Starch packing material prodn. - in which particles are finely coated with nucleating agent, fused in extruder, expanded, cut, dry expanded again, and cut to final size

摘要

Packing material of starch particles is produced by applying a nucleating agent finely distributed over the surface of starch granules and to a weight of 0.1-0.2% of the weight of granules, using nucleating agent particles of about 40 micron dia.; the treated granules are then fed to an extruder where they change to a high viscosity liquid; the nucleating agent is decomposed by the heat and the foamed starch formed is extruded immediately after it has greatly expanded; the extruded material is cut off, fed into a holder, stored, and finally subjected to a secondary expansion to acquire its final particle size. - Pref. extruded material is cut to a length which after its expansion yields packing particles approx. 15-30 mm long; the extruder die used forms the product into two parallel and hollow tubes joined together by a narrow web.