Global casting production continues to grow. In percentage terms, the growth rates for aluminium castings are certainly higher than those for the other alloys, but more than 70% of all castings are still produced in iron: Nodular, malleable and grey iron. In the major countries, this part of the market has been subject to a continuous concentration process. Large foundries and foundry groups expand their capacities to adapt to the cost pressures from the automotive industry. Production is automated, continuously optimised and the number of operators minimised. The foundry equipment industry is actively involved in and supporting foundries in this development. Large-scale production is being optimised, production lines are getting ever more complex. However, these high-performance lines will only reach their break-even point if they are run for 15 shifts or more per week.
Small and medium-sized
And there is another side to the foundry industry: The many small and medium-sized, often family-owned foundries that supply customers in their immediate regions with the everyday, small-series castings that are also needed all around the world. These small and medium-sized operations can be found anywhere, not just in industrialised countries. They’re the overwhelming majority of foundries and contribute to the smooth running of life everywhere.
But what kinds of machines and equipment do these foundries use in their production? DISA figures indicate that, in China, there currently are around 50 000 to 60 000 jolt-squeeze machines in operation. Until now, the leading foundry equipment manufacturers have had no specific approach for equipping these customers with more efficient, cost-effective and flexible moulding lines. In Central Europe, this market segment was covered by less flexible, mostly mechanised, tight-flask high-pressure moulding systems with heavy foundations. This approach does not scale globally, as the price of a single flask is equivalent to around three monthly wages of, for example, a Thai foundry worker. Thus, most of the foundries with an annual production of less than 5 000 t/y, and even parts of the <10,000 t/y segment, continue to operate with jolt-squeeze machines.
In light of this finding, it’s important to bear in mind that the shortage of labour in foundries is a global problem, as are increasing cost pressures, the demand for more flexibility and the growing complexity of castings.
The inexpensive and fast production of high-end cast products in large series on vertical moulding machines with very short cycle times has been the state-of-the-art for many years. This article has looked at foundries producing castings in small series, sometimes with the intensive use of cores. In addition to the use of automatic core setters, which require the use of core masks, the use of automatic sliding doors, which allow the direct setting of cores into the mould, has been described in detail. For this application, a new type of vertical moulding machine has been developed. Built at Norican Group facilities in India and China, it can be offered at competitive prices – around 50% lower, compared to traditional Disamatic technology. These systems are not designed for high output, but for use in small and medium-sized foundries for which a move to vertical moulding technology has previously not been economical.