GB/T 24498-2025Gaskets for doors, windows and curtain walls of buildings (English PDF)

3.1 Gaskets

The seal, installed in the opening or fixed part of doors, windows and curtain walls, has a sealing function.

5.4.10 Brittle temperature

The specimen of the coated sponge complex weatherstrip shall not have cracks or breaks after the test at -20 °C.

5.4.11 Repeated water absorption performance

After the water absorption test of the coated sponge complex weatherstrip is repeated for 4 cycles, the product shall meet the following requirements.

a) The mass change rate is no greater than 5%;

b) The deflection recovery is no less than 90%;

c) The compression force change value is no greater than 30%.

5.4.12 High and low temperature resistance

After the high and low temperature test of the coated sponge complex weatherstrip is repeated for 4 cycles, the product shall meet the following requirements.

a) The deflection recovery is no less than 90%;

b) The compression force change value is no greater than 30%.

5.4.13 Fatigue resistance

After 200,000 fatigue tests on the coated sponge complex weatherstrip, the product shall meet the following requirements.

a) The deflection recovery is no less than 90%;

b) The compression force change is no greater than 30%;

c) The surface coating film shall not be damaged, fractured or cracked; and the coating film shall not be separated from other composite materials.

5.4.14 Compression force

The compression force shall meet the sealing requirements of doors, windows and curtain walls.

The classification shall be agreed upon by the supplier and the purchaser according to the needs.

The compression force (DN) classification shall comply with the provisions of Table 14.

The test shall be performed in accordance with the provisions of GB/T 528-2009, using a type 1 dumbbell-shaped specimen (sponge rubber extruded foam sheet), and the test speed is 500 mm/min±50 mm/min.

6.2.3 Tear strength

The test shall be performed in accordance with the provisions of GB/T 529-2008, using a right- angle, uncut specimen.

6.2.4 Compression permanent deformation

The test shall be performed in accordance with the provisions of GB/T 7759.1-2015, using type A specimen, test temperature 100 °C (thermoplastic elastomer test temperature 70 °C), test time 220.5 0 h, specimen compression (25±2)%.

6.2.5 Aging in hot air

The test shall be performed in accordance with the provisions of GB/T 3512; test temperature 100 °C, test time 168 h ± 1 h. Prepare and test the specimens according to the hardness and tensile strength requirements.

6.2.6 Hardness change

Put the specimen (with diameter no less than 30 mm, thickness no less than 6 mm) in a constant temperature container at -20 °C ±2 °C, 0 °C ±2 °C, 23 °C ±2 °C, 70 °C ±2 °C; take it out after 2 h±0.25 h; measure the hardness within 10 s according to the method specified in GB/T 531.1;

and calculate the hardness difference of each temperature section according to Tables 3, 4, 6, 7.

6.2.7 Low temperature brittleness

The test shall be performed according to the provisions of GB/T 1682.

6.2.8 Oxygen index

The test shall be performed according to the provisions of GB/T 10707.

6.2.9 Vertical combustion performance

The test shall be performed according to the provisions of GB/T10707.

6.2.10 Smoke density

The test shall be performed according to the provisions of GB/T 8627; the specimen size is (25.4±0.3)mm x (25.4±0.3)mm x (6.2±0.3)mm.

6.2.11 Water-swelling performance

6.2.11.1 Volume swelling ratio

The test shall be performed according to the provisions of Appendix A in GB/T 18173.3-2014.

6.2.11.2 Repeated immersion test

The test shall be performed according to the provisions of 6.3.5 in GB/T 18173.3-2014.

6.3 Product appearance

Visually inspect the product appearance quality under natural light or equivalent artificial light source at a distance of 0.3 m.

6.4 Product dimension tolerance

Take a 2 mm to 3 mm thick cross-section test piece of the product and test it with a non-contact measuring instrument with corresponding graduation value (such as a projector or scanner that can magnify 5x or 10x).

6.5 Product performance

6.5.1 Product density

Dense gaskets shall be tested in accordance with the provisions of Method A in 7.1 of GB/T 533-2008.Sponge gaskets shall be tested in accordance with the provisions of GB/T 6343.Five specimens of 200 mm ± 10 mm shall be cut from the gasket product. The volume of the specimen is the product of the cross-sectional area of the sponge gasket and the actual length of the tested specimen.

6.5.2 Deflection recovery

Cut three specimens of 100 mm in length from the gasket product. Perform the test and calculation according to the following steps.

a) Use a non-contact measuring instrument to measure the free height (H0) of the specimen, accurate to 0.05 mm.

b) Fix the specimen on the test device; apply a uniform load on the pressure-bearing working surface; compress the specimen to the maximum value of the design working range (W).

And place it in an environment of 70 °C ± 2 °C for 240 -2h; after taking it out, cool it to ambient temperature and unload it.

c) Place the specimen in a standard temperature and humidity environment in a horizontal state without pressure and with the working surface facing upward for 240 -2h; and measure the average free height (H1) after the test according to the method in a).

d) Calculate according to Formula (1); take the arithmetic mean of the three specimens; and retain 3 significant figures for the result.

specimen to expose the added wire with a length of 10 mm; and peel off the other side of the specimen to remove the added wire with a length of 10 mm. Place one group of specimens after treatment in 70 °C ± 2 °C and -20 °C ± 2 °C environments, respectively; and take them out after 1 h. Under standard temperature and humidity conditions, clamp 6 mm at both ends of the product in the longitudinal (length) direction; and pull at a uniform speed of 100 mm/min ± 10 mm/min until it is broken. After the test, check whether the added wire of the specimen is pulled out.

6.5.9 Friction coefficient

The test shall be performed according to the provisions of Appendix C in GB/T 21282-2007.

6.5.10 Brittle temperature

The test shall be performed according to the provisions of GB/T 1682.

6.5.11 Repeated water absorption performance

Cut 6 specimens of 100 mm±10 mm from the gasket product; and measure the compression force and deflection recovery grade of the product before testing 3 specimens. Soak the other 3 specimens in 23 °C±2 °C distilled water for 16 h; take them out and dry them at 70 °C±2 °C for 8 h. Then soak them in distilled water for 16 h; take them out and dry them for another 8 h. This is one cycle. And the test time deviation is ±0.25 h. After 4 repeated cycles, measure the deflection recovery and compression force; and calculate the rate of change.

6.5.12 High and low temperature resistance

Cut six specimens of 100 mm ± 10 mm from the gasket product. Measure the compression force and deflection recovery grade of the product before the test of three specimens. Place the other three specimens in the air at 23 °C ± 2 °C for 18 h; and then the specimens were placed in a -20 °C ± 2 °C low temperature box for 3 h. The specimens were taken out of the low temperature box and immediately placed in a 50 °C ± 2 °C constant temperature box for 3 h.

This is one cycle; and the test time deviation is ± 0.25 h. After 4 repeated cycles, measure the deflection recovery and compression force; and calculate the rate of change.

6.5.13 Fatigue resistance

Cut six specimens of 100 mm ± 10 mm from the gasket product. Measure the compression force and deflection recovery grade of the product before the test of three specimens. Place the other 3 specimens on the fatigue testing machine; adjust the amplitude of the fatigue testing machine to the specimen working range, accurate to 0.1 mm. Compress the working surface of the specimen from the zero-compression position to the designed working range. Repeat the test, the specimen frequency is (600±30) times per hour. After the test, remove the specimen;

place it in a standard temperature and humidity environment for 240 -2h in a horizontal state without compression and with the working surface facing up; measure the deflection recovery and compression force; and calculate the rate of change.

7.2.2 Qualification judgment rules

When the inspection items do not meet the requirements of Clause 5, the batch of products is judged to be unqualified.

7.3 Type inspection

7.3.1 Inspection timing

Type inspection shall be carried out in any of the following situations.

a) When new products or old products transferring to other factory for trial design and identification production;

b) When there are major changes in cross-section, materials, and processes that may affect product performance, after formal production;

c) When production is resumed after product discontinuation;

d) When during normal production, it is carried out once a year; light aging test is carried out once every 3 years;

e) When the exit-factory inspection results are significantly different from the last type inspection.

7.3.2 Batching and sampling plan

The continuous production with the same raw materials, process, formula, and specification are considered as a batch; and the mass of each batch is no less than 5,000 kg. If the output is less than 5,000 kg, the output of 7 days is considered as a batch. Samples and products are taken for inspection at 3 times the number of samples and products in the test method of Clause 6.

7.3.3 Qualification judgment rules

When the product does not meet the requirements of this Document, the samples shall be doubled from the original batch for re-inspection; if it still does not meet the requirements, it will be judged as unqualified.

8.1 Marking

8.1.1 The finished product should be marked with the manufacturer's information.

8.1.2 The obvious part of the product packaging or the certificate of conformity attached with the box shall indicate the following. ......