Functional purpose

Xylan/PTFE coating is a functional coating family used where low friction, release behaviour, controlled assembly, anti-stick properties or additional barrier performance is required. It should not be specified as a generic colour paint. The correct system depends on substrate, base coat, operating medium, temperature, abrasion and assembly requirement.

For many steel parts, Xylan may be used over a metallic base such as zinc-nickel where corrosion protection and friction/release characteristics are both relevant. The base coat and topcoat must be approved as a combined stack.

Surface preparation and base coat

Adhesion and durability depend strongly on surface preparation. Blasting profile, cleaning, activation, base coat compatibility and time gap between processes affect final performance. Smooth, oily, passive or contaminated surfaces can cause weak adhesion even if the coating appears visually acceptable immediately after curing.

Where chemical exposure is expected, the exact chemical, concentration, temperature, immersion/splash condition and cleaning cycle should be disclosed. A coating suitable for one environment may not be suitable for another.

DFT, curing and dimensional stack

Xylan/PTFE films add measurable dry film thickness. A typical functional coating thickness may significantly affect threads, bores, pins, slots and mating faces, especially when applied over zinc-nickel or another metallic layer. The total stack should be reviewed before the job is accepted.

Curing temperature and time must suit the coating system and substrate. Heat-sensitive assemblies, elastomer-adjacent parts, springs, precision components and hardened parts require careful review before coating.

Inspection and validation

Inspection can include DFT, visual finish, adhesion, masking accuracy and sample assembly. For functional surfaces, customer validation should include the actual mating part, torque/drag requirement, release behaviour or chemical exposure condition.

The coating can be damaged by sharp metal-to-metal abrasion, mishandling, impact, hard stacking or unsuitable packaging. Post-coating care should be defined before dispatch, especially for expensive machined parts.

RFQ and approval checklist

  • Exact coating system or Xylan grade, base coat requirement and colour if specified.
  • Operating temperature, chemicals, friction requirement and assembly condition.
  • Required DFT, masking, threads, bores and fitment-critical dimensions.
  • Curing limitations, substrate hardness/heat-treatment condition and part sensitivity.
  • Packaging method preventing abrasion, sticking, contamination and compression marks.

Related technical guide

For customer-side care after dispatch, packaging material selection and storage control are as important as process control. See the dedicated article: Xylan/PTFE coating over zinc-nickel base.