What Is Optical Brightening Agent?

Have you ever wonder why your white clothes glow bluish under ultraviolet (UV) lighting or blue color bits can be seen in washing powders? The phenomenal is a fluorescent effect and the blue bits are optical brightening agents, a chemical that causes white fabrics to glow bluish under UV lighting making white fabrics bluer which appears to be brighter.

Optical Brightening Agent (OBA) or fluorescent whitening agent (FWA) is a chemical that absorbs energy in the UV energy from the electromagnetic spectrum and when interact with the chemical, it re-emits this energy in the blue region. The blue reflectance spike is dependent on the dosage of the OBA or FWA. OBA is used to create whitening effect, thus making white looks whiter and is a cost-effective method to enhance the whiteness of paper and fabrics.

OBA are used in the following to enhance whiteness.

  • Laundry detergent / washing powder
  • Paper
  • Textile / fabric whitening

A common problem faced by manufacturers is the dosage of OBA as this compound is expensive. The fluorescent effect is a combination of the ambient lighting UV energy and the amount of OBA used in the preparation of the fabrics or paper.

To accurately achieve the desired whiteness without excessively using OBAs, a UV calibration standard with a spectrophotometers that is able to illuminate the right amount of UV is critical to ensure consistent and traceable whiteness index.

Spectrophotometers like the Konica Minolta CM-3600A or CM-2600d, have the capability to illuminate a sample with controllable UV energy, patented as numerical UV control (NUVC), NUVC technology provides precise control of UV energy and with the Data Management Software SM NX Pro, accurate fluorescent effect of whiteness can be measured accurately.

For more information regarding color science and color application, you can contact Konica Minolta Sensing Singapore at 6563 5533 or write to us at ssg@gcp.konicaminolta.com.