Cap piercing
Cap piercing brings challenges in terms of strength, resistance to wear, venting and non-coring tips.
- Column strength can be improved by the choice of a cobalt-chromium alloy and by a strong assembly between the tubular pipette and its collet, such as laser welding or brazing.
- Resistance to wear with a surface modification such as a coating (hard chromium, TiN, DLC) or an ion implantation (kolsterisation)
- Venting may be achieved through longitudinal machined groves, multi-lumen tubing or by separating the functions with a sampling probe circulating inside a piercing needle
Non coring tips may be pencil points, side-cut or specific bevels