GB 18581-2020Limit of Harmful Substances of Woodenware Coatings (English PDF)

3.1 Polyurethane coatings

A type of coating that uses polyurethane resin formed by the reaction of polyisocyanate and active hydrogen-containing compound as the main film-forming material.

3.2 Nitrocellulose coatings

A type of coating that uses nitrocellulose prepared by the esterification reaction of a mixture of nitric acid and sulfuric acid with cellulose as the main film-forming material.

3.3 Alkyd coatings

A type of coating that uses alkyd resin prepared by polyacid, fatty acid (or vegetable oil) and polyhydric alcohol as the main film-forming material.

3.4 Unsaturated polyester coatings

A type of coating that uses unsaturated polyester resins with carbon-carbon double bonds on the polymer chain that are easily crosslinked with reactive diluents as the main film-forming materials.

3.5 Volatile organic compound; VOC

Organic compounds that participate in atmospheric photochemical reactions, or organic compounds determined in accordance with relevant provisions.

3.6 Volatile organic compound content; VOC content

The mass of the volatile organic compounds in the coating that is measured under the specified conditions.

6.1 Sampling

Sampling according to the provisions of GB/T 3186, or according to the agreed method. The sampling amount is determined according to the inspection requirements.

6.2 Test methods

6.2.1 VOC content

6.2.1.1 Density

Perform according to the provisions of GB/T 6750-2007; the test temperature is (23±0.5) °C.

6.2.1.2 Luster

Perform according to the provisions of GB/T 9754-2007. Use a wet film preparation device with a groove depth of (100 ± 2) µm to prepare a sample plate on a flat glass plate. The varnish shall use black glass or flat glass with a matte black paint on the back as the substrate. After drying the sample plate for 48h at a temperature of (23±2) °C and a relative humidity of (50±5) %, test it with a 60° specular gloss meter.

6.2.1.3 Moisture content

Perform according to the provisions of Appendix A.

6.2.1.7 VOC content in radiation curable coatings (including filler)

Perform according to the provisions of GB/T 34675-2017. Filler samples are not tested for moisture content (moisture content is set to zero) and density.

6.2.2 Formaldehyde content

Perform according to the provisions of GB/T 23993-2009.

6.2.3 Total lead (Pb) content

Perform according to the provisions of GB/T 30647-2014.

6.2.4 Soluble heavy metal content

Perform according to the provisions of GB/T 23991-2009.

6.2.5 Total sum content of glycol ether and ether ester

Perform according to the provisions of GB/T 23986-2009. The calculation of the content of glycol ether and ether ester is carried out according to 10.2 in GB/T 23986-2009; and converted into milligrams per kilogram (mg/kg).

6.2.6 Benzene content, total sum content of toluene and xylene (including ethylbenzene)

6.2.10 Methanol content

Perform according to the provisions of GB/T 23986-2009. The calculation of methanol content is carried out according to 10.2 of GB/T 23986-2009.

7.1 Type inspection

7.1.1 Under normal production conditions, the type inspection shall be carried out at least once a year. The type inspection items include all the requirements listed in this Standard.

7.1.2 The type inspection shall be carried out at any time in one of the following situations:

7.2 Judgment of inspection results

7.2.1 The judgment of the test result shall be carried out according to the rounding-off comparison method specified in GB/T 8170-2008.

7.2.2 When reporting the inspection results, the application ratio under the specified application condition of the product shall be indicated at the same time.

7.2.3 When the inspection results of all items meet the requirements of this Standard, the product meets the requirements of this Standard.