What Is The Purpose of The Protective Film on Color Coated Aluminum Coils? How Many Days After Construction Can We Remove The Protective Film From Color Coated Aluminum Coil?

Purpose of the Protective Film on Color - Coated Aluminum Coils

1. Protective coatings

During the manufacturing process of colour coated aluminium coils, one or more layers of coatings are formed on the surface, and these coatings usually have specific decorative, anti-corrosive and functional properties. The main role of the protective film is to protect these coatings from damage during transport, storage and construction.

2. Preventing scratches and contamination

During the handling and installation of colour coated aluminium coils, the surface of the coating can easily be scratched or contaminated due to a variety of factors (e.g. tools, dust, stains, etc.). Protective film can effectively prevent these external factors from causing damage to the coating.

3. Maintaining aesthetics

Protective films keep the surface of colour coated aluminium coils clean and aesthetically pleasing, preventing oxidation, discolouration or other forms of natural deterioration of the coated surface when exposed to air.

4. Increase durability

Some high-performance protective films are also UV and ageing resistant, further increasing the durability and service life of colour coated aluminium coils.

Data sheet of protective film

Material	Thickness Range	Unit
Colored Aluminum Film - Coated PVC (Polyvinyl Chloride)	0.08 - 0.2 mm	Millimeter (mm)
Colored Aluminum Film - Coated PET (Polyethylene Terephthalate)	0.05 - 0.15 mm	Millimeter (mm)
Colored Aluminum Film - Coated PE (Polyethylene)	0.1 - 0.3 mm	Millimeter (mm)

1. General Recommendation

It is generally recommended to remove the protective film within 1 - 2 weeks after the completion of construction. This time period allows for the settlement of dust and other potential contaminants during the construction process. Removing the film too early may expose the surface to additional risks of damage and contamination during the final stages of construction.

2. Consideration of Environmental Factors

In areas with high humidity or a lot of rain, it may be necessary to remove the film earlier to prevent the film from adhering too tightly to the surface due to moisture. In dry and clean environments, a slightly longer period may be acceptable, but it is still advisable not to leave the film on for an extended period (more than a few months) as it may become difficult to remove and could potentially damage the color - coated surface.

3. Type of Construction and Usage

Preventing scratches and contamination:During the handling and installation of colour coated aluminium coils, the surface of the coating can easily be scratched or contaminated due to a variety of factors (e.g. tools, dust, stains, etc.). Protective film can effectively prevent these external factors from causing damage to the coating.

If the color - coated aluminum coil is used for exterior decoration of buildings, and there is no other construction work that may damage the surface after the main construction is completed, the film can be removed relatively early. However, if it is used in industrial facilities where there may be subsequent installation of equipment or other operations that could pose a risk to the surface, it may be better to leave the film on until all such work is completed.

Specific environmental conditions affect the removal time of the protective film

Temperature

Low Temperature:

In cold environments, the adhesive on the protective film may become less sticky and more brittle. This can make the film more difficult to remove cleanly, as it may crack or break during the removal process. For example, at temperatures below freezing, the film may adhere more tightly to the color - coated aluminum coil surface due to the change in the physical properties of the adhesive. In such cases, it is advisable to let the coil warm up to a more suitable temperature (above 10 - 15°C) before attempting to remove the film.

High Temperature:

High temperatures can cause the adhesive to soften or even melt. If the temperature is too high, the film may become sticky and difficult to peel off without leaving residue. For instance, in extremely hot climates or near heat sources, the film's adhesive can become gooey and transfer onto the color - coated surface when removed. Ideal removal temperatures usually range from 15 - 30°C to ensure the best results.

Humidity

High Humidity:

In humid conditions, the protective film can absorb moisture. This can lead to the film adhering more tightly to the surface of the color - coated aluminum coil. The moisture can also cause the adhesive to become more active and potentially cause the film to bond more strongly to the surface. In areas with high humidity, such as tropical regions or near bodies of water, it may be necessary to remove the film earlier to avoid problems such as the film becoming difficult to remove or leaving a residue when removed. The relative humidity should preferably be below 70 - 80% for easier film removal.

Low Humidity:

In dry environments, the film may be less likely to adhere too tightly due to lack of moisture - related adhesion. However, extremely low humidity (below 30 - 40%) can cause static electricity buildup, which may attract dust and other particles to the film. This can make the film appear dirty and may also affect the quality of the surface when the film is removed.

Exposure to Chemicals

If the color - coated aluminum coil is exposed to chemicals such as solvents, detergents, or industrial pollutants during construction or storage, the protective film's adhesive can be affected. Chemicals can either dissolve the adhesive, making the film loose and prone to premature detachment, or cause it to harden and adhere more tightly. For example, exposure to strong solvents like acetone can soften the adhesive and make the film peel off more easily than intended, while exposure to some acidic or alkaline substances can cause the adhesive to react and bond more strongly to the surface. It is important to keep the coil away from such chemical exposures and, if exposed, to assess the condition of the film and its adhesive before attempting removal.

UV Radiation

Prolonged exposure to ultraviolet (UV) radiation can degrade the protective film and its adhesive. UV radiation can cause the film to become brittle and yellow over time. In outdoor applications, if the color - coated aluminum coil is left exposed to sunlight for an extended period with the protective film on, the film may become more difficult to remove. The UV - induced degradation can also lead to the film's adhesive leaving a residue on the color - coated surface when removed. To minimize the impact of UV radiation, it is advisable to limit the exposure time of the coil with the film on, especially in regions with strong sunlight.