By reducing the number of set-ups - necessary with its previous equipment - a mechanical seal manufacturer has eliminated error between operations on its high value components.

As a leader in the design, manufacture and supply of mechanical seals for process fluids in rotating equipment for the chemical, pulp and paper, food, petroleum, water and other global industries, Aesseal prides itself on the service it offers to its customers. This policy is exemplified by the 25% compound year on year profitable growth achieved since its formation in 1979. Now, 47 branches in 25 countries and more than 750 employees make up the Group, which is administered from its Rotherham Headquarters.

AESSEAL plc is accredited to ISO9001 (2000), OHSAS18001, ISO14001 and Investors In People standards.

It has also won six Queens Awards, the only Company in South Yorkshire to do so.

Based on a fundamental modular design concept, the seal manufacturer is split into low volume rapid turnaround products, where seals are manufactured in hours rather than weeks; medium volume manufacture at Bradford of more complex seals; and higher volume manufacture at Rotherham, where batch sizes average 30-50 components.

Here, magazine bar feeders are used on some machines, supported by in-cycle measurement - enabling continuous lights out production.

The Pollard supplied Mori Seiki machines have 4-axes and sub-spindle capacity to further enhance process capability on one-hit manufactured, seal-critical rotary elements.

True utilisation (i.e spindle uptime including set-up, tip changes and in-cycle gauging) is above 87% across 168 available hours.

152 hours are 'attended' over 7 days using a bespoke Aesseal derived shift pattern.

The component parts of each seal demand a combination of turning, milling and drilling operations, lending themselves to one hit machining methods directly from 316 stainless bar and tube.

More exotic materials such as Alloy 20, Hastelloy and titanium are used for around 10% of the parts.

Richard Cook, Production Director for Aesseal said, 'The majority of parts we manufacture require 3 or 4 axis machining plus positioning moves, as opposed to continuous contouring moves'.

'The Mori Seiki 3 and 4 axis machines are ideal and with pneumatic chucks we are able to bar feed 92mm through the spindle which produces considerable cost savings.' Already a committed user of Hitachi Seiki machines, the transition to Mori Seiki was a natural progression offering Aesseal a combination of quality and reliability.

Cook added, ' Our experience has shown that we made the right choice, we have been very pleased with the reliability.' The company has expanded its capacity both in the number of machines, introducing the NL series lathes into its volume production workshop, and also by increasing its manufacturing envelope, enabling it to offer seals of 280mm diameter shaft size and above.

To produce the larger seals, the company purchased a Mori Seiki SL603 lathe with driven tooling, capable of chucking a 1.5 tonne billet for first operation work at up to one metre diameter; an MH630 with 5th axis able to take 1.5 tonnes on the table and 0.5 tonnes on the 5th axis; and a GV503 trunnion table machine for complex medium size parts.

Cook said, 'By reducing the number of set-ups which were necessary with our previous equipment we have eliminated the possibility of error between operations on these high value components'.

'In addition, integrating the manufacture has enabled us to significantly reduce the lead time on large seals.' Preparing this manufacturing facility in advance of customer demand is consistent with Aesseal's ongoing policy of providing the very highest levels of customer service.

UGS Solid Edge CAD and NX 2 CAM are used to design the products and produce the multi-axis programs for the Mori Seiki machines, linked together by Aesseal's comprehensive IT infrastructure, which controls production and links the company's other manufacturing sites both in the UK and internationally.

Consistent process methods are ensured by utilising templates, allowing the programmers to create around 40 new CNC programs daily.

Chris Ward, Chief Programmer for Aesseal explained, 'Some of the Mori Seiki machines can hold up to 40 tools, enabling us to utilise sister tooling, probing and tool breakage detection'.

'Typically we work from tube, bar or castings, aiming for one-hit machining wherever possible, turning, milling and drilling in the main spindle, then parting off and turning the rear face in the sub-spindle, all without operator intervention.' Aesseal is able to hold large stocks due to the modularity in the design of its seals, many parts are common to different applications ensuring continuity of supply to its customers.

Richard Cook concluded, 'We have an entirely flexible approach to manufacturing, from one-piece sequential flow through to one-hit operations carried out in parallel, it is just a volume and diversity equation which is continually managed'.

'However, like any customer focused business, our batch sizes are reducing and order frequency increasing'.

'Our product portfolio expands every year, leading to increased diversity and making a strong case for more one-hit manufacture'.

'In this area the Mori Seiki machines from Pollard have proved to be robust, reliable and are producing repeatable results, which is a key factor in maintaining our high levels of service.' * About Pollard - formed in 1911, Fredk Pollard and Co is a privately owned company, and is one of Britain's premier suppliers and manufacturers of high quality, high precision machine tools and workholding equipment.

It works in partnership with its customers using its engineering expertise to cost effectively implement high precision and leading edge technology solutions.