Classification Criteria

There are many ways you can classify polytetrafluoroethylene tubes in the market. It varies from application, and physical properties, to dimensions.

1. Dimensions

Dimensions form important PTFE tube specification criteria. You can determine the PTFE tube sizes by measuring:

• Outside diameter
• Inside diameter
• Wall thickness
• Length

With these, you can determine the pressure rating and volume of the PTFE tubing. Again, using these variables, some examples include:

• Thin wall PTFE tubing – with respect to the wall thickness
• 10 mm PTFE tube or 150 mm PTFE tube – it denotes the tube’s capacity or size.

2. Color

Naturally, PTFE tubing is translucent. However, you can add other pigments during the manufacturing process to get custom color options. For instance, you may have a blue PTFE tube, green PTFE tube, red PTFE tubing, etc.

3. Material Grade

Virgin PTFE tube is extruded from pure polytetrafluoroethylene. Usually, it is a high-grade tubing suitable for high-purity applications. However, at times you may wish to improve the performance properties of PTFE tubing.

Consequently, you add certain fillers:

• Glass filled-PTFE tube: It has glass fibers for better strength and creep resistance
• Carbon filled-PTFE tube: It has carbon fibers for high compressive strength
• Bronze filled-PTFE tube: The bronze makes tubing hard-wearing
• Graphite filled-PTFE: Reduces friction further while improving electrical and thermal properties

You can add any compatible fillers, depending on the specific performance characteristics you want from the Teflon tubes.

4. PTFE Tubing Manufacturing Process

There are two main types of polytetrafluoroethylene tubing here – extruded PTFE tube and PTFE molded tube.

PTFE is known for its high melting temperature, inability to flow, and high viscosity. Consequently, it makes adopting the conventional injection molding and extrusion processes virtually impossible.

Again, when it comes to extruding polytetrafluoroethylene tubing, PTFE paste extrusion and PTFE ram extrusion remain popular techniques. Extruded PTFE tubes using paste extrusion are flexible. However, producing long and continuous PTFE is limited.

Even so, high-quality PTFE tube extrusion must conform to the ASTM D4894-19 for PTFE extrusion.

For molded PTFE tubes, dry molding, and sintering are the most suitable techniques. Compression molding remains a reliable option for producing PTFE molded tubes.

5. Classification by Design

It refers to the general appearance or configuration of the polytetrafluoroethylene tubes. Some common options include:

• PTFE convoluted tubing or Corrugated PTFE tube– the design is such that the outer wall can fold easily.
• Flexible PTFE tube– these are tubes you can bend without damage or reducing performance
• Split PTFE tubing– you can split these tubes longitudinally. Most tubes have a ridge.
• Multi-lumen PTFE tubing– this is where many small tubes are surrounded by one large tube.
• Heat shrinkable PTFE tubing– usually they are thin PTE tubing with the ability to shrink when subjected to hot air.

6. Classification by Applications

There are certain applications requiring specific PTFE tubing. As a result, we have specific tubing designed to meet the dynamic needs of such industries, for example:

• Clean room PTFE tubes– they are also called medical grade PTFE tubes. The tubes are FDA-compliant, made from virgin PTFE, and designed to meet high purity or hygiene standards.
• Expanded PTFE tubes– also called PTFE porous tubes, they are air-permeable. These tubes have micro-pores for applications requiring permeable materials.

Other custom PTFE tubes may include PTFE rigid tubes, PTFE shrink tubes, and PTFE square tubes, among others.

Benefits of Polytetrafluoroethylene Tubes

There are many reasons why Teflon tubes are popular in today’s industries:

• Best for handling highly reactive fluid such as acids or alkalis
• Meets high hygienic standards hence suitable for medical applications
• Being chemically inert, the tubes can handle virtually all solutions
• It has a wide temperature of operations
• Neither attracts, develops static charges, or sticks on particles
• Recommended for high-heat applications
• It can effectively handle sticky solvents or solutions
• Allows for seamless flow of solutions due to non-sticky property
• Tubes are easy to clean since substances do not steak easily on the surface
• Allows for easy sterilization due to chemical and high heat resistance
• PTFE tubes are flexible
• Semitransparent allowing for faint visibility while also ensuring substances that must not be exposed to direct sunlight are safe
• Durable since they never deteriorate while not in use

Even with all these, it will be unfair not to mention some limitations of PTFE tubes. Although there are some studies still going on, PTFE tubes show poor resistance to radiation and are costly.

Additionally, melt processing is also becoming a challenge alongside low strength. For these reasons, other tubes such as PFA tubes, FEP tubing, and ETFE tubes can be alternatives for certain applications.

HANSA is a reputed manufacturer of PTFE tubes in China. Our tubes come in different grades, with custom options available upon request. Contact us now for all your PTFE tubes.