What's the matter with the black five-centimeter board sawed by the chainsaw?

The reason why the five-centimeter board of hand-held chainsaw is blackened is that the wood is affected by high-temperature heat treatment during processing. When sawing a five-centimeter board with a chainsaw, a large amount of heat will be generated due to friction and high-speed rotating blades, which exceeds the thermal resistance limit of the wood, resulting in an increase in the surface temperature of the wood. When the surface temperature of wood reaches a certain level, cellulose molecules in wood will begin to carbonize, making the surface of wood black.

We can explain this phenomenon from a physical point of view. When the chainsaw comes into contact with a five-centimeter board, the heat energy generated by friction on the saw blade will be transferred to the wood, which will increase its surface temperature. When the temperature exceeds the thermal resistance limit of wood, wood can not effectively dissipate heat, resulting in local temperature increase.

From a chemical point of view, cellulose molecules in wood will undergo cracking reaction at high temperature, producing a large number of powders and gases. Part of the powder is deposited on the wood surface to form a black substance, while the gas is carried away through the air.

In the process of processing, it may also be affected by oxygen, moisture and dust in the air. The black substance produced on the wood surface may be due to the oxidation reaction with oxygen in the air, or it may be due to the dust or moisture in the air adsorbed on the wood surface, thus forming black spots.

The blackening of the five-centimeter board of chainsaw is due to the increase of the surface temperature of wood caused by high-temperature heat treatment, which makes the cellulose molecules in wood carbonized and blackened. Chemical reactions and environmental factors will also have a certain impact on the production of black substances on the wood surface. In order to reduce this phenomenon, the cutting speed can be reduced, the heat generated by friction can be reduced, and the sharpness of the blade can be maintained, thus making the cutting process more stable and smooth.