Grooved rubber covered touch roll under the paper machine dryer
The grooved touch roll is generally used under the large cylinder
of the paper machine, and has the function of draining paper and
draining water before entering the drying cylinder.
The grooved touch roll is a rubber-covered roller. The alloy layer
is used to cut a spiral groove with a width of 0.5 to 0.6 mm, a
depth of 1.0 to 3.5 mm, and a groove pitch of 3.0 to 3.6 mm.
The opening ratio of the grooves is an important parameter
affecting the dehydration. The opening ratio refers to the
percentage of the groove opening area. Studies have shown that the
opening rate of the grooves should not be too large. If the opening
rate is too large, the dehydration effect is not good. The grooved
roller with wide grooves and many buckles has a small contact area
during pressing, and it is difficult to form the pressure necessary
to press water from the felt into the grooves. The narrow trench
helps reduce the amount of water returned from the trench to the
felt. The aperture ratio is generally considered to be better at
16%.
When using ordinary needle felt blankets, the grooves should be
narrow and deep, otherwise indentations are likely to appear in the
paper. The bottom mesh needle-punched blanket is relatively stiff
and not easy to appear indentation. The groove processing should be
wide and shallow. The rubber hardness of the corrugated roller
should be greater than that of ordinary press rubber rollers,
because the rubber roller with low hardness can easily deform the
corrugations and affect the dehydration efficiency. The hardness of
the corrugated roller rubber layer is generally 85 to 90 Shore
hardness.
Compared with ordinary pressing, grooved pressing is easier to
dewater, the line pressure is lower during pressing, and the
thickness of the rubber layer is increased. Therefore, the middle
and high height of the roller can be reduced, and the two sides of
the paper can be prevented from having high moisture and
unevenness, which can cause ribs. The orientation of the felt and
wet paper is also important when pressing. At the press outlet, the
wet paper should be separated from the felt as soon as possible,
and the felt should also be separated from the grooved roll as soon
as possible to prevent water from getting back into the felt and
wet paper sheet. Roll grooves must be kept clean to prevent
blockages. Pay attention to the drainage of water in the grooves.
When the speed of the paper machine is high, the corrugated roller
needs to be equipped with a soft scraper to remove the
high-pressure water punched from the roller groove to the roller
surface.
| ROLL BODY | DIAMETER | SHAFT | Rubber thickness | Rubber hardness |
| δ16mm, Q235 steel plate | Depends on paper machine width | #45 STEEL Quenching and tempering | 20-40mm | SR A90º±2 |
According to the drawings provided by customers or our professional
meticulous rigorous drawing, advanced processing technology and
equipment are used, and the rubber has good elasticity, moisture
resistance, heat resistance, acid and alkali resistance and
corrosion resistance, and the surface has accurate and uniform
hardness. The maximum tolerance of hardness should be within the
allowable range, and the aging resistance is good. Ensure that the
rubber roller can perfectly fit the customer's paper machine,
extend the service life, save costs for customers, and create more
revenue.
