The process of redispersing latex powder

In clean reactor in proportion to add a certain amount of water purification. Heating up to about 50 C, at first open mixing mechanism. According to join the reactor 25% of the water to protect the colloidal powder, adding process to add slowly. Prevent the powder in the water, at first do not add to the side wall of the reactor. After adding 1% of the total defoaming agent, recommended to choose silicone defoaming agent. Cover the feeding hole and heat up to about 95 C. For I hours, the liquid in the reactor will form a transparent sticky glue. No white particles, sampling, test the viscosity and solid content, the required viscosity reaches about 2500Mpas.

The modulated protective colloid is add to the mixing kettle. And then add the polymer emulsion in proportion, the protective colloid and emulsion mixed evenly. Appropriate to add defoaming agent, generally equivalent to about 0.1% of the total. Defoaming agent should be use with self-emulsified silicone defoaming agent, and add water to adjust the viscosity of 70-200Mpas, solid content of 39% -42%. Heating up to 50_55 C. Sampling test, pending use.

Turn on the dry equipment:

The present invention use a spray drying tower. Heating up to the inlet temperature of around 145 C. Use a screw pump to deliver the prepare dispersion inlet at the top of the spray drying tower. High-spee centrifugal atomizing discs will atomize the dispersion into microdroplets. The droplet diameter is approximately 10,100 microns. The dispersion is atomize into microdroplets while rapidly heated with high temperature airflow. Add the isolation agent. When the dispersed microdroplets become sticky, the isolation agent contained in the hot airflow will adhere in time. The water in the microdroplet is quickly evaporat by high temperature airflow.

A solid dispersion of 1000 kg was transported to the drying tower at a certain pressure, and 51 kg of isolation agent was added as to the above method. After spray drying and solid gas separation, 461 kg of powder product with appropriate fineness was obtained.


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