PTFE
- January 12, 2022
This new case study from Gallagher Fluid Seals outlines the benefits of using a PTFE spring energized seal in high friction applications.
Our customer is a manufacturer of power transmission products with a focus on magnetic force. Their product line includes magnetic capping heads, shaft couplings, current-controlled brakes, and clutches.
CUSTOMER PROBLEM:
The customer's magnetic clutch and was having design problems with high friction and break-away force, ultimately causing delayed production schedules.
- July 28, 2021
The machining of polymers such as PTFE, still remains somewhat of a specialty operation. While there are a plethora of machine shops dotted across the country focused on metal turning and milling operations, few specialize in plastics.
Only someone experienced in metalworking might call machining something like PTFE easy. PTFE is much softer and easier to cut than something like steel or aluminum.
While this certainly is true, polymers present their own unique set of manufacturing challenges, especially when tight-tolerance parts are required. And with Eclipse’s business of aerospace and specialty applications, they almost always are.
- July 16, 2021
As the operating parameters of industrial technologies and manufacturing processes get more extreme, the need for optimal sealing solutions become that much more important.
Elevated temperatures and pressures, higher speeds, extreme environments, faster gas decompression, and aggressive medias all make sealing more critical. This extends right across static, reciprocating, rotary, and oscillating applications.
This challenge has been met very effectively by the inventive addition of energizers to seals. Energized seals give the ultimate performance in the most demanding conditions and critical applications.
Spring or o-ring energizers can extend the normal limits of PTFE and plastic materials to deliver durable ultra-tight sealing capability. Here’s a rundown of how energizers work and how they can elevate your next sealing challenge.
- March 26, 2021
Polytetrafluoroethylene (PTFE) resin is a highly effective material for seal consumers due to its extremely low friction, high heat tolerance and chemical inertness.
With the right additives, PTFE resin can perform even better in terms of strength, thermal performance, chemical resistance and abrasion.
However, there are a few design considerations when using PTFE resin, particularly when combined with glass fiber and bronze.
This blog will examine PTFE fillers to enhance PTFE performance.
- November 06, 2020
Below, we’ll explore how Teflon is processed for sealing purposes, and why we sometimes see variation in surface quality and/or cracks in finished Teflon seals.
The Two Ways to Process Teflon® for Seals
There are different grades of Fluoropolymers that can be used to manufacture seals. There are melt processable fluoropolymers, which are rarely used in the seal manufacturing process due to cost, and granular PTFE.
Melt processable fluoropolymers allow for injection molding, and exhibit many of the same characteristics as granular PTFE. But the first grade
- February 07, 2020
The term “plastics” is generic way of describing a synthetic material made from a wide range of organic polymers. Organic polymers describes a man-made substance that is formulated using polymer chains to create what we commonly refer to as…(you guessed it), plastics.
Before plastic, leather had been used to create Backup ring devices behind O-rings. Leather allows fluids to be retained, providing lubrication for the O-ring when the system was running dry.
The problem with leather was that it could become dry and shrink away from the sealing service, exposing the elastomer to same pressure it was intended to protect against.
With the advent of polymers, a piece of plastic could be cut or formed into the exact shape to allow for zero extrusion gap, and for continued protection for the O-ring.
Some polymers were very brittle. Since they needed to be deformed to allow for installation into solid glands, the cut of the plastic could nibble at the O-ring, causing premature failure of the element it was supposed to be protecting.
The Revolution of PTFE
When PTFE moved out of the lab and into industrial use, it quickly found itself adjacent to the O-ring. PTFE offers extrusion resistance and, at the same time, doesn’t erode or nibble at the O-ring due to the “softness” of the polymer.(Hardness between 55 and 65 Shore D)
Given the composition of PTFE, or Teflon, it could be utilized as a sealing element to protect Backup rings and conform to the shaft. The bonus was it was generally easy on shafts (depending on the filler added to the PTFE).
There are some negative aspects to Teflon that needed to be overcome by early engineers. First, it has a fairly high rate of Thermal expansion which, by its own nature, could often times lose contact with the sealing surface. This meant some kind of loading was necessary to ensure contact.
PTFE is as tough as other polymers, so the fact that it could seal on a shaft made it vulnerable during installation for tears or nicks on sealing surface.
Second, if it were stretched during installation, the material had to be sized back to its original shape due to its poor elastic properties.
- October 11, 2019
Better known as Teflon in the industry, Polytetrafluoroethylene is widely used in practically every industry on and off the planet (and even beneath its surface!)
Medical Uses
This material’s primary claim to fame is its resistance to most chemicals. It inherently has an extremely low coefficient of friction, it’s easily machined from rods, tubes, or compression-molded shapes.
It’s one of the few polymers that are approved for medical implants due to its inertness to bodily fluids — the immune system principally ignores its presence in the body.
Moving away from the body, you’ll find PTFE or Teflon products in medical
- September 10, 2019
The search for the ideal Polytetrafluoroethylene (PTFE) gasket has been elusive. Competing applications and workplace variables have led to the creation of myriad solutions, yet none that has proven fully adaptable and appropriate for universal adoption.
Garlock Sealing Technologies considered this to be a critical yet entirely solvable shortcoming. And it is against this backdrop that in 2016, they set out to compile a comprehensive list of attributes for the ideal PTFE gasket — a wish list, as it were — in order to build a better gasket.
Working with a third-party survey development company, Garlock developed an exhaustive questionnaire that probed every aspect and functionality of PTFE gaskets, testing and adjusting the questions until they had a workable, finalized version.
Using this final questionnaire, Garlock conducted extensive interviews at 15 major chemical processor companies, speaking with 20 engineers responsible for process operations, projects, maintenance and reliability. The goal was simple: to discover the ideal characteristics and their relative importance that engineers sought in a PTFE gasket.
After several months of data collection, Garlock analyzed the feedback and noted the most popular responses:
- 28% of respondents said that they struggled with how different gaskets required different compressive loads and how to ensure that those gaskets had been installed properly
- 21% expressed frustration with the creep properties of PTFE gaskets
- 21% desired a gasket that seals with less compressive load
- 14% expressed frustration at the installation inconsistencies of their fitters
- 14% expressed frustration with leaking, especially after a successful installation and start-up
From those answers, Garlock drew the following conclusions, representing the most desirable and essential PTFE gasket characteristics:
- Seal: Seals easily
- Installation and assembly: Forgiving of poor installation or assembly practices
- Forgiving: Forgiving of poor flange conditions
- Retention: Maintains a seal after installation
- Flexible: Can be used in a broad range of services to avoid user confusion and reduce inventory
Introducing: GYLON EPIX
Garlock used this feedback in developing a next generation PTFE gasket — GYLON EPIX. Featuring a hexagonal surface profile, GYLON EPIX offers superior compressibility and sealing for use in chemical processing environments. Its enhanced surface profile performs as well or better than existing 1/16″ or 1/8″ gaskets, allowing end-users and distributors to consolidate inventory, lower the risk of using incorrect gasket thicknesses and reduce stocking costs.
GYLON EPIX checks off the most desirable gasket attributes:
- Installation and assembly: Even distribution of the bolt load over the contacted area of the gasket during the assembly process
- Retention: Retention of the bolt load administered at assembly
- Seal: Efficient translation of bolt load to sealing performance
- Forgiving: The ability to perform in imperfect flanges and installation conditions
GYLON EPIX with its raised, hexagonal profile allows it to perform the job of both traditional 1/16” and 1/8” gaskets. It accomplishes this by combining the bolt retention of the former with the forgiveness for bad flange conditions of the latter, a truly innovative feature for PTFE sheet gasketing.
- August 29, 2019
Polymer wear rings were developed to offer an alternative to dissimilar metal wear rings.
One of the advantages to using a polymer material such as nylon or filled-Teflon instead of a metallic bearing . Whereas when you use bronze or metallic bushings, these materials are prone to point loading on the edges of the bearing.
This property of polymer bearings combined with solid lubricants can yield a product that is much less likely to damage moving components.
5 Advantages to Polymer Wear Rings
- Polymer style bearings can be held to very close tolerances in the radial dimension to provide support without excessively opening the extrusion (E) gap by a large amount. Polymer bearings such as filled Teflon can support a compressive load up to 1000 PSI. Nylons up to 36,000 PSI and polyester fiber with resin, up to 50,000 PSI.
- Hydraulic cylinders that are found in excavators often use higher compression materials because they experience extreme
- July 30, 2019
PTFE and its many applications
Polytetrafluoroethylene (PTFE) has an interesting history and has been used in a number of ways over the years. There is, of course, the best-known PTFE brand Teflon® – the miracle cookware coating. But PTFE is also used in aerospace and computer wiring, and it’s even coated the fiberglass dome of the Hubert H. Humphrey Metrodome in Minneapolis. But the Metrodome isn’t the only sports-related application for PTFE. Because it’s so slippery and resistant to extreme temperature changes and chemical reactions, PTFE is an excellent component for many parts such as: bearings, gears, and of course, seals – like those used in so many motorsport vehicles. So, what role does PTFE play in the exciting world of motorsports?
PTFE in racing cars and trucks
TRITEC Seal’s PTFE rotary lip seals can be found in the race cars of nearly every