Types of Industrial Adhesives
Epoxies
Two-part structural adhesives:
- Standard Epoxy: General purpose, 5-30 minute set time
- Fast-Set Epoxy: 1-5 minute initial cure
- High-Strength Epoxy: 3,000-5,000+ psi shear strength
- Flexible Epoxy: Vibration and impact resistant
Best for:
- Metal-to-metal bonding
- Structural assemblies
- Gap filling applications
- High-temperature environments
Cyanoacrylates (Super Glue)
Instant adhesives:
- General Purpose: Multi-surface bonding
- Rubber Toughened: Impact and peel resistant
- Low Viscosity: Wicking into tight spaces
- High Viscosity: Gap filling, vertical applications
Best for:
- Small part assembly
- Plastic bonding
- Quick repairs
- High-speed production
Anaerobic Adhesives
Cure in absence of air:
- Threadlockers: Prevent fastener loosening
- Low strength (removable): Purple
- Medium strength: Blue
- High strength (permanent): Red
- Thread Sealants: Seal pipe threads
- Retaining Compounds: Secure bearings and bushings
- Gasketing: Form-in-place gaskets
Best for:
- Threaded fasteners
- Pipe thread sealing
- Bearing retention
- Metal flange sealing
UV Cure Adhesives
Cure with UV light exposure:
- Instant cure: Seconds to full strength
- Shadow cure: Secondary moisture cure
- Low viscosity: Penetrates tight spaces
- High viscosity: Gap filling
Best for:
- Glass bonding
- Clear plastic assembly
- Medical device manufacturing
- High-speed production lines
Silicone Adhesives/Sealants
Flexible, temperature resistant:
- Acetoxy: General purpose, vinegar smell
- Neutral Cure: Non-corrosive, sensitive electronics
- High Temperature: 500°F+ continuous
- Low Temperature: Flexible to -65°F
Best for:
- High-temperature applications
- Outdoor/weatherproofing
- Flexible bonds
- Electrical insulation
Polyurethane Adhesives
Tough, flexible bonds:
- One-Part: Moisture curing
- Two-Part: Faster cure, higher strength
- Foaming: Expands to fill gaps
- Non-Foaming: Dimensional stability
Best for:
- Dissimilar materials
- Flexible substrates
- Outdoor applications
- Automotive assemblies
Material Compatibility Guide
Metals
Steel/Stainless Steel:
- Epoxies (structural)
- Anaerobics (threadlocking)
- Cyanoacrylates (small parts)
- UV cure (with primer)
Aluminum:
- Epoxies (structural)
- Cyanoacrylates (with primer)
- Silicones (flexible bonds)
Copper/Brass:
- Epoxies
- Cyanoacrylates
- Anaerobics (active surface)
Plastics
ABS:
- Cyanoacrylates
- Solvent cements
- Epoxies
Polycarbonate:
- UV cure adhesives
- Cyanoacrylates (low bloom)
- Silicones
PVC:
- Solvent cements
- Cyanoacrylates
- Polyurethanes
Polyethylene/Polypropylene:
- Specialized primers required
- Two-part epoxies with primer
- Hot melt adhesives
Composites
Carbon Fiber:
- Epoxies (structural)
- Polyurethanes (flexible)
- Cyanoacrylates (small repairs)
Fiberglass:
- Polyesters
- Epoxies
- Vinyl esters
Strength Requirements
Shear Strength Guidelines
Light Duty (<1,000 psi):
- Temporary fixtures
- Non-structural assemblies
- Decorative applications
Medium Duty (1,000-3,000 psi):
- General assembly
- Consumer products
- Non-critical components
Heavy Duty (3,000-5,000 psi):
- Structural assemblies
- Load-bearing bonds
- Industrial equipment
Extra Heavy (>5,000 psi):
- Critical structural bonds
- Aerospace applications
- High-stress environments
Environmental Considerations
Temperature Resistance:
- Standard epoxies: -60°F to 300°F
- High-temp epoxies: to 500°F+
- Silicones: -65°F to 500°F
- Cyanoacrylates: -65°F to 180°F
Chemical Resistance:
- Epoxies: Excellent chemical resistance
- Polyurethanes: Good moisture resistance
- Silicones: Excellent weather/ozone resistance
- Anaerobics: Good solvent resistance
UV Resistance:
- Silicones: Excellent
- Polyurethanes: Good (with additives)
- Epoxies: Fair (yellow without UV stabilizers)
- Cyanoacrylates: Poor (outdoor grades available)
Application Methods
Manual Application
- Hand-held cartridges
- Squeeze bottles
- Brush applicators
- Best for: Low volume, repairs, maintenance
Meter-Mix-Dispense
- Two-part adhesive systems
- Precise ratio control
- Repeatable application
- Best for: Production lines, quality control
Automated Dispensing
- Robotic application
- Programmable patterns
- High-speed production
- Best for: High volume manufacturing
Spray Application
- Large surface areas
- Contact adhesives
- Fast coverage
- Best for: Laminating, packaging
Surface Preparation
Cleaning Requirements
- Degrease: Remove oils with solvent cleaner
- Abrade: Light sanding for mechanical bond
- Clean Again: Remove sanding dust
- Dry: Ensure surface is completely dry
Primer Usage
When primers are needed:
- Difficult-to-bond plastics (PE, PP, PTFE)
- Enhanced cyanoacrylate bonds
- Improved moisture resistance
- Critical structural applications
Curing Considerations
Cure Time Factors
Open Time:
- Time available for assembly
- Varies by adhesive type
- Temperature dependent
Fixture Time:
- Time until parts can be handled
- Typically 50-70% of full strength
- Important for production speed
Full Cure:
- Time to maximum strength
- Can be 24-72 hours
- Continue to strengthen after handling
Temperature Effects
- Warmer temperatures: Faster cure
- Cooler temperatures: Slower cure
- Below minimum: May not cure properly
- Heat acceleration: Can speed production
Quality Control
Bond Testing
- Peel Test: Flexible substrates
- Shear Test: Structural bonds
- Tensile Test: Pull-off strength
- Destructive Testing: Production samples
Inspection Methods
- Visual inspection for coverage
- UV fluorescence for coverage verification
- Ultrasonic testing for voids
- Torque testing for threadlockers
Storage and Shelf Life
Storage Conditions
- Temperature: 40°F - 80°F ideal
- Humidity: Control for moisture-sensitive adhesives
- Light: Protect UV adhesives from light
- Refrigeration: Extends life for some products
Typical Shelf Life
- Epoxies: 1-3 years (unmixed)
- Cyanoacrylates: 12-18 months (unopened)
- Anaerobics: 2-3 years
- Silicones: 12-24 months
- UV Cure: 12-24 months
Safety and Handling
PPE Requirements
- Safety glasses with side shields
- Nitrile gloves (check chemical compatibility)
- Ventilation for solvent-based products
- Respiratory protection when needed
First Aid
- Skin contact: Wash with soap and water
- Eye contact: Flush 15 minutes, seek medical attention
- Inhalation: Move to fresh air
- Ingestion: Seek medical attention immediately
Bulk Purchasing Considerations
For industrial users:
- Volume discounts on gallons/drums
- Custom packaging available
- Consignment programs
- Technical support included
- JIT delivery options
Machrio offers competitive pricing on industrial adhesives with volume discounts and technical support for process optimization.