Resin-Bonded Laminated and Reinforced Abrasive Products P. L. SHANTA The Carborundum Co., Niagara Falls, N . Y.
Constructions of various sorts used in the manufacture of reinforced resinoid
’ abrasive products are discussed, and representative figures on important physi-
cal properties are given. A survey of physical property values in comparison with those of nonreinforced products shows why the reinforced products provide improved performance, expanded utility, and greater safety. Having provided these characteristics, reinforced resinoid products have enjoyed widespread acceptance. Acceptance is expected to broaden as new developments make it easier and less expensive to reinforce more abrasive products.
A
S EARLY as 1878 ( 1 4 ) , methods for reinforcing manufactured abrasive articles were successfully used. Since that time, numerous modifications for strengthening these products against the various stresses to which they are subjected have been disclosed. This article reviews the materials and methods which have been responsible for the steady improvement and acceptance of reinforced abrasive wheels. Reinforcement of abrasive wheels provides improved performance, broader utility, and greater safety. Vitrified wheels, normally operated a t or below 6500 s.f.p.m. (surface feet per minute) have been supplanted in many operations by resin-bonded abrasives operated a t 9500 to 16,000 s.f.p.m. Resinoid’s higher strengths and resistance t o mechanical shock allowed safe operation a t the higher speeds. Grinding performance, in the form of higher stock removal rates ( l a ) , hence, resulted from the higher speeds. In thin cutting-off wheels where reinforcing methods have been most widely adopted, speeds up to 16,000 s.f.p.m. are common. When and if reinforced wheels can ultimately provide adequately safe operation a t still higher speeds, even greater efficiencies are expected. Such efficiencies are expected to result in faster cutting and longer wheel life. Entirely new products, which would otherwise be impracticable, have been made available in reinforced constructions. For example, depressed center or
