GB/T 46022-2025Cover glass for vehicle displays (English PDF)

3.1 Cover glass for vehicle displays

Transparent glass material that is used inside motor vehicles for the surface of displays to protect the display components.

3.2 Scratch resistance

The ability of a specimen surface to resist scratching by a hard object.

NOTE. it is expressed as a critical load value.

[source. GB/T 39815-2021, 3.3, modified]

3.3 Gloss

Under specified light source and receiving angle conditions, the ratio of the luminous flux reflected in the specular direction of an object to the luminous flux reflected in the specular direction of glass with a refractive index of 1.567.

3.4 Contact angle

The angle between the tangents of the gas-liquid interface and the solid-liquid interface at the gas-liquid-solid three-phase junction point.

NOTE. the symbol theta, and the unit is degrees (°).

[source. GB/T 30447-2013, 3.1, modified]

3.5 Depth of layer “DOL”

When light enters chemically tempered glass at a certain angle, and the refractive index difference along the glass thickness direction from the surface layer to the interior just reaches its maximum value, the depth, at which, retro-refraction is generated.

NOTE. the DOL value is less than the ion exchange layer depth but greater than the compressive stress layer depth.

3.6 Micro-waviness

The degree of minor fluctuations and unevenness on the glass surface.

[source. GB/T 20314-2017, 3.4]

3.7 Roughness

The unevenness of the glass surface formed during acid etching, characterized by small spacing and minor peaks and valleys. [source. JC/T 2462-2018, 3.4]

5.1 Appearance Quality

The appearance quality shall comply with the provisions of Table 1.

5.2 Dimensional Deviations

The thickness, length and width deviations of the cover glass shall conform to the provisions of Table 2.For irregularly shaped cover glass, the dimensional deviations shall be agreed upon by test, the absolute value of the difference in water contact angle shall not exceed 10°.

5.11 Surface Stress (CS)

The surface stress (CS) shall not be less than 550 MPa.

5.12 Depth of Layer (DOL)

The depth of layer (DOL) shall not be less than 10 m.

5.13 Scratch Resistance

After the test, no scratches longer than 3 mm shall appear.

5.14 Vickers Hardness

The Vickers hardness shall not be less than 5.80 GPa (591.426 kgf/mm2). NOTE. 1 GPa = 101.97 kgf/mm2.

5.15 Impact Resistance

After the test, the number of specimens damaged shall not exceed one.

5.16 Corrosion Resistance

Coated cover glass with anti-fingerprint function shall undergo this test. Before and after the test, the absolute value of the difference in the water contact angle shall not exceed 5°.

5.17 High Temperature and Humidity Resistance

Coated cover glass with anti-fingerprint function shall undergo this test. Before and after the test, the absolute value of the difference in the water contact angle shall not exceed 5°.

6.1 Test Conditions

Unless otherwise specified, the test shall be conducted under the following environmental conditions.

a) Ambient temperature. 20 C  5 C;

b) Relative humidity. 40% ~ 80%.

6.2 Appearance Quality

Use the product as a specimen, place the specimen in a dark chamber in front of a fluorescent lamp with an illuminance of not less than 1,000 lx, and at a distance of 300 mm from the specimen, visually inspect it at eye level or by rotating it upside down, and record the results.

Use a reading microscope with a division value of 0.01 mm and a steel ruler with a division value of 1 mm to measure the dimensions of point-like defects and scratches, and the distance between any two defects.

6.3 Dimensional Deviations

Use the product as a specimen, place the specimen on a measuring platform, and use a vernier caliper or other measuring instrument with an accuracy of not less than 0.02 mm to respectively measure the distance between the two parallel sides in the middle of the long and wide sides.

Use a micrometer with an accuracy of not less than 0.001 mm to measure the thickness at the midpoint of the four sides of the specimen, and it is necessary to avoid the printing area. The thickness value is expressed as the average value of the four points and retained to three decimal places. The difference between the measurement value and the nominal value is the dimensional deviation.

6.4 Warpage

Use the product as a specimen, place the specimen with its outer surface facing upwards on a measuring platform (00-grade flatness marble). Use a feeler gauge to measure the maximum distance between the lower surface of the specimen and the platform surface. Flip the specimen, so that its outer surface faces downwards and measure the maximum distance between the lower surface of the specimen and the platform surface again. Take the maximum value of the measurement result.

6.5 Visible Light Transmittance

6.5.1 Specimen

Use the product as specimens or cut specimens from the product. Alternatively, use 100 mm  100 mm test pieces prepared with the same material and process as the product. The number of specimens is 3.

6.5.2 Test procedures

In accordance with the method specified in GB/T 2680, measure the visible light transmittance of the viewing area of the specimen. The result is expressed as the arithmetic mean of the 3 specimens and rounded to 0.1%.

6.6 Gloss

6.6.1 Specimen

Use the product as specimens or cut specimens from the product. Alternatively, use 100 mm  100 mm test pieces prepared with the same material and process as the product. The number of specimens is 3.

6.6.2 Test procedures

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