Coatings with a particularly high solids content, so-called UltraHighSolids, not only meet the requirements for VOC but also stand for rapid drying and accelerated production processes. FreiLacke offers various single- and double-coat solutions for this purpose, which boast high resistance.
Geared motors, actuators and pump systems ensure motion – in machines – and plant construction, as well as in shipping or building technology, to name just a small selection. They are exposed to many environmental influences and have to withstand factors such as corrosion, chemicals, UV exposure, etc. depending on their later place of use. High-performance surface protection is indispensable if they are to remain permanently usable. “Traditionally, these drive elements are protected by multi-layer structures”, explains Florian Pauel, Project Manager Drive Technology at FreiLacke. As well as cathodic ECs, multiple 2C epoxy primers are also used in combination with 2C PU top coats. Disadvantage of this process: Several coating layers require a lot of time for application, cooling and drying, which ultimately leads to higher expenditure and correspondingly high coating costs.”
UltraHighSolid coatings, or UHS for short, as offered by the Black Forest manufacturer FreiLacke, are faster, more efficient and more energy-efficient. By using sustainable and environmentally sound raw materials, a product range has been created in which just a few solvents are contained with a solids content of around 80% and are therefore VOC-compliant. The proportion here is less than 350 g/l and thus well below the limit values called for by the 31st Ordinance of the German Federal Emission Control Act (BImschV).
The UHS systems of the coating expert Frei include a single-layer system, two primers and a high-gloss top coat. The UR1422 single-layer system, with its VOC-compliant solids content of 80% (up to 55 g/m² possible), is externally resistant and offers high corrosion protection. The coating is already dust-dry after just 45 minutes. The entire layer thickness can be applied in a single operation. The elimination of intermediate flash-off time and the interim forced drying of the primer where necessary mean that cycle times for the coating can be significantly reduced. In addition, solvent savings – especially for cleaning purposes – can also be saved.
“When using the new single-layer system, not only is more throughput achieved, but an application system can also be saved”, says the FreiLacke project manager. “By moving to a single coating system, handling of the coating materials is also optimised with regard to logistics and storage. As well as that, it is possible to avoid any coating product mix-ups during operating processes.”
To achieve a high degree of resistance and corrosion protection, the manufacturer FreiLacke recommends a range of substrate pretreatments such as zinc phosphating, iron phosphating or sandblasting for single-layer coating on steel.
FreiLacke’s UHS platform technology offers particularly high corrosion protection: It consists of the UHS primer UR1937, based on PUR, or the UHS primer ER1936, based on epoxy, and can be combined with the UHS top coat UR1409. Primers and top coats offer very good resistance to creepage and can also be applied very well with Airmix. Their VOC content is below 350 g/l.
Based on the 2C-UHS Epoxy Primer ER1936, layer thicknesses of up to 400 μm can be applied in a single operation. “Of course, our ER1936 can also be combined with various HS and UHS top coats in the conventional layer thickness range from 60 to 80 μm. These two-layer structures achieve salt spray resistances of more than “1000 hours”, explains Pauel. The system therefore meets the requirements for high-grade coatings with high popping-free layer thicknesses, drying that meets the needs of real-life situations and good surface properties all at once.
The 2C PU UHS primer UR1937 can also be applied as a single-layer coating and easily withstands 750 hours on blasted steel in a salt spray test. The coating is available in all RAL colours or also specially coloured according to customer requirements. Parts primed with UR1937 can be easily stored outdoors thanks to their light fastness and can be overcoated after repeated cleaning. Easy application – regardless of whether pneumatic, Airmix, Airless or ESTA – and excellent resistance levels distinguish this system.
If the focus is on very fast drying, the use of the two-layer system UR1407/UR1984 is recommended. Both primer and top coat are dust-dry after 10 min. each, therefore total process times of up to 90 min. are possible here. This sometimes eliminates the need for a furnace throughput and helps operators save large amounts of energy”, stresses Pauel.
This coating system offers good efficiency of application, very good corrosion protection and is available in a wide range of colours. Its high running and popping limits make it easy to use.
FreiLacke supplies the UHS systems ready to use, where curing agent has to be added, but no additional dilution is required. The same curing agent and the same mixing ratio of PUR primer and top coat help to avoid processing errors. The Black Forest coating specialist offers HS and UHS coatings both as 2C polyurethane systems and as 2C UHS epoxy systems. All formulations are free of reactive thinners.