The formation of dense small bubbles in the adhesive layer of polyurethane adhesives is mainly related to the excessive water content in the material, which cannot be eliminated and will seriously affect the bonding strength of the material. In order to ensure low moisture content in the polyurethane material, 120-degree negative pressure is generally used for heating and stirring, which can remove part of the moisture in the material. To achieve a stable and bubble-free effect, it is recommended to use molecular sieves. Molecular sieve activation powder has strong hydrophilicity and can evenly spread the polyurethane material. inside, adsorbing the moisture in the material and keeping the material's moisture content low to avoid the formation of bubbles.
#Polyurethane #Adhesive #Bubble #Material #Water content #Negative pressure heating stirring #Molecular sieve #Activation powder #Hydrophilicity #Adsorption #Generation