А1:
u is the meaning of um, which means micron, also called silk 52U, 52U tape is the thickness of the film and glue together, which is 52 microns.
How to identify the quality of the sealing tape
- In fact, there are two standards for distinguishing the quality of the sealing tape, one is the initial adhesion force, and the other is the retention force, and the two are inversely proportional.
- Generally speaking, tapes with an initial adhesion lower than No. 10 have less glue coating, generally only about 20 microns, such as stationery tapes, and tapes for ordinary promotional binding. The initial bonding force of normal sealing tape is between No. 15-20, and the thickness of this tape glue generally has 22-28 micron. This is the standard thickness.
- At present, most of the tapes on the market are mixed with impurities, so the thickness increases. In order to cover the impurities, the glue is also mixed with toner, so the scotch tape appears egg yellow and light green. This kind of tape is generally inferior.