Starch Adhesives Research Articles

Influence of particle size on physicochemical properties of pharmaceutical powders. VII. Fluidity and packing property of binary mixtures.

Influence of particle size of boric acid, aspirin or magnesium alumino silicate on fluidity and packing property of the binary mixtures of starch was investigated. For the mixtures of starch and boric acid or aspirin, angle of repose decreases gradually with the increase of proportion of boric acid or aspirin above critical size, while minimum angle is obtained for the mixture containing a certain proportion of smaller particles. It is suggested that cohesion of starch particles is scarcely influenced by adhesion of starch to particles above critical size, and that it decreases by the adhesion to them below critical size. Porosity of the mixture is a little larger than the arithmetic mean value of porosity of starch and boric acid or aspirin. Remarkably small values of angle of repose and porosity are obtained for the mixture of starch and magnesium alumino silicate. Magnesium alumino silicate particle is suggested to take moisture away from starch particle.

On the Simple Method of Estimating Wet Strength of Adhesives for Corrugated Board

In connection with the studies on the synthetic high polymers giving wet strength to starch adhesives of corrugated board, a convenient method for estimating the adhesiveness was devised. The method is based upon the determination of resistibility of sample piece of pasted paper against stripping in a definite condition. The sample pieces of pasted paper are prepared by a definite means. The manipulations of the method was described. If the determination tests are repeated in the constant conditions, the results obtained are accurate and reproducible. For a comparison, similar estimation tests were made by use of the tensile tester of Schopper type, and the like results were obtained. The method devised by the authors, however, has rather advantage in simplicity. Using the new method, the effects of the wet strength of water-soluble synthetic polymers upon starch adhesives were studied.