Although there are many types of fluorescent whitening agents, powdered fluorescent whitening agents are still the primary product formulation. Suitable for various types of optical brighteners. It has the advantages of strong habit of processing equipment, simple operation, low production skills, convenient packaging and transportation, and good product storage stability. It is more suitable for countries and regions where the printing and dyeing plant and the fluorescent whitening agent production plant are relatively scattered, storage and transportation cycles are long, and climate changes are large.
Because the powdery fluorescent whitening agent has small particles, it simply causes dust to fly and pollute the environment during production and use. This is a defect of the powdered dosage form. Some dustproof agents, such as paraffin oil, alkylbenzene, Polyoxyethylene and alkyl phosphate with low polymerization degree are made into dustproof powdery fluorescent whitening agent. It will be better to participate in a few surfactants in the dustproof agent. The surfactant can be alkylphenol ethylene oxide adduct, fatty alcohol ethylene oxide adduct, polyoxyethylene of polyol fatty acid ester Most of ethers are non-ionic.
Powdery fluorescent whitening agent products are often added with other additives and diluents, such as: sodium sulfate, sodium chloride, urea, dioctyl phthalate or polyvinyl chloride and dispersing agents; also can be used as Concentrate, add a small amount of additive or not add it at all. The method of processing the concentrate depends on its application. Regarding the pre-spinning whitening of composition materials, high-purity fluorescent whitening agents are commonly used without adding additives. Fluorescent brightener is suitable for powder formulation under the following conditions.
1. Enterprises with small production scale and intermittent production. In this situation, the more economical box-type drying method is generally adopted. After drying, it is mostly into lumps, and it is made into powder after being destroyed by thousands of methods.
2. The fluorescent whitening agent has low heat-resistant temperature and is not suitable for other granulation methods.
3. There are no other granulation conditions due to the limitation of production plant equipment.
4. Fluorescent brightener products with specific uses.