Why Does Paper Machine Felt Bubble

Blasting means that the air brought in by the slurry or felt locally accumulates to form bubbles between the felt and the paper sheet, causing the paper sheet to burst or local delamination and blistering between the layers of the wet paper sheet. It basically occurs on the cage of the multi-cylinder paper machine, at the entrance of the press nip and in the dryer part.

Causes and solutions for bubbling:

1. When producing board paper, the degree of beating of each layer of slurry is too large, resulting in differences in bonding between layers.

2. Improper adjustment of the pressure of the bed roller line.

3. The vacuum in the vacuum water suction box is too low, which causes a huge difference in moisture content of the wet paper sheets between the pulp layers, causing bubbles in the wet paper sheets.

4. Partial dirt on the wire and felt causes poor local dehydration and poor air permeability; the water-absorbing blade of the lying roller is partially jammed; when the water-retaining cloth is uneven or has holes, the pressed water will rewet, etc.

5. The angle before the wet paper sheet is pressed is incorrect, and the eccentricity and linear pressure of each press are incorrectly adjusted.

6. The drying temperature curve of the dryer cylinder is not adjusted well.

There is a large amount of air in the pores of the new felt, and the new felt cannot meet the needs of normal production due to factors such as uneven initial surface, excessive air permeability, insufficient vacuum, and high water content in the felt. It is easy to cause the gap between the paper sheet and the felt. Bubbles are generated at the entrance of the pressure zone. Email address: leizhanworld@gmail.com.