Dry Manufacturing Process For Pre-insulated Bushings: Technical Analysis And The Trend Towards Silicone-free Production.

In existing high-voltage power equipment assembly processes, the evolution of solid insulation technology is changing the manufacturing logic of components. When selecting a pre insulated sleeve, many technicians will focus on the stability of its internal media. Traditional oil-filled designs are gradually being replaced by more streamlined structures; this shift stems from breakthroughs in materials science regarding electrical stress control.

Interface Treatment in Pre-insulated Sleeve Molding

This new manufacturing method primarily relies on epoxy resin casting in a high-vacuum environment. During the manufacturing process, the inner shielding layer of pre insulated junction sleeve achieves molecular-level bonding with the insulating layer. This physical fusion eliminates air gaps, making the electric field distribution, which previously required liquid dielectric assistance, more uniform.

Chemical Crosslinking Process of Solid Insulation Materials

By precisely controlling the heating and curing cycle, the capacitor screen spacing inside the pre-insulated sleeve is permanently fixed. This structure no longer relies on any fluid flow or pressure maintenance, but instead relies on a highly crosslinked solid insulator to bear voltage.

• Reaction Temperature Monitoring: An automated temperature control system tracks the resin's exothermic curve in real time.

• Vacuum pressure gradient: Injection molding is completed under negative pressure, eliminating all microbubbles.

• Mold coating technology: Special release agents are used instead of traditional lubricating media, reducing chemical interference.

Dry evolution of the internal structure of the pre-insulated sleeve

Eliminating the liquid filler layer means streamlining the production line. Technicians directly utilize highly elastic composite materials for prefabrication, ensuring that the insulated joint sleeve has complete electrical insulation strength before leaving the factory. This dry design exhibits extremely high mechanical precision during assembly.

This process path not only shortens the static placement testing cycle but also fundamentally improves the overall protection level of the component. Currently, most high-end production lines have completed the transition to this clean process.