High-precision machining solutions for the medical sector: the coordinated development of 3D printing and CNC processing

With the accelerated advancement of personalized medicine, higher requirements are placed on the precision and structural complexity of medical devices. Traditional processing technology is difficult to meet this trend. Therefore, exploring more efficient and accurate high-precision machining solutions for the medical sector has become the key to the development of the industry.

In recent years, 3D printing (additive manufacturing) and CNC machining (subtractive manufacturing), as the two major representatives of advanced manufacturing, have gradually become the focus of attention in the medical industry. Can the combination of the two bring new breakthroughs? This article will discuss the technical characteristics, integration strategies and applications of the two in medical scenarios, and reveal the high-precision machining solutions for the medical sector in the future.

1. Brief introduction to 3D printing and CNC processing technology

(1) Basic principles of 3D printing:

3D printing technology is based on digital models and generates three-dimensional entities by stacking materials layer by layer. The operation process is as follows:

● Model construction: Design the three-dimensional structure through CAD software to accurately describe the product size and shape;

● Slicing: Use special software to process the three-dimensional model in layers to generate printing path data;

● Layer-by-layer printing: The printing device stacks materials such as metal powder, polymer, etc. in sequence according to the path instructions;

● Post-processing process: Remove the support structure and perform surface treatment to improve the performance and appearance of the finished product.

(2) CNC precision machining principle:

CNC machining accurately controls the movement of the machine tool through a preset program to achieve precise cutting, drilling and milling of materials. Its main process is as follows:

● Three-dimensional modeling: Use the CAD system to model parts;

● Path programming: Generate machining instructions (G code) through CAM software;

● Automatic machining: CNC machine tools complete cutting operations according to the program;

● Inspection and correction: Use measuring equipment to inspect the size and quality of the finished product.

(3) Technical comparison summary:

3D printing uses the method of adding materials layer by layer to manufacture parts, while CNC machining is formed by gradually removing materials. The two are completely different in manufacturing methods, but they are highly complementary in many medical applications.

2. Comparison of the advantages and complementary values ​​of the two technologies

(1) Outstanding features of 3D printing:

●Support complex structural design: can easily print complex geometric shapes such as hollow structures and topological optimization frames;

●Quickly realize personalized products: no special molds are required, suitable for customized medical device development;

●High material utilization rate: adopt the method of stacking materials on demand to reduce waste;

●Support diversified materials: such as titanium alloy, bioceramics, medical polymer materials, etc. can all be used.

(2) Disadvantages of 3D printing:

●The surface of the printed part is relatively rough;

●Dimensional accuracy and tolerance control are not as good as traditional processing;

●The printing speed is relatively slow, not suitable for large-scale production.

(3) Technical advantages of CNC processing:

●High precision and excellent surface quality: meet strict dimensional control and surface treatment requirements;

●Maintain the mechanical properties of the material: will not damage the internal structure of the material, and the finished product is stronger;

●Suitable for the processing of high-strength materials: such as titanium alloy, stainless steel and other hard materials.

(4) Technical limitations of CNC machining:

● Restrictions on machining of parts with complex structures;

● Low material utilization during machining;

● Relatively high equipment and labor costs.

(5) Value of fusion:

Combining the structural flexibility of 3D printing with the precision control capability of CNC can significantly improve the comprehensive performance of medical device manufacturing - it can not only cope with complex shapes, but also ensure dimensional accuracy and biocompatibility.

3. Specific practice of fusion manufacturing strategy in high-precision machining solutions for the medical sector

(1) Process flow based on 3D printing + CNC finishing:

Applicable to the scenario of first printing a nearly molded structure and then achieving local precision improvement through CNC.

Application examples:

● Orthopedic implants: such as hip joint brackets with porous structures, the joint surface is polished by CNC;

● Dental implants: Print the basic structure, and CNC completes the high-precision machining of the implant area;

● Preoperative simulation model: After rapid printing, the key parts are trimmed by CNC to enhance the actual value of the model in guiding surgery.

(2) Reverse process: CNC pre-processing + 3D printing supplementary structure

Applicable to the situation where the basic parts are processed by CNC and then the auxiliary functions are expanded by 3D printing.

Typical applications:

●Surgical guide: first process the frame, then additively print the bonding structure;

●Ophthalmic devices: CNC makes the main structure, and 3D printing completes the fine surface structure;

●Minimally invasive surgical tools: CNC ensures the sharpness of the tool, and 3D printing adds functional components such as ergonomic handles.

4. Application scenario case analysis

(1) Personalized implant manufacturing

Based on CT image data, design artificial joints that conform to the patient's bone morphology;

First 3D print the overall contour, and then use CNC to trim the bonding area;

Value realization: Improve adaptability, shorten operation time, and reduce postoperative risks.

(2) Minimally invasive surgical instrument manufacturing

Micro surgical robot components;

3D print the internal pipeline structure, CNC ensures the flexibility of key parts;

Enhance operation accuracy and improve safety.

(3) Development of tissue engineering scaffolds

Porous artificial bone substitutes;

Printing bionic porous scaffolds, CNC improves the flatness of the contact surface;

Promote tissue cell attachment and regeneration, and promote the development of tissue engineering.

5. Challenges in fusion processes

Although fusion manufacturing has opened up a new path for medical precision processing, the actual implementation still faces the following challenges:

● Software integration barriers: There are compatibility issues with the software systems used by 3D printing and CNC;

● Material adaptation issues: It is necessary to ensure that the material properties of the same part are consistent under the two processes;

● Difficulty in precision coordination: Printing errors require precise CNC correction, especially in microstructure processing;

● Cost and efficiency balance: How to reduce the overall manufacturing cost while meeting quality requirements still needs to be solved by optimizing the process route and intelligent manufacturing methods.

6. Conclusion

In the era of high-precision and high-personalization medical manufacturing, a single manufacturing method can no longer meet comprehensive needs. The integration of 3D printing and CNC processing not only realizes the unity of complex structures and precision control, but also provides strong technical support for the innovation of high-precision machining solutions for the medical sector.

In the face of ever-changing medical needs, this integrated manufacturing model will become a key driving force for customized, high-performance medical products, helping the medical industry move to a higher level of development.