{"id":10968,"date":"2024-04-12T10:43:33","date_gmt":"2024-04-12T10:43:33","guid":{"rendered":"https:\/\/protoandgo.com\/design-tips-for-vacuum-casting-in-silicone-molds\/"},"modified":"2024-07-12T11:48:58","modified_gmt":"2024-07-12T11:48:58","slug":"design-tips-for-vacuum-casting-in-silicone-molds","status":"publish","type":"post","link":"https:\/\/protoandgo.com\/en\/design-tips-for-vacuum-casting-in-silicone-molds\/","title":{"rendered":"Design tips for vacuum casting in silicone molds"},"content":{"rendered":"\t\t
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The vacuum casting process<\/a><\/b>, also known as polyurethane molding<\/strong> or silicone molding<\/strong>, is a method used for low volume production. It is a process for manufacturing plastic parts<\/strong> in a relatively simple way and without high costs or long lead times, unlike other processes such as steel or aluminum molds. <\/p>\n

In this article we explain key factors and elements to take into account during the vacuum casting process in silicone molds<\/strong>. <\/p>\n

Silicone mold tolerances<\/strong><\/h2>\n

It is important to note that, in vacuum casting<\/strong>, the tolerance<\/a> depends on the quality of the 3D printed part<\/strong> or CNC machined<\/strong> master. <\/p>\n

Typical tolerance of a rigid material is \u00b10.25mm (0.010in) or \u00b10.5% above standard. <\/p>\n

At Proto&Go! we use these two technologies: CNC machining<\/b><\/a> and 3D printing<\/b><\/a>. We normally opt for CNC machining<\/strong> whenever possible, in order to maintain tighter tolerances. However, not all geometries are suitable for machining technology. Therefore, in such cases, we use a high-resolution 3D printing<\/strong> process (such as Polyjet or SLA). <\/p>\n

Wall thickness<\/strong> <\/h2>\n

Consistent wall thickness is an essential factor in the urethane casting<\/b><\/a> process. Thickness variation can lead to unequal cooling and curing rates, which may result in deformities or weak spots in the part. <\/p>\n

The size that works best with urethane castings<\/strong> are walls between 1.5 and 4 millimeters. In addition, although it is not a requirement, it is advisable to maintain a uniform wall thickness. <\/p>\n

On the other hand, it is important to note that thinner sections (less than 1 millimeter thick) run the risk of not filling completely. <\/p>\n

Another essential factor is the size of the piece, since the larger it is, the larger the wall must also be to ensure adequate support. <\/p>\n

Finally, the optimum thickness may depend on the specific project and the material selected, two factors that must always be taken into account. <\/p>\n

Materials and finishes<\/strong> <\/h2>\n

This process is ideal for many different types of polyurethane<\/b><\/a> plastics, from rigid to flexible. In Proto&Go!<\/strong> you can find the following: <\/p>\n