Precautions For CNC PEEK Material Processing

CNC machining, on the other hand, is commonly used to process PEEK in a way that PEEK shapes are stronger and harder than most plastics, but softer than most metals, so there are some tips to keep in mind when machining.

1. Select the appropriate cutting tool and machining parameters: Because PEEK material has a high degree of hardness and toughness, so it should be milling with a smaller feed to ensure processing efficiency and accuracy, and to avoid tool damage as much as possible. Usually, in the milling transition process, should be used as far as possible to try to choose a large front angle, chip removal, good, sharp end milling cutter processing, and the tool diameter and depth should be limited to 50% of the diameter of the cutting tool in order to obtain the best surface finish.

2. The use of appropriate coolant: due to the PEEK material is easy to heat deformation and softening, so in the processing should be used in the appropriate use of water-soluble or petroleum-based coolant, which can effectively control the surface temperature of the material to reduce the risk of deformation.

3. Control the temperature of the processing zone: PEEK material processing and processing temperature range is narrow, the processing zone temperature should be controlled at 60-80 ℃ or so, in order to maintain the stability of the material structure.

4. Select the appropriate fixture: In the process of processing, PEEK heat generated by the deformation is not released, after the completion of processing appears to be flat, but take down the workpiece after the amount of deformation generated by the workpiece is likely to be greater, so the need to choose the appropriate fixture according to the shape and characteristics of the parts:

4.1 If it is a thin plate parts, the use of specialized thin plate type of fixture, so that the fixture body surface composite double-sided adhesive paste layer can be processed PEEK thin plate parts directly pasted in the fixture, the workpiece force uniformity, does not produce local stress, to avoid local deformation of the PEEK thin plate parts, to solve the pressure plate screws to fix the workpiece method and affect the quality of the product, so as to not only ensure the accuracy of the processing This can not only ensure the processing accuracy, but also minimize the risk of deformation.

4.2 If it is a box type peek parts, the following cases to choose fixtures:

4.2.1. If it is a simple box class PEEK parts, you can use flat jaw fixture, you can adjust the width of the jaws to achieve clamping.

4.2.2. If the processing of complex shapes of box type PEEK parts, you need pneumatic vise fixture, this fixture can automatically adjust the clamping force according to the shape of the workpiece.

4.2.3. If the processing of more special box class PEEK parts, you can consider homemade fixtures. Homemade fixtures can be designed and produced according to the shape and size of the workpiece to ensure clamping strength and stability.

4.3 If it is a shaft type PEEK parts, choose the fixture in the following cases:

4.3.1. If it is a longer shaft type PEEK parts, you can use the support cone fixture, this fixture can be adjusted to achieve clamping by adjusting the height and angle of the support cone to ensure axial accuracy.

4.3.2. If you are machining short shaft PEEK parts, you can use the spring clamp, this fixture through the elastic deformation of the workpiece clamped in the fixture, you can improve machining efficiency and shorten the machining time.

4.3.3 If you want to process irregularly shaped shaft PEEK parts, you can use the universal thimble fixture, which consists of a number of adjustable thimble, according to the shape and size of the workpiece for flexible adjustment, the choice of fixture should be based on the shape and size of the workpiece.

When selecting the fixture, it should be selected according to the specific conditions to ensure moderate clamping force and stable clamping to avoid damage to the workpiece. At the same time, the surface of the workpiece should be cleaned before clamping to ensure that the quality of processing will not be affected. In addition, we also need to pay attention to the anti-vibration performance of the fixture to avoid vibration in the process of machining parts, thus affecting the machining accuracy and surface quality.

5. Sticky knife problem: Due to the characteristics of the PEEK material itself, high temperature performance and viscosity, resulting in easy to stick in the workpiece when processing the tool easily, which affects the machining accuracy and surface quality, so you can choose to use coated cutting tools to process, increase the cutting speed and reduce the depth of cut, so that you can effectively reduce the contact time between the tool and the workpiece and the adhesion force to alleviate the processing of sticking knife situation.

6. Thread processing: special attention should be paid to the material tapping, PEEK material is more wear-resistant, tapping wear will be very fast, so always check the thread size. Tap wear due to increased extrusion pressure is easy to make the product deformation, or even cracking. When tapping the tap must be coated with coolant or tapping oil, the feed should be small, tapping deep holes as much as possible using segments of multiple tapping.

7. Drilling: when the need for drilling, can not be directly drilled with a large drill, you can first use the diameter of less than 10mm drill hole, and then a smaller boring tool boring, and then finally a large boring tool boring; drilling should be repeated several times to retreat from the drill chip; to ensure that the cutting fluid coolant cooling sufficiently in a timely manner, you can quickly reduce the amount of heat, and appropriately reduce the drilling feed rate, when the bit is worn out in a timely manner when the bit should be repaired and sharpened.