Sand moulds are formed using sand in combination with a binder.
This binder may be clay and water (greensand) or a chemical (resin bonded). The sand mixture is placed in the pattern box and compacted so that it precisely fits the pattern.
Sand moulds are used when large castings need to be made.
The Patternless® Process, invented and developed by Cti, uses CNC machining to cut the mould directly into a block of resin bonded sand, based on a computer generated 3D model. This does away with the need for expensive pattern equipment, which makes the process particularly suitable for one-off or small production quantities.
3D printing of sand moulds & cores enables complex cores that would normally require multiple core-boxes, to be made in one piece, through a process of printing layers.