rcfere.blogg.se - Ithoughts how to keep certain bubbles closed

Perform routine checks on your applicator system to make sure that all seals/gaskets are functioning properly with no potential for moisture contaminated air to seep into the system.Please ensure that splashing, especially with low viscosity encapsulants, is minimized or eliminated altogether to prevent turbulence in the liquid from creating bubbles.Small bubbles will most assuredly form if the prepolymer is not degassed properly or the finished product is not degassed sufficiently prior to filling and/or pouring during application.Insufficient degassing of encapsulant during manufacturing and filling.This typically results in surface bubbles. Also, if water-based mold-release agents are improperly applied, a resultant can be moisture contamination of the encapsulant. In high-humidity environments, condensation will form if the mold is cooled but not reheated afterward. Molds insufficiently annealed (above the boiling point of water) may experience surface moisture or condensation.Note: moisture contamination originating in either the adhesive or primer produces small bubbles visible only at the bond line. CO 2 vapor manifests itself within the encapsulant as a bubble.

Moisture reacts with the isocyanate in a polymer, which then produces carbon dioxide.

Moisture can come from many sources, such as the prepolymer, catalyst, adhesive or primer.

Moisture contamination in some coating can cause bubbling.

This blog focuses on “bubbles” forming within the encapsulant itself. While potting materials provide many positive attributes when used to protect PCBs, sometimes other issues arise during and post application of these compounds. Encapsulant solutions are commonly used to enhance protection of circuit boards from environmental and liquid contaminants, chemical attack, and electrical shortages.