GC TOP 311

Sealing with higher resistance for a wide variety of requirements

The GC TOP sealing systems developed by Hillebrand Chemicals offer a wide range of applications for visually attractive surfaces with simultaneously improved corrosion protection. They are designed to be used with GC PASS passivation. On electro depositions the combination of these two coatings influences the chemical and mechanical resistance of the entire system.

GC Top 311 is a product specifically designed to meet the increasing demands of the automotive industry to fulfil the requirements for cyclic environmental resistance.

The sealing film is between 1.5 and 3 µm. Along with good corrosion resistance on passivated zinc and zinc alloy surfaces, it also offers good media resistance against acidic and alkaline cleaning agents. The GC TOP 311 coating process is ideally suited as a concentrate to process bulk goods in immersion centrifuges with hot-air injection at 80 to 120 °C.

GC TOP 311L and GC TOP 311LSC are lubricated versions of the sealing product which do not experience any deterioration in their corrosion protection properties.

GC TOP 311L

GC TOP 311L is designed for defined friction adjustment to zinc, especially for coating wheel bolts. The high lubricity of the product is still intact even after being tightened up twenty times. That is to say after repeated changes from summer to winter tyres, perfect attachment with the specified tightening torque is still maintained.

The friction coefficient µtot, is typically 0.10 to 0.11 for the first tightening, and this changes very little to the tenth tightening where it is 0.12. Even after the twentieth Tightening, the total friction coefficient does not rise above 0.14.

GC TOP 311LSC

GC TOP 311LSC is particularly suitable for coating large dimensions. Here, a defined friction coefficient µtot of between 0.11 and 0.13 is achieved.

Both GC TOP 311L and GC TOP 311LSC show no settling behaviour under temperature load, whereby the finished connections offer excellent heat loosening properties.

Corrosion resistance in accordance with DIN EN ISO 8227 depending on the substrate:

Zinc 8-12µm, blue passivated, GC TOP 311(L, LSC) WR > 120 h RR > 360 h
Zinc 8-12µm, thick-layer passivated, GC TOP 311 (L, LSC) WR > 200 h RR > 480 h
Zinc-nickel 8-12µm, transp. passivated, GC TOP 311 (L, LSC) WR > 600h; RR > 1000h