By Kanglin Xing

  Kanglin Xing is PhD candidate in the field of Mechanical Engineering at Polytechnique School of Montreal

Kanglin Xing is PhD candidate in the field of Mechanical Engineering at Polytechnique School of Montreal

Paper­making is one of the four great inventions of China, and also a brilliant invention in the history of civilization. In ancient times writing was generally on bones, tortoise shells, and bamboo slips or on pieces of silk. Once a Chinese idiom described a learned man. He needed five carts to carry his books when he traveled around teaching. Books at that time were made of wood or bamboo slips so they were heavy and occupied a lot of space. Reading or studying at the time needed not only brainwork but also physical strength. Because of this, many people thought these kinds of writing surface were unsuitable.

In the year of 105 A.D., Cai Lun, an officer of the Imperial Court of Han dynasty, wants to invent a new lightweight writing surface which was not too thick or too heavy. He thought of using tree bark, hemp, rags, and fishnets to make paper. His idea was based on barkcloth, which was very common in China and also made from mulberry bark. He formed a set of relatively economic papermaking process, the process can be roughly divided into four steps:

The first step is the separation of raw material, the retting or cooking methods were selected to make raw materials scatter into fibrous in alkali solutions; The second is beating, this step is to use the method of cutting and struck to make the fiber broom, and become the pulp; The third step is the manufacturing of paper with pulp, pulp water will be penetrated into slurry using woven bamboo mat to form the thin wet paper; The fourth step is drying, the wet paper will be hung up in the sun, and then become the dry paper. The light paper could be got after peeling.

After the successful experiment, Cai lun made a report to the emperor on the process of paper-making, and received high praise for his ability. From this time paper has been in use everywhere and spread to the rest of the world through the Silk Road. Later, the king of paper has its name the "paper of Marquis Tsai”.

With the invention of this cheap and easy writing surface, ideas, skills can be easily passed on to other people. So the use of paper changed the way people taught and learned. Nowadays, the technique of paper-making had gone through different processes to be a refined and perfected process. It truly is one of the best inventions made by Chinese. 

To go further : The Invention of Paper, A Mankind's Everlasting Evolution