Pulp blending and dilution in the papermaking process of the paper machine

What is the pulping process in the papermaking process of the paper machine? How to formulate the pulp?

Answer: In the process of papermaking, in order to improve the properties of paper or meet the needs of papermaking performance, and in some cases to save high-quality long fibers, it is often required to use two or more types of pulp to make paper. , which is called blending.

There are two methods of mixing pulp, batch and continuous.

Batch blending is to measure the volume and concentration of the pulp in the pulp tank, and send it to the mixing tank in batches according to the required proportions.

Continuous blending is that various pulps first pass through a concentration regulator to stabilize the concentration, and then continuously pass through a flow control device. Its advantage is that it is easy to realize automatic control, suitable for large-scale factories with stable varieties, and equipment for continuous control of pulp volume. Some use electromagnetic flowmeters, but the most commonly used is pulp mixing box.

Why should the paper stock be diluted before entering the wire section of the paper machine? How?

Answer: The slurry concentration in the pulp storage tank in front of the paper machine is generally high (usually 2-3.5%). Such high slurry concentration is directly sent to the wire part, which is not conducive to the forming of the paper sheet, and the uniformity of the paper sheet is copied. Also bad. Therefore, the slurry is usually diluted to a concentration of 0.25-0.35% before the selection of the paper material to meet the needs of the slurry on the Internet.

The easiest way to dilute the slurry is to send both the slurry and the dilution water to the mixing box. The mixing box is equipped with several overflow baffles. The slurry flows up and down through these overflow baffles, and is thoroughly mixed and then sent to the net. Department. This dilution method is simple in equipment and easy to operate, so it is widely used.

The above is the pulping and dilution in the papermaking process of the paper machine.