Automotive Tools Help Medical Industry

Companies supplying components to the medical industry sector are under pressure, not only for shorter lead time deliveries but to reduce costs and according to one of the UK's leading contractors to the hip and knee replacement and special tool sector, some customers are even adopting automotive strategies of annual cost-down reviews.

Says Martin Koerner, commercial director of Amdale based in Portsmouth: "Investment in the latest technology equipment is the only way to compete and maintain the business and you need to be very lean and mean in what you are doing." His company Amdale was established in 1988 providing a subcontract wire EDM service to textile and mould making industries but such has been the change in the sector that this only now accounts for around two per cent of his turnover of 1.4 million (pounds sterling).

Still maintaining his special skills as a wire EDM company and an avid user of Fanuc wire EDMs from 600 Centre in Shepshed, Mr Koerner is fighting back by progressively upgrading his EDM machines over the last 18 months. Indeed, two new Fanuc Alpha-OiC machines have replaced four reliable, but ageing Fanuc wire machines and he has found such is the added productivity factor on the latest developments from the Japanese maker, that Amdale is experiencing a three-fold increase in throughput over previous working methods.

The short delivery times prevalent in the medical industry mean that both Amdale's new Alpha machines work 24 hours a day, five days a week, plus some Saturday mornings when demand dictates. "Many of the components are quite complex," he says, indicating a guide for knee replacement saws manufactured from 174PH, a heat-treatable stainless steel. "This particular part takes around seven hours on one of the new Alpha-0iCs which is around three times quicker than our previous generation of wire EDM machines."

He maintains that when you total that saving up across a typical batch of 40 parts, you can quickly see the difference the investment has made. "Further savings are also being achieved because we can now wire cut this part complete in a single set-up: rather than three set ups previously because we couldn't wire cut tapers in excess of 10o."

Amdale's business is certainly benefiting from the keep fit phenomenon that took off in the late 1970s, launching a nation of jogging, squash playing, and aerobic fanatics adding to the footballers and rugby players injuries. No one could have predicted quite how much business it would create for people requiring knee or hip replacement surgery says Mr Koerner. Also many of the instruments required for these procedures are manufactured and supplied by Amdale and these are going to customers worldwide.

Amdale's move into the medical sector started about 11 years ago. "We got a lucky break," admits Mr Koerner. "We won a contract to manufacture spinal implants from titanium which was very successful. The customer was a world-leader in medical devices and it had the credo to educate both its staff and suppliers in medical component technology. We were invited to attend a seminar and it really opened our eyes, in fact it was quite inspiring and led us to focus on the application of our expertise in that sector."

Today the ISO 9002 accredited company has benefited from what turned out to be an important strategic decision, enabling it to grow to a 26-employee business with a turnover of 1.4 million (pounds sterling). "Our old wire machines were not capable of the accuracy and speed required for the hip and knee instrumentation in which we now specialise. So this was a major factor in our decision to pursue an upgrade programme.

The latest Fanuc Alpha-0iC wire EDM machines feature the world's fastest 'disconnection to reconnection' automated wire feed (AWF) mechanism - taking just 12 seconds to complete using thermal melting techniques. "The AWF is so fast, much quicker than I originally thought, but it gives us an advantage by eliminating the need for operator attention over long running periods. The AWF technology is also very reliable," explains Mr Koerner. A further feature of the Alpha-0iC machines that benefits Amdale is its taper cutting ability. "We taper cut up to 40 (Degrees) on a regular basis," he says, "but the Alpha makes it easy, involving very little machine setting.

Amdale is also able to take advantage of the Fanuc Alpha-0iC's well-proven functions such as high speed non-electrolysis AC cutting and the latest AI active corner control. This enables pre-emption of any changes in either the roughing or finishing cutting path and keeps the wire feed taught, thus giving a more precise corner control without having to result to modifying or compensating the programmed cutting path.

The ultra-high speed AWF system thermally melts the wire, which dramatically simplifies the design of the wire cutting mechanism, improving reliability and reducing service demands. The annealing effect of the heat generated in the wire also improves its straightness and creates a very sharp edge at the point of cut. With the thermal melting system, wire disconnection takes just four seconds and wire reconnection eight seconds. The sharp edge created helps automatic insertion of the wire in the wire guide and eliminates any need to use a split guide. Wire threading can also be performed while submerged on workpieces up to 100 mm thick, which eliminates time to drain and refill the tank and hence further improves the productivity of the process.

The Fanuc Alpha-OiC has a maximum workpiece capacity of 750 mm by 500 mm by 250 mm with table travel of 320 mm by 220 mm. Both the U and V axis travels are ± 60 mm by ± 60 mm and maximum standard taper angle is ± 30 (Degrees) over 80 mm. As an option, this can be increased to ± 45 (Degrees) over 40 mm using an additional wire guide. Wire size as standard, is between 0.1 mm to 0.3 mm but Fanuc also offer an option of ultra-fine 0.05 mm to 0.3 mm wire diameter. Maximum wire capacity is 16 kg however, an optional 20 kg supply reel is available for extended running.

The majority of component designs received by Amdale are electronic CAD files. Toolpaths are generated off-line using VisiWire CAM before being sent via Amdale's network to the control system of the machine. Today, most of the company's medical components fall into the 100 mm³ envelope, demanding precise slot tolerances of ± 0.003 mm and + 0.01 mm with angle tolerances of ± 0.25 (Degrees). Surface finish is mostly in the realm of 0.25 Ra.

A further benefit to Amdale of the latest 0iC machines is that the whole cutting process is immersed. The previous generation machines deployed co-axial flushing, which occasionally led to problems from corrosion and impaired surface finish. "There is no doubt we get a far better job from the 0iC's," confirms Mr Koerner.

Although Amdale still has customers in other industries, such as Formula One and textiles, the company now actively promotes its medical manufacturing capability. With customers across the UK and also in Switzerland and America, Amdale is now creating awareness at medical exhibitions in Germany, Turkey and China in a bid to tap into the booming medical industry markets.

That said: "If we get a lead of an order for batches in excess of 500 parts we usually hold-off bidding because we know it will probably go to the Far East," says Mr Koerner. "However, for small batches of value-added or very complex medical components, UK sub-contractors can compete and there are growing opportunities overseas to perform this type of work. Markets such as China have a booming medical industry, which seems to be facing a supply and demand problem on which we are hoping to capitalise. We can compete head to head because we are using the most advanced machining technology that is available!"

SOURCE: Amdale Limited