Soft Calendering Machine

The fixed crown soft calendering machine (single nip and double nip) is suitable for calendering paper with a deckle less than 1880 mm. The internal multi-zones crown controllable roll soft calendering machine (single nip and double nip) is suitable for calendering paper with a deckle more than 1880 mm.

The soft calendering machine can not only produce good effects, but greatly improves uniformity of sheet density and ensures less dots or imperfections and better printing on paper. Consequently, the soft calendering machine is replacing the hard calendering machine in many paper mills.

Working Principle

Calendering is a repeating process, passing paper between a smooth roll surface and a coarse web surface after paper comes out of the drying section. The working principle of a soft calendering machine can be equivalent to ironing, making smooth passes with heat and pressure. The common calendering machine and super calendering machine both achieve great effects through the repeated pressure of multiple rolls. The soft calendering machine accomplishes the calendering process rising the surface temperature of rolls and width of nip. After process is finished, the smoothness of paper can be increased up to 30-40% while the paper thickness only reduces 10%.

Advantages

When pressurizing, elastic deformation of soft roll leads to surface contact between hard roll and soft roll. The surface contact width of soft calendering machine is 10-25 mm, which is 15 times more than a hard calendering machine. In addition, the unitary linear pressure of the soft calendering machine is generally 20-40 N/mm, even if the linear pressure is higher; it’s just 1/2-1/4 of the hard calendering machine. The sheet stays longer in the nip while the heat energy passes to sheet and makes it fiber plastify. The softening fiber is easier to be calendered, thus increasing smoothness.

The rebound resilience of surface material makes the soft roll face suit any bad flatness of sheet and base weight change, so the soft calendering machine can achieve better softness than a common calendering machine, increasing color, spots can be eliminated and printability can be greatly improved.

Another advantage of the soft calendering machine is, when paper is being pressed black and basic elimination of color spots, sheet can be in motion to hold higher moisture. The temperature, nip pressure, width and number of soft calendering machine all have effect on smoothness or shiny results.

Main parameters

Applications of the CCR Soft Calendering Machine

1. Standard newsprint (DIP)

2. Improved newsprint

3. SC-B rotogravure

4. LWC (Light weight coating paper) offset

5. Coated or uncoated woodfree paper

6. Coated or uncoated board

7. Print and writing paper

We are a China soft calendering machine manufacturer and supplier. We offer various types of products such as super soft calendering machine, hard calendering machine, multi-functional up and down double-sided press calendering machine and two roll fabric calendering machine.