Roll Processing in the µm Range

We Deliver Perfection for the Most Demanding Requirements

Using sophisticated electroplating processes, CNC-controlled machines and specialists with many years of experience, we machine rolls with the highest precision in terms of concentricity, cylindricity and surface quality.

We achieve the right surface structure and geometry for every application – from high-gloss, transparent or matt films to stringent requirements for release properties, durability and reproducible process quality.

From our perspective, simply precise is not precise enough.

Using CNC control, we grind rolls with face lengths of up to 10,000 millimetres to within 2 µm cylindricity and concentricity.

A hair is approximately 70 µm thick and therefore far too coarse to serve as a benchmark for us.

Coating

With chrome and nickel

Chrome Plating

Hard. Low Friction. Durable.

  • Chrome plating of rolls with a diameter of up to 2,000 mm, a length of up to 6,000 mm and a weight of up to 20,000 kg
  • Hard chrome plating in vertical tanks
  • Any required layer thickness can be provided
  • Degassing is possible

Because surface hardness is important, we specialise in hard chrome plating. Our chrome layers have a hardness of approx. 65 HRC. We have a total of seven vertical tanks for different-sized rolls.

All tanks are supplied with computer-controlled rectifiers as a power source. The modern rectifiers vary the current in intensity (pulse mode) and direction (reverse mode), which guarantees a denser crystal structure and ensures exact reproducibility.

With our special chrome plating technology, we not only produce any required layer thickness with the best possible microstructure quality but also provide high-quality electrolytic matting. Modern cooling equipment keeps the electrolyte temperature permanently at the optimum level. If required, we can degas the roll: a process where the hydrogen absorbed during chrome plating is driven out of the roll by controlled heat treatment.

Nickel Plating

Corrosion-resistant. Adherent. Rebuilds worn rolls.

  • Nickel plating of rolls with a diameter of up to 1,000 mm, a length of up to 4,200 mm and a weight of up to 7,000 kg
  • In addition to chrome plating or as an alternative
  • Repair of the roll surface

Nickel plating offers the possibility of repairing rolls that show distinct signs of wear from heavy use in production and over time have fallen below their original diameter.

Depending on the requirements for the roll surface, nickel plating can either be used in addition to chrome plating or as a substitute for it. This is because our nickel plating approaches the hardness of hard chrome plating (approx. 55 HRC). A nickel layer can also be easily applied as a base coat in combination with a chrome top coat without compromising production quality.

Finishing

With a wide range of surface roughness and roll profiles

Grinding

Precise. Ground. Perfect.

  • Precise grinding of rolls with a diameter of up to 3,500 mm, a length of up to 10,000 mm and a weight of up to 40,000 kg
  • Grinding at operating temperature
  • CNC technology provides any required roll face profile
Our grinding machines can achieve the highest possible precision for different types of rolls. We even process particularly large rolls with diameters of up to 3,500 millimetres and grinding lengths of up to 10,000 millimetres. For example, we are able to grind a calender roll weighing 25,000 kg and measuring Ø 1,000 × 5,000 mm face length to an axis parallelism of less than 1 µm.

Seven grinding machines with traversing grinding saddles are currently in use, while six further grinding machines with travelling workpieces are used for smaller rolls. All are equipped with a modern CNC control system. This means that any deviation from the target profile can be limited to 1 µm. The grinding result, run-out and concentricity are measured and documented electronically.

Notably, we also grind rolls at operating temperature, i.e. at the same temperature the customer runs them at in production. With the help of powerful heating systems, we can grind at all temperatures between 20 °C and 220 °C. As with cold grinding, the profile error can be limited to 1 µm.

We also grind and polish hard-coated rolls to the required surface roughness and roll profiles. Depending on customer requirements, we process these rolls at ambient temperature or at higher operating temperatures of up to 220 °C.

Finish

Matt. Polished. High gloss.

  • Polishing for glossy surfaces
  • Matt finish for matt surfaces
  • Combination of polishing and matting is possible
The final step of processing, known as finishing, consists of two main areas: polishing and matting. This treatment is largely responsible for the properties and appearance of the surface.

The finish is used to create the roughness of the roll surface. We offer matting in a range of up to Rz 50 µm – higher on request. For polishing, we offer a range from simple industrial polishing to an absolute mirror finish down to Rz 0.05 µm.

Machining

Maintenance and repair of rolls

Service

Refurbished. Checked. Ready for operation.

  • Repair and maintenance
  • Restoration of journal contours
Our mechanical workshop is very well equipped for a wide range of maintenance and repair work on your rolls and other cylindrical workpieces. We ensure that repairs are carried out quickly and smoothly so that you can continue to produce at a high level.

Our services include, for example, replacing the plugs of peripherally drilled calender rolls, regardless of the design principle. We then pressure-test the roll for leaks at ambient temperature or at working temperature.

We can rebuild and/or modify the journal contour of your roll.

 

Here is an overview:

  • Flushing and cleaning the inside of the rolls
  • Plug replacement and resealing of calender rolls
  • Journal repair
  • Service and maintenance of the roll