Coatings and paint company Hempel Paints has collaborated with technical design company Noen, in the Czech Republic, on a pro- ject involving the design and manufacture of a new type of bucket-wheel excavator, the KK1300.

The companies worked together to come up with an unusual colour scheme for the machine, which was implemented using Hempel protective coatings.

“The new wheel excavator will not only meet all technical parameters specified by the customer, but it will also have an unconventional modern colour form, unparalleled in the Czech mining industry,” says Noen designer Jaroslav Veverka.

Hempel’s Hempadur 15302, Hempadur Fast Dry 17410 and Hempathane 55610 products were used on the machine.

Hempadur 15302 is an epoxy primer containing zinc phosphate, which cures to provide a strong, rust-preventing coating.

Hempadur Fast Dry 17410 is a high-build epoxy paint containing zinc phosphate, with a rela- tively high-volume solids content that can be used for both shop and on-site application.

Hempathane 55610 is a glossy acrylic polyurethane topcoat that combines maximum protection in severely corrosive environments with speed and gloss retention. It can be coloured any shade, using Hempel’s multitint system.

The coating system for the steel structures and machinery was a 280 µm dry film thickness, comprising Hempadur 15302 light grey primer, two 90 µm coats of Hempadur Fast Dry 17410 light grey intermediate, and a 60 µm topcoat of Hempathane 55610 in the required colour.

All items were prepared and bristle-blasted before primer application. The complex assembly process meant that many parts had to be fully coated before assembly, as they would be concealed once fitted together.

The KK1300 has an overall height of 53 m, is 180 m long, has a wheel diameter of 13 m, a bucket volume of 1 300 ℓ, a conveyor belt speed of up to 4.1 m/s and a total weight of about 5 000 t.

The newly painted KK1300 is destined for operation on the northern strip of the Bilina Quarry, currently the deepest opencast coal mine in Europe, producing high- grade, low-sulphur coal, mainly for heat and power generation purposes.

The Bilina Quarry and the KK1300 are set to operate for at least 40 years, and Hempel’s coating system has an esti- mated maintenance schedule of over 15 years.