Preparation of prevulcanized latex
The concentration of concentrated latex is 60%, and the required concentration during production is 50~55%. In addition, vulcanizing agent, active agent and various coordination agents needed for latex processing should be added into the latex. In order to ensure that the coordination agent is evenly dispersed in the latex, a series of processing processes, such as grinding, stirring and mixing, should also be carried out.
The production of latex products is a very complex process, which involves a series of complex physical and chemical processes such as colloidal chemistry.
In order to ensure the processing performance of latex, preliminary processing is carried out before the matching of latex.
In the transport and storage process of concentrated latex, ammonia is used as anticoagulant (0.7% or so). Generally, the ammonia content of general products is generally required to be 0.2-0.4% or so. Excessive ammonia content will cause adverse effects, such as easy foaming, peeling and film forming difficulty of latex in impregnated products.Therefore, before latex with appropriate to ammonia.The commonly used ammonia removal methods include stirring ammonia removal method and formaldehyde neutralization method.
The preparation of emulsion with dispersing agent is a kind of aqueous emulsion. All kinds of dispersing agent must be dispersed and stabilized in water to make emulsion or stable turbid liquid.The preparation methods are as follows:
Grinding insoluble in water with a grinding machine grinding agent, adding a moderate amount of dispersant to prevent agglomeration and precipitation, can be grinding one or more agents together;Available equipment is a variety of ball mill, sand mill, colloid mill, etc.
Solutions and emulsions can be prepared using equipment such as agitators or ultrasonic emulsifiers.
Preparation of various kinds of dispersing liquid of coordination agent with latex can be mixed under the action of stirring to mix the required performance of products with latex.With the good latex must go through filtration, defoaming, maturation and other processes before entering the next processing process.
Prevulcanization treatment due to the different production process of latex, some products need to be prevulcanized latex molding manufacturing, and some processing technology in the dip molding at the same time, prevulcanization treatment.Pre-vulcanization treatment is the mixed latex before use slowly heated to 70 degrees, constant temperature to the required degree of vulcanization, cooling to room temperature.
Gelation and film formation of latex
Different from the dry rubber production method, the manufacture of latex products is made of liquid latex through the process of gelation, film forming, solid products.