BOC has developed a small high pressure cylinder for use in a needle free drug injection device. The aluminium microcylinder provides the power pack for this device releasing a supersonic stream of gas for drug delivery.
This paper outlines some of the key product design criteria for the microcylinder, assesses the possible means of manufacture and finally demonstrates the suitability of laser Nd:YAG welding for high speed Good Manufacturing Practice (GMP) manufacture. A detailed evaluation of the key manufacturing tolerances was carried out in an experimental evaluation phase prior to the development of a full scale pilot plant. High product quality is essential, particularly as the microcylinder is a component of a medical device. The pilot plant is aiming at zero defects through stringent process control and in process monitoring.
The manufacture of the high pressure microcylinder provides an excellent example of the flexibility of the Nd:YAG laser which is used in three separate ways; continuous wave (CW) welding, pulsed welding and marking.
The design, development and manufacturing implementation shows how laser technology is the only viable manufacturing technique for the high volume production rates that will be required.