SAVER has the know-how and the necessary experience to produce both Dry Filament Winding (polyester, glass, aramid) vacuum-impregnated tubes and Dry Fabric Winding (glass, aramid, hybrid) vacuum impregnated tubes.

Inside of complex electrical apparatuses, designed for voltage ranges between 72,5 and 1000 kV (high and very high voltage), is very often necessary to use composite materials vacuum-impregnated. In particular, considering Saver’s range of products, for some applications in HV apparatuses vacuum-impregnated tubes are often preferred to traditional wet winding tubes.
The technology of vacuum-impregnation, compared to the traditional wet one, is able to completely eliminate the presence of micro vacuoles of air inside the composite materials and to optimize the adhesion in depth between reinforced fibres (or fabric) and the matrix (the resin system formulation) obtaining as a consequence the best electrical characteristics technically feasible.

The process is based on a dry winding of long fibres (glass, polyester and / or aramid) or fabric on metallic mandrels specifically designed.

Therefore, in  the case of winding of fibres - like for traditional wet winding - the design of the tube is very flexible. The winding angle can be chosen for each layer of the winding process, in order to give the composite materials specific mechanical characteristic requested by the customer depending on the final application.
After the dry winding, the semi-finished product is impregnated with an epoxy based resin system in vacuum conditions. This makes the resin completely dip the fibres (or the fabric), eliminating by definition any presence of air inside the product. The subsequent operation of thermal polymerization brings the composite materials in a stable and irreversible phase, giving drastically increased electrical and mechanical characteristics.
After this phase, the necessary machining, the possible bonding to metal flanges and varnishing can be done…
Usually metal flanges are designed to assemble the vacuum-impregnated tube inside the electrical apparatus like circuit breakers, disconnectors etc.…