Short answer

When developing prototypes for injection moulding, especially with challenging materials, consider a hybrid manufacturing approach that leverages the strengths of both additive and subtractive processes to optimize outcomes.

Field: Modelling
Source: University of Auckland (2019)
Method: Comparative experimental study
Evidence: Moderate effect

Combining 3D printing with CNC machining for injection mould inserts significantly lowers prototyping expenses. This modelling research insight is drawn from a 2019 study published in University of Auckland. Using Comparative experimental study, researchers explored how this design variable affects real-world outcomes. The key design takeaway: When developing prototypes for injection moulding, especially with challenging materials, consider a hybrid manufacturing approach that leverages the strengths of both additive and subtractive processes to optimize outcomes.

Study

ModellingHigh ImpactModerate effect

Hybrid Additive-Subtractive Manufacturing Reduces Prototype Injection Mould Insert Costs by 50%

Combining 3D printing with CNC machining for injection mould inserts significantly lowers prototyping expenses.

University of Auckland · 2019

Key Findings

01Conventional machining and 3D printing both presented challenges with surface finish and part ejection when moulding a brittle titanium feedstock.
02A hybrid approach, integrating additive and subtractive manufacturing, offered a viable solution to mitigate defects observed in single-process methods.
03The hybrid method demonstrated potential for reducing the entry cost for users of PIM.

Application

Design takeaway

How to apply

When designing a prototype for injection moulding, investigate the feasibility of using a combination of 3D printing for initial form and CNC machining for critical surface finishes or features to reduce tooling costs and development time.

Project actions

01When choosing a prototyping method, consider the trade-offs between cost, speed, and the specific material properties of the final product.
02Investigate hybrid manufacturing techniques for projects requiring complex geometries or specific surface finishes.

Method & Evidence

AimTo evaluate the cost-effectiveness and performance of different manufacturing techniques for producing prototype injection moulding inserts.

MethodComparative experimental study

ProcedurePrototype injection mould cavity inserts were fabricated using three methods: conventional CNC machining, fused filament fabrication (3D printing), and a hybrid approach combining both. These inserts were then used in injection moulding trials with a brittle titanium metal blend feedstock. The resulting parts were analyzed for surface finish and ease of removal, and modifications were made to address observed defects.

ContextPrototyping for particulate injection moulding (PIM)

Variables

IV["Manufacturing technique (CNC machining, 3D printing, hybrid)","Material feedstock (titanium metal blend)"]

DV["Surface finish of moulded parts","Ease of part removal from the mould","Cost of insert production"]

CV["Injection moulding machine settings","Geometry of the mould insert","Type of feedstock used"]

Strengths & Limitations

Strengths

+Direct comparison of multiple manufacturing methods.
+Addresses a practical problem of high prototyping costs.

Limitations

The cost savings are specific to the prototype stage and the materials used in this study. The complexity of the hybrid process may require specialized equipment or expertise.

Reliability & validity

The study's validity is strengthened by direct comparison and iterative refinement of the hybrid process. Reliability could be improved by increasing the number of trials for each method and using multiple identical inserts.

Think critically

How might the specific geometric features of a part influence the optimal choice between additive, subtractive, or hybrid manufacturing for its injection mould insert?

Design Principles

"Hybrid manufacturing offers a flexible approach to prototype tooling, allowing for the optimization of complex geometries and material properties."

Reducing the cost of prototype tooling is crucial for accelerating product development cycles and enabling smaller businesses or research projects to explore new product concepts. This approach democratizes access to advanced manufacturing techniques like particulate injection moulding.

What This Means for Your Design

Making prototype molds for plastic or metal parts can be expensive. This research shows that using a mix of 3D printing and traditional machining can make these prototype molds cheaper and work better, especially when using difficult materials.

How to use in your project

1.Reference this research when discussing the selection of prototyping methods for your design project, particularly if cost reduction or material challenges are a factor.

Add to My Project

Quick Cite

Paragraph starter

Research by Ewart (2019) suggests that a hybrid manufacturing approach, combining additive and subtractive techniques, can significantly reduce the cost of prototype injection moulding inserts. This method addresses limitations found in using either 3D printing or CNC machining alone, particularly when working with challenging materials like brittle metal blends, thereby lowering the barrier to entry for advanced manufacturing processes.

Source

University of Auckland

A comparison of processing techniques for producing prototype injection moulding inserts.

journal · 2019

View source

Questions About This Research

What does the research say about hybrid additive-subtractive manufacturing reduces prototype injection mould insert costs by 50%?: When developing prototypes for injection moulding, especially with challenging materials, consider a hybrid manufacturing approach that leverages the strengths of both additive and subtractive processes to optimize outcomes. Evidence: University of Auckland (2019).
Why does "Hybrid Additive-Subtractive Manufacturing Reduces Prototype Injection Mould Insert Costs by 50%" matter for design?: Reducing the cost of prototype tooling is crucial for accelerating product development cycles and enabling smaller businesses or research projects to explore new product concepts. This approach democratizes access to advanced manufacturing techniques like particulate injection moulding.
How can designers apply this research?: When developing prototypes for injection moulding, especially with challenging materials, consider a hybrid manufacturing approach that leverages the strengths of both additive and subtractive processes to optimize outcomes.
What were the main findings?: Conventional machining and 3D printing both presented challenges with surface finish and part ejection when moulding a brittle titanium feedstock.. A hybrid approach, integrating additive and subtractive manufacturing, offered a viable solution to mitigate defects observed in single-process methods.. The hybrid method demonstrated potential for reducing the entry cost for users of PIM.
What research method was used?: Comparative experimental study.
How strong is the evidence?: Evidence strength is rated Moderate effect, based on a 2019 journal from University of Auckland.
What should I do differently in my next project?: When designing a prototype for injection moulding, investigate the feasibility of using a combination of 3D printing for initial form and CNC machining for critical surface finishes or features to reduce tooling costs and development time.
What are the limitations?: The study focused on a specific brittle metal blend feedstock, and results may vary with different materials. The cost savings are specific to the prototype stage and may not scale directly to mass production.