Custom-Made Sealant Bead Tips for Spray Nozzles

1) What Is a Sealant Bead Tip?

A sealant bead tip is a specially designed nozzle for dispensing high-viscosity adhesives and sealants such as silicone, polyurethane, MS-polymer, butyl, or epoxy. Unlike conventional spray nozzles that atomize liquid, the bead tip creates a continuous bead or line with controlled width, height, and geometry. These tips are commonly mounted on cartridge guns, drum-pump systems, or automated dispensing robots.

2) Applications

• Construction & Facades: Panel joints, glass glazing, stone-wool panel connections

• Automotive: Body flange sealing, dust and water protection seams

• White Goods & HVAC: Cabinet assembly, vibration damping

• Marine & Rail: Deck joints, panel seams

• Wood & Furniture: Edge bonding, groove filling

• Electronics: IP-rated gasketing (form-in-place gaskets)

3) Design Principles

3.1 Outlet Geometries

• Flat / Fishtail: Wide, ribbon-like beads (10–30 mm)

• V-Notch: Triangular profile; ideal for finishing and pressing

• U-Notch: Rounded top surface; aesthetic finish

• Tapered Round: Narrow bead (3–8 mm); precise start and stop

• Dual-Channel: Two parallel beads or gasket profiles

3.2 Angles & Ergonomics

• 0°, 30°, 45°, 60° angled bodies for hard-to-reach spots

• Swivel adapters for easy right- or left-hand operation

3.3 Materials

• Stainless Steel AISI 304/316: Corrosion and solvent resistance

• Anodized Aluminum: Lightweight and cost-effective

• Nickel-Plated Brass: Economical for short cycles

• PTFE / UHMW-PE Liners: Non-stick, low friction

• Hybrid: Metal body with PTFE insert

3.4 Connections

• 1/4", 3/8", 1/2" BSPP/BSPT/NPT threads

• Quick couplings for facade sealant guns

• Luer-Lock fittings for lab and fine bead applications

4) Process Parameters & Sizing

4.1 Viscosity & Pressure

• Sealants typically range 30,000–1,000,000 mPa·s

• Operating pressure: 5–60 bar

• For high viscosity, heated hoses/tips (30–60 °C) improve flow

4.2 Bead Size Rules of Thumb

• Bead Width (W) ≈ 1.2–1.5 × Nozzle Opening (W₀)

• Bead Height (H) ≈ 0.25–0.6 × W

• Line Speed inversely affects height

* Based on 10–30 bar, 23 °C, medium viscosity sealant.

5) Custom Manufacturing Options

• Nozzle Geometry: V-notch angle (60°/90°), rounded edges, chamfers

• Shim System: 0.1–0.5 mm shims for width adjustment

• Heated Tips: Integrated cartridge heaters, PT100 sensors

• Wear-Resistant Coatings: Ni-P, TiN, or DLC

• Quick-Change Locking: Spring pins or quarter-turn systems

• Visual Guides: Laser-etched scale, alignment markers

• Purge Port: Solvent or nitrogen cleaning connection

• Inspection Windows: Transparent cover for bead monitoring

6) Technical Specification Example

• Model: MAST-U10-45-QCF

• Outlet: 10 mm U-notch, ±0.05 mm

• Angle: 45°

• Material: AISI 316L body, PTFE liner

• Connection: 3/8" BSPP + quick coupling

• Max Pressure: 60 bar (tested at 1.5×)

• Seals: FKM (optional EPDM, FFKM)

• Temp Range: 5–80 °C (up to 120 °C with heating)

• Tip Hardness: DLC ~2500 HV

• Cleaning: Solvent-resistant; purge port M5

• Weight: 145 g

7) Installation & Setup

1. Clean surface (dust/oil free)

2. Mount tip (torque e.g., 8–12 Nm for 3/8" BSPP)

3. Start with 15 bar, 35 °C, adjust as needed

4. Test line on 200 mm sample panel

5. Match line speed with pressure

6. Keep standoff at 2–4 mm

7. Reduce pressure gradually to avoid tailing

8) Maintenance

• Daily: Clean tip with compatible solvent and purge

• Weekly: Check liner and O-rings

• Monthly: Inspect nozzle lips with gauges or profilometer

• Storage: Cap the tip, store dry and UV-protected

9) Troubleshooting