Vacuum casting

    Vacuum casting is a technology that allows parts to be reproduced in polyurethane resin using a silicone mould. It is also suitable for the rapid production of prototypes and short series of high quality or products for final use.

    Vacuum casting

    Vacuum casting is the technology that allows us to reproduce pieces in polyurethane resin using a silicone mould. For the manufacture of this mould we use, generally, a first model of stereolithography (SLA). However, this technique allows us to use as a master almost any type of piece made with other technologies, such as laser sintering (SLS), molten deposition modelling (FDM) or machining (CNC).

    We can produce short series of pieces with polyurethane resins whose characteristics (flexibility, transparency, resistance to high temperature, fiber loading, fire retardant -V0-) are similar to those of the final product: ABS, Polypropylene, Polycarbonate, etc. There are also polyurethanes with FDA approval suitable for food use.

    Different types of surface finishes, such as painted, chrome, tinted or metallic, among others can be applied to the parts that have been manufactured using this technique.

    What is vacuum casting?

    It is a process for the rapid manufacturing of parts in silicone moulds. This technology makes it possible to reproduce pieces in polyurethane resin in a silicone mould made generally from a master generated by additive manufacturing.

    How does vacuum casting work?

    The casting process is carried out inside a vacuum machine in which the two components that will form the polyurethane inside the chamber are introduced separately. Once the machine has completed the vacuum the two components are mixed and slip into the silicone mould.

    The casting process is carried out under vacuum, mainly to facilitate the entry of the fluid into the mould cavity, thus avoiding the possible resistance of air that might remain inside. In this way, the mould is filled exclusively by the action of the force of gravity and the risk of bubbles forming in the material is minimized. Therefore, high precision and very good finishing products are obtained.


    The wide range of polyurethane (PU) materials allows to select in a very suitable way the material that best adapts to the properties and requirements of the pieces.

    Applications of vacuum casting

    The pieces that are manufactured by vacuum casting are especially suitable for obtaining a pre-series. This is because the pieces generated by means of silicone molds are obtained with a high level of quality, comparable to those produced by injection or other processes.

    Some applications:

    • Conducting tests prior to the launch of new products
    • Market research
    • Prototypes
    • Manufacture of short series (low volume manufacturing)
    • Advertise new products

    Advantages of vacuum casting

    Some of the advantages of vacuum casting are:

    • Variety of materials
    • Variety of finishes
    • Low investment in moulds or tools for short series
    • Finishing quality comparable to other technologies or processes
    • Obtaining first pieces in a short period of time

    Aspects to consider

    Some considerations regarding the vacuum casting are:

    • Price per piece high if the size is large
    • Useful life of the silicone mould

    Vacuum casting also allows a wide variety of finishes. For this purpose, we offer a wide range of services to offer our customers different levels of finishing adapted to their needs.

    INEO PROTOTIPOS S.L. Design, prototyping and additive manufacturing.
    Avenc del Daví, 6 Pol.Ind.Can Petit Terrassa, 08227 Barcelona Spain
    Tel. +34 937 337 000 Email: contact@ineo.es