The Thing About Sealant "Modulus"

low modulus sealant

what is it?

Recently, low modulus (alcohol type) weathering sealants have caused a new trend among practitioners in the building door, window and curtain wall industry. Many owners, door and window curtain wall construction companies and building curtain wall designers have shown great enthusiasm for it, even if it poses a little challenge to the cost control of the project, they will face it. The magic of that low modulus (alcohol-based) weathering sealant makes everyone so fascinated.

The benefits of alcohol-based sealants must have been known for a long time. Alcohol-based silicone sealants are more environmentally friendly, non-toxic and low VOC release than acidic and neutral ketoxime-based silicone sealants. Therefore, they are the key to improve the development of the industry and the quality of construction products. One of the guarantees. So what exactly is a low modulus sealant? According to the definition in the national standard GB/T 14683-2017 "Silicone and Modified Silicone Construction Sealants" and the ISO international standard ISO 11600-2011 "Building construction-Jointing products-Classification and requirements for sealants", the The tensile results should meet the specifications for low modulus in Table 1.

From Table 1, we can know that when the low-modulus sealant is stretched by 60% or 100% (distinguished according to the displacement capacity), the strength modulus corresponding to the internal stress at 23°C is not greater than 0.4MPa, And the strength modulus corresponding to the internal stress at -20 ℃ is not more than 0.6MPa, and these two requirements can be called low-modulus silicone sealant at the same time. Under a certain displacement and deformation, lower internal stress can reduce the probability of interfacial bonding failure of the weather-resistant sealant during service, and can protect the shape and dimensional stability of the bonding substrate during service.

The company also launched a series of ketoxime-type low-modulus weather-resistant sealants in previous years. Last year, it launched a series of high-modulus alcohol-type door and window adhesives and high-modulus alcohol-type weather-resistant adhesive products.

This result is consistent with the results in Figure 2, that is, the mechanical properties of brand A decay faster with the increase of storage time. The mechanical properties of brand B do not decay very fast with the increase of storage time, but will gradually change from high modulus to low modulus at the beginning, so it will cause trouble for customers' application selection.

Whether our products are high-modulus alcohol-based products or low-modulus ketoxime-based products, the mechanical properties decay slowly with the increase of storage time, and the high and low modulus classifications remain unchanged during the shelf life.

3Premium choice

We believe that for market customers, choosing the right product for the right application site is the basis for ensuring the safety and functionality of construction projects, and our sealant products can better serve construction projects. Therefore, whether it is high modulus or low modulus, whether it is alcohol-type adhesive or ketoxime-type adhesive, it is a real good adhesive that meets the application requirements and maintains stable performance to meet the needs of engineering applications.