Why is a horizontal match bent when burning?

Did you notice when burning a match and wonder why the burnt woody body will be bent up there?

The cause of the match is horizontal bending when burning

The British scientists have studied the phenomenon of matches being bent when burning and found that, if a match is allowed , this phenomenon will occur. If the match is upright, it will not bend.

Matchsticks will be bent when horizontal

According to the measurement results, the cause of the bent match is the vertical air flow in the burned area. This air flow moves from bottom to top according to convection principle. The upper temperature is always higher than the lower temperature. Therefore, the upper part of the wood always burns with a higher temperature than the lower part.

During the burning process, the volume and volume of the match are reduced. The higher the temperature, the greater the change. Thus, the upper part burning with higher temperatures will change with a greater degree, the lower part with lower temperature will have less change. As a result, the match is curled up during the burning process.

However, if the match is left upright, this difference is negligible and cannot cause the match to be bent during the burning process.