How to correctly test the degree of pulp release

[Chinese Packaging Network News] popular in the pulping process popular phrase: "three-point papermaking, seven-point beating." Understanding the literal meaning of this sentence will fully appreciate the importance of beating in the pulping process. In the actual production process, the inspectors often overlook the factor that the pulping has a very large influence on the finished product quality.

The degree of beating can also be referred to as the degree of decompression. It is an important indicator of the ease of comprehensive filtration of slurry. In simple terms, the greater the degree of compromise, the easier it is to filter water; the smaller the degree of resolution, the more difficult it is to filter water. Or it can be understood as: the degree of decompression is inversely proportional to the speed of pulp suspension filtration.

The current domestic implementation standards for the deterrence degree meter are: GB/T3332-2004 Slurry freeness determination method (Shobel-Rygler method).

Correctly testing the degree of pulp release requires an understanding of the testing process. The process is as follows: 2 grams of dry pulp to be tested is fully diluted to 1000 ml. After uniformly stirring, pour it into a filter bucket of a degrading instrument and allow the diluted slurry to pass through a standard 100-mesh copper net. The amount of water discharged from the side flow pipe that has been filtered for a specified period of time is represented by the scale of the dedicated graduated cylinder.

Take the QZ-SDJ Beating Degree Tester as an example, a qualified knockout meter should satisfy several basic technical parameters:

1. Measurement range: 0--100° SR (Shorber degree).

2. The rising speed of the sealing cone is: 100±10mm/s.

3. Flow rate of the bottom hole: Take out the umbrella frame, close the hole of the side flow tube with a stopper, block the bottom hole with your finger, pour 20±0.5OC of distilled water into the separation chamber, and record the drainage time of the bottom hole. This time should be 149±1s.

4. Remaining volume: Block the bottom hole with your finger and pour 20 mL of distilled water of 20±0.5OC into the separation chamber. After the excess water is completely drained from the lateral flow tube, let go of the bottom hole and collect the water from the separation chamber. stand up. The volume of this water should be between 7.5 and 8.0 mL.

Under the premise of meeting the above basic parameters, we should also pay attention to the following issues during the use of the QZ-SDJ freeness tester. The first is the mastery of sample and water temperature. Different temperatures have a great influence on water filtration. It is also necessary to pay attention to the internal cleaning of the instrument. Regularly check whether there is fiber precipitation in the filter bucket, separation chamber, copper mesh and other components. If any precipitation must be cleaned in time, we recommend using acetone with a soft brush for cleaning. But can not destroy the copper network. Blank test can be done with distilled water after washing to check the cleaning effect. If the blank test exceeds 4°SR, the copper mesh should be replaced in time.

Knowing the principle of mitigation and the precautions in the process of use, we can correctly test the degree of pulp release by using the QZ-SDJ freeness tester.

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