Consumable Pattern Ceramic Molding
Process Description
Waukesha’s Consumable Pattern Ceramic Molding is best described as a hybrid between investment casting and lost foam casting, using elements of each. The process begins with a consumable pattern made from one of several material types: Styrofoam (CNC milled or blown), Polymethyl methacrylate acrylic (PMMA, 3D printed), or Stereolithography (SLA, 3D printed).
These patterns are alternately coated in ceramic slurry and stucco, with drying between each application. Once the required number of layers is built up, the foam is evacuated and the shell is fired to develop maximum strength. The resulting ceramic molds are cleaned, inspected, and buried in sand prior to metal pouring.
The end result is a durable ceramic mold capable of producing castings with high dimensional accuracy and complex geometry.
Key Waukesha Advantages
- Ideal for very complex castings that would often require cores
- High dimensional accuracy with minimal draft angles
- Excellent near-net surface finish, reducing the need for machining
- Applicable for both high and low production volumes, depending on pattern type
- Versatile process compatible with multiple pattern materials
- Wide alloy selection, including Waukesha’s proprietary specialty metals
Waukesha Investment Casting Capabilities
- Part weight range: Approximately 5 lbs to 2,500 lbs (depending on part envelope)
- Section sizes: 0.250″ to 14″
- Surface finish: Approximately 300 RMS, depending on part size and processing
Please contact us for specific part and size feasibility.
Pattern Material Options
Waukesha Foundry supports four consumable pattern types for ceramic molding, making the process highly adaptable across a wide range of part designs and lead times: Machined Foam, Blown Foam, 3D Printed PMMA, and 3D Printed SLA.
Each pattern type is selected based on project requirements such as lead time, geometry, and production volume. All patterns are coated in ceramic slurry and stucco to form a shell. Once shell building is complete, the patterns are evacuated in a furnace, fired, and buried in bonded sand before pouring. Shells are poured at ambient temperature.
3D printed PMMA and SLA patterns are well-suited for rapid prototyping and short-run production. These pattern options eliminate the need for hard tooling and help reduce turnaround time without compromising on part integrity or material choice.
Advantages Over Investment or Lost Foam Casting
- More versatile pattern material options
- Accommodates a wider range of part sizes and geometries
- Higher mold strength and better dimensional stability
Disadvantages Compared to Investment or Lost Foam Casting
- Surface finish typically limited to 300 RMS, compared to 125 RMS for investment
- Tolerances are not as tight as those achieved with investment or lost foam processes
How Our Process Compares
Waukesha Foundry’s Consumable Pattern Ceramic Molding process offers multiple patterning methods to align with different project needs, whether it’s rapid prototyping, low-volume runs, or high-volume production. The table below summarizes how these pattern types compare to traditional methods.
Pattern Method Comparison Table
| Manufacturing Process | Lead Time | Part Size | Volume Suitability | Applications |
|---|---|---|---|---|
| Machined Foam Pattern, Ceramic Shell | 4–8 weeks | 5 to 2500 lbs | Low | Quick lead time for low-volume, complex designs |
| Blown Foam Pattern, Ceramic Shell | 20–26 weeks | 5 to 500 lbs | Very High | Cost-effective for high-volume production |
| 3D Printed Pattern, Ceramic Shell | 6–8 weeks | 5 to 2500 lbs | Low | Rapid prototyping or complex geometries |
Note: All manufacturing processes require at least a 2D engineering drawing. A 3D model expedites the process.
Process Comparison Summary Table
| Process | Advantages | Limitations |
|---|---|---|
| Consumable Pattern Ceramic Molding | Multiple pattern types, higher mold strength, adaptable to various part sizes | Max 300 RMS surface finish, wider tolerances than investment |
| Investment Casting (Low-Cost Country Sourcing) | Suitable for high volumes of smaller parts, re-usable wax patterns | Mold must be poured hot, limited to smaller part sizes |
| Lost Foam (or Lost Wax Casting) | Similar to investment but with foam patterns, fewer cores needed | Foam is not removed prior to pour; quality can be impacted by residue |
See what we can do for you.
Customer satisfaction is important to us. We work closely with our customers to engineer the right process for their application. To find out what Waukesha Foundry can do for you, contact us today.