Vacuum mold casting is one of the most versatile services offered here at Firstpart. In today’s blog post, we take a closer look at the process and all the benefits for small and medium scale product manufacturing firms. Before we go any further, let us look at a proper definition for vacuum casting.
Vacuum casting is a production technique used in the manufacture of prototypes and low-volume end use parts using elastomers (silicone rubber mold) to create copies of a high-fidelity part. This high-fidelity part maybe an SLA, 3D-printed master, injection-molded master or CNC machined part. Vacuum casting is typically applied when engineers seek to develop a highly-accurate prototype part that not only resembles the master physically but embodies many of the properties in the casted copies.
The Vacuum Casting Process
The vacuum casting process entails the use molds and models. The model is the original part for which copies are to be casted. The mold in vacuum casting is made from elastomers. During the process, the internal cavity of the mold will hold the shape of the product to be formed with the pressure from a vacuum. The vacuum is also used to flow the liquid material into the mold. It is particularly important to note that the essence of the vacuum medium is to deal with instances of air or gasses that often have an effect on the cosmetic, functionality and strength of casted production parts. For best results, de-gassing the material mixture before the forming begins.
An overview of the process steps may be summarized into obtaining the high-quality master model, the curing process, filling the resin and the final curing operation to obtain the casted part. We shall go into more detail on the technicalities behind the vacuum casting process in subsequent blogs.
Materials
Vacuum casting can be used to create high-quality prototypes and low-volume units from a truly diverse and numerous types of materials. Depending on the intended properties of the final part, the materials often used in vacuum casting include:
— ABS – For high strength and rigidity
— Filled ABS – For fire retardance and fire resistivity
— Rubber – For strength, flexibility and shock absorbance
— Polyamide – For rigidity
— HPDR/Polypropylene – For high elasticity
— PMMA/Polycarbonate – For shock absorbance, high temperature applications and semi-transparency
Advantages and Applications
Vacuum casted products find high use in the event of rapid prototyping, bespoke or custom grade manufacturing and low-volume manufacturing. Generally, they are mostly used in food and beverage (for production of packaging materials), household products like food processors, cosmetics and an array of consumer goods and commercial products (fashion, sunglasses, phone cases, pens etc.)
The advantages of vacuum casted products include their exceptional dimensional accuracy, product consistency and thickness, excellent cosmetic finish due to the absence of moisture, clean, environmentally-friendly process, economical and its suitability for manufacturing parts with complex shapes and geometry.
Downsides
As is the case with all manufacturing techniques, vacuum casting too has one downside. This relates to the number of times for which the elastomer mold can be used. Averagely, a silicone mold will produce a maximum of 20 prototypes. This is because the molds will distort and revert their form some time after they have been used for prediction. Additionally, due to the low-cost of silicone molds, silicone tools generally have no more than 90 days of lifespan.
FirstPart Vacuum Casting in China
Firstpart offers excellent vacuum casting services in China for quick low-volume manufacturing and high-quality prototyping. Along with our other services such as CNC machining, 3D printing, sheet metal services and injection molding operations, we collaborate with small and large product designers, manufacturing giants and design experts to deliver affordable, eco-friendly parts that can serve as ready-to-use end parts or instant prototypes. We also provide free quotes and design guides on all inquiries. Click here to get in touch and contact us now!
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