Burrs are undesirable but unavoidable residues on cast parts. Molten metal spreads throughout the casting tool, it penetrates into joints and then solidifies there. The excess material is removed using a trimming press (trim press). Trimming presses are available as hydraulic 3 and 4 column machines and as C-frame presses. Size and stroke vary while the pressing force can reach several hundred tons. Even when old, trimming presses usually work smoothly so that the used machines are also in great demand. Surplex often auctions off used trimming presses from locations all around Europe.
Castings are produced out of metal, which as a liquid stated are poured into a mould and taken out after it has cooled down. There are channels engraved on the casting tool, which are used for the metal to be poured in and for air to be leaked out. During the process, excess metal material collects in these channels (this collected material is called "burr"), which then later has to be removed. A seam forms within the intersection between the two workpiece halves and occasionally this has to be modified. A trimming press is a separating work tool that is used to process castings. They are implemented for the manufacturing of serial parts used in casting processes. Trimming presses are an important element for continual production.
A trimming press is a misunderstood term, because a trimming press does not press, it punches. During the pressing process a piece of material is reformed and the punching machine separates it. The main task of a trimming press is the separation of material. The pouring and ventilation channel of the cast piece is generously designed. This is to ensure that the cast receives the maximum amount of filling. After the cooling off process, the emerging burr is normally very thick. Depending on the cast piece, this burr can be several centimetres thick. Very high pressure is required to successfully remove these burrs. Therefore, trimming presses are generally hydraulically operated. For every cast piece there is a specially fitted work tool. The exact dimensions of this work tool are not so important; it just cannot be smaller than the dimensions of the workpiece.
The workpiece can be shaped into the correct dimensions using a grinding station. An alternative to deburring using a trimming press, is to saw it off. However, using a trimming press is the preferred option due to the high level of abrasive wear that occurs on milling machines and sawing machines when they are used for the processing of numerous workpieces.
Trimming presses are available in a variety of forms. Therefore, for every size of cast piece, a corresponding trimming press can be adjusted to the appropriate size. Mechanical or pneumatic trimming presses can be used for small cast pieces. From time to time, a normal industry press that is equipped with a corresponding work tool is enough. Hydraulically operated trimming presses are mainly used for large pieces. Several different accessories are usually required for this.
Trimming presses are used for the processing of solid cast pieces. A loading robot is useful for continuous work with a trimming press. Because the separated burrs are usually very solid, the disposal of scrap metal should be included in the planning. Under some circumstances the use of a removal robot could be useful.
In case you have any questions please feel free to contact the Surplex Customer Care at any time.