FACILITIES

Microfinishing

LPE Medical has recently added fully automated microfinishing of large diameter femoral heads and acetabular devices to its range of medical device manufacturing capabilities.

The significant investment in the plant was necessary in order to ensure LPE Medical could continue to offer orthopaedic device manufacturers a single source, cost effective supplier partnership for metal-on-metal bearing joints together with the manual metal finishing techniques required for the more complex geometry associated with femoral stem production.

LPE Medical staff have worked together with the machine tool supplier since the purchase of the plant was agreed in order to ensure both the machine tool and the software would meet all the specified requirements for accuracy, precision and current Regulatory requirements for validation purposes.

Since acquiring the plant, the microfinishing process has been continually monitored, measured and developed over a significant period of time in order to determine the optimum operating conditions and preferred process parameters. Consequently this has necessitated the purchase of additional high precision metrology equipment, capable of measuring to less than nine tenths of one micron, in order to measure the devices and determine compliance to the close tolerance requirements as dictated by the customer specification.

The equipment is now in routine production use following the successful in-house process development and validation and subsequent customer regulatory approval and commercial product launch.

As an overview, following the pre-machining of the cobalt chrome femoral head and acetabular device, components are processed through the microfinishing plant to achieve the specified requirements for size, sphericity and surface finish. In-process measurement and gauging is a key asset to this process. Parts are then 100% verified off the machine, secondary processed, laser marked and ultrasonically cleaned prior to packaging and labelling in the LPE Medical class 10,000 clean room before terminal sterilisation and supply to the customer.

The LPE Medical developed microfinishing process is capable of routinely producing parts within a tolerance of less than 4 microns, in a 'free state', within a single process cycle (i.e. off the machine tool), with no further manufacturing process requirements, whilst still maintaining efficient cycle times.

Marcus Daniels, Managing Director, commented 'The significant investment and process development required in the acquisition of such processes would further demonstrate LPE Medical's commitment to move forward 'side by side' with customer innovation and to continue to be at the forefront as a provider of reliable, cost effective medical device sub-contract services.'