Spectrophotometer:
A spectrophotometer is a physical tool that is eminently suited to measure the most important variable of all, the shade and strength of the dyestuffs themselves, whether they be in solution or on the fiber. Spectrophotometer used by dyeing factory and colorant manufacturers all over the world. Normally lab managers analyze the color of the swatch with the help of a spectrophotometer. Flow chart of color matching process with spectrophotometer is as follows:
Spectrophotometer
Functions of spectrophotometer:
- Color difference
- Metamerism
- Pass/fail operation
- Fastness rating
- Shade library
- Cost comparison
- Color match production
- Reflectance curve.
Flow Chart of Color Matching Process with Spectrophotometer:
Spectrophotometer in Dyeing house
A spectrophotometer is a special machine that measures the light intensities as a function of wavelength. In dye houses, a spectrophotometer is used to analyze the color of a sample, and also to arrive at a recipe for dye mixing. It can quantify the difference between an achieved color and its original standard. These differences are called Delta E (error) Values. There’s a separate Delta E Value for Hue, Value, and Chroma. The delta acceptance levels are sometimes specified in the customer’s quality manual.
If any degree of success is to be expected from spectrophotometers and computer formulation and quality control systems, repeatable techniques for measuring dyed samples must be established. Failure to establish a repeatable measurement technique will introduce a significant potential for error into all aspects of the formulation and quality control programs.
A repeatable measurement technique includes specification of the number of layers of material to use, the positioning of samples, the number of measurements to make, instrument settings, and clear communication with the system operators. Failure to fully test and confirm the quality of a measurement technique will be a source of error for the life of the program. While the tables above may be used as a guide for the number of measurements required on most materials to obtain repeatable results, it is recommended that system users evaluate their own specific materials to confirm the final established measurement method.
Author of this Article: Rana Sohel Executive Engineer Sunman Textile Mills Ltd. Chittagong Cell: +8801912-420118 Email: rsohel07tex@gmail.com