The tape factory shares with you the water resistance and water resistance test methods of the sealing tape

The water resistance of the sealing tape generally refers to the degree of influence of water or water vapor in the environment on the various properties of pressure-sensitive adhesive products. If there is no effect at all or the effect is small, it is considered that the water resistance of the sealing tape is very good or better. If the impact is large or large, it is considered as poor or poor water resistance. The decrease in performance is mainly caused by the absorption of moisture by the sealing tape in the environment of water or water vapor. For example: paper pressure-sensitive adhesive products in the water or high temperature environment because the paper substrate absorbs more water, the strength of the paper substrate is significantly reduced, so that the tensile strength, shear strength, and shear strength of the pressure-sensitive adhesive product The mechanical properties such as peeling strength are significantly reduced, and the substrate even breaks during the test. Other pressure-sensitive adhesive products, especially the sealing tape made of emulsion pressure-sensitive adhesive, will also change the viscosity of various pressure-sensitive adhesives due to the absorption of certain moisture by the pressure-sensitive adhesive layer in water or high humidity environments. , Generally, with the increase of water absorption, the adhesion holding performance decreases, and the initial adhesion and peel strength first increase and then decrease. It can be seen that water resistance is also a very important performance of pressure-sensitive sealing tape.

There are many methods that can be used to study and characterize the water resistance of the sealing tape. The most common method is to directly measure the absorption rate, water permeability and water vapor transmission rate of the sealing tape. In order to study and characterize the water resistance of pressure-sensitive adhesives, it is also possible to determine the water absorption and solubility of pressure-sensitive adhesives, as well as the initial tack, 180° peel strength and holding performance of the sealing tape along with the immersion time in water. Or the change of the storage time in a saturated water vapor environment, and further research and measurement of the pressure-sensitive adhesive products in environments with different relative humidity in the above-mentioned pressure-sensitive adhesive performance difference.

Water absorption is usually measured by gravimetric method. After being immersed in water at a certain temperature or stored in an environment with a certain temperature and relative humidity for a certain period of time, accurately weigh the mass W of the tested sealing tape or pressure-sensitive adhesive sample. If the mass of the sample before the test is W1, the quality of the sample Absorption rate: W-W1/W1*100%, the unit is %.