In today’s advanced manufacturing sectors—particularly in electronics, power systems, new energy, rail transit, and aerospace—components are required to deliver unprecedented levels of reliability, electrical insulation, and environmental resilience. Against this backdrop, vacuum casting has emerged as a leading encapsulation and molding technology, increasingly adopted by forward-thinking enterprises worldwide. But why choose vacuum casting? What core value does it bring to your products?
1. What Is Vacuum Casting?
Vacuum casting is an advanced manufacturing process in which liquid resin (such as epoxy or polyurethane) is injected into a mold and cured under a vacuum environment. By evacuating air and volatile gases, the process ensures complete filling of even the most intricate geometries while minimizing internal voids, bubbles, and impurities.
2. Key Advantages of Vacuum Casting
1) Eliminates Bubbles Completely, Enhancing Density and Structural Integrity
During conventional atmospheric casting, air can easily become entrapped in the flowing resin, forming microscopic bubbles. These not only compromise aesthetics but also act as stress concentrators or weak points under electrical or mechanical loads.
Vacuum casting removes trapped gases through negative pressure, allowing the resin to uniformly infiltrate every cavity. This significantly improves part density and structural integrity—making it ideal for high-voltage insulation components such as current/voltage transformers, insulators, and transformer windings.
2) Superior Electrical Insulation Performance
Air gaps are a primary cause of partial discharge (PD). In high-voltage equipment, even micrometer-scale voids can trigger insulation breakdown.
By virtually eliminating internal defects, vacuum casting dramatically enhances dielectric strength and long-term operational stability, helping products meet stringent international safety standards such as IEC and UL.
3) Exceptional Environmental Protection
Vacuum-cast components are fully sealed, offering robust resistance against:
- Humidity, salt spray, and dust
- Chemical corrosion (e.g., acids, alkalis, oils)
- Mechanical vibration and shock
This ensures reliable performance in demanding environments—including outdoor installations, marine applications, and heavy industrial settings.
4) High-Fidelity Reproduction of Complex Geometries
Under vacuum, resin exhibits improved flow characteristics, enabling perfect replication of fine details, thin walls, and areas around embedded components. This high-precision molding supports integrated design strategies and reduces the need for secondary assembly steps.
5) Improved Consistency and Yield
Automated vacuum casting systems, combined with precise temperature control and material mixing ratios, ensure consistent product quality across batches. This minimizes human error and scrap rates—making the process ideal for high-volume, high-quality production.
3. Typical Applications
- Power Equipment: Dry-type transformers, current/voltage transformers, high-voltage switchgear insulation parts
- New Energy: PV junction boxes, EV electronic control units, battery module potting
- Electronics: Sensors, connectors, LED modules, PCB encapsulation
- Rail Transit: Traction converters, signaling and control modules