Cause of ink leakage from ballpoint pen
b) In case from the back of the pen
b-4) If put in a washing machine
When you put the pen in the washing machine, it takes a strong centrifugal force to move the ink in the pen, such as during dehydration, and the ink may flow out at the end of the pen or core (in some cases, front).
The way ink leaks depends on the structure of the pen, the type of ink, and the way the centrifugal force is applied depending on the position the pen is placed in the washing machine and the direction of the pen.
The pen that I put in the washing machine seems to be usable because it was able to write, but most of it is temporary, the ink that leaked out inside the pen suddenly comes out to the outside. Therefore, please do not use the pen that was put in the washing machine.