Blending of powders

Creation of non-segregating blends of powder ingredients, as in sintering of fines for steel or agricultural chemical granules. 

Lloyd PJ, Yeung PCM, DC. Freshwater, The mixing and blending of powders. J Soc Cosmetic Chem 1970 21 205-220. 

Epoxy-nylon film adhesive can be manufactured by solution casting processes. However, a more efficient and environmentally acceptable method is to calender dry blends of powdered nylon with a bquid epoxy resin with accelerators and other modifying resins directly... 

When validating new equipment or procedures, the sampling techniques must reflect the quality of the material being tested, the blend of powders, moisture in granulation, or coating integrity. 

This overview has hardly touched several important topics of current interest pertaining to the mixing of particulate materials and blending of powder. Such topics include the formation of ordered or partially ordered mixtures and prevention of segregation due to percolation in preparing mixtures capable of maintaining specified compositions by various means (see, e.g., [5], [7]). These mixtures are often involved when medicines are produced in the form of pills, tablets, and controlled release devices as well as when advanced materials, e.g., composites and semiconductors, are manufactured. 

If filled polymers are used, they are usually first extrusion compounded into pellets which are then pulverized, often cryogenically. Blends of powdered polymer and filler mineral do not work well since there is no means to force the wetting of the filler powder by the plastic as it melts. 

L. Pernenkil and C.E. Cooney. A review on the continuous blending of powders. Chemical Engineering Science, 61(2) 720-742, 2006. 

---