How to Deal With the Surface Protection of Aluminium Extrusion Profiles?

Nov. 11, 2022

Solving these problems is a headache for many aluminium extrusion profile manufacturers. Measures to address the surface of aluminium extrusion profiles will be mentioned below.


The surface of aluminium extrusion profiles forms a very thin oxide film in the atmosphere, which gives it a certain corrosion resistance; however, because the film layer is loose, porous and uneven, it cannot be used as a reliable protective film layer, and the film layer is amorphous , so that aluminium and its alloys lose their lustre for a fixed distance and cannot be used as a satisfactory external decorative film. NB Technology aluminum profile protective films are made using low-density polyethylene. These self-adhesive protective films also come in a variety of colors, such as transparent color, black and white, etc. Additionally, our aluminum profile protective film can be customized according to the customer’s specific requirements.

Self Adhesive Protective Film For Aluminum Profiles And Plates

Self Adhesive Protective Film For Aluminum Profiles And Plates


The thickness of the oxide film obtained by chemical oxidation of aluminium extrusion profiles is generally 0.3-4p", and its softness, wear resistance and corrosion resistance are lower than that of the anodic oxide film. Therefore, it is rarely used alone except for special applications. Promote its better adsorption ability to paint the surface and effectively improve the corrosion-resistant parts of aluminium profiles and the oxide film after anodic treatment; its thickness is generally 5-20p" and the thickness of the modified anodic oxide film can reach 60-25p".


1. Film-forming speed of aluminium extrusion profiles differs from that of different types of aluminium profiles

After electrochemical conversion treatment, the difference in colour appearance is more pronounced than the difference in oxide film obtained from other process formulations. High aluminium purity results in a slow film formation rate; low aluminium purity results in the opposite.


Therefore, the oxidation needs to be mastered according to the different aluminium extrusion profiles. In order to do this, different types of aluminium extrusion profiles are not allowed to be tied to the same string, so as not to control the proper oxidation time.


Chemical and mechanical treatment, or direct chemical treatment. For severely oxidised metal surfaces with a thick oxide layer, aluminium extrusion profiles cannot be cleaned directly with solvents and chemically treated, it is better to first mechanically treat them.


Self Adhesive Protective Film For Aluminum Profiles And Plates

Self Adhesive Protective Film For Aluminum Profiles And Plates

2. Some treatment methods for aluminium extrusion profiles can be used as reference

①Degreasing treatment, wipe with absorbent cotton with solvent to remove the oil, and then wipe with a clean cotton cloth several times. Commonly used solvents are trichloroethylene, ethyl acetate, acetone, methyl ethyl ketone, petrol, etc.


② After degreasing, chemical treatment in the following solution: ammonium difluoride 3-3.5, chromium oxide 20-26, sodium phosphate 2-2.5, concentrated sulphuric acid 50-60, boric acid 0.4-0.6, water 1000 at 25°C-40°C soak 4.5min-6min, i.e. wash and dry. This method has high bonding strength and can be bonded within 4 hours after treatment. Suitable for epoxy glue and epoxy nitrile glue.


③ After degreasing, anodising in the following solution: 10min-15min immersion in 22g/l of concentrated sulphuric acid with a DC strength of 1-1.5A/dm2, then 5min-20min immersion in a saturated potassium dichromate solution at 95°C-100°C, followed by washing and drying with water. The treated metal surface is highly reactive and more susceptible to contamination by dust, moisture, etc., so the treated metal surface should be glued as soon as possible.


When the surface film of aluminium extrusion profiles is contaminated, the quality of the subsequent coating will be affected. If the aluminium profile is not treated in the way described above, the new aluminium profile surface can form its own film. With this latest film-forming technology, the resistance to oxidation is better than before. The conventional technology is advanced.

NB Protective Film offers an easily affordable solution. If you’re curious about aluminum profile protective films installation, click the button below to request a free estimate.

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