Industrial Strength Adhesives: A Practical Selection Guide
Industrial Strength Adhesives: A Practical Selection Guide
Industrial strength adhesives bond materials where mechanical fasteners are impractical, where weight must be minimized, or where the joint must seal as well as hold. Selecting the right adhesive requires matching the chemistry to the substrate, the cure time to the process, and the performance properties to the end-use environment. Permabond and MG Chemicals cover the most common industrial adhesive chemistries used in electronics manufacturing, assembly, and repair.
Industrial Adhesive Types Compared
| Adhesive Type | Cure Mechanism | Typical Strength | Best For |
|---|---|---|---|
| Cyanoacrylate (CA) | Moisture (ambient humidity) | High tensile, low peel | Fast bonding of close-fitting parts; plastics, rubber, metals |
| Epoxy (Two-Part) | Chemical reaction (mix ratio) | Very high tensile & shear | Structural bonding, gap filling, high-load joints |
| Electrically Conductive | Heat or two-part cure | Moderate | PCB repair, component attach, EMI shielding, grounding |
| Flame Retardant | Varies by chemistry | Moderate to high | Assemblies requiring UL 94 V-0 compliance or fire resistance |
| UV-Cure | UV light exposure | High | Optical assemblies, glass bonding, fast production lines |
| Anaerobic | Absence of oxygen + metal ions | High shear | Threadlocking, retaining, sealing metal assemblies |
How to Select the Right Industrial Adhesive
Start with the substrate: not all adhesives bond all materials. Cyanoacrylates work well on most plastics and metals but perform poorly on polyethylene, polypropylene, and PTFE without a primer. Epoxies bond a broader range of substrates and fill gaps up to several millimeters. Electrically conductive adhesives are formulated specifically for PCB and electronic applications where solder is not an option.
Next, consider the cure process. Fast-cure cyanoacrylates set in seconds but require close-fitting joints (gap fill typically under 0.15 mm). Two-part epoxies allow longer open time for positioning and can be formulated for room-temperature or elevated-temperature cure. UV-cure adhesives offer on-demand cure but require line-of-sight UV exposure to the bond line.
Finally, match the adhesive to the end-use environment: temperature range, chemical exposure, vibration, and whether electrical conductivity or flame retardancy is required.
Frequently Asked Questions
What is the difference between cyanoacrylate and epoxy adhesives?
Cyanoacrylate adhesives cure rapidly (seconds to minutes) via ambient moisture and are best for tight-fitting joints on plastics, rubber, and metals. They have high tensile strength but low peel and impact resistance. Two-part epoxies cure via a chemical reaction between resin and hardener, offer much higher shear and structural strength, fill larger gaps, and are more resistant to heat, chemicals, and vibration. Epoxies are the better choice for load-bearing or harsh-environment applications.
When should I use an electrically conductive adhesive instead of solder?
Electrically conductive adhesives are used when heat-sensitive components cannot withstand soldering temperatures, when the substrate is non-solderable, or when a reworkable or low-temperature bond is required. They are also used for EMI shielding, grounding straps, and PCB trace repair where solder is impractical.
What does flame retardant mean for an adhesive?
Flame retardant adhesives are formulated to meet UL 94 V-0 or similar fire resistance standards, meaning they self-extinguish when the ignition source is removed and do not drip flaming particles. They are required in assemblies that must comply with electrical safety standards for consumer electronics, industrial equipment, and transportation applications.
Can industrial adhesives replace mechanical fasteners?
In many applications, yes. Adhesive bonding distributes stress across the entire joint rather than concentrating it at fastener points, which can improve fatigue life and reduce stress cracking. Adhesives also seal the joint against moisture and contaminants. However, adhesive joints are generally not reworkable and may require fixturing during cure, so the process must be designed accordingly.
Shop all industrial adhesives at MTE Solutions, including Permabond and MG Chemicals.
