Paper Makeing Machine Roll

The press section is an essential process in the paper forming process. This step will further remove the moisture from the paper, solidify the paper sheets and improve the paper density. There are many types of rollers in the press section. Due to the different models, speeds and usage locations of paper machines, there are also large differences between the press rollers. The press rollers include rubber rollers, stone rollers, vacuum rollers, etc.

(1) Rubber roller

The surface of rubber roller generally has a thread pitch of 2.5 to 3 mm. The roll body is generally made of cast iron or cast steel with a hardness of about 850 HS.

When the line pressure in the pressure zone is the same, the roll with a high rubber hardness has a high dehydration rate, but the cross-sectional moisture uniformity is poor, so the medium and high precision requirements of the roll are higher.

(2) Stone roller

Stone roller are made of natural granite or artificial stone. There are countless micropores on the surface of the stone roller, which makes it easier for paper sheets to peel off its surface. Granite stone roller have poor bending strength and are not suitable for lower pressure rolls to avoid breaking. Overcooling or overheating will also cause the roll surface to explode. The surface of the stone roller cannot be directly exposed to strong acids and alkalis to avoid damaging the surface gloss.

(3) Vacuum roll

Generally, it is made of stainless steel roller body with color rubber. Generally, the rubber layer thickness is 35mm and the hardness is 850HS. The vacuum chamber is welded by cast iron or steel plate. It can be disassembled and assembled by relying on the two rollers of the vacuum chamber. There are two sealing strips on the upper layer of the vacuum chamber. There is a water-filled rubber hose under the sealing strip to support the sealing strip to prevent air leakage. When using the sealing strip, it is necessary to install a water spray pipe in the roller to lubricate the inner wall sealing strip and reduce mechanical wear.