Introduction To The Uses of Sealant

    My neighbor's house has been renovated, and they invited me to come over and see it. The renovation is very impressive, with a style that perfectly matches the homeowner's temperament, reflecting their taste. The doors and windows are made of high-quality aluminum-clad wood, and the windows have excellent sound insulation, so much so that when they're closed, almost no outside noise can be heard. However, after spending a bit more time in the rooms, there seemed to be a slight odor. Upon closer inspection, it was discovered that the cause was poor-quality sealant used for the doors and windows.

    Sealant is a widely used chemical product with extensive industrial applications. It can be found in many places, such as aerospace sealing, electronic product sealing, transportation, solar energy, bathroom and gap filling in construction, as well as for sealing pipes and fish tanks in daily life.

There are various types of sealants, including acrylic, silicone, epoxy, among others. The choice of sealant type is crucial, as improper use can lead to numerous issues. For structural purposes on curtain walls, silicone sealants are used. If polysulfide sealants are used instead, they may not withstand aging, leading to the detachment of curtain wall glass. Silane-modified polyether sealants are used in prefabricated buildings.

    The sealants commonly used for doors and windows mainly include butyl sealant, polysulfide sealant, and silicone sealant for glass, while silicone sealant is typically used for windows. But sealant is used for bonding aluminum spacers and glass, while polysulfide or silicone sealant is used for bonding between glass panels. Window sealants are used for connections between windows and walls, as well as for sealing gaps between glass and pressure bars. For LOW-E glass that needs to be filled with argon, polysulfide sealant is preferred for glass sealing, as silicone sealant may not effectively prevent gas leakage. The primary sealing of insulating glass must use butyl sealant due to its lowest water vapor transmission rate. Insulating glass uses two layers of sealing, with a combination of butyl sealant and polysulfide sealant used for insulating glass in doors and windows. Neutral silicone sealant should be used for window sealing, as acidic sealant can corrode doors and windows and even emit harmful substances to the environment. The quality of sealant used on door and window glass should be carefully identified, as some unscrupulous manufacturers in the market may adulterate sealants with small molecule materials, leading to sealant failure. The common phenomenon of "tearing" in insulating glass is caused by the addition of cheap impurities. Sealants have many performance characteristics that require testing in professional laboratories. However, there are also some simple testing methods. Polysulfide sealant is a two-component sealant, so attention should be paid to the ratio of the two components, and simple tests such as the butterfly test and cup test can be conducted.

    When purchasing sealant, it is essential to buy from formal sales channels with complete relevant department procedures. Special attention should be paid to purchasing sealant within its shelf life, with a longer period until expiration being preferable. It is also important to ensure that the sealant capacity is sufficient, as insufficient capacity may indicate poor quality.