Powder coating is the finish that decides how an ALPES sliding window looks on day one — and how it survives ten years of sun, salt air, and weekly cleaning. For a product built on 6060-T66 aluminium profiles, the coating is the thin barrier standing between the metal and everything the weather throws at it. This guide explains what powder coating is, why it matters specifically for sliding windows, how ALPES applies it, and how to specify the right finish for your project.
Powder coating is not liquid paint. It is a dry, free-flowing blend of resin, pigment, and additives that is sprayed onto the aluminium using an electrostatic charge so the particles cling evenly to every edge. The profiles then pass through a curing oven where the powder melts and cross-links into one continuous, solvent-free film bonded to the metal.
A credible coating line runs four controlled stages:
The result is a hard film, typically 60–80 microns on architectural aluminium, that blocks moisture, chlorides, UV, and acidic pollutants from reaching the metal beneath.
Sliding windows move. Tracks, rollers, and interlocks mean more edges and more surfaces for the environment to attack than a fixed pane. A sound coating protects those edges and keeps the frame looking new between cleanings. Four properties matter most:
The sliding window in kitchen and every other opening in the ALPES range starts from 6060-T66 aluminium, 1.8–2.0 mm thick for the sliding series, paired with PA66GF25 multi-chamber thermal break. Powder coating is applied to those profiles before they become a TS130 side-press window — the side-press sliding model with a 130 mm frame, ROTO hardware, 200 kg load-bearing pulleys, and four-sided continuous sealing.
ALPES offers a standard palette and custom matching:
If you are specifying a sliding window black frame to match a streetscape or a dark façade, the near-black Aurora Gray and Starry Sky Gray tones are the relevant options — and a dark exterior can be paired with a lighter interior through dual-colour coating.
Anodizing is the other common aluminium finish, and it works by a different mechanism: instead of laying a film on top, it grows a hard oxide layer from the metal itself in an electrolyte bath. That makes it integral to the substrate — it cannot peel or flake — and gives a translucent metallic look. Powder coating wins on colour range, dual-colour options, and field repairability. Anodizing wins on raw abrasion resistance and zero UV colour shift, but its palette is limited to metallic tones and damage cannot be touched up on site.
| Property | Powder coating | Anodizing |
|---|---|---|
| How it forms | Cured polymer film on the surface | Oxide layer grown from the metal |
| Colour range | Any RAL, matt/gloss/textured | Silver, bronze, black, champagne |
| Dual-colour | Yes, inside/outside | Not practical |
| Field repair | Touch-up possible | Requires panel replacement |
| Best for | Homes, apartments, colour-matched façades | Metallic commercial feature windows |
For most residential sliding-window projects the broader palette and repairability of powder coating make it the practical default; anodizing suits projects that specifically want the bare-metal look.
When you order or ｒｅｐｌａｃｅ windows, the colour name alone is not enough for production. Confirm these points on the drawing and the window schedule:
Industry quality labels such as Qualicoat and AAMA 2604/2605 define durability classes by weathering performance, and coating suppliers rate their powders against them. ALPES can confirm the exact coating standard and the warranty that applies to your specific order — ask for that document rather than assuming a number, because the right grade depends on where the window will sit. If you are planning a sliding window replacement, locking the coating spec at the RFQ stage avoids a colour mismatch years later.
Powder-coated frames are low maintenance but not zero maintenance. In coastal, industrial, or tropical sites, wash the frames quarterly with mild detergent and water to remove salt and pollutants before they can sit on the surface; inland sites can be cleaned less often. Avoid abrasive pads that cut the film, and touch up any chip promptly with colour-matched paint so the barrier stays closed.
The right powder-coating spec is the difference between a frame that looks planted on day one and one that still looks planted a decade later. Tell ALPES your project location, the colour you have in mind, and whether you need dual-colour, and request the coating standard and warranty in writing before production. That turns a finish choice into a documented, repeatable specification you can reorder against.
