Silicone sealants are essential tools for ensuring robust assemblies and efficient maintenance in industrial, electronics, construction and beyond. Mascherpa, with its DOWSIL™ range of products, offers advanced solutions to meet every specific need. In this guide we explore the main types of silicone sealants and their characteristics to help you choose the right product.
Types of silicone sealants
Over time, silicone sealants have been produced with a wide range of formulation options, such as:
- RTV Sealants
- Heat-curable sealants.
- Heat sealants (hot-melt)
- One-component sealant
- Two-component sealant
- Silicone foams
RTV sealants (curing at room temperature)
RTV silicone sealants work through a chemical reaction that occurs in the presence of moisture. They are easy to apply, low cost and suitable for a variety of surfaces. The curing process can be accelerated with increased temperature and humidity.
This type of silicone sealants provides ease of installation and good adhesion. In addition, these sealants have a competitive cost and are ideal for general sealing and industrial assemblies.
Heat-curable sealants.
Heat-cure sealants are distinguished by their short curing times and automated applicability, making them perfect for high-throughput industrial environments. These sealants have fast curing, compatibility with automated processes, and high strength, making them perfect for application in processes such as industrial component manufacturing and in automation
Heat sealants (hot-melt)
Hot melt sealants offer instant resistance to deformation and cracking, improving productivity in industrial environments. The advantages in using hot melt sealants are instant strength, reduced processing time, and aggressive adhesion to various substrates. These silicone sealants are used in the automated production of industrial components and gaskets.
One-component sealant
Single-component sealants have all the properties needed for treatment and use moisture, heat, or UV light to complete the curing process. These silicone sealants are easy to apply and compatible with many surfaces. Single-component materials, such as single-component polyurethane sealant, can be applied at room temperature and are ideal for sealing gaskets in domestic or industrial environments.
Two-component sealant
Two-component sealants consist of two separate reactive ingredients, offer greater control over curing time and shelf life. Application of these sealants in the assembly of complex electronic and industrial components provides rapid curing, the ability to customize mechanical properties, and resistance to extreme temperatures.
Silicone foams
Silicone foams are an economical solution for environmental seals, providing protection against dust, moisture and splashing water. These products offer flexibility, light weight, fast curing time and compatibility with robotic applications. These properties make them suitable for application in gaskets for environmental protection in industrial devices.
Factors to consider when selecting silicone sealant
In choosing the right sealant for one’s purpose, it is necessary to take into account certain properties of sealants, which might make the products more or less useful for our application:
- Chemical composition
- Operating temperature
- Adhesion to substrates
- Hardening time
Chemical composition
Silicone sealants are formulated with different chemical bases (acetic, alcoxi, oxime, etc.), each with specific properties:
- Acetic sealant: cheap, fast curing, but potentially corrosive.
- Alcoxi: neutral curing, low VOC emission, excellent adhesion.
- Ossima: high transparency, fast curing, good stability.
Operating temperature
Crucially, consider the temperature range to which the sealant will be exposed. Some materials withstand up to 350°C, making them suitable for ovens and extreme environments.
Adhesion to substrates
The ability to adhere to materials such as metals, plastics or glass varies among formulations. It is always necessary to check the manufacturer’s specifications to ensure that the sealant is compatible with the substrates involved.
Hardening time
Film formation time and total curing time are crucial for productivity. Hot-melt and two-component sealants are preferred for rapid industrial processes.
DOWSIL™ Sealing Silicones.
Dow offers a variety of silicone sealants for different applications. Here are some of the main products:
- DOWSIL™ 732 Sealant: Ideal for general sealing with excellent adhesion.
- DOWSIL™ 734 Fluid Sealant: Perfect for filling voids and cracks.
- DOWSIL™ 7091 Adhesive Sealant: Flexible solution for bonding materials with different coefficients of expansion.
- DOWSIL™ HM-2600: hot-melt sealant for high mechanical strength.
Conclusions
Selecting the right silicone sealant depends on the specific needs of the project. If you are in doubt, consult our Mascherpa experts to receive a personalized evaluation. The silicone sealants in the Dowsil range, with their wide choice of formulations, offer solutions for almost any application, ensuring reliable and long-lasting performance.
