Difficulties and solutions in CNC machining of small medical equipment parts

CNC machining of small medical device parts is a highly complex and technically demanding process. It not only involves high-precision equipment and technology, but also requires consideration of the particularity of materials, rationality of design, optimization of process parameters, and strict quality control. This article will explore how to deal with these difficulties and how to deal with them.

Content

1.Design and development challenges

2.High precision and accuracy requirements

3.Material challenges

4.Tool wear and error control

5.Process parameter optimization

6.Error control and measurement

1.Design and development challenges

The design and development of a medical device is a critical stage for its success. Improperly designed medical devices fail to meet regulatory requirements and cannot be brought to market. Therefore, the process of CNC processing medical parts needs to be closely integrated with the rationality and feasibility of product design. To ensure compliance with relevant regulations and standards in the medical device manufacturing industry, parts processors need to obtain necessary certifications, such as medical device production licenses and quality management system certifications.

2.High precision and accuracy requirements

When manufacturing body implants such as hip replacements and knee implants, extremely high machining precision and accuracy are required. This is because even small machining errors can have a significant impact on a patient’s life and well-being. The CNC machining center can accurately manufacture parts that meet the patient's needs through CAD models and reverse engineering technology based on the requirements of orthopedic surgeons, achieving tolerances as small as 4 μm.

Ordinary CNC equipment may be difficult to meet demands in terms of processing accuracy, rigidity and vibration control. The feature sizes of small parts are usually at the micron level, which requires equipment with extremely high repeatability positioning accuracy and motion control accuracy. When processing small parts, small vibrations can lead to reduced surface quality and inaccurate dimensions. CNC processing of small medical equipment parts requires choosing CNC machine tools with high resolution and high-precision feedback control systems, such as five-axis machine tools, which use high-speed spindles with air levitation or magnetic levitation technology to reduce friction and vibration.

3.Material challenges

The medical industry requires implants to be made of biocompatible materials such as PEEK and titanium alloys. These materials tend to generate excessive heat during processing, and the use of coolants is often not allowed due to concerns about contamination. CNC machine tools need to be compatible with a variety of materials to handle these challenging materials, as well as effectively control heat and avoid contamination during machining.

CNC machining of small medical device parts requires research and understanding of the properties of different medical-grade materials, including metals, plastics and ceramics, and their performance in CNC machining. Develop targeted machining strategies and parameters, such as appropriate cutting speeds, feed rates and cooling methods, to suit the needs of different materials.

4.Tool wear and error control 

When CNC processes small parts, tool wear will directly affect the processing quality. Therefore, advanced tool materials and coating technologies, as well as precise error control and measurement technology, are required to ensure accuracy during machining and tool durability. Using specially designed tool materials such as cubic boron nitride (CBN) and polycrystalline diamond (PCD), along with proper cooling and lubrication techniques, can reduce heat build-up and tool wear.

CNC machining of small medical parts selects and uses micro-cutters and precision fixtures specially designed for the processing of tiny parts. Introducing an interchangeable head system to adapt to different processing needs, reduce tool replacement time and improve processing flexibility.

5.Process parameter optimization

In order to improve the processing quality and efficiency of small parts, it is necessary to optimize process parameters, such as cutting speed, feed speed and cutting depth. These parameters directly affect the machined surface quality and dimensional accuracy:
1. Cutting speed: Too high a cutting speed may cause tool overheating and increased wear, while too low a speed will reduce processing efficiency.
2. Feed speed: If the feed speed is too high, it will easily cause chip clogging and rough processing surface. If the feed speed is too low, it will affect the processing efficiency.
3. Cutting depth: Excessive cutting depth will increase the tool load, leading to tool wear and machining errors.

The optimization of these parameters needs to be based on the physical properties of the material and the performance of the processing equipment. The process parameters can be optimized through experiments and simulations to find the best cutting conditions.

6.Error control and measurement

The characteristic dimensions of small medical parts are extremely small, and traditional measurement methods cannot meet the requirements. High-precision optical measuring instruments and coordinate measuring machines (CMM) are required to ensure processing quality. Countermeasures include real-time monitoring and compensation of errors during processing, use of high-precision measuring equipment for workpiece inspection, and necessary error analysis and compensation. At the same time, statistical process control (SPC) and other quality management procedures must be implemented to continuously monitor the production process and make timely adjustments.

GPM focuses on CNC processing services for precision medical equipment parts. It has brought together a series of cutting-edge production equipment and technical teams. It has passed ISO13485 medical device quality management system certification to ensure that it provides excellent products and services to each customer and is committed to providing customers with the best Ask us for cost-effective and innovative medical device parts manufacturing solutions.


Post time: May-23-2024