Instant adhesives are based on cyanoacrylate monomers. They initiate anionic polymerization triggered by trace moisture in ambient air. Thin adhesive layers achieve initial fixture strength within seconds, and full bonding strength develops after 24 hours.
Standard general-purpose grades form densely cross-linked, rigid films with extremely low elongation at break, prone to cracking when bonding flexible materials. Rubber-toughened variants incorporate elastomers to deliver vibration resistance and bending flexibility.
Classification of Instant Adhesives
- General Purpose (401/502) Low cost; only suitable for rigid, low-shrinkage small parts. Brittle cracking easily occurs under dynamic service conditions.
- Toughened Vibration-Resistant Grade (SG438/SG480) Rubber-modified formulation, ideal for dissimilar material bonding including TPU, silicone, rubber and metals.
- Low Blooming / Silicone-Specific Grade Formulations compatible with primers or primer-free formulas, solving poor adhesion issues of low-surface-energy silicone substrates.
- Surface-Insensitive Grade Suitable for porous plastic substrates with minor oil contamination on surfaces.
Applications of Instant Adhesives
Electronic small component assembly, rapid bonding of hardware and plastic parts, miniature rubber seals, mold repair, fast positioning on production lines.
Proper Operating Instructions for Instant Adhesives
- Degrease and dedust substrates with alcohol;
- Apply a thin layer of adhesive on one side only, press and clamp the mated parts for 10–30 seconds;
- Avoid load bearing within 30 minutes after initial fixture; full curing takes 24 hours before subjecting bonds to stress.
