Determination of low temperature flexibility of building sealing materials

The low-temperature flexibility test of building sealing materials can measure the low-temperature flexibility of building sealing materials, and can also measure the low-temperature flexibility of single-component elastic solvent-based sealing materials after high-temperature and low-temperature cycle treatment.
Zhongke Testing and Reliability Experiment Center has the capabilities of environmental testing and reliability performance testing of various building materials, products and components, and provides professional mechanical property testing services such as density, low temperature and temperature properties, compression properties, elastic recovery properties, mass and volume change properties, etc. for building sealing materials.

1. Sealing materials can be divided into two categories according to their strength: shaped sealing materials (sealing strips, pressure strips, etc.) and non-shaped sealing materials (sealing paste or caulking paste, etc.).
Amorphous sealing materials can be divided into plastic sealing paste, elastic-plastic sealing paste and elastic sealing paste according to their raw materials and their properties.
2. Sealing materials can be divided into polysulfide, polyurethane, silicone, chloroprene rubber, butyl rubber, acrylic glue, etc. according to their chemical composition.
At present, the three types that are used in large quantities on the market are silicone, polyurethane, and polysulfide.

1. Under the specified conditions, use a mold frame to adhere the sealing material sample to the substrate. After high-temperature and low-temperature cycle treatment, bend the sample under the specified low-temperature conditions. Report cracking of sealing material or bond failure.
2. At the end of the third processing cycle, make the test piece and the round bar in the cryogenic chamber at the specified test temperature at the same time, and bend the test piece around the round bar with the specified diameter by hand. When bending, the side of the test piece with the sample attached to it faces outward. The bending operation is completed within (1~2) s.
3. Immediately after bending, check the specimen for cracking, partial delamination and bonding damage. Minor surface cracks, hairline cracks or edge cracks are negligible.

GB/T 13477.7-2002 Test methods for building sealing materials Part 7: Determination of low temperature flexibility
GB/T 13477.2-2018 Test methods for building sealing materials Part 2: Determination of density
GB/T 13477.16-2017 Test methods for building sealing materials Part 16: Determination of compression characteristics
GB/T 13477.17-2017 Test methods for building sealing materials Part 17: Determination of elastic recovery rate
GB/T 13477.19-2017 Test methods for building sealing materials Part 19: Determination of mass and volume changes
GB/T 13477.7-2017 Test methods for building sealing materials Part 7: Determination of low temperature flexibility
GB/T 13477.21-2022 Test methods for building sealing materials Part 21: Determination of color changes after artificial accelerated weathering
GB/T 13477.3-2017 Test methods for building sealing materials Part 3: Method for determining the extrudability of sealing materials using standard instruments
GB/T 13477.4-2017 Test methods for building sealing materials Part 4: Determination of extrudability of one-component sealing materials in original packaging