ZB-COBB125Paper surface absorption weight tester

Surface water absorption of paper and cardboard（Cobb）Value: The mass of water absorbed per unit area of paper and cardboard surface within a specified time under certain conditions, measured in grams/Square meters（g/m²) represents.

Operating procedures:

1、Preparation of test samplesCut the sample into pieces125mmSquare or diameter125mmCircular test piece10Zhang (front and back respectively)5Zhang), to ensure each one100 cmThe experimental area of square meters.

2、Place the sampleBefore placing the sample, ensure that the cylindrical surface in contact with the sample is dry. Accurately measure with a measuring cylinder100mLPour distilled water into the cylinder, then place the weighed circular test piece on the circular surface of the cylinder, with the tested surface facing downwards in the direction of water. Cover the sample with a pressure cap to secure it to the cylinder, and tighten it with a compression nut. Gently pull out the spring cylinder pin, shake the handle to flip the cylinder over180When you hear the "click" sound of the spring cylinder pin inserted into the positioning hole,The stopwatch starts automatically timing.

3、Water absorption timeThe water absorption time refers to the time from the contact between water and the sample to the end of water absorption. This time can be selected based on the different water absorption properties of paper and cardboard, and is consistent with the following table. If necessary, the time can be extended or shortened, but it should be noted in the test report. When hearing the buzzer beep (after the end of water absorption)10～15sGently pull out the spring cylinder pin again and shake the handle to flip the cylinder over180Turn the cylinder upright.

Recommended Reference Table

4、paperweightNow place a piece of absorbent paper on the instrument table, remove the sample from the cylinder, place it on the absorbent paper, and make sure that the absorbent side of the sample is facing downwards before reaching the absorbent time2sThen, place two sheets of absorbent paper on top of the sample and use a smooth roller on a flat and hard surface of the instrument4sPress the sample back and forth once to make the surface of the sample shiny without water. Quickly take out the sample and weigh it accurately0.001gPlease note that each sample can only be tested once and cannot be reused. Absorbent paper can be reused multiple times as long as its absorbency is guaranteed.

5、Discard the sampleIf there is still excess water on the surface after absorbing water with absorbent paper or if the sample itself has been penetrated by water, the sample should be discarded. If abandoned beyond20%At this time, the test time should be shortened until satisfactory results are obtained, but the shortest test time is10s.

6、add water: Every measurement5Next, add a certain amount of water based on the water absorption capacity of the paper.

Test results and reports

1.Test results

1The experimental results are calculated according to the following formulag/m² represents, accurate to one decimal place.

C=（G2-G1）×100

Where:C- Cobb water absorption value

G2Weigh the sample mass after absorbing water,g

G1- Weigh the sample mass before absorbing water,g

2Calculate the average water absorption value of each test surface and calculate the standard deviation.

3Using standard symbols, such as: int℃'sCobb60.

2.Test Report

1The standard number on which the experiment is based;

2The water absorption time and temperature used in the experiment;

3The average, standard deviation, or coefficient of variation of the results obtained from the experiment;

4Number of abandoned samples and reasons for abandonment.