Product category:
Materials and components
News Release from: Victrex USA | Subject: Victrex Peek polymer
Edited by the Engineeringtalk Editorial
Team on 08 November 2007
Polymer handles tough aircraft job
Victrex Peek polymer houses the system built into aircraft landing gear, which must be able to survive some of the most extreme environments and loading conditions.
Crane Aerospace and Electronic specified Victrex Peek polymer for the hubcaps containing a new tyre pressure monitoring system for the landing gear of Boeing 777 aircraft It chose the material because of the its high temperature resistance and mechanical strength, as well as its chemical resistance to the caustic elements found on the runway
This article was originally published on Engineeringtalk on 31 Dec 2001 at 8.00am (UK)
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According to Jeff Tonn, Design Engineer at Crane, "The tyre monitoring system on the Boeing 777 is designed to assure proper tyre air pressure for take-off and landing".
"The hubcaps include a conduit which allows a rim-mounted pressure sensor to communicate with an onboard system providing real-time data to the cockpit".
"Maintaining proper tyre pressure is critical to aircraft safety".
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In addition to Boeing 777 aircraft, the Crane Tyre and Brake Monitoring System may be selected for use on other commercial aircraft.
Aircraft landing gear must be able to survive some of the most extreme environments and loading conditions, according to Tonn.
"For example, temperatures at altitude can be as low as -54C whereas temperatures on braking can reach more than 200C".
"Landing gear must be able to withstand repeated hard landings as well as impacts from flying debris".
"In addition, landing gear is exposed to both ozone and to chemicals in jet fuel, hydraulic fluid and de-icing solutions".
Using Victrex Peek polymer enables the hubcaps to withstand these extreme conditions.
John Walling, Regional Business Manager for Victrex said "Victrex Peek polymer maintains its mechanical properties in hot/wet environments".
"With a continuous use temperature of 260C, the polymer has proven to be the most stable when compared to other high-heat thermoplastics".
"It exhibits no loss in tensile strength after ageing at 200C for one year".
Victrex Peek polymer has excellent fatigue performance, wear resistance and chemical resistance.
Walling said "This combination of properties has allowed Victrex Peek polymer to successfully displace metals, traditional composites and other plastics in a growing number of aerospace applications".
Weight also played a major factor in selecting Victrex Peek polymer to displace aluminium for the hubcaps.
By specifying Victrex Peek polymer, each hubcap now weighs less than 7kg.
With 14 wheels per plane, the weight reduction is considerable.
Another advantage of Victrex Peek polymer is that it can be easily fabricated into tight tolerance parts.
The hubcaps are injection moulded and painted to provide an added layer of UV protection.
A nominal wall thickness of 3.75mm is thick enough to protect the hubcap from high-impact events.
Moulds are filled evenly on conventional equipment with standard viscosity Victrex Peek polymer".
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