| 500–800 mPa·s | Low-to-medium viscosity water-based PVA or dextrin adhesive | Air-assisted spray | Diaphragm or low-pulsation gear pump with adjustable flow control | 0.5–0.8 mm | 1.5–3.0 bar | Usually not required; keep the adhesive within the supplier’s specified temperature range | Fine, narrow bead or light mist with controlled overlap | Folding cartons, light paperboard, small side-seam areas | Check overspray control, atomizing-air stability, filter size, and minimum controllable flow |
| 800–1,200 mPa·s | Standard water-based PVA, dextrin, or modified-starch adhesive | Air-assisted bead or spray | Progressive-cavity, diaphragm, or precision gear pump | 0.6–1.0 mm | 2.0–4.0 bar | Optional low-temperature conditioning for consistent flow | Continuous bead, short intermittent bead, or narrow fan spray | General folding cartons, corrugated sleeves, paper bags | Choose a pump with low pulsation and a positive shut-off valve to prevent stringing |
| 1,200–2,000 mPa·s | High-solids PVA, dextrin, starch blend, or filled water-based adhesive | Pressure-fed bead system | Progressive-cavity or precision gear pump; use a pressurized reservoir for stable supply | 0.8–1.2 mm | 3.0–5.0 bar | Optional jacket or hopper warming, commonly around 25–40°C when permitted by the adhesive specification | Defined bead or controlled curtain; avoid excessive atomization | Heavy paperboard cartons, rigid box wraps, laminated paper structures | Verify shear sensitivity, solids content, filter capacity, hose diameter, and cleaning access |
| 2,000–3,000 mPa·s | Thick PVA, dextrin, starch-based, or water-based adhesive with higher solids | Positive-displacement bead application | Progressive-cavity or robust gear pump with a short, large-diameter fluid path | 1.0–1.5 mm | 4.0–6.0 bar | Often beneficial; use controlled warming only if approved for the adhesive | Continuous bead, segmented bead, or wide low-pressure stripe | Rigid setup boxes, thick board, large-area side seams | Prioritize torque capacity, pressure relief, anti-drip shut-off, and easy flushing |
| 3,000–4,000 mPa·s | Very high-solids water-based adhesive, thick dextrin, or heavily modified starch adhesive | Heated or conditioned bead system | Progressive-cavity pump or high-torque gear pump with pressure monitoring | 1.2–1.8 mm | 5.0–7.0 bar | Frequently required for stable metering; use temperature feedback and insulated lines | Large, slow-moving bead rather than atomized spray | Heavy-duty cartons, rigid paperboard cases, specialty packaging | Confirm maximum allowable temperature, pump seal compatibility, dwell time, and nozzle-cleaning procedure |
| 4,000–5,000 mPa·s | Extremely viscous water-based adhesive or hot-applied adhesive measured at its process temperature | High-pressure precision bead system | High-torque progressive-cavity or precision gear pump with a heated, recirculating supply circuit | 1.5–2.2 mm | 6.0–8.0 bar | Normally required for consistent flow; temperature must remain within the adhesive supplier’s safe operating range | Thick continuous bead, segmented bead, or controlled stripe; atomizing spray is generally unsuitable | Heavy rigid boxes, thick board laminations, high-bond-strength seams | Use pressure relief, heated hoses where approved, temperature interlocks, and a nozzle sized to prevent excessive back pressure |