FUNCTION OF PAPER-MAKING FELTS

Felts function as conveyor belts to transfer wet paper web without damage. Felts allow as much squeezing of water as possible out of wet paper web. Felts keep an even smooth surface of wet paper web.

Desirable Properties of Paper-making Felts

There are many kinds of paper grades such as newsprint paper, printing/information paper, sanitary paper, specialty paper, liner board and white paper-board. Each kind of paper is manufactured on the appropriate paper-making machine under the proper conditions, but the principles of manufacturing respective paper is more or less the same. Paper-making machines generally have forming, pressing and drying sections and paper-making felts are mainly used at the pressing section. The role of the pressing section is to receive wet paper web from the forming section by way of felt and to squeeze water from the wet paper web.
Therefore, paper-making felts need to:

Drawings
Newsprint and wood free paper
Liner board and corrugation medium
Tissue paper
  • Function as conveyor belts to transfer wet paper web
  • Allow as much squeezing of water as possible out of wet paper web
  • Keep an even smooth surface of wet paper web
Paper-making felts require the following properties:

1. Dewatering ability or drainability
To remove as much water as possible out of wet paper web.
2. Transferability of wet paper web
To transfer wet paper web safely to the next position by adhering the wet paper web to the felt.
3. Runnability
To avoid such undesirable conditions as snaking, deviation, vibration and wrinkling.
4. Wear resistance and resistance to hair shedding
To avoid wear in short running periods and to keep shed fibers to a minimum.
5. Compaction resistance
To avoid choking by increasing density and/or deposition of contaminating substances and to maintain resiliency and elasticity in the early running stages.
6. Paper surface smoothness
To avoid any felt or roll markings.
7. Break-in
To reach the desirable operating speed in the shortest time.
8. Uniformity
To achieve a uniform evenness in felts.
9. Simple installation
To enable easy felt installation onto paper-making machines requiring the least number of people and in the shortest time.

The significance of these important requirements is delicate and variable according to the grades of paper, types of paper-making machines and the positions where the felts are used. In this sense, each position of the paper-making machine requires different felts. Accordingly, felt designs which meet customers' various needs are created by a wide range of research and development on raw materials and manufacturing technology, together with up-to-date information on paper-making technology and abundant experience.