The main joining methods in manufacturing are adhesive bonding, <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/1.1.7-thermal-joint-welding/'>welding</a>, screwing, riveting, clipping, soldering and brazing. Joining is a fundamental aspect that allows for the assembly of components into a final product. Each method has its advantages and is suitable for specific materials and applications.

When choosing a material for a specific application, various factors need to be taken into account to ensure that the material performs effectively under the intended use conditions: expected mechanical forces, thermal and electrical properties, <a style='color: #E1000F; text-decoration: underline;' href='https://www.loctitex.com/en/manuals/bonding/2.2.3.4-chemical-resistance/'>chemical resistance</a>, <a style = 'color: #E1000F; text-decoration: underline;' href='https://www.loctitex.com/en/manuals/bonding/2.2.3.1-environmental-factors/'>environmental impact</a>, durability and lifespan, regulatory compliance, and <a style='color: #E1000F; text-decoration: underline;' href='https://www.loctitex.com/en/manuals/bonding/4.2.5-health-and-safety/'>health and safety</a>.

Understanding how a joining technique distributes force is crucial for ensuring the assembly's structural integrity, functionality, and longevity. It impacts the assembly's ability to perform under various operational conditions without failing or degrading prematurely.

Automotive-grade adhesives are widely used in vehicle manufacturing and repair due to their bonding strength, durability, and resistance to various environmental factors (e.g. chemical exposure, moisture, temperature, etc.). Common applications areas include body panels, bumpers, windshields/windscreens and windows, interior components and under-the-hood applications such as gasketing or <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/6.6.1-threadlockers'>threadlocking</a>.

Environmental factors play a crucial role in <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/7.3-critical-factors-when-selecting-adhesives/'>selecting adhesives</a> for automotive manufacturing, as vehicles are exposed to various environmental conditions throughout their lifespan. The choice of adhesive must ensure that it maintains its bonding strength and integrity under these conditions. The most critical environmental factors include extreme temperature, moisture and humidity, UV radiation, <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/4.5.4-chemical-exposure/'>chemical exposure</a>, vibration, and impact.

When selecting an adhesive for a specific application, several factors come into play to ensure optimal performance and compatibility. These include environmental conditions, type of <a style='color: #E1000F; text-decoration: underline;' href='https://www.loctitex.com/en/manuals/bonding/2.2.1.7-overview-of-substrate-properties/'>substrate(s) and surface properties</a>, <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/6.2.1-cyanoacrylates/'>curing time and process</a>, temperature and chemical resistance, viscosity and application method, and health and safety considerations.

The importance of strength versus flexibility in an adhesive depends mainly on the bonded assembly's performance requirements. Generally, rigid adhesives are ideal where the bond must withstand high loads or <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/4.4-stresses-on-joints/'>stresses</a>, while flexible adhesives are ideal where the bonded materials might experience movement, <a style='color: #E1000F; text-decoration: underline;' href='https://www.loctitex.com/en/manuals/bonding/4.4.8-thermal-expansion/'>expansion</a>, or <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/5.2.1.4-substrate-thermal-expansion-and-contraction/'>contraction</a>.

When choosing an activator for two-part, no-mix acrylic adhesive systems, several key factors should be considered, including fixture time, bond strength, on-part life of the <a style='color: #E1000F; text-decoration: underline;' href='https://www.loctitex.com/en/manuals/bonding/4.3.5-surface-preparation-chemical-activators/'>activator</a>, activator form, material compatibility, and viscosity and flow properties.

Two-part acrylic adhesives, known for their strong bonding capabilities and versatility, possess several distinctive characteristics, such as, fast curing, cured high-strength bonds, high gap-filling capabilities, good tolerance to oily surfaces, <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/4.5.2-operating-temperature/'>temperature</a> and chemical resistance, durability, and flexibility in application.

Two-part acrylic adhesives cure through a chemical reaction that occurs between the two components when they are mixed. The key curing process involves mixing resin and hardener, <a style='color: #E1000F; text-decoration: underline' href='https://www.loctitex.com/en/manuals/bonding/6.2.1-cyanoacrylates/'>polymerisation</a>, cross-linking, and exothermic reactions.

UV/LED light curing technology offers several manufacturing process design benefits, including fast curing times, lower operating temperatures, energy efficiency, longer lifespan, consistent output, reduced maintenance of automated dispensing systems, and environmental responsibility. These benefits contribute to a more efficient, cost-effective, and adaptable manufacturing process.

UV/LED light cure adhesives are favoured for their rapid curing speed, ease of automation in manufacturing processes, and strong, clear bonds. Typical usage includes plastic bonding, electronics, automotive manufacturing, medical device assembly, optical and glass assembly, jewellery and watchmaking, and dental and orthodontic applications.