UK first as foundry adopts new technology
06 February 2013
Sheffield Forgemasters is the first UK foundry to adopt a state-of-the-art mould and core coating technology, further improving its high-integrity castings and creating greater efficiencies.
The technology enables Forgemasters to apply a coating of uniform composition and thickness to its moulds, used to form the largest and most complex steel castings in Europe, leading to reduced preparation time, enhanced casting surface finish and easier removal of refractory material from the casting.
Installing the coating system at a six-figure cost is part of the engineering specialist’s ongoing investment programme, which reached £50m in October and has seen the company plough all of its profits back into the plant, in order to capitalise on technology and skill to break new markets.
Simon Alexander, foundry director at Sheffield Forgemasters, said: “Part of Forgemasters’ ongoing strategy is to refine systems and invest in technology where it can demonstrate a measurable improvement to what we do and the new coatings system is a prime example of that approach.
“We are champions of technology which helps to make our products the best that they can be and we are pleased to be the first adopters of the system in the UK.
“It essentially enables us to create an even coating of the moulds and cores, and because the control system is automated, it eliminates manual preparation of the coating slurry. As the new process works on a closed system, we have also dramatically reduced the amount of waste slurry.”
The coating acts as a sealant and barrier between the mould and the molten steel and its use reduces the amount of work required to clean and finish each casting once it is removed from the mould, which is formed of sand and resin.
Forgemasters’ new coating initiative is a two-part system consisting of two computer controlled coating preparation plants by Foseco Ltd, designed to deliver slurry coatings with consistent viscosity and density, and a dedicated core and mould drying oven, supplied by Omega Foundry Machinery Ltd, to control the drying of the coating.
Simon added: “We use water based zircon slurry, which used to be applied following dilution and quality control testing by hand, which inevitably leads to inconsistent coating quality and thickness.
“Seasonal temperature variations in the Foundry also complicate the traditional manual approach. The slurry, which is temperature controlled, is now automatically diluted and tested, then pumped to an application nozzle for the operator to direct over the Sand Mould. The uniform composition and density enables ‘flow coating’ of Cores and Moulds to achieve a constant and accurate layer thickness.
“Any excess coating is collected and recycled. Trials are now taking place to develop spray application for use on large moulds or core sections that cannot be directly flow coated.”
The system’s mobile oven will reduce the drying time for coatings from several days to an astonishing four hours from start to finish.
Mounted on rails, the oven and is able to service four separate areas, each one measuring 4m square, where items are placed ready for drying.