The appearance of a product is very important specially for body of appliance. Plastic products can begin to yellow, giving them a color that negatively affects their appearance and hurts customer appeal. Optical brighteners migrate to the surface of the plastic and make a thin  UV absorber layar and violet region and re-emit that light in the blue region.The appearance of a product is very important specially for body of appliance. Plastic products can begin to yellow, giving them a color that negatively affects their appearance and hurts customer appeal. Optical brighteners migrate to the surface of the plastic and make a thin  UV absorber layar and violet region and re-emit that light in the blue region. This can enhance the appearance by making it appear cleaner, brighter and more white.