How to avoid contamination and damage during precision CNC machining process

Work environment management

Keep clean:

The floor, walls, and equipment surfaces of the processing workshop should be regularly cleaned and wiped to prevent dust and debris from accumulating. For example, using industrial vacuum cleaners and dust-free wiping cloths to clean the workshop daily and reduce suspended dust particles in the air.

For precision CNC machine tools, special protective covers or enclosed machining areas should be set up to prevent chips and coolant generated during the machining process from splashing onto key components of the machine tool, such as CNC systems, motors, and precision guides.

Control temperature and humidity:

Precision machining has strict requirements for environmental temperature and humidity. Install air conditioning and humidity control systems to maintain the workshop temperature at 20 ℃± 2 ℃ and relative humidity within the range of 40% -60%, in order to avoid thermal deformation of parts and machine tools caused by temperature and humidity changes.

Avoid setting up heat sources or air conditioning vents around the machine tool to blow directly towards it, in order to prevent local temperature changes from affecting machining accuracy.

Raw material and workpiece processing

Raw material cleaning:

Before processing, thoroughly clean the raw materials to remove surface oil stains, rust, and impurities. For example, cleaning metal materials with organic solvents or removing surface oxide layers through sandblasting.

For high-precision parts, the raw materials can be placed in a clean storage environment and sealed in packaging before entering the processing workshop to prevent contamination during storage and transportation.

Workpiece clamping protection:

Choose appropriate clamping tools, such as soft jaw chucks, high-precision flat pliers, etc., to avoid damage to the surface of the workpiece during the clamping process. When clamping, add soft gaskets such as copper or rubber pads at the contact area between the workpiece and the fixture to prevent damage to the workpiece.

For thin-walled or easily deformed workpieces, special clamping methods such as vacuum suction or auxiliary support devices are used to ensure uniform distribution of clamping force and reduce the possibility of workpiece deformation.

Processing technology control

Tool selection and use:

Select appropriate cutting tools based on processing materials and precision requirements. For example, when processing hard alloy materials, coated hard alloy cutting tools with high hardness and wear resistance are used.

Before use, the cutting edge of the tool should be checked for integrity to avoid using damaged tools for machining, in order to prevent vibration during the machining process, which may affect machining accuracy and potentially damage the workpiece and machine tool. At the same time, regularly replace cutting tools to prevent excessive wear and tear, which can lead to a decrease in machining quality.

During the tool replacement process, operators should wear clean gloves to prevent oil and impurities from contaminating the tool and handle, which can affect the installation accuracy and service life of the tool.

Optimization of cutting parameters:

Reasonably set parameters such as cutting speed, feed rate, and cutting depth to avoid excessive cutting force causing workpiece deformation or machine vibration. For example, when machining thin-walled parts, reducing the cutting depth and feed rate, using high-speed cutting to reduce the impact of cutting force on the workpiece.

According to the actual situation during the machining process, such as tool wear, changes in workpiece material, etc., adjust cutting parameters in a timely manner to ensure the stability and quality of the machining process.

Coolant and Lubrication Management

Coolant selection and maintenance:

Choose the appropriate coolant, which should have good cooling, lubrication, rust prevention, and cleaning properties depending on the processing material and method. For example, when processing aluminum alloys, specialized aluminum alloy cutting fluids are used to prevent oxidation and corrosion of the aluminum surface.

Regularly check the concentration, acidity, and cleanliness of the coolant, and promptly replenish or replace the coolant. Remove chips and impurities from the coolant through a filtering device, maintain the cleanliness of the coolant, and avoid affecting the machining quality and machine tool service life due to coolant contamination.

Lubrication system maintenance:

The guide rails, screws, and bearings of precision CNC machine tools require good lubrication. Regularly check the oil level and oil pipes of the lubrication system to ensure that the lubricating oil can be accurately delivered to each lubrication point.

According to the user manual of the machine tool, select the appropriate lubricating oil and replace it according to the prescribed cycle. For example, for high-precision ball screws, use high-grade precision machine tool guide oil and replace it every 3-6 months.

Personnel operation standards

Training and skill enhancement:

Operators should receive professional training and be familiar with the operation process, equipment performance, and safety precautions of precision CNC machining. Regularly organize operators to participate in skill training and assessment to improve their operational level and quality awareness.

Operators should understand the characteristics of different processing materials, the use of cutting tools, and the impact of various processing parameters on product quality, and be able to make reasonable adjustments based on actual situations.

Personal hygiene and operating habits:

Operators should change into clean work clothes and shoes before entering the processing workshop to avoid bringing external dust and impurities into the workshop. During the operation of the machine tool, wear clean gloves to prevent sweat and grease from contaminating the workpiece and machine tool.

Avoid placing unrelated tools and items on the machine tool worktable and keep the worktable clean. After processing, clean the machine tool and work area in a timely manner, and properly dispose of chips and waste materials.