masterbatch use aluminum paste

masterbatch use aluminum paste

08-07-2026

Requirements for Aluminum Silver Paste Used in Masterbatch

I. Core Selection Rule: Prioritize Non-Leafing Aluminum Silver Paste

1. Non-leafing Aluminium Paste (Universal Standard Grade)

Aluminum flakes are coated with oleic acid or high-molecular resin, delivering excellent compatibility with plastic substrates including PE, PP, ABS, PC and PET. Under high-shear twin-screw extrusion, aluminum flakes embed evenly into the resin matrix instead of floating entirely to the product surface.
Advantages:

  • No silver peeling or poor friction resistance after injection molding & extrusion

  • Compatible with multi-layer co-extrusion, lamination and secondary topcoating without haze

  • High heat resistance & anti-oxidation, free from darkening during long-term outdoor exposure

    Applications: Home appliances, automotive plastic parts, packaging, pipes and general silver masterbatch

2. Leafing Mirror Silver (Only for Special Decorative Masterbatch)

Coated with stearic acid, flakes float to the surface to create an intense chrome mirror finish. Not recommended for regular masterbatch production.
Drawbacks:

  • Coating layer decomposes and aluminum powder oxidizes & darkens under extrusion heat

  • Exposed aluminum layer on product surface results in poor abrasion resistance; recoating is unavailable

  • Only suitable for low-shear, low-temperature one-off decorative pieces (mirror-effect toys, decorative casings)

II. Eight Mandatory Technical Indicators for Masterbatch Production

1. Low Volatiles & Low Moisture (Prevent Pinholes & Bubbles)

  • Non-volatile matter (aluminum solid content): 78%~85% (standard plastic grade: 80%±2%)

  • Free mineral oil / high-boiling carrier oil: white oil with distillation range 250~350℃, no volatilization during processing

  • Moisture content ≤0.15% (strict control required; moisture generates massive pinholes and bubbles under high-temperature extrusion)

  • Low-molecular solvent free, no low-boiling aromatic hydrocarbons; no smoke or odor during extrusion

2. Superior Heat Resistance (Match Processing Temperatures of Various Plastics)

Aluminum flakes feature high-temperature passivation coating to withstand prolonged high shear & heat inside twin-screw extruders:

  • PE/PP masterbatch: ≥240℃, no darkening or discoloration within 5 minutes

  • ABS/PS: ≥270℃, stable for 5 minutes

  • Engineering plastics (PC/PET/PA): ≥290~300℃, anti-oxidation for 5 minutes

    Key requirement: Coating layer stays intact under high temperature; aluminum flakes avoid breakage, agglomeration and darkening

3. High Shear Resistance & Intact Flake Morphology (Eliminate Flow Marks & Silver Streaks)

Thin, flat aluminum flakes with high aspect ratio resist cracking and curling under strong twin-screw shear force.
High-molecular passivation coating withstands shear stress without loss of metallic luster after processing.
Consequences of substandard paste: Gray tone from broken aluminum powder, weld lines, flow channel marks and matte surface on finished products.

4. Excellent Dispersibility, No Hard Agglomerates (Free of White Spots & Color Specks)

  • Pre-dispersible grade, rapidly wets and blends with PE wax, EVA wax and carrier resin

  • Wet sieve pass rate ≥99.5%, free of coarse particles and agglomerates

  • Uniform dispersion after one-time twin-screw mixing; no repeated kneading needed

5. Controllable Particle Size Distribution (For Custom Metallic Effects)

Three D50 median particle size grades for different demands:

  1. Fine silver masterbatch (fine matte / silky silver): 3~10μm, high hiding power, ultra-smooth surface

  2. Standard glitter silver (general home appliances & packaging): 12~25μm, balanced metallic sparkle

  3. Coarse glitter silver (high flash & 3D metallic appearance): 30~80μm, strong sparkling effect

    Requirement: Narrow particle size distribution, no oversized coarse grains to avoid protruding particles on products

6. Anti-Migration & No Blooming

Modified resin-compatible coating prevents aluminum pigment migrating to product surface or blooming after high-temperature molding. Applicable for food-contact articles and long-term indoor/outdoor products.

7. Environmental Compliance (REACH / GB 9685 Food Contact Standard)

  • Total heavy metal impurities (Pb, Cd, Hg, Hexavalent Chromium) ＜100ppm

  • Free of phthalates and SVHC substances of very high concern

  • Food-contact grade: Specific aluminum migration ≤5mg/kg, usable for food packaging masterbatch

8. Storage Stability

No oxidation, precipitation or delamination within 6 months under sealed storage; no darkening under low/high temperature storage; no crusting after opening.

leafing aluminum paste for masterbatch


Get the latest price? We'll respond as soon as possible(within 12 hours)

Privacy policy