Technical Guide: Anti-Corrosion and High-Abrasion Protection for Tinplate Dry Shampoo Aerosol Cans
In Aerosol Packaging R&D and manufacturing, powder-based products such as dry shampoos and powder antiperspirants present significant abrasive challenges. Formulation ingredients like starch, silica, and rice powder act as active abrasives. Without optimized internal protection, these formulations frequently cause internal coating wear, leading to pinhole corrosion and product leakage.
This guide is designed for cosmetic R&D teams, packaging engineers, and supply chain managers. It analyzes the root causes of internal wall pitting in tinplate dry shampoo aerosol cans and provides systemic anti-abrasion packaging solutions.
1. Degradation Mechanism of Internal Coatings by Powder Particles
An Aerosol Can operates as a dynamic, high-pressure system. Under these conditions, insoluble powder particles act as micro-abrasives against the interior walls:
Mechanical Cutting and Wear (The Sandpaper Effect)
Consumers regularly shake Aerosol Cans prior to use. During agitation, settled powder particles rub against the inner epoxy or phenolic coating, creating micro-scratches on standard-hardness films.
High-Velocity Fluid Scouring
When the valve actuates, high-pressure propellants (e.g., propane, butane, isobutane) push powder particles at extreme velocities through the container. This causes severe fluid erosion along the bottom dome and inner wall corners.
Pinhole Corrosion and Electrochemical Perforation
Once a standard coating (pencil hardness 1H–2H) is scratched down to the bare tinplate, moisture, alcohols, or active ingredients in the formula react with the exposed metal. This initiates localized electrochemical corrosion, rapidly resulting in pinhole leaks.
2. Technical Specification: The "Hard + Slip" Dual Protection Strategy
Standard coating thickness is insufficient for highly abrasive formulations. Effective protection requires reinforcing both physical film hardness and surface lubricity:
Increasing Film Hardness: Pencil Hardness ≥ 3H
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Technical Approach: Utilize high-crosslinking epoxy-phenolic coatings or integrate nano-ceramic fillers.
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Engineering Effect: Increases film density and scratch resistance, preventing powder particles from penetrating or cutting the coating upon impact.
Reducing Coefficient of Friction: CoF < 0.15
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Technical Approach: Apply a specialized polymer Lubricated Overprint Varnish (OV) as the top layer.
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Engineering Effect: Significantly lowers the internal Coefficient of Friction (CoF). Powder particles slide smoothly across the surface instead of creating dry friction, eliminating the primary cause of mechanical scratching.
3. Performance Matrix: Standard Aerosol Cans vs. SAILON High-Abrasion Cans
| Test Metric | Standard Aerosol Can | SAILON High-Abrasion Can | Primary Engineering Benefit |
| Internal Pencil Hardness | 1H – 2H | ≥ 3H | Prevents starch and silica from scratching the film |
| Coefficient of Friction (CoF) | 0.35 – 0.45 | < 0.15 | Minimizes particle drag and surface wear |
| Simulated Shake Test | Base metal exposed at 1,000 shakes | Zero scratches at 10,000 shakes | Ensures durability across the full product lifecycle |
| Leakage Risk Rate | 1% – 3% | Near 0% | Prevents pinhole corrosion and batch quality failures |
4. Packaging Engineering FAQ
Q1: Powder formulations often cause valve clogging in addition to internal wall scratching. What are the packaging best practices?
SAILON Engineering Response:
Valve clogging typically stems from powder settling and agglomeration. In addition to specifying high-abrasion interior coatings, optimize the bottom dome profile to prevent powder trapping, and pair the container with a high-flow powder valve featuring an integrated mesh filter.
Q2: Does increasing coating hardness to 3H compromise film flexibility during can necking and seaming?
SAILON Engineering Response:
Traditional high-hardness coatings often suffer from brittleness and reduced adhesion. SAILON utilizes a Flexibility & Hardness Balance formulation that maintains 3H scratch resistance while retaining high metallic adhesion. This prevents cracking or flaking under high-speed necking, flanging, and double-seaming pressures.
5. Technical Support & Inquiries
Selecting the correct internal coating system is essential for maintaining supply chain stability and eliminating quality claims for powder aerosol products.
📩 Evaluating or resolving internal corrosion issues in dry shampoo packaging?
Contact the SAILON engineering team to request the Powder Aerosol Anti-Abrasion Test Report and technical evaluation samples.