ADHESIVES/ SEALING & BONDING

Sealing and bonding are two distinct yet often related processes used to join materials and prevent unwanted substances from passing through interfaces. While both involve applying a substance between surfaces, their primary goals and the properties of the materials used differ. Let's explore each in more detail:

Sealing

The primary goal of sealing is to create a barrier that prevents the passage of liquids, gases, dust, or other environmental elements across a joint or opening. A sealant fills the gap between two substrates, creating a watertight, airtight, or dust-tight seal.

Key Characteristics of Sealants:

• Flexibility: Sealants typically need to accommodate movement between the substrates due to thermal expansion, vibration, or other stresses. Therefore, they are usually flexible and elastic.
• Adhesion: While adhesion to the substrates is important for maintaining the seal, it's not always the primary focus. The sealant needs to adhere well enough to stay in place and maintain the barrier.
• Low Strength: Sealants are generally not designed to provide significant structural strength to the joint. Their main function is to fill gaps and prevent leakage.

Applications of Sealing:

Sealing is crucial in a wide array of applications, including:

• Construction: Sealing joints around windows, doors, countertops, and tiles to prevent water and air infiltration.
• Automotive: Sealing seams and components to prevent leaks of fluids and gases.
• Plumbing: Sealing pipe joints to prevent water leaks.
• Aerospace: Sealing aircraft structures to maintain pressure and prevent environmental ingress.
• Packaging: Creating airtight or watertight seals for food and other products.

Bonding

The primary goal of bonding is to join two or more substrates together in a way that provides structural strength and load transfer across the joint. An adhesive creates a strong attachment between the surfaces.

Key Characteristics of Adhesives:

• High Strength: Adhesives are formulated to provide significant tensile, shear, and peel strength to the bond.
• Adhesion: Strong adhesion to the substrates is paramount for effective bonding. The adhesive must interact strongly with the surface materials.
• Variable Flexibility: Adhesives can range from rigid to highly flexible, depending on the application requirements. Structural adhesives often exhibit high stiffness and strength.