Vacuum Injection is a most common uses rapid prototyping technology, when you need a short run of your 3d cad model. The parts are made out of a Polyurethanes with properties close to real injected plastics such as ABS,PA, POM ,PA or TPE’s or TPR rubbers. Usually series of 10-100 pieces will be run using this casting technology. Each Silicone mold can make maximum 20 to 25 pieces.
WHAT ARE THE ADVANTAGES OF VACUUM INJECTION?
The main advantages of this process are a much lower tooling costs and a quicker turn-around than traditional steel mould making. The lead-time to create casted models is around 7-10 days. The products have an exceptional detail and accuracy which comes close to the final injected plastic parts. Flexible silicone moulds allow significant undercuts, simplifying mould-making and containing costs.
The first step of vacuum injection process involves encapsulating/enclosing a master model in a liquid Silicone rubber. This model is usually made by 3d printing, SLA stereo lithography or CNC machining. Then a vacuum is applied to the mould. The mould is then cured in an oven at around 70Â°C. Once cured the mould can be split up in 2 or more parts, at which point the master model is removed leaving a mould cavity perfectly replicating the master model.