February 5, 2002 -- Arrive at the entrance of Greene, Tweed in Nottingham and you are immediately confronted with a modern, science park-style building, which gives the impression of being home to a high-tech software development business. It certainly does not look like your average engineering company.

Yet this is the European manufacturing centre of Greene, Tweed & Co Inc., of North America, which designs and manufactures a comprehensive range of speciality seals and plastics components for a wide range of industry sectors. At the site it also produces its own PTFE materials, using a large isostatic press in the mould shop.

First impressions count and, in reality, this advanced manufacturing business knows exactly where it is and where it's going! The Ruddington-based company has invested heavily in advanced CNC machine tools, including nine multi-axis CNC lathes and four vertical machining centres, of which two have a full five-axis capability as well as 3-D co-ordinate measuring machines.

In order to optimise its programming routines, Greene, Tweed has also invested in EdgeCAM offline programming software supplied by Pathtrace of Reading and, as manufacturing manager Barry Williams comments: "The software has made a big impact on production efficiency."

He describes how on a number of thermoplastic seals, programming time has been reduced from around 30 minutes to just 30 seconds. Meanwhile, on complex profile milling operations used on composite type materials, program preparation times are now on average some 250 per cent faster than the previous shopfloor programming methods. "Combined with ease of use, flexibility and direct links to our SolidWorks CAD system, EdgeCAM has also contributed to the trimming of product lead times by upwards of 10 per cent and is enabling us to be even more responsive to customer demands."

When the company decided to move away from on-machine programming and invest in a CAM system for both lathes and machining centres, it investigated the benefits of a number of different packages. From initial market research, a shortlist of three systems was drawn up which were then subjected to further detailed analysis.

Barry Williams recalls: "We finally selected EdgeCAM because it best met our ease of use, flexibility, speed and simulation demands. It would also enable us to automate certain elements of our programming cycle. The software dovetailed neatly with our CAD system without the need for data translators and we could see how easily it would reduce programming times which was particularly important on some of our small batch runs."

Established in the UK in 1982, Greene, Tweed & Co currently employs 106 people and it moved into its modern 35,000 (square feet) facility on the Ruddington Fields Business Park some two years ago. Specialists in the design and manufacture of sealing elements and systems it also produces, custom designed bearings and precision components from specially formulated elastomers and thermoplastics.

Its customer base is spread across aerospace, fluid handling, motor sport, oil field, medical and semi-conductor industries with approximately one-fifth exported. Aerospace accounts for a significant part of the business, involving production of sealing assemblies for landing gear, flight control, fuel systems and a whole range of sub-systems. In addition, high strength thermoplastic aerospace components used in engines, suspension units and landing gear are produced at the Nottingham facility.

For the future, the medical sector is a rapidly developing business area for which Greene, Tweed is using its expertise in design and materials to replace metal components with special thermoplastics. It is also utilising its engineering and production to good effect particularly for in-vitro diagnostics, haematology systems and other extremely demanding applications.

The company also produces components out of Orthtek (trademark), an advanced polymer composite, for a range of surgical instruments. With stiffness properties exceeding those of aluminium and almost half the weight, these structures are gradually replacing traditional metals in fixators, guides and robotic surgery devices. As well as strength and weight advantages, this material is also inherently radiolucent, which enhances the X-ray visibility of critical areas without interference from the surgical tools.

It is here that EdgeCAM has played a key role by streamlining the production of these highly complex surgical tools. For example, a series of surgical fixtures used in hip joint replacement are required in batches of just 20 and are machined directly out of solid plates of Orthtek using the company's latest Mazak five-axis vertical machining centres. Polycrystalline diamond tooling is utilised to carry out typical operations of profile milling, slotting and drilling of interlocking elements which then make up the surgical tool.

One such part, which acts as a drilling fixture, is machined from a 203 mm by 101 mm by 25 mm thick composite block. Prior to EdgeCAM, it took some four hours to program but this can now be achieved inside 90 minutes through EdgeCAM working directly from a solid CAD model. A 25 mm by 101 mm femoral fixator is now also programmed in just 45 minutes compared to 112 minutes and it is much the same story on a number of other composite parts where, on average, programming time savings are averaging around 250 per cent.

Depending on customer demands, Greene, Tweed can be called upon to produce 20 new programs a week. Most of these are now handled by EdgeCAM which is DNC linked to the CNC machines. With average batch sizes ranging between 10 and 50, the company needs to be able to program quickly and accurately which, as Barry Williams concludes: "Is exactly the capability that EdgeCAM has provided."

He maintains that the new software speeds up programming routines, enables modifications to be more readily incorporated and provides the graphical simulation which ensures that part programs are right first time. "Without doubt, EdgeCAM has helped us to optimise our investment in CNC machine tools and is a key element in expanding our business into more complex plastics machining projects," he says.

For more information, please visit www.edgecam.com or email Email Contact.