There are also precautions to take when using polyurethane adhesives

1. What treatments need to be done on the bonding surface before using Polyurethane Adhesive?

 

Surface treatment is the crucial first step to ensure the bonding effect. First of all, it is necessary to thoroughly remove impurities such as grease, dust, moisture and rust from the surfaces to be bonded to ensure they are clean and dry. For surfaces of metals, plastics, etc., it is recommended to use sandpaper for moderate grinding to increase the surface roughness, thereby enhancing the mechanical bite force of the adhesive. After processing, it is best to wipe it with a cleaning agent (such as acetone) and let it completely evaporate and dry. Only in this way can the best wetting and adhesion basis be provided for the adhesive.

 

2. When preparing and using adhesives, what operational details need special attention?

 

For two-component polyurethane adhesives, weighing and mixing must be carried out strictly in accordance with the proportion specified in the product manual. Proportion deviation will seriously affect the final curing performance and strength. When mixing, stir thoroughly and evenly, and pay attention to stirring in one direction to reduce the entrainment of air bubbles. The mixed adhesive solution should be used up within the "pot life" (i.e., the time when the adhesive solution remains in a usable state), otherwise it will thicken or even cure and fail due to excessive reaction. When applying the glue, it should also be done evenly to avoid any area being too thick or too thin.

 

3. What environmental factors need to be controlled during the curing process?

 

Temperature and humidity are two core factors. Most polyurethane adhesives require a certain temperature (such as room temperature above 25℃) to fully cure. Low temperatures can significantly slow down the curing speed or even prevent curing at all. Meanwhile, polyurethane adhesive is sensitive to moisture. Excessive environmental humidity may cause carbon dioxide bubbles to form during the curing of the adhesive layer, affecting the bonding strength and appearance. Therefore, the curing process should be carried out under well-ventilated, dry and warm conditions, and appropriate pressure should be applied to the bonded parts to ensure close contact of the adhesive layer, expel air and achieve the best performance.