Producing a properly sealed can lid requires precise adhesive application through three critical stages: punching, glue dispensing, and drying. While most manufacturers focus on the circular adhesive pattern, the radial distribution (how adhesive spreads from center to edge) often determines sealing reliability.

Radial distribution involves three key measurements:
– Glue band width across the lid surface
– Distance between adhesive edge and chuck wall
– Material balance between surface coating and groove filling

Getting this right starts with material selection. The adhesive’s viscosity and solid content must match the lid dimensions. Thicker formulas work better for larger lids, while faster-spinning chucks (controlled through gear adjustments or variable frequency drives) help spread thinner adhesives evenly.

Common application errors reveal themselves through material behavior. Low-viscosity glue tends to flood groove areas, creating messy overflow. High-viscosity formulas might leave uneven bands or excessive edge gaps. When this happens, technicians typically tweak either the adhesive formula or equipment settings – sometimes moving the dispensing nozzle closer to the edge helps compensate for slow-spreading materials.

The gold standard remains a seamless “O” pattern without skips or bubbles. Even minor defects matter – a single pinhole can compromise the entire seal. Watch out for these frequent troublemakers:
– Glue pumps delivering inconsistent amounts
– Chucks wobbling during rotation
– Nozzles with partial clogs
– Air pockets formed during adhesive mixing

Most production issues stem from equipment maintenance rather than material flaws. A sticky chuck that doesn’t rotate smoothly or a nozzle needing cleaning often causes more headaches than the adhesive itself. Regular machine checks prevent 80% of common application defects.