GB/T 14683-2017Silicone and modified silicone sealants for building (English PDF)

3.1 Silicone sealant for building

Room-temperature-cured single-component and multi-component sealants, with polysiloxane as the main component, which are divided into acidic and neutral according to the curing system.

3.2 Modified silicone sealant for building

Room-temperature-cured single-component and multi-component sealants, with silane-terminated polyether as main component.

3.3 Set at maintained extension

The remaining deformation of a test piece after it is stretched to a certain length and allowed to recover freely for a certain period of time, expressed as the ratio (theta) of the remaining deformation to the given elongation.

4.1 Types

6.3 Density

Carry out the test in accordance with the provisions of GB/T 13477.2.

6.4 Sag

Carry out the test in accordance with the provisions of 6.1 in GB/T 13477.6-2002. Place the test piece vertically in a (50±2) °C constant temperature box for 4 h.

6.5 Tack-free time

Carry out the test in accordance with the provisions of GB/T 13477.5-2002. Type inspection shall adopt method A test, and ex-factory inspection can adopt method B test.

6.6 Extrusion

Carry out the test in accordance with the provisions of 8.2 in GB/T 13477.3-2017. The extrusion hole diameter is 4 mm and the sample test temperature is (23±2) °C.

6.7 Working life

6.7.1 Carry out the test in accordance with the provisions of 8.3 of GB/T 13477.3-2017. The extrusion hole diameter is 4 mm and the sample test temperature is (23±2) °C.

6.7.2 Test three samples and extrude each sample three times, with one extrusion at appropriate intervals. Calculate the extrusion rate according to Chapter 9 of GB/T 13477.3-2017; draw a graph of the arithmetic mean of the volume extrusion rate and the time after mixing; read the time corresponding to the extrusion rate of 50 mL/min, which is the working life. Accurate to 0.5 h.

6.8 Elastic recovery rate

Carry out the test in accordance with the provisions of GB/T 13477.17-2017. The test elongation is shown in Table 5 of this Standard.

6.9 Tensile modulus

Carry out the test in accordance with the provisions of GB/T 13477.8-2017; determine and calculate the secant tensile modulus (MPa) when the sample is stretched to the corresponding elongation specified in Table 5 of this Standard.

6.13 Adhesion after immersion in water and exposure to light

Carry out the test according to the provisions of 5.12 of JC/T 485-2007. The immersion and illumination time is 300 h. The test elongation is shown in Table 5 of this Standard.

After the test, inspect the samples according to 7.1 of GB/T 22083-2008 and evaluate the damage of the samples according to 7.3 of GB/T 22083-2008.

6.14 Adhesion/cohesion properties at variable temperatures

Carry out the test in accordance with the provisions of GB/T 13477.13-2002. The tension and compression range of the test are shown in Table 5 of this Standard. After the test, inspect the samples according to 7.1 of GB/T 22083-2008 and evaluate the damage of the samples according to 7.3 of GB/T 22083-2008.

6.15 Mass loss rate

Carry out the test in accordance with the provisions of GB/T 13477.19.

6.16 Alkane plasticizer

Carry out the test according to the provisions of Chapter 7 in GB/T 31851-2015.

6.17 Set at maintained extension

6.17.1 Test equipment

6.17.1.1 Tensile testing machine. capable of stretching the test piece at a speed of (5.5 ± 0.7) mm/min.

6.17.1.2 Positioning pad. used to control the width of the stretched sample, enable the sample to maintain an elongation of 30% of the initial width.

6.17.1.3 Vernier caliper. the graduation value is 0.1 mm.

6.17.2 Test procedure

Remove the isolation pads from the prepared and cured samples (6.1.3); measure the initial width Wi at both ends of each sample. Place the test piece in a tensile testing […]

7.2 Batch

Products of the same type and grade are inspected in batches of 5 t; those less than 5 t are also considered as a batch.

7.3 Sampling

For single-component products, randomly select 3 packages from the batch of products, and randomly select 4 samples from each package, for a total of 12 samples.

For multi-component products, randomly take samples according to the ratio, with a total of 6 kg; the samples shall be sealed and packaged immediately after sampling.

After sampling, divide the samples into two equal parts. Use one part for testing, and the other for backup.

7.4 Determination rules

7.4.1 Single item determination

For the tests of sag, tack-free time, tensile properties at maintained extension, tensile properties at maintained extension after immersion in water, adhesion after UV irradiation, and adhesion/cohesion properties at variable temperatures, if each test piece complies with the requirement, judge the item to be qualified. If the test results of other items meet the standard requirements, judge the item to be qualified.

When one of the tensile modulus of high modulus products at 23 °C and -20 °C meets the requirements in Table 2 or 3, judge the item to be qualified.

When the tensile modulus of low modulus products at both 23 °C and -20 °C meet the requirements of Table 2 or Table 3, judge the item to be qualified.

7.4.2 Comprehensive determination

When the test results meet all the requirements of Chapter 5, judge the batch of products to be qualified. […]