The closing part of the easily worn ball seat (the ball seat material is nickel-platinum-copper or stainless steel, which is much easier to wear than the ball), if in contact with the written material for a long time, even if the written material is paper, the ball seat cannot withstand wear and tear, which can cause the ball to fall off.
When using a ballpoint pen to write, keeping the angle controlled between 55 and 70 degrees is the most ideal. At this time, only the ball and the paper are in contact (the ball is very hard, made of tungsten carbide or ceramics, and is not easily worn), and the closing part does not touch the written material, thus ensuring that the ballpoint pen can be used for a longer time in good writing condition.
When writing, if the pad is too thick, the pen tip closing part will touch the paper and be easily worn and detached. It is recommended that the 0.4 ball cannot be overwritten; the 0.5 ball can only be overwritten once, not more; the 0.7 ball can be overwritten 3 to 4 times at most, not more. When overwriting, it is best to write at 75 degrees.
The role of dye is to give the ink enough color depth. The dyes used in the ink for ballpoint pens can be divided into oil-soluble dyes and alcohol-soluble dyes. The dye used in this experiment is a phthalocyanine dye, which is insoluble in solvents, has good dispersion in ink, has strong adhesion to film-forming agents, and does not penetrate into the interior of paper. Moreover, the color is bright and has good weather resistance.
The appropriate amount of dispersant can reduce the adhesion between the ink and the surface of the paper, making the ink written on the surface of the paper have erasability within a certain period of time. The dispersant can also maintain the writing fluency and long-term stability of the ink.
The film-forming agent is an important component of the erasable ink for ballpoint pens. Its main function is to form a film evenly on the surface of the paper and serve as a carrier for the dye. It is required to have a certain adhesion to the paper surface, not easy to peel off, but can be gently erased with an eraser, strong adhesion with the coloring agent, good solubility in solvents, and stable interaction with other components for long-term preservation.
In erasable ballpoint pen ink, the role of solvent is to dissolve the dye, film-forming agent, and various additives, provide a certain flowability, and have appropriate volatility to effectively control the drying speed during the writing process. The experiment shows that using a cosolvent is better than a single solvent.