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| Mass production of plastic injection moulded components for medical / pharmaceutical devices, in particular drug delivery systems such as inhalers, is a particular specialisation of Tech Group Europe’s, Dublin, Ireland facility. The company's recent purchase from LK of three co-ordinate measuring machines (CMMs), as well as fixtures and inspection programmes, has halved the time it takes Tech Group Europe to develop systems for quality control of its high precision mouldings. |
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The Tech Group Inc serves nine of the world’s top 20 pharmaceutical companies. These global enterprises all need fully tested prototypes of new designs in the shortest possible time for clinical trials and therefore speed is of the essence at The Tech Group Inc. The sooner the trials are completed to the satisfaction of the relevant authorities worldwide, most importantly the Food & Drugs Administration (FDA) in the USA, the quicker the drug, complete with its delivery system, can be launched onto the market.
Tech Group Europe’s Quality Manager, Tom Clarke and Quality Engineer, Craig Keyworth have achieved dramatic savings in the so-called measurement system development (MSD) time cycle by programming inspection routines directly from CAD models of new medical components using LK's CAMIO Studio software, running off-line so as not to disrupt operation of the CMMs. By the time mould tools and fixtures to clamp the components on the CMMs have been manufactured, all of which takes typically four to six weeks, the programs are already written and ready for use after only minimal editing.
Working from CAD data of the components sitting in their fixtures "in cyberspace", as Mr Keyworth puts it, is twice as fast as the conventional procedure. This is to wait for the fixtures and first-off moulded components to become available before preparing the programs on the CMM using the teach-in method, ie moving the probe physically around the moulding to fix each inspection point.
It was in June 2003 that Tech Group Europe acquired its first LK machine, a G-90C with a nominal measuring envelope of 600 by 500 by 400 mm, prior to which component inspection was sub-contracted to a firm in the UK. However, the moulding specialist wanted closer control over the quality function and the faster turnaround that an in-house CMM facility could offer, both for inspecting prototypes and for validation of the production processes.
For the same reasons, six months later the company installed an LK G-90CS CMM of 2000 by 700 by 600 mm capacity for routine inspection of mouldings on a sample basis when volume production has started. A rigorous six-sigma approach to proving out the process for each new project is carried out using R&R (repeatability and reproducibility) studies.
The third LK CMM, due to be installed in November 2004, will be in support of a specific project involving a medical device comprising 11 unique parts for a major European pharmaceutical customer. Design and development for such a project would normally take 18 months, but at the request of the customer it was telescoped into one third of that time with the help of the LK machines. A number of the mouldings are complex and underwent four iterations between project inception in November 2003 and September 2004, each time incorporating refinements stipulated by the FDA.
To manage such a project, a team of around 30 people is set up across various organisations including the customer, toolmaker, design house, material suppliers, testing organisations and LK, whose customer support division in this case undertook programming of the eight plastic components. Manufacturing and quality systems are currently being set up and will be held in place pending volume manufacture of the product. Tens of millions of the medical devices will be produced every year and the new LK CMM will be working round-the-clock in support of the operation.
Another major medical device that Tech Group Europe is working on is even more complex. The entire MSD has been outsourced to LK’s customer support division, which is writing part programs for inspecting the components, and designing and manufacturing all the fixtures.
Early prototypes are already being measured on the LK machines. One particularly complicated moulding requires 89 dimensions to be checked. Measuring cycle times vary from two to 10 minutes according to component complexity and tolerance is down to ±10 microns, which is extremely tight in plastic materials.
Another feature of LK's CAMIO Studio software is its comprehensive graphical reporting in real-time, with the information constantly updated on the screen. It speeds and largely automates the preparation of reports, illustrated with tables and graphics, for both management and production staff internally, and for customers. The style may be varied to suit individual preferences.
Craig Keyworth is currently evaluating the use of analogue scanning on the LK machines, which is also supported within CAMIO Studio. The technique can accelerate measuring cycles and provide vastly more data for analysis and reporting than is possible using discrete point capture with a touch-trigger probe, as is currently used at the Dublin facility.
Download: Tech Group Europe uses LK CMM for medical component inspection (PDF file)
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