According to the design principle, the gap between the spiral belt and the shell of the customized mixer can be 4-10mm, and the material can be driven by friction to participate in the mixing process. However, due to the different particle sizes and friction coefficients of the materials, the mixing time of various components of the materials will vary, resulting in unevenness of the product. Currently, some manufacturers have realized this and made improvements to their products. One is to pay attention to machining accuracy and reduce the bottom gap to about 3mm; Another way is to make the position between the spindle and the housing adjustable, and adjust the gap between the spiral belt and the housing frequently according to the wear amount. When choosing a mixer, these two forms of products should be good choices.

The ability of the double helix belt used for stirring and mixing to push materials in opposite directions should be basically consistent. Due to the fact that the pitch of the inner spiral belt should be smaller than that of the outer spiral belt, in order to achieve consistent material pushing ability, the pitch of the inner spiral belt should be smaller than that of the outer spiral belt, and the width should be larger than that of the outer spiral belt, otherwise it will cause the material to concentrate in one direction. Therefore, it is important to pay attention to this when choosing a mixer.