PMT Foundry Presentation
David Moore, Prof MICME, (Quality & Technical Manager with PMT Industries Ltd) treated 19 members of the Lancashire branch of ICME to a very interesting presentation, (prepared jointly with Eric Thomas, PMT Foundry Manager) about the company, which is now part of the PMT Group and owned by Italian company, the Nugo Group. The group has two main divisions, power generation and paper machinery. PMT Industries is part of the paper machinery division along with PMT Italia spa. David was able to describe the fact that, as one of only a few, deep pit foundries in the world, the company is capable of casting very large components not only for the paper industry but also for other industries including construction and oil and gas. It is recognised for its excellence in quality castings. PMT Yankee, MG and Paper dryers are designed and manufactured in Bolton, UK at the company’s 11,720 sqm. factory, where state of the art, computerised design, engineering, foundry and machining resources combine with traditional skills and craftsmanship in a unique single location.
Around 500 Yankee and MG dryers have been designed and manufactured since 1884 and thousands of paper dryers, continually developing the designs and production techniques and building up a vast experience and know-how in this specialised area of papermaking technology.
The castings manufactured range in size from 1 tonne to 144 tonnes in grey and ductile cast iron, and David was able to describe the various stages in production that the company uses, particularly some of the unusual moulding techniques that are necessary in order to produce the very large castings. It is one of very few foundries to use loam (a mixture of red sand, clay, water and horse manure) applied by hand to a refractory brick lining. A rough coat is applied by hand, followed by a slip loam facing and finally the surface is coated with blacking, applied by trowel. Clearly this work is very labour intensive and requires skilled operators but the company believes that this is the best way to manufacture the particular castings for which they are famous. The company also uses cement sand for some of the large diameter castings, again a process that is unusual.
David also described the facilities that the foundry has including one of the largest melting capacity medium frequency electric furnace installations in Europe. The twin 9 MW inverter powered and computer controlled furnaces melt 38 tonnes of iron per hour, with each 12 tonnes charge being melted to 1450° C in just 38 minutes.
He also explained the process control techniques that are used by the company and the quality standards to which the company is certified, including ISO 9001 and the ASME authorisations for unfired Pressure Vessels; the internal diameters of the castings used in paper manufacture are subjected to high pressure steam being forced through them. The company is committed to investing in its future with 7 apprentices currently. Clearly in such a specialized field the workforce comprises people with specific experience derived from the long tradition of this plant as a world-class leader in the manufacture of castings and products for paper machinery industry and training and development of its people will continue to be an important part of the continued growth of the company.
PMT also hosted the meeting at provided refreshments.