1. Appearance: glue on blank paper, fold the glue in half, and observe whether the glue is fine and uniform, with or without mechanical impurities, air bubbles, etc. High-quality glue is generally uniform and fine without mechanical impurities.

2. Gloss ratio: The glossiness of different quality glues is different. The high-quality glue has a strong gloss after curing, no matter the color, some of the low-quality glue has no gloss after being beaten. luster.

3. Check the particles: The high-quality silicone sealant is a chemically synthesized material that has been thoroughly and evenly stirred. The texture is fine and uniform, and it is smooth, smooth and shiny after the sizing is cured. The worse the quality of the silicone sealant, the more particles and impurities can be seen. After the sizing and curing, the surface of the rubber strip is not smoother and smoother than the good quality glue.