Then the thickness of 0.9 1* film (in microns) is the gram weight of BOPP film per square meter.
For example, the weight of a 40 micron BOPP film per square meter is 40 * 0.95438+0.
With the gram weight per square meter, you can know the weight of the whole roll of film.
The weight * length * width per square meter is not bad.
Know that the weight per square meter divided by the density is the volume of the film. Divided by the width of the film, it is the cross-sectional area of the rolled film. Since the paper core tube is in the middle of the film, subtracting the paper core tube is a big circle. The diameter of paper core tube is known, but the diameter of rolled film is unknown. This is a math problem in primary school. I'm sure I can work it out.