Reasons and solutions for foaming of epoxy resin potting glue

The curing of epoxy resin potting glue will produce bubbles to some extent unless the sealing operation is carried out in a vacuum environment. Therefore, in the process of sealing epoxy resin, we only try to reduce the amount of bubbles in the epoxy resin as much as possible to reduce the impact of bubbles on the product caused by the epoxy resin potting glue.

In the actual operation process, besides many reasons such as the formula composition of the manufacturer, moisture removal of raw materials, mixing form, and degree of vacuum, this article only discusses the bubble problem that users will encounter. Even for the best products provided by the best manufacturers, the bubble problem will reappear at the user's location. Several user factors cause bubbles:

1. In winter or at low ambient temperatures, the viscosity of materials is relatively high;

2. The stirring speed is too fast when mixing A/B

3. Quick curing adhesive

4. Summer, high ambient temperature, or excessive amount of disposable mixture can cause the curing rate to be too fast

5. After mixing the adhesive, if it stays for too long during use, the adhesive will lose its low viscosity stage

6. Casting devices with quartz sand or small gaps

How to overcome bubbles:

1. Control the ambient temperature or material and curing temperature to operate the material at the lowest viscosity stage and slow down the curing process

2. Uniform stirring reduces artificial bubbles

3. Two times filling, the primer is filled with high-viscosity materials to 4/5 of the total volume of the product, and then the low-viscosity surface sealant is filled to 1/5 of the total volume to the highest position after the primer gel

4. Manual defoaming in the gel stage (the gel solution has not thickened to the curing stage after 3-6 hours of filling):

(1) Hot air cylinder blown out

(2) Artificial needle puncture

(3) Spray a small amount of solvent (alcohol, acetone) onto the surface of the product, being careful not to spray too much to avoid affecting quality, causing issues such as aging resistance and surface cracking.

5. A/B mixture is vacuum defoaming before and after sealing, but it must be completely removed, as a lax vacuum will cause more bubbles.