Guidelines

Automotive Visual Inspection Standard For Applied Window Film

Installed automotive film on glass surfaces is not expected to have the same level of visual quality as glass. The following criteria apply to the installed film only and not to any defect inherent in the glass.

Installed film normally has a slightly delayed time for full adhesion to be achieved since installation utilizes a surfactant or slip agent solution in water to float the film onto the glass: the excess water is then squeegeed out, but inevitably some residual water will remain between the film and glass.

This residual water will initially affect the visual clarity and full adhesion to the glass. The time to achieve full adhesion is often referred to as “the adhesive cure time,” but on automotive films it is really the “drying time” of the residual moisture. Adhesion will be increasing from a lower value to the normal expected value during this time. The time it takes for the film to fully cure is related to thickness of the film and the various specialized coatings on the film. Typical cure times may also be extended or shortened according to climatic conditions and vehicle storage.

Certain films with special high-performance coatings may have lengthened cure times. Consult the manufacturer for expected cure times of these films.

Inspection for visual quality can be made before full cure is attained. It should be noted that certain observations during clearing and drying, such as water distortion, and water haze are not to be regarded as defects.

The glass with applied film shall be viewed at right angles to the glass from inside the vehicle, and outside the vehicle from a distance of 3 feet. Viewing shall be carried out in natural daylight.

The installation shall be deemed acceptable if all of the following are unobtrusive (effects during cure should be disregarded): Dirt Particles, Hair and Fibers, Adhesive Gels, Fingerprints, Air Bubbles, Water Haze, Scores and Scratches, Film Distortion, Creases, Edge Lift, Nicks and Tears. Inspection may be made within 1 day of installation. Obtrusiveness of blemishes shall be judged by looking through the film installation in natural daylight.

The top edge may have a maximum edge gap of 1/32 – 1/16 inch (1-2 mm). This ensures that film edges are not lifted up by contact with the frame gasket when a window is raised and lowered inside its frame. In certain installations where top edge “shaving” has been performed, there may appear to be no gap at all.

Architectural Visual Inspection Standard For Applied Window Film

1. Installed film on flat glass surfaces is not expected to have the same level of visual quality as glass. The following criteria apply to the installed film only and not to any defect inherent in the glass.

2. Installed film has a discrete time for full adhesion to be effected since installation utilizes a detergent solution in the water to float the film onto the glass: the excess water is squeegeed out, but inevitably residual water will remain between the film and glass. The time to achieve full adhesion is often referred to as “the adhesive cure time”. Adhesion will be increasing from a lower value during this time. Visual and adhesive cure time is related to thickness of the film and various metallic coating on the film. Typical visual cure times may be extended or shortened according to climatic conditions.

3. Inspection for optical quality can be made before full visual cure is attained. Table 1 provides a guide for typical visual cure times. It should be noted that effects during cure, such as water bubbles, water distortion, and water haze are not to be regarded as defects.

4. The glass with applied film shall be viewed at right angles to the glass from the room side, at a distance of not less than 6 feet (2 meters). Viewing shall be carried out in natural daylight, not in direct sunlight, and shall assess the normal vision area with the exception of a 2 inch (50mm) wide band around the perimeter of the unit.

5. The installation shall be deemed acceptable if all of the following are unobtrusive (effects during visual cure should be disregarded): Dirt Particles, Hair and Fibers, Adhesive Gels, Fingerprints, Air Bubbles, Water Haze, Scores and Scratches, Film Distortion, Creases, Edge Lift, Nicks and Tears. Inspection may by made within 1 day of installation. Obtrusiveness of blemishes shall be judged by looking through the film installation under lighting conditions described in 4.

6. The 2 inch (50mm) wide band around the perimeter shall be assessed by a similar procedure to that in 3 and 4, but a small number of particles is considered acceptable where poor frame condition mitigates against the high quality standards normally achieved.

7. Edge gaps will normally be 1/32 – 1/16 inch (1-4mm). This allows for the water used in the installation to be squeegeed out. This ensures that film edges are not raised up by contact with the frame margin. Contact with the frame margin could lead to peeling of the film.

8. For thicker safety films the edge gaps will normally be 1/32 – 1/16 inch (1-4mm), with 1/32 – 1/8 inch (1-5mm) being acceptable for films of (7 mil (175)). Combination solar control safety films will also fall within this standard. An edge gap of up to 1/16 inch (2mm) is recommended, especially for darker (tinted, metallized, tinted/metallized, and sputtered) films, to minimize the light line around the edge of the installed film.

9. Splicing of films is necessary when larger panels of glass are treated, where both length and width of the glass exceed the maximum width of film. The splice line itself should not be viewed as a defect. This line should be straight and should be parallel to one edge of the frame margin. The two pieces of film may be butt jointed. The maximum gap at any point in the splice line should be 1/64 inch (1mm). Film may be overlapped, spliced or butt jointed.

10. Certain films with special high performance coating may have lengthened cure times. Consult the manufacturer for cure times of these films.

Table 1 – Typical Cure Times

Film thickness in mils Film thickness in microns(µ) Typical Cure Time (days)
Up to 4 Up to 100 30
4 to 8 100 to 200 60
8 to 12 200 to 300 90
Over 12 but not more than 17 Over 300 but not more than 425 140

*Special adaptation of information received from the Glass and Glazing Federation; reproduced with their permission.

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Bullet Resistance Statement

Our industry believes there are adequate and acceptable standards and methods for testing of products as protection against ballistics. Since window films are an addition to a glazing and not intended for use as the glazing itself, we firmly believe that an individual glazing should be tested both with and without film installed on it for any comparison of improvement in total performance.

In some cases, we have seen demonstrations or claims that the use of film imparted some bullet resistant value when, in fact, the glazing itself without film had almost those same bullet resistant qualities. Extreme caution should be taken, however, to make sure that any claims about performance due to the addition of a film layer clearly state the specifics of the glazing itself as supplied by the glazing manufacturer, the specifics of the film itself as supplied by the film manufacturer, and all relevant specifics of the ballistics used and the conditions ofthe test.

Any attempt to imply performance due to the application of the film under any other conditions (different manufacturer, different glazing, different ballistics, different conditions), we believe, would be irresponsible as the margin for error could be one of life safety.