Customizing PTFE Seals and Gaskets for Enhanced Performance
Not All Seals and Gaskets Are the Same; Here Are Some Performance Characteristics and Other Factors to Consider
In many instances, hardware parts specified by design engineers are considered “commodity” or “generic” items, non-proprietary items that are more or less the same, regardless of the supplier. This view may be common to those who order PTFE parts, the synthetic polytetrafluoroethylene that is marketed under the brand name Teflon® by the chemical giant DuPont.
Generally speaking, PTFE is well known for its toughness, low coefficient of friction, temperature resistance, chemical inertness, and other properties that are required in a range of applications and industries. PTFE seals and gaskets are examples of items that have become standard in a myriad of applications.
However, when it comes to the supply of the PTFE seals and gaskets commonly used in combination with other parts that make up many components and assemblies, there are a number of important factors that specifiers need to consider, according to industry experts.
Those factors include the seal and gasket manufacturer’s capabilities to consistently meet dimensional, material, and quality requirements, as well as expert in-house engineering assistance. Other vital supplier capabilities include the ability to provide reliable delivery of orders, and the expertise to offer a range of customized PTFE materials or blends that will better serve a specific type of application.
“Some manufacturers of PTFE gaskets and seals may assume that filling an order is mainly a matter of meeting a customer’s spec and bidding it successfully,” said Rich Stockglausner of Midwest Industrial Sales, Fallon, Mo., a manufacturer’s rep that specializes in the commercial refrigeration market as well as a variety of other industrial applications.
“The specifying engineer may not realize it, but there are alternatives to the use of standard PTFE for many applications,” Stockglausner explained. “PTFE can be filled with many different additives. You can put glass fiber in it, or molybdenum, bronze, or carbon. Each of those additives can enhance or optimize certain PTFE properties, such as heat or chemical resistance, to provide a more effective seal for certain applications.”
Stockglausner, who has been a manufacturer’s rep for Prolon, Elkhart, Ind., for over 20 years, added that it is important for many engineers and purchasing agents to validate their specifications for PTFE seals and gaskets with a supplier that can provide the in-house engineering expertise to customize alternative compounds that are appropriate to a given application.
“In this case Prolon’s engineering department had the expertise not only in gaskets and seals, but were also highly familiar with specific applications,” he said. “For example, we have worked with some projects recently with one of the largest refrigeration valve manufacturers in the world. Prolon’s engineers guided these people through the right valve seal design during a telephone conference call. So, they are a vital asset to that organization and the customers.”
Quick and Reliable Turnaround
The ability of a supplier to meet quick turnaround requirements and provide reliable deliveries of orders is often a crucial requirement to many manufacturers who use PTFE seals and gaskets.
“Many of these seals and gaskets are relatively inexpensive,” said Matt Walling, a sales rep with manufacturer’s representative Integrated Design Elements, Elkhart, Ind. “Yet it sometimes happens that a shortfall in the supply of a five-cent seal can create downtime on the production of an expensive component or assembly — a catastrophic situation.”
Walling, whose company represents Prolon in Indiana, Michigan, and Ohio, said that he can meet quick turnaround requirements on new orders and consistently provide normal deliveries within a six-week period, while the industry norm is approximately eight weeks.
“You’ve got to hit the dock dates,” said Stockglausner. “You have got to be able to put the order on the customer’s loading dock when they need it. Customers are running with very little inventory these days. They’ll have at the most a week’s worth of excess inventory in their system. We’ve been able to meet deliveries of hundreds of millions of PTFE parts over the years thanks to Prolon’s ability to meet scheduled deliveries that prevent gasket and seal shortages.”
The ability to customize PTFE seals and gaskets while making reliable deliveries of parts of consistent quality are dependent on a supplier’s production capabilities. That includes equipment as well as staff expertise.
“I was able to get one of my biggest customers on board because of a problem with consistent quality,” says Walling. “They were getting supplied with a seal, and they were getting a good price but weren’t satisfied with the quality of the part. When we got a shot at the business we made certain that the quality of the part was perfect. To ensure that, Prolon used exactly the same gauge as the customer. And that worked quite well.”
Prolon, a leading manufacturer of PTFE products and engineered plastics, invests in the latest CNC-driven lathes and other equipment.
“Their newer machines can zero in on tolerances to within a couple of thousandths on seals or rings,” said Stockglausner. “Having the latest in high-volume production equipment is also important to the customer in terms of capacity and lead times,” he added. “The newer machines go faster and also produce consistently accurate parts.”
For more information, visit www.prolon.com.
Publication date: 3/10/2014