Every engineer, manufacturer, constructor or house builder needs the right sealant for their specific application needs. For example, only the right solution can provide complete safety to constructors and house builders against future problems such as leakages, seepage or cracks. Similarly, choosing the right sealant for manufacturing equipment can be crucial for companies as using the wrong sealant can lead the seal to break, thereby causing loss of time and product.
Other considerations include the risk of contamination and unintended chemical reactions without the right sealant.
Consequently, professionals usually have to spend hours going over different catalogues, trying to find the right sealant solution. Manufacturers usually offer a range of high-quality sealants and adhesives to suit different needs. What can help is having a systematic approach for selecting the right sealant out of the wide variety of products available in the market.
Sealants are usually used to seal cracks, gaps or joints and can also be useful for glazing joints and sealing permeable surfaces with non-porous ones. You can read more about their use in the following helpful guide: When and Why Use Silicone Sealants?
Hence, to cater to different needs there are different kinds of sealants. The chemical components of the sealants determine which product is best suited for different industries/uses. The different types of sealants include silicone, acrylic and polyurethane (PU) sealants.
Let’s have a look at the several types of sealants and their uses.
Silicone sealants are the most commonly used sealants – they are usually transparent and can dry quickly, thereby forming a sealing surface over the required area, joint or gap. While they are resistant to high temperatures, their movement accommodation is not as good compared to polysulphide sealants. Furthermore, silicone sealants are also available in white and black colour due to special needs and offer long term durability.
Uses: Silicone sealants are normally used to fill in gaps around fixtures and fittings or for fitting wooden/aluminium frames with glass such as in windows. They are also used in structural engineering, sanitary areas or for special applications involving fire protection, natural stones, etc. They also offer easy application and are available in ready to use cartridges. When cured, silicone sealants turn into flexible rubber like seals which are waterproof, have high durability and offer a long-lasting seal.
Similar to silicone sealants, acrylic sealants are also made of single component elastomeric acrylic which are usually white in colour. They also dry quickly, but are not as flexible as polysulphide or silicone sealants. They also have low chances of shrinkage and offer increased adhesion to building materials. Acrylic sealants are particularly useful for vertical joints and offer enhanced appearance and finish due to their acrylic properties and colour. Additionally, these sealants can be easily painted over.
Uses: These sealants are suited for sealing the gaps between window sills and window frames of varied materials such as metal and wood. Acrylic sealants like silicone sealants are also very durable, easy to use and are suitable for both external and internal application. They can also be used in structural engineering, sanitary areas and for special applications.
Polyurethane (PU) sealants
Polyurethane sealants are supplied in both single and two-part components. While single component polyurethane sealants are toothpaste like, the two component sealants have a mix ratio similar to polysulphide sealants.
In other words, their base part has additional weight compared to the accelerator part. Polyurethane sealants are made of polyurethane polymers, additives and pigments which are commonly used to seal the joints in buildings. Nevertheless, these sealants are also used in different industries and for different purposes – they can be used for glass and window construction, underground and structural engineering, vehicles, ventilations, electrical engineering and air-conditioning technology among other special applications.
Additionally, it is important to note that polyurethane sealants do not shrink, are UV resistant and very flexible.
Uses: As polyurethane sealants are shrinkage free, fast curing and flexible, they are used in building construction, sanitary ware joints, plumbing, contraction and expansion joints. Some are also ideally suited for horizontal application such as floors while others are used for vertical as well as overhead application. The selection of PU sealants therefore depends on the area of application.
The most important property of sealants is that they are shrinkage free. Additionally, good sealants also have excellent adhesion and bonding properties while being resistant to water, heat, high and low temperatures. While most sealants commonly have these properties, different variants and types are used for diverse purposes –some sealants are more commonly used for construction and manufacturing equipment while others are more suitable for underground engineering or vehicle construction.
Hence, it is crucial to choose the right type of sealant for your specific industry; otherwise untold damage to the product can potentially become a safety hazard for people.