Dr E. Ramanathan PhD | WhatsApp: 9444929163
Alkaline degreaser is a water-based cleaning solution containing alkaline salts and surfactants used to remove oils, grease, dirt, and other contaminants from metal or other hard surfaces. It is widely used in metal pretreatment (like before phosphating or painting), automotive, and industrial cleaning.
Composition
Typical components:
- Alkaline builders: Sodium hydroxide, sodium metasilicate, trisodium phosphate (TSP)
- Surfactants: Nonionic or anionic types like NP-9, SDS
- Sequestrants/Chelating agents: EDTA, sodium gluconate (for hard water tolerance)
- Corrosion inhibitors: For aluminum or mild steel
- Solvents (optional): Glycol ethers for tough grease
Types of Alkaline Degreasers
| Type | pH Range | Typical Use | Suitable Substrates |
|---|---|---|---|
| Mild Alkaline | 8.5–10.5 | Light duty cleaning, aluminum-safe | Aluminum, zinc, soft metals |
| Moderate Alkaline | 10.5–12.5 | General purpose degreasing | Mild steel, stainless steel |
| Heavy Duty / Strong Alkaline | 12.5–14 | Tough oil/grease removal, carbonaceous deposits | Mild steel (not safe for aluminum) |
Application Methods
- Dip tank (immersion)
- Spray (high-pressure or low-pressure)
- Manual wiping
- Ultrasonic cleaning (for precision parts)
Selection Considerations
- Metal type (avoid strong alkali for aluminum or zinc)
- Oil/soil type and load
- Temperature (cleaning efficiency increases with heat)
- Compatibility with downstream process (e.g., phosphating)
Related Posts
SaitechAI — Technical Notes Non-Ionic Surfactants — Overview Non-ionic surfactants are surface-active agents that do not carry any electrical charge in their hydrophilic (water-loving) head group. Their molecules generally contain polyoxyethylene (EO) or polyoxypropylene (PO) chains linked to a hydrophobic (oil-loving) tail such as a fatty alcohol or alkyl phenol.Common types include: Fatty alcohol ethoxylates…
Dr E. Ramanathan PhD Chat on WhatsApp Coating Operator’s Toolkit Contents SaitechAI Metal Pretreatment Chemicals Formulator’s Toolkit. It includes: Dilution (C₁V₁ = C₂V₂) Normality / Molarity helpers FA/TA titration calculators + FA/TA ratio ppm ⇄ g/L ⇄ % w/v converter Replenishment dosage Drag-out loss estimator Coating weight (g/m²) Cost per bath liter & cost per…
https://youtu.be/YDYWKiPnOjg?si=rC6Y2D4axc4gfiY9 SaitechAI: Source Doc. Dr Ramanathan’s technical manuscripts and Verified by Ms. Pavani CauseEffect on Bath / SurfaceRemedy / Corrective ActionCarryover of oil/grease from previous operations (machining, stamping, forming oils)Floating oil film, poor acid-metal contactIntroduce/strengthen alkaline degreasing step before derustingInadequate or bypassed pre-cleaning stageNon-uniform derusting, patchy cleaningEnsure proper hot alkaline cleaning/emulsion cleaning stageDrag-in of oil…
This content is password-protected. To view it, please enter the password below. Password:
Dr E. Ramanathan PhD
Case Study The middle image: untreated Hot rolled steel, The left image: two stage iron phosphated HR sheet, The right image: two stage iron phosphated CR sheet Discuss. Observation, causes, remedies Observation Middle (Untreated Hot Rolled Steel):Heavy mill scale, uneven oxidation, rust spots, and burn marks visible. Surface contamination is…Continue Reading Iron Phosphating on Hot Rolled Steel Components
Dr E. Ramanathan PhD
A paint stripper (also called a paint remover) is a chemical product designed to remove paint, varnish, lacquer, or other coatings from surfaces such as wood, metal, masonry, or plastic. Need and Importance of Paint Stripping 1. Surface Preparation for Recoating Paint stripping ensures that old, degraded, or incompatible coatings…