Vacuum Casting
Vacuum casting is a fast and cost-effective technique for producing high-quality plastic parts comparable with injection-molded components.
Parts are casted through a silicone mold, created from a printed part (the so called ‘master’). Vacuum Casting is suitable for functional testing, marketing purposes or limited series of end-use parts.
As silicone tooling is used to cast parts, the tool can be applied multiple times to reproduce the same part. The materials used are resins, with properties comparable to those of most known plastics.
Applications in Vacuum Casting
Materials Vacuum Casting
Medium flexible and rigid (‘ABS/PS/PEEK-like’)
Good mechanical properties
High thermal resistance
Flexible (PP/HDPE)
High resistance against abrasion
High shock resistance
Rubber elastic (rubbers)
High elongation/tensile strenght at break
Glass clear, UV-stable (PMMA)
High UV-resistance
The process
Creating the master model: The master model is designed and produced from, a 3D-file and be the reference for all subsequent copies. This part is referred as the master model.
Creating the mold: After cleaning and finishing, the master model is placed in a mold box, ensuring it is securely positioned. The silicone rubber is poured over the master model in the mold box.
The mold box is in a vacuum chamber to remove air bubbles, allowing the silicone to cure. The curing time depends on the silicone used and environmental conditions.
Mold Preparation: After curing the master model is removed (cut) from the silicon mould. This process creates a cavity that replicates the shape of the master model.
The mold pieces are reassembled and secured to ensure they a tightly and correctly fit.
Casting Process: The casting resin or material and is mixed according to instructions.
The resin is poured into the mold cavity. The filled molds are placed in a vacuum chamber to remove air bubbles and ensure the resin completely fills the mold cavity.
Curing: The curing time can vary based on the type of resin used.
Demolding: Once the resin has fully cured, the mold pieces are carefully removed.
Post-Processing: After inspection for defects or imperfections, the necessary finishing operations are performed, such as trimming, sanding, painting, or additional machining to achieve the desired surface finish and dimensions.
Repeat multiple parts: For production of multiple parts are needed, repeat the casting process will be repeated using the same silicone mold until the mold wears out or the required quantity is produced.
