Insulation medium polyester resin (UP resin)

Low-voltage windings with Voltatex® 4030

Due to its good fl ow behaviour, this impregnating resin provides the right conditions for optimal resin uptake in round-wire windings. The resin thus achieves good penetration with low drip losses. With a short and effective VPI process, the impregnation is ensured.

Traction windings with Voltatex® 4202

This low-emission impregnating resin is environmentally friendly and pioneering in terms of elasticity and resistance. Due to its higher viscosity, the impregnating resin must be preheated to a temperature of 40 °C. This slightly greater input during vacuum pressure impregnation, however, is reasonable especially for traction motors that are exposed to all kinds of environmental influences, for instance if used as underfloor engines.

Wind turbine generators with Damisol® 3340

Large wind turbine generators with a bore diameter of up to 5 metres are impregnated with this polyesterimide resin. With its medium viscosity the impregnating resin is easy to handle and offers a good ratio of resin application and impregnation.

High-voltage windings with Damisol® 3309

This polyesterimide resin is part of the insulation system Samicabond® by Von Roll and meets the requirements of thermal class 180 (H). Both storage and impregnation can be performed at room temperature. To further improve the flow properties of the impregnating agent, the windings are preheated. Thus, even thicker insulation sleeves will be thoroughly impregnated. Due to its comparatively simple handling, this impregnating resin is in great demand. Despite the slightly poorer electrical properties as compared to the epoxy resin system, all electrical characteristics of the applicable standards are met. With this impregnating resin rated voltages up to 13.8 kV can be reliably handled.

Technical parameters for the use of impregnating agents

Impregnating agent / VPI system Container dimensions (base) Filling level impregnating agent
Voltatex® 4030 0,8 m × 1,4 m 0,7 m
Voltatex® 4202 1,0 m × 1,1 m 0,9 m
Damisol® 3340 Ø 5,0 m approx. 1,5 m
Damisol® 3309 Ø 4,3 m
(rings 3,9 m)
approx. 2,5 m (max.
3,3 m)
Epoxy resin EPR 162 approx. 2,7 m × 4,2 m approx. 2,4 m

Current-UV insulation

Current-UV impregnation is an innovative dipping process for low-voltage round-wire windings. In this process a low DC voltage is applied to the winding. The current flow effectively generates the required process heat. Upon submerging the preheated winding, the viscosity of the impregnating agent decreases. The agent can now penetrate into the smallest cavities. With continuous heating the impregnating resin forms a gel at the hot conductors of the winding. After the submersion the resin can drain off at the cooler laminated core.

Compared to vacuum impregnation, a higher filling level is achieved in this process. Especially when processing larger quantities, current-UV impregnation can replace the entire vacuum process, including oven drying.  The current-UV process is automatically controlled until the curing of the impregnating agent is completed.

The winding is heated and dried using electric current. UV-lamps cure the light-sensitive resin on the laminated core.

Without the need for conventional oven drying, energy and time savings are achieved. In combination with the use of a low-emission impregnating agent the environmental impact is reduced.

technical data

  • Diameter of the object to be insulated max. 900 mm
  • Submersion depth (height of insulation medium) max. 1.000 mm
  • Capacity of the loading station 1 × 500 kg zzgl. 2 × 100 kg
  • System power (per station) 100 kW (max. 100 V / 1.000 A)