Low friction Non-stick PTFE Teflon Plastic CNC Machining For Medical Implants

Plastic CNC Machining is one of the popular machining processes across different industries. Manufacturers often make machined parts for diverse applications because of plastic material availability. Besides, the CNC machining process is more accurate and fast and offers the preferred tolerances in plastic machined parts since it uses computer numerical control to execute tasks.

However, there is a wide range of plastics with varying properties and chemical composition, hence the need to understand the process and determine the ideal plastic for your projects. This article discusses everything you need to know about plastic CNC machining, common engineering plastics, and standard machining processes.

What is PTFE?

PTFE (Polytetrafluoroethylene), also known as Teflon, is a soft, low friction engineering plastic with lots of advantages. PTFE is one of the slickest solids and readily available for daily use. There is a wide range of industries benefit from the PTFE machined parts as its high flexibility and excellent properties, product designers often select it for broad purposes.

Material Properties

PTFE Material Types/Options:

– Virgin (Unfilled) Grade PTFE

– Glass-filled PTFE

– Bearing grades of PTFE

– Reprocessed PTFE

Characteristics of PTFE:

– Outstanding chemical and heat resistance

– Low friction, non-stick

– Good weathering resistance

– Stable at temperatures up to 500℉

– Excellent electrical insulating properties

– The relatively high strength-to-weight ratio

Mechanical Properties of PTFE:

– Density: 2.15 g/cm3

– Surface Hardness: SD63

– Tensile strength: 1,500 – 3,000 PSI (25 MPa)

– Flexural modulus: 72,000 PSI (0.70 GPa)

– Water absorption (immersion 24 hours): <0.01%

– Coefficient of friction (dynamic): 0.10

Applications of PTFE and PTFE Machining Parts:

– Medical and surgery: tissue and organ grafts, medical implants

– Building and decoration: coating materials

– Garment Industry: clothing materials

– Vehicle and automobile: lightweight chassis and vehicle parts

– Aerospace industry: coatings, cable insulation, fuel hoses, protecting surfaces for doors

– Food processing: bakery and food processing contact machinery

– Oil & gas: brake lines, hoses and oil pipelines, PTFE potting covers

– Electricity and electronics: insulators, cathode and anode end blocks, arc shields, etc.

– Components for mechanical and various equipment: seals, gaskets, valve, fittings, pump parts, manifolds, semiconductor equipment, bearings, bushings, slide blocks, washers, mechanical gears, etc.

CNC PTFE - Teflon Machining Tips

PTFE (Teflon) can be machined to produce CNC components for different uses. What should you pay attention to when machining PTFE plastic? The CNC machining of Teflon requires knowledge and familiarity with the properties and shortcomings of the material and skills or experiences for operating the machines.

– High-quality finishing services are subject to certain limitations. The high coefficient of expansion and stress creep properties make Teflon difficult to achieve tight tolerances, while the finishing makes it even lower. Non-aromatic, water-soluble coolants, such as pressurized air and spray mists, are recommended to use for optimum surface finishes and close tolerances.

– The softness causes higher difficulty in maintaining tolerance in plastic machining. A good rule for tolerances of plastic parts is +/- .001 per inch of dimension, tighter tolerances are possible with very stable, reinforced materials.

– When machining Teflon, consider that PTFE may deform if it is placed under extreme pressure, including the stress on the moving components.

– Unbalanced, bowl-shaped or disk-shaped components are not suitable to process with PTFE.

– Notice the difference between plastic and metal materials, for example, compared to metals, the thermal expansion of plastics is several times that of metals, dissipate heat more slowly, so avoid localized overheating.

– It’s better to use carbide tooling with polished top surfaces to protect the tool and improve surface finish.

– Support material sufficiently to limit deviation from the tool.

– Build sufficient chip clearance to prevent clogging.

Polestar Metal: Your Trusted Partner in Precision Plastic CNC Machining

Choosing our Plastic CNC Machining services ensures not only precision and quality but a partnership built on trust and reliability. At Polestar Metal, we are committed to delivering excellence in every aluminum component we produce. From prototyping to full-scale production, we are equipped to meet your specific needs and bring your designs to life.