Spray drying, bleach processing

In relation to detergent ingredients, different microencapsulation technologies are often used for fragrances and flavors. Coacervation and spray drying are mentioned in various patent applications (see example of coacervation in Ref 139 and spray drying in Ref 140). In the case of bleach active substances, microencapsulation of TAED using a polycondensation process is described in Ref 141, and a coacervation process for the encapsulation of PAP is mentioned in Ref 142. In both cases, the use in liquid applications is intended. 

Certain ingredients such as perfumes, enzymes, and bleach cannot be processed in this way, and therefore, they are added to the spray dried product (blown powder) afterward. 

A biodetergent is usually just a normal detergent which contains enzymes. However, enzymes are not thermostable and cannot be e msed to the high temperatures and humidities encountered in the powder detergent production process. Therefore, they are postadded to the spray-dried powder with other heat-sensitive ingredients, such as perfumes, bleaching... 

The oil is loaded into the reactor, shown with both an agitator and a pumped circulation-spray loop, and heated under vacuum (110-130°C) to reduce water and peroxide contents. Next, the oil is cooled to 70-90°C and the catalyst is added as dry powder at 0.05-0.15 percent or suspended in dry oil. Randomization requires about 30 min, with an additional 15-30 min allowed for completioa After the reaction is complete, the batch is transferred to a postbleacher where the process is arrested by inactivating the catalyst by addition of water or an (phosphoric or citric) acid solution. Bleaching earth, added to absorb the inactivated catalyst and soaps removed by filtration and the oil sent to blending or deodor-ization. Losses from the formation of FFA and FAME are —10 times the catalyst weight, with... 

The first step in the restoration process is dry cleaning with soft erasers. Old mounts or supports, usually highly acidic, are removed. Immersion in water is prescribed for removal of discoloration in the more stable forms of art on paper etchings, prints, engravings, and some drawings. For specific stains that cannot be removed with water or other solvents, bleaching agents are applied locally. Deacidification by total immersion is preferred a spray is used when this is not possible. 

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