Chesterfield & Sheffield Branch Technical Seminar
The recent ICME Chesterfield and Sheffield branch technical seminar proved to be a popular event with more than 40 members and guests of ICME in attendance to hear the four presentations.
The first presentation was by Norbert Benz of Huttenes-Albertus Chemische Werke GmbH and was entitled “New Developments in Alkaline Phenolic Ester Cured Binder Systems.”
Norbert spoke about the international structure of the company before moving on to talk about the Sinotherm process which is a no-bake binder based on the ester cured alkaline phenolic and has been developed with low odour as the main objective. He explained that in the UK foundries are seeking products with reduced phenol as the odour is the issue. The system has been developed to have the following key advantages – it can be used for all sand systems, has good hot strength when compared with furan based systems, is water based (ie no VOCs), has low levels of nitrogen and sulphur and low odour whilst being resistant to hot tears and enebling easy pattern release. The disadvantages include a slower strength development, higher benzene emissions, lower reclamation rates and a limited shelf life (1 to 6 months).
As with any binder system the optimisation of the mix is required to get the most from the system by the foundry but it can then be used for both small, intricate castings, as well as large ones.
Norbert explained that the company is now about to launch on new hardeners which will improve the usability of the reclaimed sand which will improve reclaim rates. They also have a low benzene version, Sinotherm 8402, which is currently undergoing foundry trials. This has almost 30% less benzene whilst offering comparable mould strengths.
The second presentation was by David Moore of PMT Industries who spoke about his company, the production of large cylindrical castings it produces and the high skill levels and bespoke practices, (including the use of loam) that the company uses to ensure quality castings are manufactured at its foundry in Bolton, UK. David explained that as one of only a few, deep pit foundries in the world, the company is capable of casting very large components (up to 144 tonnes) 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. A full write up of this presentation was included in the May 2009 issue of the Foundry Trade Journal, available from ICME.
Dr Karl Ableidinger is well known internationally for his expertise on Induction Furnace Melting Practice for Carbon and Low Alloyed Steel Castings. Delegates was able to ask Karl about his thoughts on the measurement of active oxygen compared with that of total oxygen and the importance of realising the difference in order to be able to produce quality steel for casting. He also spoke positively about the increase in the use of porous plug technology to purge with argon gas. He explained how the cost of investing in a dip probe to be able to monitor the active oxygen would be money well spent in his view, since the foundry needs to consider the total cost of producing defective castings. Delegates spent many minutes quizzing Dr Karl on all aspects of steel melting in what proved to be a very well received presentation.
The final presentation of the afternoon was by Dr Reinhard Stotzel, Ashland-Sudchemie-Kernfest GmbH, entitled “New Steps for Reducing Pollution in Acid Curing Binder Systems”. Dr Stotzel spoke about the foundry facility that the company uses for detailed and thorough testing all of it products. He then focussed on a new alumina based refractory coating that the company has developed to for use with chromite sand to protect the metal from the low melting point constituents of this sand. The coating has a lower wetting angle so that wetting by slag is improved which then means that any slag defects are shallower and therefore easier to remove.
He also spoke about a new ‘clean top’ cover that the company is developing. This is a refractory ‘blanket’ that can be placed above the mould once the metal has been poured and which acts to collect gaseous emissions from metal mould reactions or given off from the breakdown of the binders. He reported that, in trials, benzene and toluene emissions were reduced by a factor of 3 and sulphur levels were also markedly reduced. This leads to a reported 35% reduction in smells and odours.
This event proved to be a successful change from the usual branch programme bringing as it did a number of high profile speakers together with branch members and enabling an informative and enjoyable event to be held thanks to the hospitality of the branch. Branch President, Mike Leaney, of Cat International Ltd, thanked all those who had attended and particularly the speakers who had provided such as interesting range of topics and contributed to the lively discussion. The branch council is considering whether to repeat this format again in future years.