Quantitative weight of paper and paperboard refers to the mass of paper and paperboard per square meter, in g/m². Every kind of paper and board has certain quantitative standards. The physical properties of paper and cardboard, such as tensile strength, bursting strength, tear strength, etc., are all related to quantitative.
(1) Test equipment
Quantitative testing instruments include electronic balances and quadrant scales with a sensitivity of 0.01g. Before the test, it is necessary to calibrate the instrument used to check the error between the standard value of the weight and the reading of the instrument. The difference should be within ±0.5%. When the mass changes by 0.2%, the electronic balance should respond.
(2) Test method
Before the test, samples should be taken according to the national standard GB450, and the temperature and humidity pretreatment . Test according to the national standard GB451.2 "Determination of Quantitative Paper and Cardboard". Cut a 100mm×100mm sample from the paper sample, and the dimensional accuracy is 0.1mm. It can also cut 250mm×200mm samples, and the dimensional accuracy is 0.5mm. Calculate the area of the sample and take out the sample for weighing. If the paper sample is a coil paper with a width of less than 100mm, five samples with a length of 300mm should be cut according to the full width of the reel and weighed together. At the same time, the long side and short side of the sample should be measured. The long side accuracy is 0.5mm, The accuracy of the short side is 0.1mm, and then calculate the area.
(3) calculation
① Quantification of paper and cardboard
G=M/A=M/na
In the formula, G——quantitative, g/m²
M—mass of sample stack, g
A - the area of the sample stack, m²
a——area of each sample, m²
n - the number of layers of each stack of samples.
