Structural Sealant is a type of silicone adhesive that transmits the external and internal forces of the bonded material. It is mainly used for the bonding of glass curtain walls, window frames, and metal (aluminum) frames.
According to the European ETAG 002-1 requirements, the initial mechanical strength and the residual strength after natural aging must be equal or higher than 75% of the sealant’s initial strength measured at 23 degC.
Adhesives are a form of sealant that is used to keep two surfaces together over time. They provide high-strength, long-lasting bonds that can be applied accurately using a meter or mix dispensing system.
There are many types of adhesives, and each is designed to be used in a specific application. The best adhesives for each situation are selected based on the target substrate, the conditions that will affect the bonding, and the durability of the results.
For example, epoxies are a great choice for adhering metals because they offer strong shear and peel strength as well as excellent chemical resistance. They are also suitable for bonding glass, rubbers, ceramics, and composites.
Polyurethane structural adhesives represent another family of sealants that are commonly suited to long-term bonding, particularly on plastics and other non-metallic substrates. They are also known for their high cohesive strength, ease of use, and resistance to humidity.
Structural adhesives are often applied manually or in automated processes to fill gaps, prevent liquid loss, and protect components against condensation and corrosion. They are also a good choice for sealing pipes, flanges, and other joints in industrial and commercial designs.
The most common structural adhesives are epoxy and polyurethane, but there are a number of other products available as well. Some of them are UV-curable, while others are designed for room temperature curing and can be cured by manually or through applicator nozzles in automated processes.
In addition to providing an inert barrier between corrosive metals, structural adhesives can also be used to make a vapor barrier or to bond multiple materials together for a product that requires high-performance gasketing or flange sealing. They Structural Sealant can also be used to reduce weight in transportation manufacturing industries, allowing for the ability to design more lightweight designs that will save on operational costs over the life of the product.
Another type of structural adhesive is silicone, which offers a wide range of applications and properties. Silicone is a water-resistant, non-toxic alternative to traditional toxic adhesives, and it is a popular choice for a variety of structural bonding needs. It also has excellent weather resistance and can withstand both high and low temperatures.
Structural Sealant is a type of adhesive that is designed to withstand several different kinds of weather conditions, from sun and heat to rain and snow. These products are ideal for patio furniture, outdoor benches and accessories, and other items that might be exposed to the elements on a regular basis.
These products are also used in construction and building materials to ensure that a structure will be durable against a variety of weather conditions. Some buildings require a weather-resistant product that can withstand high winds or cold temperatures in addition to normal rainfall and humidity.
For example, the exterior walls of a home may need to be able to withstand a wide range of weather conditions and resist mold and rot, which can lead to damage to the interior and exterior of a building. This is why high-quality, vapor permeable weather-resistant barriers are so important.
A number of popular choices for weather-resistant thermoset plastics include phenolic resins, polycarbonate, and pDCPD. Typically, these types of materials have excellent durability and can be molded easily and manufactured quickly.
Phenolic resins are the oldest type of weather-resistant thermoset plastic and are a versatile material that can be used in many applications. They are used in a number of different industries, including automotive and marine, and in the production of weather-proof plywood.
They are also resistant to bio-deterioration and have excellent temperature stability. These properties make them ideal for use in construction and agricultural equipment, buses and trucks, industrial waste containers, and military vehicles.
These types of products are also commonly used for glazing, window and door manufacturing. They are ideally suited for bonding a wide variety of glass, metal, and other panel materials.
The chemistry of these compounds allows them to absorb moisture from the surrounding environment to cure, creating a tough, flexible rubber compound that is able to withstand a wide ranges of temperatures and conditions. These products can be formulated with one or two components, depending on the requirements of the application.
Both structural and weather-resistant sealants are designed to withstand both tensile and shear forces that act on the joints. However, the difference between them is that structural sealants are load-bearing, while weather-resistant sealants mainly play the role of sealing.
Structural Sealant is a polymer adhesive that cures by taking in moisture and then forming a tough, flexible, and temperature resistant rubber compound. These products are designed to bond and seal a wide variety of substrates including steel, aluminum, plastics, fiberglass, wood, and cementitious materials.
The performance of a structural sealant depends on the material it is made from, its chemical makeup, and additives such as fillers and plasticizers. These properties, combined with the installation conditions, affect how the sealant performs in a joint.
In addition, the sealant’s movement capability will depend on the expected movement of the joint and its specific design. It is essential that the sealing product be Structural Sealant able to accommodate these movements without compromising its overall performance.
Durability is another important property that should be considered when selecting a sealant. It relates to sealant’s resistance to environmental strains such as ultra-violet radiation, moisture, temperature, cyclic joint movement, movement during curing and biodegradation which can profoundly influence the service life of the installed sealant.
There are several standard tests that many engineering firms, contractors, distributors, and sealant applicators conduct to help select which sealants they want to specify for different applications in various climates. Some of these procedures include outdoor weathering, with movement (ASTM C1589) and a test to determine the typical cure rate in the field (ASTM C679).
During these tests, sealants are exposed to the same environment for a pre-determined amount of time and then tested for adhesion or cohesion in both situations. It is recommended that a control sample of the construction material that does not contact the sealant be used to ensure that the results of the test are not simply a result of aging or weathering.
Adhesion is a critical property that should be carefully examined for all moving joints where an early adhesion failure can lead to a loss of sealant performance. It is especially important to consider adhesion in a joint where the substrate has a large degree of surface roughness or other underlying conditions that may impact the ability of the sealant to adhere properly. In such cases, primers may be recommended to improve the sealant’s adhesion capabilities.
The performance of a sealant depends on its ability to transfer loads from one bonded component to another. For structural glazing, this means that the structural silicone sealant needs to bear the loads transferred from the glass panes and transfer them to the frame or structure that supports the glass. The stability of this load transfer is important for safety in use.
A tensile strength test is often performed by the manufacturer to determine if the sealant can be expected to hold a certain tensile force during application and during aging. This is important because the bonding strength of the silicone sealant can deteriorate over time and may not be capable of transferring the loads transferred by the glass to the frame or the support system.
This test can also be used to assess the ability of the sealant to take a joint through an expansion and compression cycle. This movement has a positive impact on the structural stability of the sealant; however, it can also cause adhesion loss or a cohesive (creep rupture) failure.
ASTM C719 is a commonly used test for the movement capabilities of structural sealants. This test measures the movement of a cured joint from its original width through an extension (+) and then through a compression (-) cycle.
After a specified length of time the movement is measured to determine the recovery rate and the adhesive or cohesive (creep rupture) failure. This test can be difficult to get reliable data from and is typically only performed on a limited number of sealants in the industry.
When using a structural sealant for SSG, it is crucial to select the right polymer chemistry type and ensure that the sealant meets the appropriate performance criteria. The choice of the right chemistry can have a major impact on the overall stability of the sealant.
A very effective test to evaluate a structural sealant is an extended tensile strength test. This test is designed to allow the sealant to withstand an extended period of time under pressure while measuring the tensile strength at various temperatures.