Low-Volume Manufacturing with Vacuum Casting
Production-quality plastic parts in small and medium-sized batches—without investing in hard injection-mould tooling.
Gelecta supplies rigid, flexible and transparent polyurethane components manufactured by vacuum casting in silicone moulds. The process combines a high-quality appearance, a wide choice of material behaviour and fast tooling, making it suitable for pre-series, bridge production and low-volume end-use parts.
Our customers have used vacuum-cast components in products sold to their own customers. We coordinate the complete delivery from manufacturability review and mould production to finishing, inspection and parts ready for assembly.
Production-quality parts without hard tooling
Vacuum casting is a practical manufacturing route when a project needs more than a few prototypes but the quantity, schedule or product stage does not yet justify an injection mould.
It is particularly suitable when you need:
- a consistent batch of high-quality plastic components
- housings, covers or other visible parts with a refined appearance
- production-like parts for functional, assembly or user testing
- pre-series or pilot-production components
- bridge production while injection-mould tooling is being prepared
- parts for market launch, customer deliveries or specialised low-volume products
- replacement or legacy components in limited quantities.
The silicone mould reproduces the geometry and surface of the finished master pattern in fine detail. This makes vacuum casting especially effective for components whose appearance and tactile quality are as important as their function.
From 25 parts to larger low-volume batches
One silicone mould typically produces approximately 25 parts. The actual mould life depends on the component geometry, casting material, surface requirements and features such as undercuts.
If more parts are needed, additional silicone moulds can be manufactured from the same master pattern. Vacuum casting is therefore not limited to a single batch of 25 parts: with planned mould duplication, it can also support considerably larger low-volume production runs.
When the total requirement begins to approach approximately 100–200 parts, we usually compare vacuum casting with injection moulding. This is not a fixed technical limit. The most economical route depends on part size and complexity, material requirements, finishing, delivery schedule, expected repeat orders and the lifetime volume of the product.
A flexible route as demand grows
Vacuum casting can help a project move forward without committing to hard tooling too early. It allows parts to be supplied for validation, launch or initial customer deliveries while demand and the design are still developing. If volumes increase, Gelecta can support the transition to injection moulding and serial production.
Visual quality suitable for customer-facing products
Vacuum casting is not limited to internal development models. With the right master pattern, material and finishing specification, it can produce components with a high-quality appearance suitable for visible parts and finished products.
Because the silicone mould reproduces the master pattern closely, the required cosmetic standard, texture and visible surfaces should be defined before mould production.
Project-specific options include:
- smooth, matt, gloss or textured surfaces
- colour pigmentation in the casting material
- painting and colour matching based on a specified colour or sample
- transparent and translucent parts
- soft-touch and rubber-like components in different Shore hardnesses
- printing, logos and other markings
- threaded inserts, magnets and other integrated metal components
- bonding, sub-assembly and parts supplied ready for final assembly
Why work with Gelecta?
Materials selected for the required behaviour
Vacuum casting uses polyurethane resins that can reproduce selected characteristics of common production plastics and elastomers. Depending on the application, options can include:
The material is selected according to the required stiffness, impact resistance, flexibility, appearance, temperature range and operating environment.
Vacuum-casting polyurethanes can simulate selected properties of production thermoplastics, but they are not chemically identical to injection-moulded ABS, PP or PC. If an exact production polymer, a specific certification or demanding long-term environmental resistance is required, we assess whether injection moulding or another manufacturing route is more appropriate.
From CAD data to a finished low-volume batch
1. Review the requirements
We review the CAD model, quantity, intended application, required material behaviour, cosmetic surfaces, critical dimensions, inserts, finishing and target schedule.
2. Master pattern and silicone mould
A finished master pattern is prepared and used to manufacture the silicone mould. The required parting lines, gates and vents are planned according to the component geometry and surface requirements.
3. Vacuum casting and finishing
Polyurethane resin is cast in the silicone mould under vacuum, cured and removed from the mould. The parts are then trimmed and finished according to the agreed specification.
4. Inspect and deliver
The batch is checked against the agreed visual, dimensional and functional requirements. Parts can be supplied painted, marked, fitted with inserts, assembled and prepared for their next production stage.
Vacuum casting or injection moulding?
Around 100–200 parts, we normally assess both routes rather than selecting a process based only on quantity. A repeat order, exact production material or long product lifetime may favour injection moulding earlier. An urgent schedule, large component, evolving design or limited lifetime demand may continue to favour vacuum casting.
Project consideration
Vacuum casting in silicone moulds
Project consideration
Tooling
Fast, lower-investment silicone moulds
Metal production tooling
Typical role
Pre-series, bridge production and low-volume end-use parts
Repeat production and higher volumes
Quantity
From small batches to larger runs using multiple moulds
Usually more economical as volumes and repeat demand increase
Materials
Polyurethane materials that simulate selected production-plastic properties
Final production thermoplastics
Appearance
High visual quality based on the finished master pattern
Consistent production finish defined by the mould
Design changes
New or modified tooling can be implemented comparatively quickly
Tool modifications may require more time and investment
Frequently asked questions
How many parts can be made from one silicone mould?
One mould typically produces approximately 25 parts. Actual mould life depends on the component geometry, casting resin, surface requirements and mould loading. If a larger batch is required, additional moulds can be produced from the same master pattern.
Can vacuum casting be used for batches larger than 25 parts?
Yes. Multiple silicone moulds allow considerably larger batches to be produced. When the requirement approaches approximately 100–200 parts, we normally compare vacuum casting with injection moulding to determine the more suitable option for the total demand, schedule and material requirements.
Can vacuum-cast parts be used in products sold to customers?
Yes. Gelecta customers have used vacuum-cast plastic components in commercial products. Suitability must still be confirmed for each application based on the required material properties, operating environment, expected service life and any regulatory or certification requirements.
Are the parts made of silicone?
Usually not. The mould is made of silicone, while the finished parts are normally cast from polyurethane resin. Flexible or silicone-like material options are also available for applications that require them.
Do vacuum-cast materials equal injection-moulded ABS, PP or PC?
No. Polyurethane casting resins can simulate selected properties of common production plastics, but they are not chemically identical. If the exact production polymer is essential, injection moulding may be the better route.
Can parts be painted and supplied ready for assembly?
Yes. Depending on the project, parts can be coloured, painted, marked, fitted with inserts, bonded or partly assembled. We can coordinate the finishing and inspection required before the parts enter your assembly process.
How quickly can a low-volume batch be delivered?
We usually respond to quotation requests within 1–2 business days and can often support urgent delivery needs. Lead time depends on the master pattern, part size and complexity, number of moulds, material, quantity, finishing and inspection. In a recent medical-equipment project, finished large housings were delivered ready for assembly within a few weeks.
When should we move to injection moulding?
Injection moulding should be evaluated when quantities and repeat demand increase, the exact production thermoplastic is required or the expected product lifetime justifies hard tooling. Around 100–200 parts, we normally compare the total economics and requirements of both processes.