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Coloring of Plastics Presented by: Color and Appearance Division

Coloring of Plastics Presented by: Color and Appearance Division. Originally Created July 2007 Last Modification 17 January 2011. Coloring of Plastics. Color and Color Science. Colorants – Pigments and Dyes. Inorganic - Organic Pigment Particles. Definitions. Color Appearance. Color. Hue.

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Coloring of Plastics Presented by: Color and Appearance Division

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  1. Coloring of PlasticsPresented by:Color and Appearance Division Originally Created July 2007 Last Modification 17 January 2011

  2. Coloring of Plastics Color and Color Science Colorants – Pigments and Dyes Inorganic - Organic Pigment Particles

  3. Definitions Color Appearance Color

  4. Hue Color Attribute Identification Chroma Value or Lightness/Darkness

  5. The Source The three elements of color vision The Eye The Object

  6. The three elements required to perceive color Light Human Color Perception An object Visual Observing Requires To quantify - each must be represented by a table of numbers

  7. The Sun Incandescent Fluorescent Light Sources Illuminants

  8. Definition metamerism, n—property of two specimens that match under a specified set of conditions whose spectral properties differ in the visible. There are four types! Illuminant, Observer, Instrument and Geometric Metamerism Illustrated

  9. The three elements required to perceive color Light Human Color Perception An object Visual Observing Requires To quantify - each must be represented by a table of numbers

  10. The

  11. The

  12. The Observer Rod shaped receptors in the eye are responsible for night vision Cone shaped receptors are responsible for our daylight vision and color reception Red,Green, and Blue are the three types of cone shaped receptors

  13. Field of View

  14. CIE Observers Experiments quantified the response functions of the human eye. Observers viewed a white screen through an aperture subtending 2o FOV. Half the screen was illuminated by a test light. The other half illuminated by observer-controlled, adjustable lights (primaries). The observer adjusted the intensity of the three primary lights until the color of the test light matched. This process was carried out over the entire visible gamut.

  15. Visual Responses Short Medium Long Tristimulus Response Functions

  16. Tabular Data The Observer Functions Data Plot The experimentally derived x, y, & z functions are the 1931 2o Standard Observer functions. These functions quantify (create a table of values for) theRED, GREEN, andBLUEcone response function of the average human observer.

  17. CIE 10o Supplemental Observer In 1931 it was believed that color vision was confined to the fovea region ~2o. Later it was determined that this is NOT true and the experiment was repeated in 1964. The result being the Supplemental Observer, called the 10o Supplemental Observer!

  18. The 10o Supplemental Observer function givers better correlation with visual observations and assessments. Most commercial applications should use this function. 2o & 10o Observer Functions

  19. The three elements required to perceive color Light Human Color Perception An object Visual Observing Requires To quantify - each must be represented by a table of numbers

  20. Tabular Data Objects & Spectral Reflectance Spectral Reflectance Curve

  21. Object Interaction with Light Light interacts with an object Light,  (zeta), will be; Absorbed, A, Reflected, R or Transmitted, T. Mathematically we express this as:  = A + R + T Hence the total amount of light incident upon a sample is equal to the sum of the amounts absorbed, reflected, and/or transmitted. The magnitude of A, R, or T depends on the object – is it transparent, translucent, opaquesmooth, or rough? (etc).

  22. The color of objects is assessed with spectrometers or colorimeters BYK-Gardner Datacolor International Hunter Lab Konica-Minolta X-Rite

  23. Coloring of Plastics Color and Color Science Colorants – Pigments and Dyes Inorganic - Organic Pigment Particles

  24. COLORANTS FOR PLASTICS Pigments Dyes Polymer Soluble Transparent Insoluble Solid Particles Generally Opaque

  25. THERMOPLASTIC RESINS Polyvinyl Chloride Polyolefin's PP, HDPE, LDPE Polystyrene Engineering Resins Nylon, PET, PBT, ASA, PC

  26. PIGMENTS Organic Inorganic Special Effects

  27. INORGANIC PIGMENTS GENERAL CHARACTERISTICS LARGE PARTICLE SIZELOWER SURFACE AREAOPAQUEHIGH HEAT STABILITYEXCELLENT LIGHTFASTNESSVARYING WEATHERABILITYLIMITED TINT STRENGTH (EXCLUDING TiO2) WIDE VARIETY OF SHAPES

  28. INORGANICS Pigment TypeExamples Manufacturing Method AL, Zn Bronze Powders Mica flakes Elemental Pigments Controlled combustion, Thermal/Mechanical decomposition, Metallurgical deposition processes PbCrO4, BaSO4, CdS, CaCO3, ZnS, Ce2S3 Precipitated from chemical solutions Precipitated Pigments Purification of natural Minerals, High temperature Solid state reactions TiO2, Fe2O3, Mixed Metal Oxides, Spinels Pyrolysis Pigments

  29. ORGANIC PIGMENTS GENERAL CHARACTERISTICS SMALL PARTICLE SIZELARGE SURFACE AREATRANSPARENT VARIABLE HEAT STABILITYVARYING LIGHTFASTNESSVARYING WEATHERABILITYHIGH TINT STRENGTHLARGE SELECTION OF COLORANTSBRIGHT CLEAN COLORS

  30. ORGANICS Naphthols Acetoacetarylides Monoazo Arylides Naphthanilides Azo Type -(-N=N-)- AzoCondensation Insoluble metal salts of acid dyes Diarylides Disazo Pyrazolones -(-N=N-)- -(-N=N-)-

  31. ORGANICS Phthalocyanines Anthraquinone Vat Type Thioindigo Flavanthrone Triphendioxazine Miscellaneous Metal Complexes Quinacridone Basic Dyestuff Complexes Carbon Black

  32. SPECIAL EFFECTS Pearlescents Modified Titanium Dioxide Multi Layered Inorganics Aluminum Flakes Brass Flakes Edge Glow, Fluorescent Marble, Frost

  33. GENERALIZED PROPERTIES OF COLORANTS DESIGNED FOR PLASTICS INORGANIC ORGANIC DYES HIGH HEAT (300 C) + - - COLOR STRENGTH - + + LARGE PARTICLE SIZE + - - TRANSPARENT - +/- + LIGHTFASTNESS + +/- +/- WEATHERABILITY + +/- +/- ALWAYS CHECK EACH COLORANTS PROPERTIES BEFORE USE

  34. COLORANT DELIVERY FORMS Forms Cons Pros Dry Pigment Least Expensive Dispersion can be inconsistent and cleanup extensive Concentrates– • Custom Color Easy dispersing Added cost, modifications limited, carrier compatibility • Cryogenic Easy dispersing Added cost, carrier compatibility. • Single Pigment (SPD) Easy dispersing, flexible Added cost • Forms- liquid & solid Cleanup minimal Custom color limitations • Paste Easy dispersing Added cost, Special feeder • Flushes EasyDispersingModerate cost, Limited types, carrier affects properties

  35. LIGHT STABILITY 0.2% Pigment with 2% TiO2 in PVC, Daylight in Northern Europe

  36. STRONG ATTRACTIVE FORCES

  37. PIGMENTS DISPERSION PROCESS

  38. Coloring of Plastics Color and Color Science Colorants – Pigments and Dyes Inorganic - Organic Pigment Particles

  39. Effect of TiO2 Level on Optical Density

  40. 100 80 60 40 20 0 1. 4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 EFFECT OF REFRACTIVE INDEX ON OPACITY (RELATIVE OPACITY OF WHITE PIGMENTS IN PLASTICS) Rutile TiO2 (2.8) Anatase TiO2 (2.6) Zinc Sulfide (2.4) RELATIVE OPACITY (RUTILE TIO2=100) Barium Sulfate (1. 6) Zinc Oxide (2.0) Calcium Sulfate (1. 6) Lithopone (1.85) Calcium Carbonate (1. 5) REFRACTIVE INDEX CCS 05

  41. OIL ABSORPTION PARTICLE SURFACE AREA PIGMENT VOLUME CONCENTRATION PIGMENT AVERAGE PARTICLE SIZE PIGMENT PARTICLE DISTRIBUTION PIGMENT PARTICLE SHAPE PIGMENT DISPERSION PIGMENT AGGREGATION PIGMENT SURFACE TREATMENTS POTENTIAL PIGMENT PARTIAL SOLUBILITY MOISTURE PIGMENT SOLUBLE SALTS COMPLEX SYSTEM REFRACTIVE INDEX pH OF ALL SYSTEM COMPONENTS SYSTEM VISCOSITY OR FLOW SYSTEM MELT TEMPERATURE SUSEPTABLITY TO SHEAR DILATANCY (THICKENS WHEN SHEARED) THIXOTROPY (THINS WHEN SHEARED) POTENTIAL PIGMENT REACTIVITY GENERAL COLORANTSPROPERTIES AND/OR PARAMETERS

  42. EFFECT OF PARTICLE SIZE ON LIGHT SCATTERING UNEFFECTED LIGHT RAY SCATTERED LIGHT RAYS REFRACTED LIGHT RAY PIGMENT PARTICLE SIZE HAS A DIRECT EFFECT ON PIGMENT EFFECTIVENESS. TOO SMALL A ND LIGHT RAYS ARE UNEFFECTED. LARGE PARTICLES WILL REFRACT LIGHT, BUT NOT SCATTER IT. PARTICLES WITH DIAMETERS ABOUT HALF THE WAVELENGTH OF THE LIGHT GIVE MAXIMUM SCATTERING

  43. COLOR CHANGE AS PARTICLE SIZE CHANGES

  44. PARTICLE SHAPE ASPECT RATIOS PLATE SPHERE BLOCK CUBE FLAKE NEEDLE IRREGULAR TYPICAL ASPECT RATIOS FOR PARTICLE SHAPES VARIOUS 20 + 4 - 30 1 ~1 1 - 4 80 - 200 ASPECT RATIO DEFINITION The Aspect Ratio is defined as the ratio of the longest length of a particle to the thickness of that particle. Aspect Ratio = Longest Particle Dimension / Thickness Dimension

  45. AGGREGATE

  46. AGGLOMERATE

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