PROCESS OF FORMATION OF UNDER-SURFACE MARK IN MATERIAL OF ARTICLE AND ARTICLE CARRYING FORMED MARK Russian patent published in 1998 - IPC

FIELD: study of materials. SUBSTANCE: invention is meant for formation of under-surface mark in polymer material letting radiation of visible and IR range pass under action of electromagnetic radiation. Products of breakdown of polymer material forming dark region clearly visible to eye or registered by present-day equipment are obtained in radiation focusing points. Flat or three-dimensional under-surface mark is formed in material of article or in part of it by multiple repetition of process of formation of dark regions. Equipment used in process ensures formation of beam with energy and intensity exceeding threshold values of energy density necessary for thermal break-down of polymer. Intensity of beam should be less that threshold value needed for local ionization of material. Mark is formed without any violation of continuity of material. EFFECT: increased efficiency of process. 3 cl