The Impact of Metallized Film Quality on the Quality of Low-Voltage Parallel Cylindrical Capacitors
Mar 11, 2026| High-quality metallized film is the cornerstone for the safe operation of capacitors. It not only grants the capacitor its most core "self-healing" capability but also determines the capacitance stability and anti-surge performance during use, ultimately manifesting as a longer service life and higher safety. Conversely, low-quality film acts like a hidden "time bomb," potentially leading to premature capacitor failure or even safety accidents.
| Dimension of Impact | Performance of High-Quality Metallized Film | Performance of Low-Quality Metallized Film |
|---|---|---|
| Self-Healing Performance | The film is uniform with minimal defects. It can quickly clear breakdown points within microseconds, achieving reliable self-healing. The capacitor can continue to operate normally with almost no impact on its lifespan. | There are more "electrical weak points" such as impurities and holes. Self-healing may fail, or require more energy to "clear" the breakdown point, potentially damaging the surrounding film. This can lead to cascading breakdowns, ultimately causing capacitor failure. |
| Capacitance Stability | The metal coating is uniform with consistent thickness. After multiple self-healing events, the capacitance decays very slowly, ensuring long-term stable operation and effective reactive power compensation. | The metal layer thickness is uneven, which not only affects current carrying capacity but also leads to uncontrolled loss of evaporated metal area during self-healing. This results in rapid, non-linear capacitance decay. When the capacitance drops below a certain threshold, the capacitor fails. |
| Current Withstand Capability | The metal coating has high purity and a reasonably designed thickness (e.g., thickened edges). It can withstand high current surges, has low contact resistance, minimal temperature rise, and operates stably and reliably. | The coating is too thin or uneven. Under high current or overvoltage surges, the metal electrode is prone to melting, fusing, or shrinking, leading to local current overload. In severe cases, this can cause the capacitor to bulge or even explode. |
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