Applications
Insulation Parts and Materials for Transformers
Insulation materials and stamped parts for oil-filled transformers, dry-type transformers, instrument transformers and reactors, tailored to any size.
Oil-filled transformers
In an oil-filled transformer, cellulose and oil form the insulation system together. Pressboard absorbs the oil completely, withstands high electrical field strength and is mechanically strong. That is why winding cylinders, separator layers, spacers and covers are mostly made from it. Rigid barriers and support strips use pressboard sheets from 1.0 to 6.0 mm, and where an additional barrier layer is required, pressboard laminate and pressboard film.
Between the winding layers sits Diamond Dotted Paper. The diamond-pattern epoxy bonds the layers during curing and makes the winding short-circuit proof without blocking oil uptake. For higher operating temperatures we supply DDP TU with a thermally upgraded base paper, along with other printed insulating papers.
Dry-type transformers
Dry-type transformers operate without oil. The insulation materials have to carry the thermal class on their own and are impregnated or cast in resin. Typical choices are polyester film, DMD laminate for class F and NPN laminate for higher demands.
On coil edges, bends and end faces, fringed tapes follow the radius without creasing and replace cutting by hand.
Instrument transformers, reactors and inductive coils
Beyond distribution and power transformers we supply further applications in the transformer and high-voltage sector: gas-insulated instrument transformers (GIS), cast resin instrument transformers (CIS), reactors and inductive coils.
For instrument transformers we also use Diamond Dotted Film. The principle is the same as with DDP, but the carrier is an insulating film instead of paper.
Sizes from control units to power transformers
The range in transformer building is wide. Small control and printed circuit transformers need fine parts in high volumes, power transformers need individual, very large cut sheets. Our machine park covers both: large format stampings up to 1,000 x 2,000 mm on one side, precise solid steel tools for small series parts on the other.
We convert web materials on six slitting lines from 23 to 2,000 micrometres, from 4 mm strip width at a tolerance of plus minus 0.1 mm.
Manufacturing at Hauler & Hermann
Stamping runs on eccentric presses with tools from our own tool shop. We use steel rule dies for samples and large area parts at moderate quantities, and solid steel tools for tight tolerances and repeat series. Cut parts are supplied in large formats, stacked and packed on request.
Production is certified to DIN EN ISO 9001 and DIN EN ISO 14001. Samples are available from a quantity of one.
Do you have an application in mind?
Describe your installation situation and we will check feasibility.
Matching Products
Pressboard for Transformers and Electric Motors
Pressboard is a natural product made from cellulose fibres and has been used in transformer and motor construction for many years.
Learn more →
Pressboard Sheets for Transformer Construction
Pressboard sheets are rigid cellulose boards from 1.0 to 6.0 mm thick, used above all in transformer construction.
Learn more →
Diamond Dotted Paper (DDP) for Transformer Windings
Diamond Dotted Paper is insulating paper with a diamond-pattern epoxy resin coating that bonds the winding layers of a transformer together during curing.
Learn more →
Pressboard PET Pressboard Laminate
This three-layer laminate consists of polyester film with pressboard on both sides.
Learn more →
Fringed Insulation Tapes for Radii and End Windings
Fringed tapes are insulation strips with notched edges that lie flat around radii and curved surfaces.
Learn more →
Cut Parts and Cover Strips
Cut parts, often used as cover strips in the slot, are among our standard tasks.
Learn more →Matching Processes
More Application Areas
Motor Construction
Custom insulation parts for over 60 years in special machinery, power tools, ventilation, conveyor, rail, aircraft and marine technology.
Learn more →
Wind Power
Insulation parts for onshore and offshore wind generators, process-reliable even for the largest generators on the market.
Learn more →
Electronics and Lighting
Flexible insulation with excellent electrical properties, Kapton for fuel cell stacks, batteries and chips.
Learn more →Frequently Asked Questions About Insulation for Transformers
Which materials do you supply for oil-filled transformers?
Pressboard, pressboard sheets, pressboard laminate and pressboard film, plus DDP and DDP TU for layer insulation and other printed insulating papers.
And for dry-type transformers?
Mainly polyester film, DMD laminate and NPN laminate, depending on the thermal class. Fringed tapes are added for radii and coil edges.
What is Diamond Dotted Paper?
Insulating paper with a diamond-pattern epoxy coating. During curing the resin bonds the winding layers and makes the winding short-circuit proof, while oil can penetrate freely between the diamonds.
How large can cut sheets and stampings be?
We produce large format stampings up to 1,000 x 2,000 mm. Cut sheets are produced roll to sheet, stacked and packed on request.
Do you produce small quantities?
Yes. Samples and prototypes from a quantity of one, and steel rule dies keep small series economical.