Reasons for Poor Adhesion of the Silicone Sealant

With the development of the past two decades, silicone sealants dominate the adhesive industry by their excellent weather resistance, wide temperature range, appropriate physical and mechanical strength, and long service life.

Ketone glue is a kind of adhesive, and good adhesion is essential. However, in actual use, the problem of poor bonding occasionally occurs. Next, we will analyze the reasons for the poor bonding of silicone sealants to better avoid and solve the problem of bonding failure of silicone sealants.

1. Is the product selection correct?

Nowadays, silicone sealants have been involved in many fields, and there will be many application points in different application fields. Silicone sealant is divided into acid type glue, alcohol type glue and oxime type glue from the reaction type. Different types of silicone sealants have different chemical systems, and the ways to form bonds are also different. If you want to form a good bond, you must choose a suitable product.

2. Is it a special substrate?

With the rapid development of the material industry, many new materials are widely available. A silicone sealant cannot guarantee good adhesion to all substrates; even if the same substrate, different surface treatments will cause silicon The bonding effects of ketone sealants are different; even the bonding effects of materials from different manufacturers and different batches of the same treatment are quite different. In this context, it is strongly required to conduct adhesion tests before using silicone sealants in order to select suitable products, cleaning agents and primers.

3. Is the primer used correctly?

Before applying the primer, the surface of the substrate should be dry and clean; when using it, a clean, lint-free cotton cloth should be used to apply a thin and even layer of primer on the interface surface. Use a brush for difficult or rough surfaces. Do not pour or excessively use the primer; after use, the silicone sealant should be used after the primer is completely dry.

4. Is the injection full?

Silicone sealant needs to be fully injected at the designed interface, and the width and thickness are both in line with the interface design requirements to achieve the expected performance requirements. At the same time, a spatula is needed to make the glue and the substrate fully contact to form an effective bond. The correct sizing should be uniform and continuous sizing, and then use a spatula to modify within the operating time range. When modifying, force the sealant to make good contact with the surface of the substrate to be bonded.

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