Abstract: The improved method of making a self-locking threaded element having a strongly adhered plastic body on its threaded surface providing strong frictional engagement between the element and a mating threaded surface in which fine particles of heat softenable plastic are applied against a heated threaded surface in a plurality of spaced successive portions in time and temperature controlled relation such that a first portion is softened by heat prior to application of a successive portion of the particles to aid in holding particles of successive portions to enable manufacture at a higher rate and/or at lower temperatures than heretofore practicable.

Abstract: A process for inhibiting scale formation using a low molecular weight hydrolyzed polyacrylamide prepared by a process involving simultaneously and continuously charging separate streams of acrylamide monomer, ammonium persulfate (as catalyst) and mercaptoalkanoic acid (as chain transfer agent) to a reaction zone containing water under reflux, the rate of charging being such that the heat of polymerization is sufficient to maintain reflux in the reaction zone without exceeding the capacity of the condenser to remove the heat of reaction, and then reacting the polymer product with sufficient aqueous caustic to hydrolyze from about 60 to 90% of the amide groups in the polymer product.

Abstract: A low molecular weight hydrolyzed polyacrylamide having exceptional effectiveness as a scale-inhibiting agent is prepared by a process involving simultaneously and continuously charging separate streams of acrylamide monomer, ammonium persulfate (as catalyst) and mercaptoalkanoic acid (as chain transfer agent) to a reaction zone containing water under reflux, the rate of charging being such that the heat of polymerization is sufficient to maintain reflux in the reaction zone without exceeding the capacity of the condenser to remove the heat of reaction, and then reacting the polymer product with sufficient aqueous caustic to hydrolyze from about 60 to 90% of the amide groups in the polymer product.