History:
The production of the early paper can be traced back to China to 105 AD where waste material was used such as hemp or fishnets. The production travelled west over the centuries and reached Baghdad in the year 793. From the Islamic culture, it reached Europe. The invention of printing brought a great need for paper in the 1450s.
In 1807, an improved paper machine was made in England, that was based on the invention of a French engineer. Progress was made on iterative design of machinery and the increased mechanisation reduced hand labour.
Sources: Papermaking - Fibres, Sources, Processes | Britannica
The base material for most paper is pulp, primarily derived from wood chips or recycled fiber. The primary goal of pulping is to extract and separate cellulose fibers from lignin, a binding organic polymer. The pulping process is categorized into mechanical and chemical methods. In mechanical pulping, mechanical force grinds wood chips to separate the fibers, while chemical pulping uses a solution of sodium hydroxide and sodium sulfide to break down lignin. This chemical process, particularly the Kraft method, is often used due to its efficiency in producing strong and versatile pulp.
After pulping, the pulp undergoes refining, where it is mechanically treated to improve fiber quality, affecting paper properties like strength and flexibility. This step is crucial for crafting the pulp to specific paper types, such as newsprint or special papers.
The forming stage transforms the pulp into a paper sheet on a paper machine. Here, a pulp slurry is spread onto a moving screen, draining water and allowing fibers to bond, forming a wet web of paper fibers. This web then goes through pressing, where rollers squeeze out excess water, enhancing paper density and strength.