Paper machine Grooved press roll

The grooved press roll is a pressing component used in the press section of a paper machine. It is characterized by a circular or spiral groove on the roll surface, also known as a groove. The purpose of the grooved press roll is to improve dehydration efficiency, improve the quality of paper sheets, and reduce the adverse effects of pressing on paper sheets.

Structural features

The structure of the grooved press roll is usually a stone roll for the upper roll and a rubber roll for the lower roll. The rubber layer of the rubber-coated roll is cut with an alloy steel knife to form spiral grooves with a width of 0.5~0.6mm, a depth of 1.0~3.5mm, and a groove pitch of about 3.0~3.6mm. The opening rate of the groove is an important parameter affecting dehydration, and it is generally believed that the opening rate is better at 16%.

Working principle

When the grooved press roll presses over the water-containing paper surface, part of the water will be squeezed into the groove. On the one hand, the groove will play the role of draining water, diverting part of the water into the connected vacuum holes to be sucked away by negative pressure; while a small part of the water will be thrown out under the action of centrifugal force, thereby achieving a better dehydration effect.

Advantages

Compared with traditional pressing rollers, grooved pressing rollers have better dehydration effect and lower pressing line pressure. In addition, the rubber hardness of grooved pressing rollers should be greater than that of ordinary pressing rubber rollers, because the grooves of rubber rollers with low hardness are easily deformed, affecting the dehydration efficiency.