Beads are dispensed by hand gun, robot or nozzle, usually round or triangular in cross-section, and sized so the adhesive spreads to the right bondline and width when the parts close. Bead size, placement and continuity are inspected by eye, by vision cameras or by weight. Gaps in a bead become leak paths and weak spots once the joint is closed.
Robot's laying a 6 millimeter bead instead of 8, and there's a skip at every corner. Recalibrate the flow.
A triangular nozzle cut gives a bead that spreads more evenly under a flat part than a round bead of the same volume.
Also heard as
- glue bead
- adhesive bead
Related terms
Squeeze-out
The excess adhesive that oozes out along the joint edges at clamp-up, read as proof the joint is full.
Bondline
The layer of adhesive between two bonded parts, and in shop talk the thickness of that layer.
Meter-mix
Dispensing equipment that pumps two adhesive components from bulk containers in a set ratio and mixes them on demand.
Sag
An adhesive bead slumping or running down a vertical or overhead surface before it sets.