Dr E. Ramanathan PhD
Caustic-Free Alkaline Spray Degreasing Liquid Concentrate
(100 kg batch)
| S.No | Raw Material | Quantity (kg) | Function |
|---|---|---|---|
| 1 | Sodium metasilicate (low Na₂O grade) | 5.0 | Mild alkaline builder |
| 2 | Sodium gluconate | 3.0 | Chelating agent, scale inhibitor |
| 3 | EDTA (Na₄) | 1.5 | Strong chelating agent for metal ions |
| 4 | Nonionic surfactant (Alphox 200) | 6.0 | Emulsifier and degreaser |
| 5 | Anionic surfactant (Sodium lauryl ether sulfate – SLES) | 4.0 | Foaming and detergency agent |
| 6 | Solvent (IPA or Butyl Cellosolve) | 5.0 | Oil dissolving and drying promoter |
| 7 | Corrosion inhibitor (Sodium molybdate) | 2.0 | Temporary rust prevention |
| 8 | Defoamer (Silicone-based) | 0.2 | Foam control |
| 9 | Demineralized Water | 73.3 | Balance to 100 kg |
Working Bath Concentrations
| Application Mode | Dilution Ratio | Concentration (% v/v) |
|---|---|---|
| Spray cleaning | 1:20 to 1:40 | 2.5–5.0 |
| Brush cleaning | 1:10 to 1:20 | 5.0–10.0 |
| Ultrasonic bath | 1:30 to 1:50 | 2.0–3.3 |
Features
- No NaOH or KOH – Safe for aluminum, zinc and painted surfaces
- Low foaming at high pressure – Suitable for spray cleaning
- Biodegradable surfactants – Environmentally friendly
- Temporary rust protection – Prevents flash rusting on mild steel
Defoamer Suggestion
Suggested defoamer brands suitable for alkaline, aqueous degreasing formulations:
- Momentive
- Y-30 or Y-45 – Silicone-based, good for low foam aqueous systems
- Evonik
- Antifoam A 204 – Non-ionic silicone compound, stable in alkaline media
- Dow
- DOW Corning 2210 or DOW Corning Q2-3302 – Silicone emulsion defoamers
- BASF
- Foamaster MO 2110 – Mineral oil-based, suitable for industrial cleaners
- Wacker
- Silfoam SE 36 or Silfoam SE 47 – Effective at low dosage in spray wash systems
- BYK (ALTANA)
- BYK-024 or BYK-066 N – Silicone-containing defoamers with strong persistence
Choose based on:
- pH stability (ensure suitable for pH 9–11)
- Compatibility with surfactant system
- Application method (spray vs immersion)
Momentive Y-30 or Wacker Silfoam SE 36 are commonly used in cleaning chemicals due to their strong performance and availability in India.
FAQ
Dilution Ratio
In industrial cleaning chemical formulations like spray degreasing liquids, the dilution ratio is typically expressed as weight by volume (w/v) unless specifically stated otherwise.
Example (w/v basis):
- 1:20 dilution (w/v) = 1 kg of concentrate + 20 litres of water
- This is common in practice because water is measured in volume and chemical concentrates in weight.
However, if both concentrate and water are weighed:
- It is weight by weight (w/w).
If both are measured in liters:
- It is volume by volume (v/v).
Recommendation:
- For consistency and field usage, use weight by volume (w/v):
1 kg of degreaser + X litres of water — easier for factory operators to follow. - Always mention units clearly in technical data sheets.
Recommended Nozzle Types for Spray Degreasing and Water Rinsing
1. Spray Degreasing (with chemical)
- Type: Flat Fan Nozzles
- Material: Stainless Steel 316 or PVDF (for corrosion resistance)
- Spray Angle: 40° to 65° (for conveyors)
- Pressure: 2–5 bar (30–75 psi)
- Flow Rate: 2–10 L/min depending on application
- Examples:
- Spraying Systems Co. VeeJet® nozzles
- Lechler Series 652 flat fan nozzles
- BETE NF Series
2. Water Rinsing (post-degreasing)
- Type: Full Cone Nozzles or Hollow Cone Nozzles
- Purpose: Uniform rinsing and flushing
- Spray Angle: 60° to 90°
- Pressure: 1.5–3 bar
- Material: Brass (soft water) or SS316 (hot/hard water)
- Examples:
- Spraying Systems Co. FullJet®
- Lechler Series 490 or 460
- BETE TF Series
Additional Considerations
- Self-cleaning nozzles are preferred in high particulate environments.
- Quick-change nozzle tips simplify maintenance.
- For high-pressure jet degreasing, use solid stream or fan jet nozzles with higher bar ratings (10–20 bar).
General Types of Spray Nozzles
Spray nozzles play a critical role in degreasing and surface preparation, especially in spray wash cabinets, tunnel washers, and inline cleaning systems. The choice of nozzle affects cleaning efficiency, coverage, fluid consumption, and even safety when working with chemical-based degreasers.
✅ Types of Spray Nozzles for Cleaning Applications
| Nozzle Type | Spray Pattern | Best For | Remarks |
|---|---|---|---|
| Flat Fan Nozzles | Narrow flat sheet | Spray cabinets, conveyor washers | Most common for degreasing; angles from 15° to 110°; good impact force |
| Full Cone Nozzles | Circular cone | Immersion spray boost, tunnel wash | Broad coverage; lower impact than flat fan |
| Hollow Cone Nozzles | Ring-shaped cone | Rinsing or foaming | High atomization; not ideal for viscous oils |
| Solid Stream (Jet) | Concentrated jet | Spot cleaning, high-pressure jets | Used for stubborn deposits or pre-wash blasting |
| Air-Assisted Nozzles | Atomized fine mist | Precision parts, electronics | For solvent-based degreasers or fine rinsing |
| Rotary Spray Heads | Rotating jets | Tank & drum cleaning | Internal CIP systems, self-powered by fluid pressure |
🔍 Key Selection Parameters for Degreasing Use
| Parameter | Typical Range / Choice | Why It Matters |
|---|---|---|
| Spray Angle | 40°, 65°, 80°, 110° | Wider angles = broader coverage, less impact |
| Flow Rate | 1–10 L/min/nozzle | Depends on pressure & nozzle size |
| Material | SS316, Brass, PVDF, PTFE | Must resist corrosion from alkalis, surfactants |
| Operating Pressure | 1–10 bar (15–150 psi) | Higher pressure = more impingement, but higher misting |
| Droplet Size | 100–400 microns | Smaller droplets rinse better, larger clean better |
| Nozzle Spacing | 100–300 mm (typical) | Even coverage, especially for flat parts |
⚙️ Spray Nozzle Configuration Tips:
- Position nozzles at offset angles to avoid shadowing on complex parts.
- Use low-angle fans (25°–40°) for high impingement, wide-angle fans (80°–110°) for full coverage.
- Counter-flow spray setups help reduce contamination and improve cleaning.
- Consider quick-release or clip-on nozzles for maintenance and changeover.
- Use inline filters to prevent clogging if solids are present in solution.
🛠️ Suggested Materials for Chemical Resistance:
| Nozzle Material | Best For | Resists |
|---|---|---|
| Stainless Steel (SS316) | Most alkaline degreasers | Corrosion, abrasion |
| Brass | Mild cleaners | Not suitable for aggressive alkali |
| Polypropylene (PP) | Low-cost, basic use | Limited temperature resistance |
| PVDF (Kynar) | Aggressive chemicals | Excellent chemical resistance |
| PTFE (Teflon) | High-end applications | Best for acids, solvents, alkalis |
FAQ
A flat fan nozzle is named for the shape of the spray pattern it produces — a thin, flat sheet of liquid that spreads out in a fan-like shape.
Meaning of “fan”:
- The term “fan” refers to the triangular or wedge-like spread of the liquid, similar to a handheld fan or fan blade.
- When viewed from the front or side, the spray pattern resembles a flat triangle or arc, with the widest area at the surface being sprayed.
Why “flat”?
- The spray sheet is thin in the vertical direction but wide in the horizontal direction, forming a flat plane of liquid.
- It is ideal for uniform coverage along a line (e.g., conveyor parts, flat surfaces).
Application relevance:
- Ensures even distribution.
- Good for overlapping multiple nozzles for full surface coverage.
In short, “fan” refers to the spread shape of the spray, and “flat” refers to the narrow thickness in one axis, making it suitable for directional, uniform spraying.
