated with sodium peroxide quickly and brightly lights up on contact with a small amount of water. The spectacle is very spectacular, but quite dangerous, therefore, without certain technical skills to perform the "focus" at home is not recommended.
Do not mess with the fire!
Paper is a serious danger in the fire sense, it quickly ignites, actively interacts with vapors and gaseous products contained in the air, burns intensely. In residential apartments and houses, a gas stove, an overheated or faulty electrical appliance, an unquenched match, a cigarette can become a source of ignition. The main cause of domestic fires is human negligence, failure to comply with basic safety rules.
Do not leave paper near heating appliances, do not overload the power supply. You can not put cardboard sheets under the TV, computer, lighted candles. So that paper does not become a source of fire, never smoke in bed, keep a fire extinguisher and a dense cloth in the house - with their help the flame will not have time to spread to neighboring objects. Overalls, as well as 100% cotton denim, are flammable.
Even if the paper burns, act with caution and do not panic. If possible, eliminate drafts - the access to fresh air adds to the fire, cover your face from acrid smoke with a damp handkerchief, turn off all electrical appliances from outlets and, having seized important documents, leave the room. Knowing and strictly observing the rules of safe behavior, you can prevent the spread of fire without risking life.
