No shrinkage in the vapour phase drying

NEW: Shield end rings and shield rings made from glass fibre reinforced plastic

Haren, Germany – Röchling opens up new areas of transformer construction: The processor of plastics is the first manufacturer of shield end rings and shield rings for oil-filled power transformers made from glass fibre reinforced resin-based materials. The rings offered under the brand name Durostone® EPX-M do not exhibit any shrinkage after the vapour phase drying and so allow designers to calculate the dimensioning with precise tolerances.

The rings are manufactured in a special winding process and consist of a glass fibre reinforcement and a resin matrix on the basis of epoxy resins. As a glass fibre reinforced high-performance plastic Durostone® EPX-M combines a high dimensional stability with an extreme strength, even at high operating temperatures.

No shrinkage in the vapour phase drying

Classic materials such as pressboard or laminated densified wood shrink during drying in the vapour phase kiln. This shrinkage must be taken into account beforehand in the dimensioning of the components for the transformers. Thanks to the high dimensional stability components produced from Durostone® EPX-M retain their original dimensions. This simplifies things for the designers in the design and calculation of the height of the wound coil in the transformer, as safe values can be expected.

Lower wall thicknesses possible

With the insulating class H (180 °C) Durostone® EPX-M has an excellent compressive strength even at high temperatures. Also the production of Durostone® EPX-M shield end rings and shield rings in lower wall thickness is possible, since even for very thin wall thickness the material has very high strength.

Very high homogeneous strength

Röchling is initially manufacturing shield end rings and shield rings from Durostone® EPX-M as a blank in one piece. In this way the components have a very high homogeneous strength. The exact processing is carried out by modern CNC machines according to customer's preliminary drawings. So weak points in segment transitions are excluded, as they can occur for rings, which have to be made up of several segments.

Almost a century of experience

With the first-time production of rings from Durostone® EPX-M glass-fibre reinforced material Röchling extends the comprehensive range of construction and insulation components offered for use in oil-filled power transformers.

Röchling has exceptional know-how in the manufacture of composites. For nearly a century the plastics processor has produced the high-performance materials Lignostone® Transformerwood® and manufactured sheets and machined components, such as shield end rings, shield rings, pressure rings, pressure beams and connecting elements from it. With Trafoboard® since 2010 Röchling has also offered an insulating material from high-quality laminated pressboard for the most demanding of electrical properties.

With the production of rings from Durostone® EPX-M Röchling has once more demonstrated its application-oriented competence for transformer construction.

Nearly five decades of know-how

Under the brand name of Durostone® for nearly five decades Röchling has been producing fibre-reinforced plastics. Durostone® enjoys an excellent reputation in a wide range of sectors, for example in the electronics industry, in generator and transformer construction, in the construction of chemical apparatus, in switchgear, as well as in transport technology and thermal insulation.

Manufacturing programme:

  • Diameter:    up to 3,500 mm
  • Height:    up to 1,600 mm
  • Wall thicknesses:    15 - 500 mm

Other dimensions on request
CNC processing according to customer drawings