Adhesives and sealants: Characteristics
Open time, set time and strength: choosing the right glue
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Commercial value depends on bond strength on the target substrates, setting speed, open time, temperature and moisture resistance, VOC content and ease of use. Construction sealants are judged on movement capability and weathering; packaging adhesives on line speed; structural adhesives on shear and peel strength and durability.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Solids content | about 40-55% for PVAc wood glue (indicative) | drying speed and coverage | indicative |
| Open time and set time | seconds for hot melts and cyanoacrylates, 10-30 min for PVAc, hours for epoxy (indicative) | matches line or job speed | indicative |
| Lap shear strength | about 10-30 MPa for structural epoxies (indicative) | replaces welds and rivets | indicative |
| Movement capability (sealants) | plus or minus 25-50% (ISO 11600 classes, indicative) | joint durability | indicative |
Commercial grades
- PVAc white glue (wood, paper)
- VAE and acrylic dispersions
- EVA and polyolefin hot melts
- Reactive PU hot melts
- Pressure-sensitive acrylic and rubber
- Epoxy structural and putty
- Cyanoacrylate instant
- Silicone and MS-polymer sealants
- Polychloroprene contact
- Cementitious tile adhesives