Have you had problems with your polyurethane seals degrading, especially when exposed to higher heat creating the need to replace your seals more often than you would like? As you probably know, seal replacement creates costly downtime that can be avoided if you have an appropriate seal for the job. Parker's Resilon® 4350 polyurethane is up for this task. Resilon 4350 is designed for sealing at higher temperatures up to 250°F continuous and can withstand short-term excursions of up to 300°F without leakage.
Understanding the approximate temperature range of Resilon 4350
Resilon 4350 polyurethane was formulated to extend the high-temperature capability of Parker’s proprietary urethanes. Where current, more ordinary polyurethane seals have failed, Parker’s new Resilon 4350 has the highest temperature rating of any specialty polyurethane on the market. It was developed for applications where high temperatures or extended heat history cause failures with current polyurethane seal materials.
In a head-to-head comparison test at 250°F continuous, the Resilon 4350 material presented minimal leakage (< 5 grams) up to 250,000 cycles during a life test. This equates to a 33% longer lifespan compared to the standard 4300 material at this elevated temperature range (Figure 1).
Additional testing was completed showing the % seal force retention as the external temperature increased from about 160°F to 250°F. The three materials tested exhibited a linear relationship between the seal force retention and temperature. The Resilon 4350 had a 7-10% higher seal force retention beyond 4300 and the leading competitor of high-temperature polyurethane during this temperature range. The Resilon 4350 still exhibited a 20% seal force retention at 250°F (see Figure 2). Based on the results of this testing, this material is promoted as having a continuous operating temperature range of -65°F to 250°F.
Parker’s Resilon polyurethanes are provided in various profiles for use in a wide variety of applications. With the introduction of Resilon® 4350 the recommended operating temperature range for best performance can now be extended 20° to 25°F higher, giving design engineers the ability to push the envelope.
This article was contributed by Eric Woodworth, application engineer, Engineered Polymer Systems Division.