“In the current global economic situation, excess manufacturing capacity is a challenge that has every foundry looking to make its processes as productive as they possibly can be. As casting purchasers demand ever-higher levels of product complexity and quality, correct sand and core usage is a vital and yet often overlooked step in metal casting and it can significantly affect a foundry’s competitiveness. Therefore the growing sophistication of inspection systems for castings is not a surprise. Advances in IT, in imaging, and in networking are matching metalcasters’ rising determination to raise product quality standards and to control costs in their operations,” said Jacques Swanepoel, National Sales Director of DZanetech.
DZanetech have invested in a laboratory size cold-box core shooter
“Having said this, foundry operators are faced with an insurmountable number of important process variables that they must control. There are so many variables that it’s a wonder anyone ever makes a good casting. The amount of time and attention that every foundry must devote to metallurgical processes is substantial.”
“However, when it comes time to focus on the sand, the attention seems to wane. After all, it’s just sand. Wise foundrymen know that nothing could be further from the truth. A mould is comprised of two things – metal and sand – and each of these is capable of introducing dozens of variables that need to be controlled as closely as possible to ensure a successful process.”
“To ensure the fulfilment of customer expectations and to consistently produce high-quality castings, sand and the sand cores should meet numerous requirements. The cores should have sufficient initial strength after the core shooting to withstand the loads induced by the handling and manipulation actions and should have adequate final strength (especially bending strength) during the casting process to resist the flow drag and buoyant forces caused by the liquid metal.”
DZanetech has its own state of-the-art laboratory, situated onsite at their Modderfontein premises. These facilities have been purpose built to test and formulate the company’s expansive range of products, as well as assist clients with technical services such as benchmarking and troubleshooting. They also regularly collaborate on new product developments and applications
“High dimensional stability and hence low thermal expansion are substantially important properties, which should be maintained until a sufficiently thick solid metal layer is solidified around the sand core. After solidification, the cores should be easily removed from the castings. For this reason, the cores should possess sufficient collapsibility, which is highly dependent on the degree and rate of heat exposure and the rate of thermal decomposition of the binder. To avoid defects like core blows, high gas permeability, and low gas evolution are needed. The former could be ensured by proper control of the sand grain size distribution, while the latter is dependent on the quantity of binder and volatile impurities present in the sand mixture.”
“Since our establishment in July 2020 when DZanetech was appointed as the sole preferred partner to distribute and service customers for foundry and timber products that AECI manufacture, we have been testing all our products externally.”
“This has now been complemented by our state of-the-art laboratory, situated onsite at our Modderfontein premises. These facilities have been purpose built to test and formulate our expansive range of products, as well as assist clients with technical services such as benchmarking and troubleshooting. We also regularly collaborate on new product developments and applications.”
Sand application testing
“We have a strong belief in sand application testing and devote many resources to this aspect of our business. We are not the only company that offers this service but we believe that an improved understanding of foundry sand properties is a key requirement for high precision casting process development and as a result dedicate more time to our clients’ requirements than is usual.”
A bend test taking place in the laboratory
“For example we will routinely collect sand and do a full analysis and performance test so that the required properties are achieved. Tests such as moisture content should be done by the foundry themselves but if necessary, we will do it for them. In our laboratory we carry out tests such as tensile testing, transverse testing, compression testing and a bounce and bend test.”
“We have developed and standardised tests and now have the historical data to benchmark existing and new clients. This allows us to offer advice on binder content and check dust and fines content. All this information then gives us the ability to give expert recommendation for existing and new projects, so that there are no quality compromises.”
DZanetech have two full time metallurgists working in their laboratory that consists of the standard equipment such as sieves, PH meters, scales, furnace and other equipment necessary for tensile, transverse, bend and bounce testing
“We have two full time metallurgists working in our laboratory that consists of the standard equipment such as sieves, PH meters, scales, furnace and other equipment necessary for tensile, transverse, bend and bounce testing. We have also invested in a laboratory size cold-box core shooter.”
“Other capabilities offered by the service include structured testing for core-sand analysis, moulding-sand analysis and casting performance evaluation. We are able to assist any foundry with an investment in high-performance sand-preparation quality control and give them the opportunity to do what they do best – cast metal.”
“After all, matching the right product to the right process is fundamental to the task of achieving the best performance.”
For further details contact DZanetech on 079 514 6885 (Jacques Swanepoel), Cape Town 083 454 5465 (Johan Jooste), 083 274 1657 (Koketso Mamogale) or 066 010 0999 (Zaid Syed) or visit www.dzanetech.co.za
