Calculating Yellowness Index of Plastics

Yellowness Index is an important factor to be tested in plastic industries. It is the degree of color shifting from whiteness to Yellowness or from transparency to getting dark yellow. This may happen due to over exposure of damaging environmental conditions such as sunlight, dust, UV radiations, temperature etc. Other reasons include processing functions and purity level of raw material.

The plastic material used for any application must be tested for its yellowness index prior its use in production. This test will create important information regarding the quality of the product and till what extent it can survive the damaging conditions. Also manufacturer can see if their production or processing program is running well or not. For measuring the yellowness index of plastic, quality labs use spectrophotometer device.

The TP 800 spectrophotometer by Testronix is designed to capture and calculate the yellowness in plastic material. The device is used widely in the polymer industry to test the purity, sustainability and degree of transparency. It uses the illumination system or optical geometry of 45/0 degree. It strictly adheres to global test standards and is designed as per DIN, CIE, ASTM and ISO standard. Has an integrated sphere having 58 mm diameter, which is considered to be the ideal setup for spectrophotometry. Device equipped with combined LED light sources for conducting ideal test conditions. Uses highest sensing technology with silicone photodiode array type sensor. It can capture a range of wavelength from 400 to 700 nm. Having an 8mm apertures size for capturing the yellowness precisely.

Works with wide range of color spaces including – XYZ, CIE LAB, LCh, Yxy, HunterLAB, CIE LUV. Equipped with HMI based display screen which offers multiple features. Spectral Value can be accessed in graphical format. Color Difference comparison test data on single screen (also in Graphical format). Yellowness index values or other Color measurement value instantly shown on screen. PASS/FAIL criteria can be set easily and based on that results can be categorized. Color Simulation, and Color Offset feature is also available.

Has an ergonomic design which is light in weight and is highly portable. It is very easy to place the device on the plastic material. User can take repeatable reading of one section to assure accuracy. The machine can even be calibrated automatically before conducting color measurement test. The calibration includes white and black calibration for the test specimen.