QC/T 236-2019Test methods for properties of automotive interior materials (English PDF)

4.8 Color fastness to light

It is performed according to the provisions of GB/T 16991. The test conditions adopt the condition 3 in clause 6.1; the test parameters are as follows:

- Black label thermometer temperature: (100 ± 3) °C;

- Test chamber temperature: (65 ± 3) °C;

- Relative humidity of the test chamber: (30 ± 5) %;

- Irradiation (under 420 nm): 1.2 W/m²;

- Light filter system: Borosilicate/soda lime.

4.9 Odor

4.9.1 Test device

- The thermostat with air circulation function, the accuracy of which is ± 2 °C;

- A glass container with a capacity of 1 L, with a gasket and a lid (no disturbing odor).

4.9.2 Test procedure

4.9.2.1 Specimen

Take 3 specimens on the same piece: when the thickness of the specimen is less than 3 mm, the size of the specimen is (200 ± 20) cm². When the thickness of the specimen is between 3 mm ~ 20 mm, the size of the specimen is (50 ± 5) cm³. When the thickness of the specimen is more than 20 mm, cut the specimen downwards along the use side to the thickness of 20 mm.

Samples need to be offline for no more than 15 days; they need to be packed in aluminum foil or polyethylene (PE) bags, and stored at room temperature and protected from light.

4.9.2.2 Test

The sealed glass container in which the specimen is placed shall have no peculiar smell at room temperature and 80 °C.

Place the three specimens in three 1 L glass sealed containers. Store them in accordance with the test conditions in Table 4.

A.1 Scope

This Appendix gives the test methods for the required load elongation and residual distortion of automotive interior decoration textiles (including woven fabrics, knitted fabrics, non-woven fabrics) and synthetic leather materials. It is suitable for testing the required load elongation and residual distortion of automotive interior decoration textiles (including woven fabrics, knitted fabrics, non-woven fabrics) and synthetic leather materials under certain conditions.

A.2 Terms and definitions

The following terms and definitions apply to this appendix.

A.2.1 Required load elongation

The rate of change between the length of the specimen under constant time and tension and the original length (before tension).

A.2.2 Residual distortion

The rate of change between the length of the specimen after a certain period of unloading and the original length (before tension).

A.3 Test device

Required load extension frame (with fixtures, weights), or electronic tensile machines that meet the test requirements can be used. The width of the clamp shall be greater than 60 mm; the length measuring device has an accuracy of 1 mm.

A.4 Test procedure

A.4.1 Specimen preparation

For woven fabric specimen, take no less than 3 specimens along the warp and weft directions, respectively, each specimen has a length of 200 mm and a width of 55 mm.

B.1 Scope

This Appendix gives the test method for the formaldehyde content of automotive interior decoration textiles (including woven fabrics, knitted fabrics, non-woven fabrics) and synthetic leather materials, which are applicable to the determination of formaldehyde content in the automotive interior decorative textiles (including woven fabrics, knitted fabrics, and non-woven fabrics), synthetic leather materials.

B.2 Principle

Hang a specimen of a certain mass and size in a sealed polyethylene bottle with a capacity of 1 L filled with distilled water. After being treated at a certain temperature for a certain period of time, it is cooled; the amount of formaldehyde as absorbed in distilled water is measured by acetylacetone spectrophotometry (the measured formaldehyde shall be divided by the dry weight of the specimen).

In an aqueous solution, formaldehyde reacts with acetylacetone and ammonium ions to produce 3.5-diacetyl-1.4-dihydrolutidine. The product is yellow, the absorption rate of which is maximum at 412 nm.

B.3 Test device

B.3.1 Electronic balance: The accuracy is 0.1 mg.

B.3.2 Incubator: The temperature shall be controlled from room temperature to 110 °C, with an accuracy of ±2 °C.

B.3.3 Spectrophotometer (wavelength 412 nm) and cuvette (1 cm) suitable for the spectrophotometer.

B.3.4 Constant temperature water bath: It can maintain the temperature at (40 ± 2) °C.

B.3.5 Drying dish.

B.3.6 Electric stove.

B.3.7 Polythene bottle (built-in steel hook, capacity 1 L).

B.5 Calibration curve

B.5.1 Preparation of formaldehyde standard solution

Add 20 ml of formaldehyde standard solution, 25 ml of iodine solution and 10 ml of sodium hydroxide solution to a 250 ml conical flask and mix. After placing it in the dark for 15 min, add 15 ml of sulfuric acid to the mixed solution. The excess iodine is back-titrated by the use of sodium thiosulfate solution. At the end of the titration, add a few drops of starch solution (to be heated and dissolved by an electric furnace) as an indicator, to determine the volume of sodium thiosulfate solution as consumed when the formaldehyde standard solution is used for the test.

Mix 20 ml of distilled water, 25 ml of iodine solution, and 10 ml of sodium hydroxide solution. After letting it stand for 15 min in the dark, add 15 ml of sulfuric acid. The excess iodine is back-titrated by the sodium thiosulfate solution. At the end of the titration, add a few drops of starch solution (to be heated and dissolved by an electric furnace) as an indicator, to determine the volume of sodium thiosulfate solution consumed in the blank test.

Use formula (B.1) to calculate the concentration of formaldehyde standard solution:

Where:

c(HCHO) - The concentration of formaldehyde standard solution, mg/l;

V0 - The volume of sodium thiosulfate solution consumed during the blank test, ml;

V - The volume of sodium thiosulfate solution consumed in the test by the use of formaldehyde standard solution, ml;

c(Na2S2O3) - The concentration of sodium thiosulfate solution, mol/l.

B.5.2 Preparation of formaldehyde calibration solution

From the prepared formaldehyde standard solution, use a pipette to remove a certain volume of formaldehyde standard solution into a 1000 ml volumetric flask, which contains 15 mg of formaldehyde (this volume can be calculated from the concentration of the formaldehyde standard solution that has been accurately determined). Add distilled water to dilute to 1000 ml. The prepared formaldehyde calibration solution contains 15 µg formaldehyde per ml.

B.5.3 Determination of calibration curve

Take six 100 ml volumetric flasks. From the formaldehyde calibration solution, remove 5 ml, 10 ml, 20 ml, 50 ml, 100 ml in sequence. Pour them into a 100 ml volumetric flask, including a 100 ml blank specimen bottle. Respectively add distilled water to dilute it to 100 ml. The concentration of formaldehyde (µg/ml) in these 6 volumetric flasks is 0, 0.75, 1.5, 3, 7.5, 15, respectively.

Take six 50 ml volumetric flasks. Use a pipette to remove 10 ml from each of the six volumetric flasks for diluted formaldehyde calibration solution. Transfer them into 50 ml volumetric flasks, respectively. The sampling sequence starts with the lowest concentration. Pipette it from low to high. In this way, use pipette to add 10 ml of acetylacetone solution and 10 ml of ammonium acetate solution to each volumetric flask. Close the cap tightly, heat it in a 40 °C water bath for 15 minutes. Take out the 6 volumetric flasks. Cool it to room temperature (about 1 h) in the dark. Then use a spectrophotometer to measure the absorbance of the solutions in these 6 volumetric flasks. Take the measured absorbance of the formaldehyde calibration solution as the abscissa and the corresponding concentration of the formaldehyde solution as the ordinate to make a curve.

The curve slope coefficient value is the correction factor f. Normally R² > 0.995 means that the calibration slope is valid.

The calibration curve shall be checked once a month.

B.6 Test procedure

B.6.1 Specimen

Take 3 specimens with a length of 100 mm and a width of 40 mm, of which 1 specimen is used to determine the water content and 2 specimens are used to determine the formaldehyde content. When sampling, ensure that the surface of each specimen is free from contamination.

If the test of the specimen cannot be carried out immediately, it shall be stored in a cool and sealed condition, wherein the amount of air shall be as small as possible; the storage time shall not exceed 5 days.

B.6.2 Water content

Use an electronic balance to weigh the mass of the specimen m1 (accurate to 1 mg). Put the specimen in a constant temperature oven at (103 ± 2) °C for 24 hours. Take the specimen out and place it in a drying dish to cool to room temperature. Then weigh the specimen mass m0. Calculate the water content (%) according to formula (B.2):

Water content (H) = (m1 - m0) / m0 x 100%... (B.2)

C.1 Scope

This Appendix gives the determination method of total carbon volatile content (TVOC) of automotive interior decoration textiles (including woven fabrics, knitted fabrics, non-woven fabrics) and synthetic leather materials. It is suitable for the determination of total carbon volatile content (TVOC) of automotive interior decoration textiles (including woven fabrics, knitted fabrics, non-woven fabrics), synthetic leather materials.

C.2 Principle

The headspace sampler is used to extract the residual volatile organic matter in the specimen; the gas chromatography-hydrogen flame ionization detector (GC-FID) is used to determine the total amount of carbon.

C.3 Test device and chemical reagents

C.3.1 Gas chromatograph: With split, splitless, injection port and hydrogen flame ion detector (FID).

C.3.2 Headspace sample injection bottle (10 ml).

C.3.3 Capillary separation column: Inner diameter 0.25 mm, film thickness 0.25 µm, length 30 m, 100% polyethylene glycol stationary phase (Wax-type, such as DB-Wax, Carbowax).

C.3.4 Electronic balance: Accuracy 0.1 mg.

C.3.5 Micro-injector: precision 5 µl.

C.3.6 Acetone: HPLC grade.

C.3.7 n-butanol: HPLC grade.

C.4 Test

C.4.1 Headspace sampler parameters

C.4.1.1 Temperature: Heating furnace 120 °C; quantitative tube 150 °C; transfer tube 180.

C.4.4.2 Blank test

The blank value is determined by the average value of the signal values obtained from at least 3 measurements by an empty sample bottle. The blank value and the quantification of the calibration result shall be consistent and reproducible.

Note: In order to keep the chromatographic column free of impurities, the chromatographic column shall be heated to 200 °C at least once a week and kept for 15 minutes.

C.4.5 Calibration

C.4.5.1 Concentration range

Basic calibration: 7 concentration points are 0.1 g, 0.5 g, 1 g, 5 g, 10 g, 50 g, 100 g acetone/liter n-butanol.

Controlled calibration: At least three concentrations of 0.5 g, 5 g, 50 g acetone/liter n-butanol solutions shall be prepared.

Note: Before calibration, the n-butanol used shall have no peaks and occurs at the same time with acetone.

C.4.5.2 Calibration cycle

When a new separation column is installed or there are changes in the instrument (such as replacing the liner, cleaning the FID nozzle, changing the basic parameters, etc.), use 7 concentrations for basic calibration;

At least 3 concentrations shall be used for controlled calibration every 4 weeks;

Take ABS as the quality control sample; make the mean control chart after each calibration curve is made; use X ± 2S as the control line. After that, test the ABS value every time the sample is tested. If the value exceeds the control line, it needs make a three-point linearity and retest the sample.

C.4.5.3 Calibration method

During calibration measurement, use a 5 µl syringe to take (2 ± 0.02) µl standard solutions at various concentrations (no bubbles in the syringe) into a 10 ml headspace bottle (the volume taken shall be adjusted accordingly based on the actual volume of the headspace bottle), then use a polyfluoroethylene bottle cap to immediately seal the headspace bottle;