1. Adjustable Squeeze Distribution
*Industry First* This optimisation feature enables operators to distribute the pressure exerted by the swing plate and pressure plate by setting the pressure of each one independently.
The amount of pressure exerted on the pattern in the mould by the pressure plate, pattern plate and swing plate can have a huge impact on casting quality and scrap.
This is particularly evident where moulds are intricate or uneven. For example, if one side of the mould is relatively smooth, flat or rounded, but the other side contains complex elements or deep pockets, exerting the same amount of pressure from both plates, can compromise quality causing increased scrap.
Thanks to Adjustable Squeeze Distribution, pressure can be precisely matched with the requirements of the mould. Pressure can be distributed at any chosen ratio from 20:80 to 80:20.
This can also be controlled extremely precisely. To allow space to squeeze the mould correctly, the machine automatically activates the operation 2A feature. The un-squeezed mould is automatically moved forward so that the swing plate exerts the right amount of pressure.
2. Pre-strip sand recompression
Loose sand is one of the biggest causes of scrap in foundries. Flaws in cast parts can sometimes be obvious, but because sand washes around in the molten iron, problems are often only detected when the part is x-rayed.
Sand displacement occurs most commonly when the swing plate (SP) and pressure plate (PP) patterns are drawn away or ‘stripped’ from the mould. To ensure this doesn’t cause defects, DISA’s Pre Strip feature recompresses the loose sand before every pour is completed.
3. Improved blow off
As detailed above, sand falling into the cavity is one of the biggest problems foundries face, however this solution from DISA offers a prevention as well as a fix.
The improved blow off innovation is a two part system. Firstly, a curtain helps stop loose sand from falling down into the cavity, and secondly, as the swing plate moves into position, an airflow nozzle gently blows the mould to remove any loose sand. This can be used in conjunction with pre-strip sand compression – so there’s no need to decide.
4. Rear or front sand slots
When producing thinner or more intricate castings, the rear sand slot position, means that pressure can be lost as the swing plate reach its mechanical end position more quickly.
This means scrap is more likely. In order to provide greater customer flexibility, the DISAMATIC D3 can be configured for thinner, more intricate castings as well as runs of more regular parts. When the machine is being manufactured, the sand slot position can be set at the front, or 50mm out of the chamber.
5. Locking parameters
Ensuring the agreed optimum process is followed can be a big challenge for foundries. If a run of castings features a high scrap rate, it can be tempting for operators to play around with pre-set parameters to fix the problem.
This poses a danger because, all too often, the cause of the scrap isn’t settings related, but something extraneous. If operators edit the parameters, scrap becomes much more likely and problems much more persistent as the audit trail can make it difficult to revert to the original optimised pre-sets. To combat this, the DISAMATIC D3 F3 control system has locking parameters.
DISA works with foundries to identify and set the correct levels of adjustables such as sand blowing pressure, Adjustable Squeeze Distribution and mould close-up pressure, to combat the problem.