Film coating of urea particles with polymer latex for controlled release

摘要

A kind of polymer latex was used to coat urea particles with a film for controlled release in a fluidized bed. Experiments showed that the spray rate of the polymer latex and the sticking of coated particles are the key factors in the preparation of controlled release urea. High rate of latex spraying easily results in the urea dissolved and embedded in the coating film after recrystallization. The sticking easily results in the film damaged.due to the tearing each other of particles. Both of them cause a high release rate of film coated urea in water. Slowing the spray rate and treating with diatomite conditioner were operated in the particle coating process. A well film coated urea particles with slow release rate were successfully achieved.