Plastic Industry
  • Desktop Spectrophotometer CS-820 for Master Batches Color Measurement

  • Color master batches is a kind of plastic colorant that mainly composed by pigment or additive and thermoplastic resin. Pigment + carrier + additive = color master batch. Color master batches are similar to resin pellets. Because the effect of light source and visual difference, we can not tell the exact color value of master batches by visual method. We use spectrophotometer to simulate human eye retina and values in coordinates to represent color. Measuring the distance of digital coordinates in standard color space will represent corresponding color difference between two colors. Avoiding the error produced by human visual, and widely used in large scale.
    Now we will introduce how to measure the color difference with spectrophotometer. Because the pellet size and space between color master is large, we will use high accurate and stability spectrophotometer CS-820. CS=820 is with 4 kinds of testing caliber and the largest caliber is 25.4mm. So we will use bench top spectrophotometer CS-820 for master batches color measurement.

    The steps as follows:
    1.Prepare the samples. (as show in figure)

    2. Calibrate the instrument.

    3.After calibration, press “cancel” to exit. And the put the sample on the testing caliber. We will test with yellow mater batches. (note: the pellet space between master batches is large, so the cuvette should be full of it and the cuvette should be closely put on the testing caliber to make sure no light will enter into the instrument.) And then test the sample. We will repeat the measurement for 3 times to check the repeatability.

    According to the above the steps, we will get the L,A,B value of the color master batches and color difference value could also been seen. The following are the values we get from our bench top spectrophotometer.

    4.We will use the same method to measure sample two and repeat for 3 times. Then we will get the color difference value between sample 1 and sample is 5.84. 

    Bench top spectrophotometer will solve the problem for color measurement of master batches. Comparing with colorimeter and portable spectrophotometer, its testing accuracy is higher. If you need more information for the measurement or inquiry, please do not hesitate to call us at +86 571 86872381 or send email to
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