Graphite packing and how it is developed

Graphite packing is manufactured from graphitized cord, which is made from a large number of graphite filaments that are twisted together to form a yarn that is then braided to increase its tensile strength and durability.

It is quite common for the yarns to be coated with other types of materials, such as PTFE, to increase their chemical resistance. Finally, locking agents are applied to seal the filaments and increase the sealing ability of the gasket.

Varieties of graphite packing

Although graphite is the core material of graphite cord and packing in general, other materials are often added to enhance its advantages. Some of the most common combinations are:

• Graphitized PTFE fibers Adding graphite reduces friction, dissipates heat and increases resistance at high peripheral speeds.
• Expanded graphite: Resistant to chemicals, it is a self-lubricating material and works excellently at high temperatures, peripheral speeds and pressures.
• Graphitized asbestos: Each asbestos strand is reinforced with graphite, as well as the overall braid for maximum lubrication.
• Kevlar: Aramid fibers impregnated with PTFE to make them durable and with high mechanical, abrasion, pressure and high temperature resistance.
• Synthetic acrylic fiber: A braid of acrylic fiber yarns, reinforced with PTFE and running-in lubricant that make it tough for general applications and perfectly suited for marine environments.
• It is ideal for pumps that need to be especially resistant to silt, sand and sludge in marine environments.

PTFE and flexible graphite

It is common for these two types of materials used in the manufacture of braid style graphite packing to be confused with each other, however, there are certain differences between them that are important to note.

To begin with, graphite is a natural material, one of the forms of carbon, and PTFE is a synthetic material. In the same sense, graphite cords are made from pure carbon (sometimes mixed with PTFE to enhance its characteristics).

On the other hand, polytetrafluoroethylene (PTFE) is a synthetic polymer obtained from the polymerization of tetrafluoroethylene. Threads of this material can be lubricated to obtain flexible packings.

If we talk about the advantages of these two materials, graphite gaskets considerably reduce friction, can be heat conductors and resist chemical products, high temperatures and pressures.

PTFE prevents shaft wear and is a good insulator for electrical applications.

At ESGRAF we have graphite packing, as well as other fibers according to customer needs. In that regard, we can offer multiple graphite products to meet your needs. If you are interested in having a consultant contact you, please go to this link.

Limitations to consider

Performance depends on graphite grade, grain orientation, temperature, load, pressure, speed, and operating environment. Material selection should be confirmed for your actual process conditions.

Information needed for a quote

To guide selection or prepare a quote, ESGRAF typically needs:

• Application and operating conditions (temperature, atmosphere, load).
• Dimensions, technical drawing, or CAD file when applicable.
• Required quantity.
• Requested grade or material currently in use.
• Observed issue with the previous part or lubricant, if any.

Request a quote

Share these details with our team at ESGRAF or request information. A specialist will review your application before recommending a grade or geometry.