Zinc diecastings can be found in all manner of manufactured products – notably in vehicles but also toys and recreational product, as well as medical devices. Via diecasting, zinc takes a wide variety of complex and lightweight forms. Not only is the diecasting process versatile, but zinc diecasting can be highly productive, with very little material loss: zinc residues can be remelted and reprocessed without any loss of quality, with cost and environmental benefits to the diecaster.
Disposal of the zinc scrap is a problem, however. The often bulky production leftovers occupy a lot of space in the plant and usually have to be removed manually at frequent intervals, which impedes production processes. Also, the sharp-edged surfaces increase the risk of injury for the workers responsible for operating the process and handling the scrap.
The M600 single-shaft shredder developed by Erdwich Zerkleinerungs-Systeme GmbH can be installed directly on the diecasting machine, offering an all-around remedy. It minimizes the space, logistics, and time required to handle zinc scrap and makes manual handling unnecessary.
For components of different sizes, Erdwich also offers the RM1350 ripper and the M465 and M(H)480 twin-shaft shredders with electro-mechanical and hydraulic drives.
The long view – Zinc diecasting has been established as a mass production process for a long time: Depending on the size of the product to be manufactured, it is possible to produce hundreds of parts per hour with just a single diecasting mold. Particularly in the production of parts for automotive assembly or for mechanical engineering, sprue and runners, punch burrs, or defective workpieces can lead to full scrap containers within a very short time. If these are not replaced quickly enough by empty containers, this results in a considerable impediment to the operating processes – in the worst case, the production speed has to be throttled.
"In many companies, the removal for scrap for remelting is often still done manually," explained Harald Erdwich, managing director of Erdwich Zerkleinerungs-Systeme (EZS.) "The personnel then are not only exposed to noise and heat, but there is also an increased risk of accidents and injuries due to the sometimes very sharp-edged diecast parts."
Efficiency on-site – How can these difficulties be avoided during production? EZS has developed shredders of different sizes that can be installed directly at the diecasting cell. In this way, the scrap parts are shredded to a more manageable size even before they are stored in containers provided for this purpose.
One of these models is the M600 single-shaft shredder, which is available with different cutting gear lengths. It was designed for shredding small diecast parts weighing up to 2 kg and can significantly reduce the volume of the parts by up to 60%. "With our plants, we always make sure that they fit the specific requirements of our customers," Erdwich explained. "That's why we offer the M600, as with most of our shredders, with different sizes of cutting gear and drive powers."
The compact machine dimensions are another advantage because, depending on model, the plant takes up just 1.5 m2 of floor space, so it’s possible to operate even in confined spaces. In addition, EZS designs emphasize long service life and ease of maintenance: The fully hardened knives, which can be reground several times, ensure the long, uninterrupted operation of the shredder.
Fully automated for integrated operation – "In addition to the M600, we also offer plants that are suitable for shredding larger scrap parts," Erdwich explained. "These include the M465 and M(H)480 twin-shaft shredders and the RM1350 ripper, which can efficiently shred and break down parts weighing up to 10 kg, or even complete body structure components.
“Each shredder meets our high safety standards and is designed for long operating times," he emphasized.
All plants can be connected directly to a casting station or diecasting machine and, as fully automated solutions, can be retrofitted into existing production lines. To ensure optimal integration of the shredders into the line, EZS offers on-site evaluations of potential installations. At a diecasting plant the EZS experts gather an overview of the conditions and then work out a solution that makes optimal use of the available space and provides the necessary shredder unit size and functionality.
After shredding by the EZS shredders, the manageable metal parts can be collected in containers via conveyor belts or transported directly back to the furnace systems. This ensures that the shredded material is returned to the production process as quickly as possible. The volume of waste cast parts is reduced by 50-60%. Thus, the entire internal logistics process can be optimized, resulting in the eradication of space consuming and cost-intensive temporary storage of the reject materials, and further removes the need for manual removal of the dangerous material.
Furthermore, the size reduction can lead to energy savings in the melting furnaces because the smaller components are more efficiently and more easily remelted. In this way, the resource-saving reprocessing of the reject material becomes an essential part of an energy-efficient and cost-saving production cycle.