abstract |
A method for marking an item including a shape memory polymer (SMP) having a visual readable and/or machine readable graphic element on the surface of the item. The method includes pretreating the surface of the item; colouring the surface of the item with a dye solution containing an organic dye and an organic solvent; cleaning and drying the surface of the item; and engraving by at least partially ablating the surface of the item. The dyeing process is suitable for colouring the surface of a shape memory polymer (SMP), wherein the information is engraved in a form of a code or other label on the coloured surface. The colouring causes an increased contrast and thus facilitates machine readability of marking and coding without affecting the other properties of the SMP. |