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Haze

Haze

Definition of Haze - Optical Property


During testing a polymeric material or plastics, knowledge of transmission, haze, yellowness, refractive index, gloss etc. is important to understand complete optical properties. Among them, haze is an important property of plastics to consider in several applications – food packaging as one example.

Haze is measured as the percentage of incident light scattered by more than 2.5° through the plastic specimen. There are several factors responsible for light scattering such as:

  • Impurities contained in the plastic material
  • Surface roughness and internal optical irregulatries caused by crystallization or material’s level of crystallinity
  • Other factors include inhomogenities (density difference, fillers, pigments…), and
  • Porosity, crystal size structure (Crosslinked) etc.
  • Mechanical and chemical degradation
  • Environmental factors such as weathering or surface abrasion

The lower the Haze value, the higher the clarity
If Haze value is greater than 30%, the material is diffusing


Haze has no specific unit. It is expressed in percentage, %.

Haze is an important property to measure where true color and visibility are necessary as well as visual performance of plastic products.



Check out more on Haze:

 » Haze Percentage Values of Several Plastics
 » How to Measure Haze of a Material


How is Haze Measured and What are Measurement Standards?


Haze measures the milkiness of the material (film or sheet). All plastics have some degree of light scattering (or transmission loss) which is usually measured by ASTM D1003. Hazemeters and spectrophotometers are used to measure the level of haze, light transmitting and light scattering properties of transparent materials.


Test Procedure - Hazemeter


In hazemeter, sample is placed between an incandescent light source and geometrically arranged photocells. The amount of light transmitted by the sample, the light scattered by the sample and the instrument, and the total incident light are measured.

From these values the percentage of transmitted light that is scattered can be calculated. The haze meter measures these variables and interrelates them so that the percentage of scattered light can be read in the meter.


Find commercial grades matching your property target using "Property Search – Haze" filter in Omnexus Plastics Database:

Omnexus Plastics Database - Property Search


Haze Percentage Values of Several Plastics


Click to find polymer you are looking for:
A-C     |      E-M     |      PA-PC     |      PE-PL     |      PM-PP     |      PS-X

Polymer Name Min Value (%) Max Value (%)
Amorphous TPI, Moderate Heat, Transparent 2.00 2.00
Amorphous TPI, Moderate Heat, Transparent (Food Contact Approved) 2.00 2.00
Amorphous TPI, Moderate Heat, Transparent (Powder form) 2.00 2.00
Celllulose Diacetate-Gloss Film 0.70 0.70
Celllulose Diacetate-Integuard Films 0.00 4.00
Celllulose Diacetate-Matt Film 72.00 72.00
Cellulose Diacetate-Window Patch Film (Food Grade) 1.10 1.10
Cellulose Diacetate-Colored Films 2.10 2.10
Cellulose Diacetate-High Slip Film 0.70 0.70
Cellulose Diacetate-Semitone Films 63.00 63.00
ECTFE - Ethylene Chlorotrifluoroethylene 4.00 4.00
EVA - Ethylene Vinyl Acetate 5.10 5.10
EVOH - Ethylene Vinyl Alcohol 0.50 1.90
HDPE - High Density Polyethylene 6.00 6.00
Ionomer (Ethylene-Methyl Acrylate Copolymer) 4.00 27.00
LDPE - Low Density Polyethylene 1.30 27.50
LLDPE - Linear Low Density Polyethylene 0.80 28.00
PC - Polycarbonate, high heat 1.00 1.00
PETG - Polyethylene Terephthalate Glycol 0.30 0.60
PFA - Perfluoroalkoxy 4.00 4.00
PLA, Heat Seal Layer 2.00 2.00
PLA, High Heat Films 2.00 2.20
PMMA - Polymethylmethacrylate/Acrylic 1.00 96.00
PMMA (Acrylic) High Heat 2.00 2.00
PMMA (Acrylic) Impact Modified 1.50 7.20
PP (Polypropylene) Copolymer 2.00 2.00
PP (Polypropylene) Homopolymer 11.00 11.00
PS (Polystyrene) Crystal 2.00 2.00
PS, High Heat 1.00 1.00
PVC, Plasticized 3.00 5.00
SAN - Styrene Acrylonitrile 0.45 0.80
SMMA - Styrene Methyl Methacrylate 0.27 0.30



Commercially Available Transparent Polymer Grades







Also, Read about Polymer Property - Gloss

Disclaimer: all data and information obtained via the Polymer Selector including but not limited to material suitability, material properties, performances, characteristics and cost are given for information purpose only. Although the data and information contained in the Polymer Selector are believed to be accurate and correspond to the best of our knowledge, they are provided without implied warranty of any kind. Data and information contained in the Polymer Selector are intended for guidance in a polymer selection process and should not be considered as binding specifications. The determination of the suitability of this information for any particular use is solely the responsibility of the user. Before working with any material, users should contact material suppliers in order to receive specific, complete and detailed information about the material they are considering. Part of the data and information contained in the Polymer Selector are genericised based on commercial literature provided by polymer suppliers and other parts are coming from assessments of our experts.

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