There are four common problems in the construction process of silicone structural adhesive: 1. Poor bonding; 2. Slow curing; 3. Insufficient bonding width of the structural adhesive; 4. There are bubbles and cavities in the structural adhesive. Today we will continue to introduce in detail how to avoid uneven mixing of the two-component silicone structural adhesive?

　　Two-component silicone structural adhesive is composed of the main agent A component (white glue) and the curing agent B component (black glue). It is used after being mixed evenly by a two-component glue machine according to the ratio recommended by the manufacturer. The mixed structural adhesive is cured for a period of time, and finally good bonding performance and physical properties are obtained. However, if the structural adhesive is mixed unevenly and used, the curing of the structural adhesive will cause quality problems.

　　The structural glue is not uniformly mixed, how to tell? The structural glue is not uniformly mixed, and white streaks will appear locally. It is easier to observe when the light is brighter. In the case of uneven mixing and uniform mixing, what problems will occur if the structural adhesive is not uniformly mixed? The strength of the structural adhesive after curing will decrease, the curing and crosslinking will be incomplete, and it will become sticky in severe cases and cannot be cured.

　　What are the reasons for the uneven mixing of structural adhesives? How to solve them? The structural adhesives with uneven mixing have the following four situations and the reasons are as follows

　　①　Continuous flower glue: Generally, the mixer is blocked, the mixer is incorrectly assembled, or the mixing unit used is not enough;

　　②　Intermittent and regular flower glue: related to systemic failures, such as leaking of the proportioning pump seal or wear of the proportioning frame;

　　③　Intermittent and irregular flower glue: related to failures, such as filter clogging/needle valve clogging/pressure plate failure/proportioning pump inlet clogging or sealing failure/safety valve and high-pressure ball valve failure, etc.;

　　④　When the gun is fired again after a short pause, a section of flower glue appears at the beginning: mainly because the glue viscosity is not ideally matched, and the system pipeline needs to be adjusted or the working pressure is reduced.

　　The above four situations where flower glue appears are all solved by troubleshooting the glue dispenser.

　　How to avoid uneven mixing of structural glue?

　　The glue dispenser should be maintained regularly to ensure that the glue dispenser can work normally. A butterfly test must be done before each startup to ensure that the structural glue is evenly mixed. The method of the butterfly test is as follows: squeeze the mixed glue from the glue maker into the middle of the paper for 5-10 grams, fold the paper to flatten the glue. Open the paper to check the glue sample. The uniformly mixed glue should have no different-colored stripes. If the glue has different-colored stripes, it means that the glue is not uniform. You should find the cause and use it after the problem is solved. To

　　The problem of uneven mixing of structural adhesives has a great relationship with the glue dispenser, which will seriously affect the curing of structural adhesives and the strength after curing, and endanger the safe application of structural adhesives. It is hoped that the customer will ensure that the glue mixing machine is normal and use the structural glue during the glue application process.