Reasons for Uneven Surfaces of Cured Silicone Adhesives, and Ways to Avoid and Resolve Them (3)-IOTA

Reasons for Uneven Surfaces of Cured Silicone Adhesives, and Ways to Avoid and Resolve Them (3)

Hits: 738 img

Adjust Thixotropy: Improve the thixotropy of silicone adhesives by adding appropriate thixotropic agents, such as fumed silica. The thixotropic agent can form a three - dimensional network structure in the adhesive. When subjected to shear force, the network structure is disrupted, reducing the viscosity and allowing the adhesive to flow smoothly. After the shear force disappears, the network structure gradually recovers to prevent the adhesive from sagging. Reasonably controlling the addition amount and dispersion degree of the thixotropic agent can ensure the good stability and uniformity of the adhesive during the glue - applying and curing processes.
Control Volatile Components: Minimize the content of volatile components in the adhesive. Select solvents and additives with low or no volatility. If raw materials containing volatile components must be used, optimize the curing process to ensure that the volatile components can volatilize evenly during the curing process and avoid the formation of pores. For example, a step - by - step curing method can be adopted. First, let the volatile components volatilize slowly at a lower temperature, and then raise the temperature for complete curing.

Select the Appropriate Glue - applying Method: Choose the appropriate glue - applying method according to the shape, size, and production batch of the adhered object. For flat and large - area adhered objects, methods such as scraping or rolling can obtain a relatively uniform adhesive layer thickness. For parts with complex shapes, spraying may be a better choice, but the parameters of the spray gun need to be precisely controlled. In automated production, a robotic glue - applying system can be used to achieve accurate glue - applying paths and uniform glue - applying amounts through programming.
Precisely Control the Glue - applying Amount: Use high - precision metering equipment, such as gear pumps and plunger pumps, to ensure the accuracy and stability of the glue - applying amount. At the same time, combine with a visual inspection system to monitor the glue - applying amount and the thickness of the adhesive layer in real - time. Once any abnormality is detected, adjust it in a timely manner. In addition, fully stir the adhesive before applying it to ensure the uniformity of the adhesive, which also helps to control the consistency of the glue - applying amount.