Metal Adhesives

Metal adhesives are specialized adhesives designed to bond metal surfaces together. In previous periods, mechanical fasteners and welded joints were the only option in many industries, but metal adhesive systems are increasingly replacing them and becoming more important. The use of metal adhesives and tapes helps to effectively eliminate disadvantages associated with mechanical bonds and seals. These adhesives are highly important in various sectors such as automotive, aviation, electronics and construction where bonding of metal components is required. Welding is a common technique for joining metal components in assembly operations. Welded joints are similar to adhesive bonds in terms of their uniformity and ability to distribute stress evenly by eliminating the need for fastener holes. However, welding applications typically result in higher labour costs due to specialized training and certification requirements for operators. Post-weld inspections further increase overhead costs. In contrast, adhesives in metal-to-metal applications provide corrosion protection and eliminate corrosion risk in welding applications. Additionally, the use of adhesives prevents rapid heating and cooling associated with welding operations. According to a report published by Data Bridge Market Research, the metal adhesives market is expected to grow at a rate of 6.4% during the 2021-2028 forecast period. The expected growth in the metal adhesives market during the forecast period is mainly driven by increasing demand in automotive, transport and industrial applications. Furthermore, rising demand for metal adhesives in increasingly developing countries is expected to contribute significantly to market expansion. As with other adhesives, proper surface preparation is important for optimum performance of anaerobic adhesives. Surfaces must be clean and free from contaminants such as oil and grease. Additionally, if there is rust on metal surfaces, it is important to remove it. Rust can weaken the metal and prevent bonding. Mechanical methods such as wire brushing or sanding can be effective in rust removal. After cleaning and preparing the surfaces, it is also important to wait for complete drying before applying the adhesive, as moisture can affect the curing process and bonding strength of some adhesives.

Types of Metal Adhesives

Epoxy Adhesives: Epoxy adhesives consist of two components: resin and hardener. These two components are mixed in a specific ratio immediately before application. The chemical reaction between resin and hardener creates a strong and durable bond. Epoxy adhesives generally show good chemical resistance. They are less susceptible to degradation when exposed to various chemicals and environmental conditions. Epoxy adhesives cure through a chemical reaction known as polymerization. The curing process can be affected by factors such as temperature, humidity and the specific formulation of the epoxy. Some epoxies cure at room temperature while others may require high temperatures. Cyanoacrylate Adhesives: Cyanoacrylate adhesives, commonly known as super adhesives, are a fast-acting type of adhesive belonging to the acrylic resin family. These adhesives are known for their strong and fast bonding properties. Cyanoacrylate adhesives are made from cyanoacrylate monomers. The most common type is ethyl cyanoacrylate, but other variations include methyl cyanoacrylate used in some industrial applications. In addition to standard cyanoacrylate adhesives, formulations with specific properties also exist. For example, flexible cyanoacrylates are available that are designed to provide greater flexibility in bonded joints. Anaerobic Adhesives: Anaerobic adhesives are a type of adhesive that cure in the absence of air (oxygen) and are commonly used to bond metal components. These adhesives are particularly known for providing strong and durable bonds in threaded assemblies. Anaerobic adhesives generally exhibit good temperature resistance, making them suitable for applications where the bonded assembly may be exposed to various temperatures. Anaerobic adhesives cure through a process called anaerobic polymerization, which means they harden in the absence of oxygen. When the adhesive is applied between two metal surfaces in close proximity and the parts are assembled, the lack of air initiates the curing process. Polyurethane Adhesives: Polyurethane adhesives are versatile adhesives known for their flexibility, durability and strong bonding properties. They are commonly used in bonding various materials including metals. Polyurethane adhesives are elastomeric, meaning they have a degree of flexibility after curing. This flexibility allows them to absorb a degree of movement or stress in bonded joints. This makes them suitable for applications where materials may be exposed to thermal expansion or contraction. Polyurethane adhesives are commonly applied in the assembly of architectural elements such as metal panels or components in the construction sector.   Sources https://www.adhesivesandcoatings.com/adhesives/ about-adhesives/metal-adhesives/ https://www.databridgemarketresearch.com/reports/ global-metal-bonding-adhesives-market   Prepared by: Murat Soygür