Latex production process
Latex product production is a very complex process, which involves colloid chemistry and a series of complex physical and chemical processes, the above process is only a very simple overview, each process has a more complex.
In order to ensure the processing properties of latex, the preliminary processing is carried out before latex matching.
In the process of transportation and storage of concentrated latex, ammonia is used as the anticoagulant of latex (about 0.7%). Generally, the ammonia content of products is required to be about 0.2~0.4%. Too high ammonia content will cause adverse effects, such as foaming, crusting and film forming difficulties in impregnated products. Therefore, the latex should be appropriate before the removal of ammonia. The commonly used methods to remove ammonia include stirring to remove ammonia and formaldehyde neutralization.
Latex is a water-containing emulsion, and all kinds of complex agents must be dispersed and stabilized in water to form emulsion or stable turbid liquid, in order to mix with latex. Preparation methods are as follows:
Grinding insoluble in water with the grinding machine grinding, adding the right amount of dispersant to prevent adhesion and precipitation, can be one or a variety of additives grinding together; Available equipment are a variety of ball mills, sand mills, colloid mills and so on.
Solutions and emulsions can be prepared with equipment such as stirring or ultrasonic emulsifiers.
Preparation of various complex dispersion liquid can be mixed under the action of stirring product properties required for the complex latex. The matched latex must be filtered, defoamed, matured and other processes before entering the next processing technology. The general order of addition is as follows;
Due to the different production technology of latex, some products need to be formed with pre-vulcanized latex, and some processing technology at the same time of impregnation molding, pre-vulcanized treatment. Pre-vulcanization treatment is to slowly heat the mixed latex to 70 degrees before use, maintain a constant temperature to the required degree of vulcanization, and cool it to room temperature for use.
Gelation and film formation of latex
Different from the production method of dry glue, the manufacture of latex products is made of liquid latex through the forming process of gelation and film forming to make solid products.