Paper is flammable, but as long as a very simple method, you can let the paper in the flame "safe and sound". Today I will take you to see how to make the paper is not ignited.
Experimental equipment
Paper, copper wire (wire can also be), lighters
Experimental process
Step 1: First, bend the copper wire into a spiral coil
Step 2: Stuff the paper into the copper coil
Step 3: Use a lighter to try to light the paper in the copper coil, you will find that no matter how long it burns, the paper in the copper coil will not burn.
Note: Keep the lighter away from other flammable and explosive materials.
Step 4: In order to verify that the paper is flammable, remove the copper coil, and then use a lighter to light it, you will find that the paper burns quickly.
Principle explanation
First of all, clarify the definition of the ignition point: the ignition point, also known as the ignition point, which refers to the specified test conditions, the application of external heat sources to make the surface of the material fire and continue to burn for a certain period of time the minimum temperature required. For ordinary paper, its main structure is cellulose, containing the main elements of carbon, hydrogen, oxygen, ignition point is generally 150 ℃ to 300 ℃. For the general lighter inside the liquid is butane, and butane combustion temperature can reach 1500 ℃, far more than the ignition point of ordinary paper, so it can easily ignite it.
Let''''s introduce another physical term: thermal conductivity. Thermal conductivity is defined as the unit cross-section, length of the material in the unit temperature difference and the unit time of the direct conduction of heat, thermal conductivity of the unit for the watt per meter per Kelvin (W/m-K). Its size can directly reflect the performance of thermal conductivity. The thermal conductivity of copper is about 400 W/m-K, this value is very large, when the fire is close to the paper wrapped in copper wire, the copper wire will be the heat generated by the lighter quickly absorbed and conducted away, so that the paper will not reach its own ignition point will not burn.
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