Vacuum Casting

In the manufacture of patterns from wax compositions and organic resins, and of dies from silicone rubber, quality is of paramount importance. The intricate die configuration, no possibility to install vents, very fine surface „design” of the master pattern – these are but only very few examples when achieving good quality is difficult, not to say - impossible sometimes.

The situation gets even worse when the materials used for patterns or dies include two or more components. If this is the case, then on mixing the base material with hardener and filler (organic resins), and of rubber with catalyst, a mixture with a large volume of the occluded air is fomed.

The cases when non-active solvents are added, i.e. the solvents that do not chemically react with the components, pouring in narrow stream, slight inclination or shaking on pouring may also deteriorate the pattern quality. To avoid these inconveniences, pouring of components after previous mixing in vacuum is commonly thought to be a remedy.

At the Foundry Research Institute in Cracow, a professional equipment made by MK–Technology from Germany is available. The equipment seems to fulfill all the imposed requirements. The vacuum is produced in a wide range of values with the possibility of stepless control. Rich accessories (two individual heating chambers, heated tank for wax composition with stepless control of temperature and mixing arm revolutions, the possibility of feeding in vacuum both hardeners and catalysts, etc,) make the equipment versatile and hence used in various applications.

The patterns made from different organic resins and wax compositions as well as the dies made from silicone rubber are characterised by high quality and as such can be used in numerous and varied applications.