JC/T 936-2004[JC/T 936-2004] One-component polyurethane foam (English PDF)

3.3 Product’s marking

The product is marked in the following order. name, combustion performance grade, packaging structure, standard number.

Example. A grade B2 gun-type one-component polyurethane foam sealant is marked as. one-component polyurethane foam sealant B2 Q JC 936-2004.

5.1 Appearance

The PU sealant is a liquid in the aerosol can, the ejected material is a foam of uniform color, without undispersed particles and impurities. It is a rigid foam- plastic having uniform cells after curing.

5.2 Physical properties

The physical properties of PU sealant shall be in accordance with the provisions of Table 1.

1 Note. CFCs. It refers to foaming agent monofluoromethylene chloride (F-11), difluoromethylene chloride (F-12) trifluorotrichloroethane (F-113) which may be used in PU sealant.

7.1 Appearance

Perform visual inspection at the time of preparation of the test piece.

7.2 Density

It is performed according to the provisions of GB/T 6343.

7.3 Dimensional stability

It is performed according to the provisions of GB/T 8811.The test conditions are (23 ± 2) °C. Perform test 72 h after preparing test piece.

7.4 Thermal conductivity

It is performed according to the provisions of GB/T 10294.The average temperature at the test point is 35 °C.

7.5 Flammability

It is performed according to the provisions of GB/T 8626.Use edge ignition.

7.6 Tensile bond strength

It may select one or more substrates in 6.3.3.1.

7.6.1 Test equipment

7.6.1.1 Tensile testing machine. The accuracy is not more than 2 N, the load ranges (0 ~ 1000) N, it is equipped with a dedicated tensile fixture, the tensile speed can be adjusted to 5 mm/min.

7.6.1.2 Vernier caliper. The accuracy is 0.02 mm.

7.6.1.3 Constant-temperature bath. The volume can accommodate the test piece, the controllable temperature is (23 ± 1) °C.

7.6.2 Test procedures

7.6.2.1 Tensile bond strength under standard conditions

Remove the pad from the test piece which has been prepared and cured according to 6.3.3.4.Use the vernier caliper to measure the size of the bonded part. Load it into the tensile machine, stretch the fixture until it is damaged.

Record the damage load (N) and the state of destruction.

Where.

tau - Shear strength, in kilocalories (kPa);

F - Damage load, in Newtons (N);

L - Length of the bonded part of the test piece, in millimeters (mm);

b - Width of the bonded part of the test piece, in millimeters (mm).

The test results take the arithmetic mean of the five test pieces, accurate to the integer position.

7.8 Foaming multiple

According to the provisions of 6.2.2, inject in layers the sample materials from an aerosol can into the formwork which has an inner size of 400 mm x 400 mm x 600 mm. Empty the aerosol can. After 72 h, use a balance which has an accuracy of 0.1 g to weigh the mass (M) of the foam block. Then, respectively from the upper, middle, lower parts of the foam block, take 5 specimens in total.

Follow the provisions of 7.2 to determine the density of the foam specimen (rho).

Use its average value to calculate the volume of the foam block (Vf). Use the formula (3) to calculate the foaming multiple, accurate to the integer position.

Where.

f - Foaming multiple;

Vf - The volume of the foam block, in liters (L);

M - The mass of the foam block, in grams (g);

rho - The density of the foam block, in kilograms per cubic meter (kg/m3);

V0 - The indicated capacity of aerosol can, in liters (L).

8.1 Classification of inspections

8.1.1 Exit-factory inspection

The manufacturer shall, according to the provisions of this standard, perform exit-factory inspection for each batch of products. The exit-factory inspection

When the appearance quality does not meet the requirements of 5.1, the batch of products is judged to be unqualified.

In the inspection results, if two or more items fail, the batch of products is judged to be unqualified. If one item fails, it is allowed to double the specimen from the same batch of products for single item re-inspection. If it still fails, the batch of products is judged as unqualified.

9.1 Marking

The outer packaging of each product shall be marked with the following.

a) Name of product;

b) Label of product;

c) Net capacity and foaming multiple;

d) Date of manufacture, shelf life;

e) Trademark;

f) Name and address of the factory;

g) Hazardous substances and signs of flammable products;

h) Method of use;

i) Safety precautions.

9.2 Packaging

9.2.1 Packaging materials

The product is packed in pressure-resistant metal can. Its technical performance shall meet the requirements of GB 13042, wherein the deformation pressure is not less than 1.5 MPa, the burst pressure is not less than 1.8 MPa.

9.2.2 Packing specifications

Specifications can be. 250 ml/piece, 500 ml/piece, 600 ml/piece, 750 ml/piece.

It can also be determined according to the user’s needs.

9.3 Transportation

Appendix A (Informative)

Method for detecting chlorofluorocarbons (CFCs) in one-component polyurethane foam sealant

A.1 Scope of application

The method is suitable for the detection of chlorofluorocarbons (CFCs) in aerosol canned one-component polyurethane foam sealant.

A.2 Principles of test

Based on the high-efficiency separation ability of the gas chromatography for the mixture as well as the accurate identification capability of the mass spectrometer for the purified material, use the gas chromatographic-mass spectrometer to qualitatively analyze the components of gas which is extracted from the aerosol can.

A.3 Test equipment

A.3.1 Gas chromatography-mass spectrometer

Gas chromatographic conditions. Quartz capillary column, carrier gas is high- purity nitrogen, column temperature is 40 °C, perform test under constant- temperature. The temperature at the sample inlet is 100 °C, the pre-column pressure is 110 kPa.

Mass spectrometry conditions. EI ion source, electron energy 70 ev, ion source temperature 150 °C, electron multiplier voltage 1.2 kV, detection mode is full scanning.

A.3.2 Airbag

Rubbery, covered with aluminum foil thermal insulation layer, for sampling of gas specimens.

A.3.3 Syringe

2 ml, which is used for extracting gas from the airbag.

A.4 Sampling of gas

Place the aerosol can which is filled with the specimen upright. Place it in a constant-temperature test chamber at 25 °C for 24 h. Carefully install the gun

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