Coob type paper surface absorption weight Tester is designed and manufactured according to the requirements of the People's Republic of CHINA industry standard QB/T1668-92 "Paper Surface Absorption Weight Tester".
Paper surface absorption weight measuring instrument is mainly used to measure the quality of water or other liquids absorbed by the surface of sized paper and cardboard, including corrugated cardboard.
It is suitable for the penetration and reflection of water or other liquids on the surface of paper. When measuring, one side of the paper is first in contact with the liquid. After a certain period of time, the increased mass (g/m2) can be measured.
The quality of the liquid absorbed by the paper pattern under the conditions of specified area, specified time, specified amount of liquid, and under specified pressure. Weigh the sample immediately before starting the test. After one side of the sample is in contact with water for a certain period of time, the pressure is dry and then weighed. The result is expressed by the increased mass of the sample, expressed in g/m2.
The instrument is composed of a base, a bracket, a cup body, a cup cover, a column, a horizontal plate, a pressure rod, a rocker arm, a handle and a pressure roller.
The instrument should be placed on a stable horizontal platform at a room temperature of 20±10°C. Adjust the adjustment screw to make the instrument level. At this time, the mouth of the cup should be in the upward position.
Turn the knob to loosen the lid, remove the lid, and pour 100ml of distilled water at a temperature of 20±1°C into the cup. (New water should be replaced for each measurement) Before each test, ensure that the edge of the cup mouth that is in contact with the sample and the rubber pad surface of the end cap are dry. Then put the weighed Φ125mm sample on the mouth of the cup, with the surface to be tested facing the direction of water, put the cup cover on the sample, turn the knob, press the cup cover tightly, and turn the cup body down 180°, the cup body is positioned by itself, and the stopwatch is started at the same time.
If the selected test time (see the table below) is 60s, turn the handle at 45s to return the cup body to its original position, turn the knob immediately, take off the cup cover, take off the sample, and put it on a piece of absorbent paper. The water-absorbing side of the sample is downward, and 2 seconds before reaching the water-absorbing time, put two pieces of water-absorbing paper on the sample, and press it back and forth once within 4 seconds with a smooth roller on a flat and hard table, so that the surface of the sample has no watery luster , Fold the sample with the wet side folded inside to avoid loss of moisture through evaporation. Quickly weigh the sample to an accuracy of 0.001g. Note that each sample can only be tested once and cannot be reused.
The test results are calculated according to the following formula, expressed in g/m2, accurate to one decimal place.
C=(g 2 —g 1 )F
In the formula: C—copper water absorption value;
g2 — mass of sample after water absorption, g;
g 1 — mass of sample before water absorption, g;
F—The test area is 100cm2
testing time
| Recommended test time | mark | Time to remove remaining water s | The time to complete water absorption s |
| 30 | Cobb30 | 20±1 | 30±1 |
| 60 | Cobb60 | 45±1 | 60±2 |
| 120 | Cobb120 | 105±2 | 120±2 |
| 300 | Cobb300 | 285±2 | 300±2 |
| 1800 | Cobb1800 | 1755~1815 | 15±2 after removing the remaining water |