Abstract
In this paper is shown the improved method for measuring the adhesion force of powders to flat plates in centrifugal field, which requires no special preparation of sample powders (e.g. size classification) and less measuring time than others.
The materials, the shape of the powders, the relative humidity of atmosphere and the contact time of the powders to the glass plate are selected as variables.
It is found that the experimentally obtained curves of separation force vs. the residual percentage of the adherent particles on the plate (separation-residual percentage curve) is well represented by the logarithmic normal distribution, Eq. 3, as shown in Fig. 4. So separation-residual percentage curve is determined by the separation force at 50% residue (f50) and the variance of the curve σ=f159/f50)
The experimental results obtained are summarized as follows,
(1) The adhesion force is variable dependent on the materials, and especially on the shape of the particles, as shown in Fig. 11.
(2) The adhesion force is independent of the size of the particles within the range of 15∼30μ.
(3) The adhesion force increases along with relative humidity, and the effect of its contact time on that tendency varies according to the materials.
(4) The mechanism of adhesion of powder to the flat plate can be investigated and presumed by f50 and σ.
