How Does Polyurethane Perform As Electrical Potting Compound

The key application of electrical potting compounds and adhesive accelerators is in the electrical and electronic industries for encapsulation purposes. The parts to be encapsulated are placed in a potting box in which the potting compound is poured in to cover the components and cures to form a solid finished product. For potting purposes, there are also different materials used but polyurethane is the most common one due to its flexibility and reliability. While it is most often compared to epoxy-based potting compounds, it is quite difficult to actually say one is better than the other because of the broad range of properties they both have.

However, many users find polyurethane electrical potting compound very advantageous due to its many properties. These include good electrical properties, curable even at low temperature, rapid final curing, flexible qualities, low shrinkage, low water absorption and water vapour permeability, chemical resistance, and many more. Prior to potting, the two components of this electrical potting compound, a base resin and an isocyanate curing agent, are mixed together in the right ratios. Once they mixed well, the curing process begins, which gives the final product a homogenous polyurethane quality. The base resin used also contains various catalysts, fillers, and additives to achieve the desired properties.

With a polyurethane electrical potting compound, many potting operations become possible. During the first step, the potting compound is being poured in the box until it encapsulates the electrical components. It will then be left to cure partially or fully until a thin layer of substance is poured over it to avoid any air bubbles from forming while giving it a smoother surface. Once these steps proceed properly, a perfect adhesion will be attained between the two layers of compounds. However, there is one thing that must be avoided during the curing process. That is to perform the potting at the right temperature, not lower than 18°C, to prevent the risk of foaming issues.