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Published: June 9, 2010
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When Manual Assembly Goes High-Tech and Beyond

The changing practices in medical device manufacturing are illustrated in the development of a new piece of dispensing equipment. Initially, it met with resistance, but over time it has been adopted by the majority of the companies involved in the manual assembly of disposable plastic circuits. Most recently, of course, high-volume production that requires a high level of labour has moved to areas of the world where labour costs are lower.

By: P. Galavotti, Nexion srl, Mirandola, Italy

The subjectivity of the operator
When I began working in the medical field around the end of 1985, I visited several cleanrooms in the Mirandola area, in northern Italy, in connection with my work. This area is also known as “Plastic Valley,” because millions of disposable extracorporeal circulation circuits (for dialysis, infusion, transfusion and nutrition) are manufactured there. The main feature of this industrial area is that a radius of just a few kilometres contains the complete production chain for disposable plastic circuits: injection moulding, tubing extrusion, assembly (mainly manual), packaging and sterilisation.
 
Back then I was a young engineer who had just returned from compulsory military service. After a few short professional experiences in other fields, I began working for a company that, among other activities, manufactured equipment for quality improvement and production optimisation in the medical device manufacturing sector.
 
During my first visits to those cleanrooms, the thing that surprised me the most was the smell of cyclohexanone. This is an extremely volatile solvent used for bonding tubing and plastic connectors and if you have never had any experience with this solvent, its odour is similar to that of acetone, which is used to remove nail polish. The workers whose job it was to assemble the disposable plastic circuits used a ceramic dish holding a piece of polyurethane sponge soaked with cyclohexanone to apply this solvent. For eight hours a day the components to be bonded were “moistened” with the solvent by means of “dipping” them onto the sponge and immediately connecting them to the other component.
 
This resulted in a highly subjective operation that required a great deal of ability on the part of the operator. If too little solvent was applied, there was the risk that the two connected pieces could come apart. If too much solvent was applied, there was the risk of the excess solvent running into the circuit and possibly causing a hole near a particular connection.
 
Innovation arrives with a solvent dispenser
In those days, in addition to the popular system of the ceramic dish, there were only a few other systems that were ingeniously designed and built by the companies themselves. The company I worked for then started to develop the first commercially available solvent dispenser to solve a series of typical problems connected with that specific procedure for applying solvent, including:
  • important factors such as ease of use, compactness, reduced maintenance and operational flexibility
  • the length and/or depth of the application by means of a special insertion bushing
  • the application inside the tubing as well as on its external surface
  • the reduction to the smallest amount possible of the wasteful evaporation of solvent in the workplace
  • the aspiration and/or elimination of the solvent not used for application, by means of the simple over pressurisation of the cleanroom
  • improvement of the employee’s working conditions
  • reduction of the time necessary for training the operators because the system requires less subjective application
  • increased productivity from the dispenser’s improved ergonomics and a substantial reduction in rejects.
 
Together with a colleague I developed and tested the solvent dispensers and collected the operators’ opinions and suggestions. I observed them while they worked with the traditional sponge system and with the first prototypes of the solvent dispenser. At first it was not easy trying to get them to use this new piece of equipment; there was much resistance to change by the personnel. There were also many small and large technical problems that were slowly resolved with subsequent versions of the solvent dispenser, which incorporated further modifications and improvements.
 
Unexpected results
With the solvent dispenser we achieved results that were surprising and in some ways even unexpected: we reduced the amount of solvent used by up to 70% under equivalent operating and production conditions; we reduced rejects by almost 90%; and there was also a considerable improvement in the operators’ working conditions. All of this was achieved with a piece of equipment that paid for itself in just a few weeks. It was a great commercial success for the company for which I worked.
 
Starting from the beginning of the 1990s, the solvent dispenser steadily became more used by the companies involved in the manual assembly of disposable plastic circuits. “Homemade” systems based on “dipping” onto a sponge placed on a ceramic dish have now completely disappeared. Today high-volume production requiring a high level of labour has moved to areas of the world where labour costs are lower, but as an engineer in training it was an exciting experience to see that the solutions to a series of problems in connection with the application of solvent were adopted over time by the majority of the companies operating in this field. 
 
Paolo Galavotti
is General Manager at Nexion srl,
Via 2 Giugno 111, I-41037 Mirandola, Italy
tel. +39 0 5352 7880
e-mail: paolo.galavotti@nexion.ws
 

I would like to dedicate this article to the memory of Eddie O’Meachair of Panmed Teo, Ireland, who passed away in February 2010. Eddie was a friend and colleague who possessed great humanity, thoughtfulness, humility and technical expertise and from whom I learned a great deal.  

Published in European Medical Device Technology, June 2010, Volume 1, No. 6



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