Textiles, papers and plastics give aesthetically undesired tans in their raw state. The reason for this in natural fibers is the presence of natural dyes and pigments, and in artificial fibers it is due to pyrolysis. Chemical bleaching can remove the yellow cast, but they retain a faint creamy color. Coloring with optical brightener can compensate for residual yellowing. Optical brighteners are used in the paper, detergent, plastic and cosmetics industries.
Fiber optical brightener manufacturer
The brewing agent absorbs the yellow light from the sun and emits a blue light that is additively combined with the yellow light from the tissue. The resulting material color is perceived as off-white with reduced total reflectance. Sunwhite Chemicals is a manufacturer Textile Whitener Chemical.
Optical brightener for textiles
Cloth Whitening Chemical, Sun White Chemical Optical brighteners, when present in textile materials, fluoresce. They absorb invisible UV light and emit visible light at the blue to purple edges of the spectrum. The maximum absorption is 300-400 nm and the wavelength of emitted radiation is 400-440 nm. They reduce reflections in the UV range by absorbing radiation and increase it in the visible range by radiation. They serve as an additional source of emissions. At the atomic level, the fluorescence phenomenon involves the emission of radiation from the lowest vibration level of the excited singlet state S1 to one of the ground state vibration levels. With high levels of optical brightener, the fluorescent reflections are too great for the human eye to see white. Such samples look very bright, but they are bluish. Under no circumstances may they replace cleaning / scrubbing and bleaching.
Chemical type optical cloth brightener
Most OBA compounds contain E-ethylene (-CH = CH-), E-azomethine (-N = CH), or a carbonyl group. When combined with benzene, naphthalene, pyrene, or a heteroaromatic ring, it can be excited by UV light. In some cases, aromatic and heteroaromatic rings can also be used directly. H. None of the three bridge groups.
These can be divided into 6 broad chemistry classes. 1) A compound with one or two stilbene groups. About 80% of all products belong to this group. One example of a compound in this group is Tinopal RSB (C.I. Fluorescent Brightener 46). Can be used for cellulose fibers, polyamides, detergents and paper.
2) The second group consists of two heteroaromatic residues or 1,2-ethylene derivatives with one heteroaromatic residue and one aromatic residue. They are used as additives for hydrophobic artificial fibers, especially melt spinning.
3) The third group is composed of coumarin derivatives. They are used for hydrophobic fibers. Some of those with a cationic group (triazolium group) can be applied to acrylonitrile fibers.
4) The fourth group is a derivative of 1,3-diphenyl-2-pyrazalin. They are used for protein fibers, cellulose acetate and polyamides.
5) The fifth group is composed of naphthalimide compounds.
