WEE Technology Company Limited - WEE are Capacitors Specialist

Differences between Aluminum Foil and Film Metallized Polypropylene Capacitors (two kinds of materials)and Single Metallized Film Capacitors (single layer material)? WEET WMH Aluminum Foil and Film Metallized Polypropylene Capacitors is a good example to compare with WEET WMF, WME series.

We call "Aluminum Foil and Film Metallized Polypropylene Capacitors "as Film/Foil Capacitors for short in below reference.

Size Difference, WEET WMH Film/Foil Capacitors are larger than Single Metallized Film Capacitors. 

WEET WMH Film/Foil capacitors consist of two plates of aluminum foil, which act as the electrodes, separated by a Metallized Film, which used as the dielectric. These materials are non-inductively wound to form the capacitor section. The wire leads are welded directly to the aluminum foil which extends out on both sides of the capacitor section, hence the term extended foil design 

In order to provide the utmost in dependability a sufficient thickness of dielectric film is essential. This construction criteria is the primary reason why the physical dimensions of Film/Foil capacitors are larger than that of the single metallized types.

In contrast to the WEET WMH Film/Foil capacitor, where the electrode is an independent layer of aluminum foil, the electrode for the metallized film capacitor is an extremely thin layer of metal which is vacuum-deposited directly onto the dielectric film. The wire lead is connected to the electrodes by means of a metal spray applied to each end of the capacitor section; the lead wire is welded to this metal end spray 

Metallized film capacitors are manufactured using a thinner dielectric film than that which is used in the same rated Film/Foil design.

This is possible due to the self-healing characteristics of the metallized film. Self-healing, or clearing, removes a fault or short circuit in the dielectric film by vaporizing the metal electrode surrounding the defect and isolating the area.