Technical consultation:

Pretreatmenet PrinciplesPretreatmenet

Pretreatmenet berfore mixing processinput time:2017-06-28     hits:32

First, the purpose of pre-treatment

  By changing the physical properties of some hard-to-mix powders, the physical properties of thevarious powders are brought close to one another to improve mixing quality and mixing efficiency。

Second,the content of pre-treatment

   When a batch of powder is more difficult to mix when the drying, crushing and other physical means can be used for large particles in the powder or powder pre-treatment of specific gravity. Adjust the physical indicators of these powders and other powders close to each other, so the purpose is more conducive to the smooth mixing work later.

Third,the key physical indicators that impact powder mixing

      Particle diameter, loose proportion, fluidity is three elements. If the parameters involved in the mixing of the powder between the parameters of the difference is not easy to mix evenly, so to go through the following adjustments:

  1,the particle size difference of powders to be mixer are too big.

     When the difference between the coarsest and the finest species in different powders is too large, it is difficult to mix them uniformly. In this case, the coarsest powder is preliminarily crushed and ground, which requires a ball mill to make the particle size approach to the whole powder The average of the diameters then participate in the mix.


    For example, in the above picture, the mixture of flour and crystal salt will appear the phenomenon of differential mixing. Because the salt particle has large diameter and large specific gravity, it belongs to differential mixing, so it is difficult to mix them evenly. So need to pretreatment, change the mixing conditions. The specific method is to grind the particle salt 180 mesh, the proportion will be reduced accordingly as shown below:

   The pictures above are refined salt and wheat flour after the pretreatment,the physical indicators are relatively close, in the actual mixing process easier to achieve the purpose of mixing evenly.

  2, Big difference of specific gravity makes the powders difficult to be mixed evenly.

     Many new material products need to add non-metallic powder in the metal powder, then there will be loose than the (specific gravity of the powder) a difference of 10 times the light and heavy powder mixing task, this is definitely a mixed process problem, there are When light, heavy powder difference of 1 times will not be easily mixed. This is because during the mixing movement, the light powder is always suspended on the main heavy powder because of its light weight. It is difficult for the light powder to be pressed into the main heavy powder by the space motion of the traditional single mixer. Even if the time is prolonged, the effect is still not satisfactory. The dual-motion mixer with full-size blade movement and the barrel at the same time overlay movement of the co-existence of coercion, it is easy to light powder wrapped in the main material into the heavy powder to complete the light and heavy powder between the full mixing!

  3, pretreatment can also solve wet, poor liquidity and other issues

    Some to be mixed powder is too wet, poor fluidity, not easy to mix evenly, and in the mixing process easily combined into pellets (ie ball). With this powder you first need to dry and dehumidify it, increase its mobility, and then participate in the mixing process is easy to mix.

  4, pretreatment is not a panacea

     Some powder is ultra-light powder, ultra-fine powder can not be roughened, heavy treatment, which should rely on other methods to solve the problem; and some powder is poor mobility is essential, drying can not solve the problem.