Precision Grinding of Diallyl Phthalate Thermosetting Plastic

Archive description

A semiautomatic grinder was designed and built at Mound Laboratory to grind molded plastic detonator heads to close tolerances. It uses a vertical spindle, dry grinding technique to decrease grinding time of some diallyl phthalate (DAP) detonator heads with wire inserts and to eliminate the problem of error in repeatability which is characteristic of the manual grinding process. The semiautomatic grinder is essentially air-operated with electrical control and was primarily designed using standard components for ease of manufacture and maintenance. As development of the semiautomatic grinder progressed, DAP detonator heads with wire inserts ground using the manual surface grinder were evaluated along with the same type of detonator heads ground using the semiautomatiac grinder. Also, a time study was conducted to determine the cost savings of grinding miniature DAP detonator heads with wire inserts using the semiautomatic grinder. Inspection and analytical results and radiographic sections of ground detonator head surfaces from each grinding technique indicated that the semiautomatic grinding technique provides acceptable ground DAP detonator heads with wire inserts at a cost savings of 83.5% and a significant reduction in grinding time.