Plastic

Mar 12, 2026

Plastics processing places more demanding constraints on pigment performance than most other effect pigment applications. Injection molding, extrusion, and blow molding expose pigments to temperatures between 180°C and 320°C depending on the polymer system — a range that eliminates most organic colorants and many specialty effect pigments from consideration before formulation trials begin. At the same time, brand owners across automotive interiors, consumer packaging, household goods, and personal care are demanding metallic, pearl, and color-shift effects in plastic components that were previously only achievable in coatings. Kolortek's plastics-relevant pigment range covers thermally stable pearlescent and effect pigments across natural mica, synthetic mica, and borosilicate substrates, with particle size options suited to masterbatch compounding, injection molding, and extrusion applications.

Kolortek's Solutions for Plastic

Application Scenario	Recommended Product / Series	Key Reason for Recommendation
PP / PE masterbatch — standard pearl effect	KT 100 Silver White Series	Thermally stable to 800°C; chemically inert in polyolefin systems; multiple particle sizes from 5–500 µm; most cost-effective substrate for commodity plastics pearl effects
ABS / PC engineering plastic — premium pearl	KT 7000 SynStar Series (synthetic mica)	Higher purity than natural mica; fewer dark inclusions visible in light-colored transparent or translucent engineering plastic parts; stable at PC/ABS processing temperatures
Injection molded consumer goods — gold and warm metallic	KT 300 Gold Series / KT 500 Metal Luster Series	Iron oxide and TiO₂-coated mica; warm gold and bronze metallic tones; non-conductive; thermally stable; stable in most standard thermoplastic systems
Automotive interior plastic — color-shift effect	KT 9000 Magic Chameleon Series / Chromashift Pigments	Angle-dependent color travel in molded plastic parts; requires sufficient part depth and appropriate base color selection; used in automotive interior trim and consumer electronics housings
High-clarity plastic — diamond sparkle effect	KT 8000 DreamStar Series (borosilicate)	Higher refractive index than mica produces more defined sparkle in transparent or translucent plastic; relevant for cosmetic packaging, luxury consumer goods, and clear plastic parts
Masterbatch compounding — iridescent interference color	KT 200 Iridescent Series	Fine to medium grades (5–60 µm) compatible with twin-screw compounding shear; interference color visible in molded parts over appropriate base color
Colored plastic with vivid pearl	KT Intense Chroma Series	Higher color saturation than standard interference pearlescents; relevant for plastics where vivid hue alongside shimmer is the design requirement
Specialty / novelty plastic — thermochromic	KT Thermochromic Pigments	Heat-activated color change in plastic parts or films; suitable for injection molding at lower processing temperatures — confirm grade-specific thermal limits before specification in high-temperature polymer systems
Specialty plastic — glow-in-dark effect	KT Glow in the Dark Pigments	Strontium aluminate phosphor; stable in most thermoplastic processing conditions; used in safety and novelty plastic components

Pigments for plastics

Particle Size Selection for Plastics

Visual Target	Particle Size Range	Why
Smooth satin effect in thin-wall injection molded parts	5–25 µm	Fine grades produce a diffuse, even shimmer with minimal platelet orientation visibility; reduces weld line and tiger stripe appearance in complex mold geometries
Standard pearl shimmer in molded parts	10–60 µm	Most versatile range for masterbatch and injection molding; balances visible shimmer with manageable orientation effects
Strong sparkle in thick or simple geometry parts	20–100 µm	Larger platelets produce more defined individual reflections; platelet orientation effects are more visible in complex mold geometries at this size range — evaluate with mold geometry before finalizing
Masterbatch compounding — mechanical shear considerations	5–60 µm preferred	Fine to medium grades are more resistant to platelet fracture during twin-screw compounding than coarse grades; coarse grades above 100 µm should be evaluated for post-compounding particle size integrity
Extrusion film or sheet	5–40 µm	Film and sheet thicknesses constrain the maximum particle size that can be accommodated without surface protrusion or optical defect in the extruded product

Substrate Selection for Plastics

Requirement	Natural Mica	Synthetic Mica (SynStar)	Borosilicate (DreamStar)	Other
Thermal stability	Stable to 800°C — suitable for all commercial thermoplastics	Stable to 800°C — suitable for all commercial thermoplastics	Stable — glass substrate; confirm grade-specific upper limit	Iron oxide (KT 300/500): stable; Chameleon: confirm grade-specific limit
Purity in transparent / light plastic	Standard — minor inclusions may be visible in clear or light-colored parts	High purity — fewer dark inclusions; preferred for transparent or translucent engineering plastic parts	High purity glass substrate	—
Luster intensity in plastic	Good	Higher than natural mica	Highest — diamond-like sparkle in transparent plastic	—
Color-shift capability	Not applicable (standard pearl only)	Not applicable	Not applicable	Chameleon / Chromashift: angle-dependent color travel
Cost sensitivity	Lower — suitable for commodity plastics at volume	Higher than natural mica	Higher than mica	Specialty effects vary
Electrical conductivity	Non-conductive — inorganic oxide coated mica	Non-conductive	Non-conductive	Aluminum pigments: electrically conductive — not suitable for electrical/electronic plastic components

Application Examples

PP Masterbatch — Silver White Pearl Product used: KT 100 Silver White Series, 10–60 µm grade Effect achieved: A visible silver pearl shimmer distributed evenly through the molded PP part, producing a consistent pearl appearance across flat and slightly curved surfaces. Formulation note: Incorporate the pearlescent pigment into the masterbatch at 20–40% loading in the masterbatch concentrate, letdown to 1–5% in the final part depending on desired intensity. Add the pigment as late as possible in the compounding sequence to minimize exposure to twin-screw shear. Evaluate weld line visibility on the target part geometry — finer grades reduce weld line appearance in complex parts.

Transparent PET Cosmetic Packaging — Borosilicate Sparkle Product used: KT 8000 DreamStar Series, 30–150 µm grade Effect achieved: A bright, diamond-like point sparkle visible through the transparent PET wall of injection-molded cosmetic packaging — the higher refractive index of the borosilicate substrate produces a distinctly more defined sparkle than equivalent mica grades in the same transparent polymer. Formulation note: In transparent polymer systems, the base resin color and clarity directly affect the sparkle appearance. Borosilicate grades perform best in water-clear or lightly tinted transparent resins. Surface defects or haze in the base resin reduce sparkle definition. Processing temperature for the specific PET grade should be confirmed against the borosilicate pigment's thermal specification.

ABS Automotive Interior Trim — Chameleon Color Shift Product used: KT 9000 Magic Chameleon Series, medium grade Effect achieved: An angle-dependent color shift visible on the molded ABS trim surface as the viewing angle changes — the perceived color travels between two complementary hues, producing a premium visual effect relevant to automotive interior design. Formulation note: Chameleon effects in injection-molded parts require a dark or black base polymer to produce maximum color travel contrast — the color shift is not visible over a white or natural polymer base. Gate location and injection speed affect the orientation pattern of the platelet pigment on the part surface; evaluate platelet orientation distribution with the specific mold tool before finalizing grade and processing parameters.

Polypropylene Safety Component — Glow in Dark Product used: KT Glow in the Dark Pigments Effect achieved: The molded PP component emits visible phosphorescent glow in darkness after light charging — green grades produce the highest brightness and longest afterglow duration; other colors available with shorter afterglow duration. Formulation note: Strontium aluminate glow pigments are moisture-sensitive — ensure the polymer is thoroughly dried before compounding and that the compounding environment is controlled for humidity. Loading at 10–20% in the masterbatch concentrate provides visible glow at standard letdown ratios. Confirm processing temperature against the grade-specific thermal specification — glow pigments have a lower upper processing temperature limit than mica-based pearlescents.

Why Kolortek

Manufacturing Experience Kolortek has manufactured effect pigments for over 20 years. For plastics and masterbatch applications specifically, this means documented thermal stability data and particle size distribution specifications that compounders and masterbatch manufacturers can use directly in their process qualification documentation. Both standard catalogue grades and custom particle size or surface treatment specifications are available for customers with defined technical requirements.

Product Range Breadth The plastics-relevant range covers silver-white pearl, iridescent interference, gold and warm metallic, borosilicate high-sparkle, chameleon color-shift, intense chroma, thermochromic, and glow-in-dark pigments — across natural mica, synthetic mica, and borosilicate substrates — in particle size ranges from 5 µm to 500 µm. A masterbatch manufacturer or compounder developing a full effects portfolio can source across all major effect categories from a single supplier, with consistent thermal stability documentation and particle size data across the range.

Technical and Compliance Support TDS, SDS, CAS numbers, and particle size distribution data (D10, D50, D97) are available for all plastics-grade pigments. For customers requiring REACH substance declarations or specific polymer compatibility information, Kolortek's technical team can provide the documentation that supports a customer's own formulation qualification and regulatory compliance process. Application development support — including masterbatch loading recommendations, processing temperature guidance, and grade selection for specific polymer systems — is available upon request.

Contact Kolortek

Plastics pigment selection depends on the polymer system, processing temperature, part geometry, visual effect requirement, and — for specialty applications — functional performance criteria such as glow duration or color-shift travel. The most efficient starting point is a technical discussion combined with a sample evaluation under your specific compounding or molding conditions.

Contact Kolortek to request grade-specific samples, thermal stability and particle size data, or formulation guidance for your polymer system and processing parameters.