These optical brighteners are designed to trick your eyes into thinking that your clothes are less yellow than they actually are. This happens because they are actually dyes in most commercial laundry detergents that alter the way clothes reflect light.
If you remember your science lessons, light is made up of a color spectrum. The optical brighteners absorb the ultraviolet light and give off light in the blue region of the light spectrum. The blue light negates the yellow tinge to the clothing and tricks your eye into thinking that the fabric looks whiter. It also makes the clothes look brighter because it gives off more visible light.
Optical Brighteners are not new
In the "old days" people used to use "bluing" (a blue dye) for the same effect. The blue color somewhat canceled out the yellow tinge and made the clothes appear white.
Optical brighteners may be known by other names such as brightening agents, fluorescent bleaches, optical whiteners, fluorescent brighteners, or fluorescent whiteners. Regardless of what they are called, they are made up of different chemical compounds.
Before these fluorescent molecules were invented in the 1940s, blue dyes were used in laundry detergents and textiles to add a little bit of blue hue to help offset the "yellowing" of white clothes and linens due to aging and staining. But those blue dyes only make laundry visually appear whiter, not brighter. The fluorescent optical brighteners work differently by absorbing invisible UV light and turn it into visible lights in blue color. Once deposited on laundry fibers, those fluorescent molecules make clothes and sheets appear to be both whiter and brighter by hiding the yellowing hue away from our visual detections. Optical brighteners have gained huge popularity in applications for laundry detergents, textiles, cosmetics, paper, and hair care products over the years. Nowadays, millions of pounds of optical brighteners are used and discharged as wastewater into our ecosystems every year
Shanxi Colorshine Chemical Industry Co.,ltd is one of the leading optical brightening agent manufacturers and suppliers in the worldwide.
