n the actual environment of the market, various types of latex powders can be described as dazzling. As a result, if the user does not have his own professional technicians or testing equipment, he can only be fooled by many unscrupulous merchants in the market. At present, there are some so-called detection methods circulating on the Internet, such as: observing the turbidity of the dissolved solution and the film-forming state. These methods are only cognition from the surface, and can not provide scientific methodological support for the user’s final determination of whether the product is suitable for him. Therefore, in this article, we will systematically popularize some basic concepts of rubber powder for free from the aspects of the most basic raw material composition, characteristics, and purpose of use of rubber powder, so that colleagues can judge for themselves what is good and what is good. defective.

First, a basic concept to understand how the true dispersible polymer powder is produced. (Redispersible latex powder is a polymer powder with redispersible properties that is modified from synthetic resin emulsion by adding other substances and spray-dried. When water is used as the dispersion medium, it can form an emulsion and has redispersible polymer powder. Redispersible The latex powder is usually white powder, but a few have other colors.) Redispersible latex powder should include: polymer resin, additives, protective colloid, anti-caking agent. 1. Polymer resin is located in the core part of latex powder particles, and is also the main component of redispersible latex powder, such as polyvinyl acetate/vinyl resin, etc. The quality of the polyvinyl acetate emulsion produced by different manufacturers and different processes will directly affect the quality of the rubber powder produced. In order to ensure the stability of product quality, normal large factories usually use a brand of polyvinyl acetate to produce redispersible polymer powder. Here we can take a practical example. In 2015, a well-known domestic brand of domestic rubber powder replaced the cheap polyvinyl acetate emulsion to produce redispersible polymer powder due to management reasons. As a result, large-scale quality fluctuations were caused. caused irreparable damage. Even some unscrupulous merchants here will use white latex and the like instead of dusting.

2. Additives (internal) work together with the resin to modify the resin, for example, a plasticizer that reduces the film-forming temperature of the resin (usually vinyl acetate/ethylene copolymer resins do not need to add plasticizers), not every latex Powder has additives. The redispersible latex powder of many small manufacturers only has the film forming temperature index and cannot be called the glass transition temperature, which is also an important parameter of the quality of the rubber powder itself.

3. Protective colloid A layer of hydrophilic material wrapped on the surface of redispersible latex powder particles, and the protective body of most redispersible latex powders is polyvinyl alcohol. The polyvinyl alcohol here is to participate in the spray drying process together, rather than simply mixing. Here is another common problem in the market. Many small workshops that claim to be producing rubber powder just do a physical mixing process. process, this product cannot strictly be called a dispersible polymer powder.

4. Additives (external) Materials added to further expand the performance of redispersible latex powders, such as adding superplasticizers to some fluidized latex powders. Like internal additives, not every type of redispersible polymer powder is used. Latex powders all contain this additive.

5. Anti-caking agent Fine mineral filler, mainly used to prevent latex powder from agglomeration during storage and transportation and to facilitate the flow of latex powder (dumped from paper bags or tankers). This filler is also the part that will greatly affect the actual production cost and efficacy of the dispersible polymer powder. Many low-priced rubber powders on the market increase the filler ratio to reduce costs. Simply put, it is the indicator of ash content that is usually referred to. Different fillers added by different manufacturers will also affect the mixing effect of rubber powder and cement. Because the bonding of inorganic adhesives to materials is achieved through the principle of mechanical embedding