Power conduit caps, also known as internal stoppers or plugs for power conduits, are widely used, easy to install, and commonly found in everyday life.

Power conduit caps in hot solvents can be attacked and dissolved by some thermoplastic plastics, such as polyethylene dissolving in xylene. Thermosetting plastics cannot be dissolved in solvents. As a source of rapid industry development, the plastic bottle cap industry holds great potential. For high-quality products like power conduit plugs and inserts, when using solid powder or granular additives, they must be ground on a three-roll mill equipped with plasticizers and plastic valve caps.