Do You Know What is Dryer Felt?

What is Dryer Felt? 

The dryer felt is used on the paper machine dryer section. For dryer section used clothing mainly have three type, polyester dryer fabric (spiral loop dryer fabric, flat yarn dryer fabric and round yarn dryer fabric), dryer felt and flocking dryer fabric. The dryer felt play a role of transferring the wet paper web from press section to dryer section, and then to the calender and reel section. During the process of transferring the wet paper web, the dryer felt can help and improve the paper web drying uniformly, so that the paper web can reach to normal moisture content. This is the basis task for dryer felt.

The dryer felt is made of needling technology which have good performance of high temperature resistance, moisture resistance and corrosion-resistant. Its have longer service life than tradition dryer canvas.

What are the Functions of Dryer Felt?

• Transfer paper web and make it go through the paper machine dryer section.
• Drive the dryer cylinder and rolls running.
• The dryer felt is adhering the surface of dryer cylinder tightly, it can increase the paper web touch the cylinder surface, so that improve the heat transfer efficiency.
• The dryer felt also can absorb the steam and moisture from the paper web when the paper web is drying. It can increase the drying efficiency and avoid the paper web creping or folded during drying process. At the same time it can give the paper web a good performance of flatness, glossiness and smoothness.

How to Choose Dryer Felt?

Excellent durability, suitable for demanding working conditions
The dryer felt under the high tension of the dryer section, in a high-humidity and heat environment, as well as under the corrosion of chemicals, wear of machine parts, and continuous repeated flexing, it is essential that the fibers and structure of the dryer felt have good durability.

Maintaining dimensions under high tension and high temperature conditions
The dryer felt must keep not lower tension of 3kg.cm-1 under the dryer section high speed running state. Under the such high tension state and high temperature environment the dryer felt must keep cross and longitudinal direction dimension stable and composition structure flat. Only in this way can the wet paper be tightly adhered to the cylinder surface under the strong and uniform tension of the dryer felt, achieving the best drying effect.

Dryer felt needs to have good breathability and water absorption to achieve efficient and quick drying
In the drying process of wet paper sheets in the dryer section, during the initial stage of drying, the activity of water molecules is activated under the action of thermal energy in the preheated state of the dryer, and some of them enter the dryer felt; The water molecules activated by thermal energy in wet paper sheets change from liquid to gas as the drying temperature increases and continue to enter the dryer felt. Some of the steam passes through the dryer felt and is discharged, while the remaining steam is reduced to water and taken away by the dryer felt. The water molecules taken away need to be further heated by the dryer felt cylinder or other heating devices such as hot air guide rollers during the return journey of the dryer felt, and then turned into gas and discharged. Such a drying cycle requires the dryer felt to have good breathability and water absorption properties in order to improve the drying efficiency of wet paper sheets in the dryer section.

Required smoothness and softness to prevent felt mark
Dryer felt should have good smoothness and softness, so as not to leave felt patterns (surface imprints of dryer felt) on the surface of the paper, and to evenly press wet paper tightly onto the surface of the dryer, improving heat transfer efficiency and drying efficiency.

If you are confused of how to choose suitable dryer felt, welcome to contact us, we will help you to choose suitable dryer felt for your paper machine dryer section.