Paper sheet making process

Taking the current most advanced application of paper-folding paper as an example, the papermaking process is described:

The paper machine is composed of two parts, the wet part and the dry part. The wet part includes a headbox (head box), a wire part and a press part; the head part includes a drying part, a calender part and a reeling machine. The paper stock suspension delivered by the purification system is sprayed through the headbox at a uniform and stable discharge speed into the middle of the two nets (usually sprayed at a 45-degree angle or a 90-degree angle), and is taken off on both sides by two nets. After the water is formed, it is sent to an advanced shoe press for press dewatering and improves sheet performance, increasing sheet tightness and surface smoothness. After the sheet is dewatered by the press machine, it is sent to the drying section for further dehydration using heat energy to meet the requirement of the moisture content of the sheet. Offset paper also needs surface sizing treatment in the drying section to improve the surface strength of the paper and meet the requirements of high-speed printing. The sheet coming out of the dryer section has a rough surface and cannot be adapted to the requirements of printing and writing. In order to improve the smoothness of the paper and adjust the thickness of the paper, the paper sheet must also be calendered by one or more metal rollers (usually a positive and negative two calender). The calendered paper can be slit into flat sheets or rolled into a web using a rewinder.