GRAPHITE & GRAPHENE THERMAL STRAPS 

X-SERIES® | THE WORLD'S HIGHEST PERFORMANCE THERMAL LINKS

thermal straps
 

Vibration transmission and waste heat removal requirements have dramatically changed as spacecraft, cubesats, larger satellites, and other aerospace equipment needs have evolved in recent years. Unfortunately, in certain applications, these requirements have effectively eliminated traditional metallic cable, foil, and graphite fiber straps as a solution. To meet these more challenging requirements, TAI offers our X-Series® PyroFlex™ product line; the world's highest thermal performance, "Zero-Stiffness" thermal straps.

X-Series® PyroFlex™ and GTL™ straps are made with Pyrolytic Graphite Film (PGF) Sheets, and are also available with Graphene Layered Foil Sheets.  When combined with our proprietary design and assembly  methods, they are entirely unique in the industry, offering a number of important benefits over other strap types, including:
  • 3 – 4X the performance of equivalent copper and graphite fiber straps
  • 10 – 30% greater thermal performance than competing carbon straps
  • PyroFlex™ offers 6X the thermal performance of al & 4X the performance of cu at room temp
  • PyroFlex™ and Graphene are both 28% lighter than aluminum, and 77% lighter than copper
  • PyroFlex™ links are the industry’s most flexible thermal straps
  • PyroFlex™ straps are exceptionally clean and passed strict PCL/PAC/FPAC testing
  • PyroFlex™ DO NOT REQUIRE ENCAPSULATION SLEEVES 
  • X-Series® PyroFlex™ straps achieved NASA Technology Readiness Level (TRL) 9 and have Flight Heritage
Because of these many advantages, TAI's X-Series®  are the ideal thermal straps for many space system and cubesat applications.  However, while they offer superior thermal performance to our CuTS®, CuFS®, and GFTS® products, all forms of pyrolytic graphite sheet and graphene foil straps have their own limitations and trade-offs to consider. Our engineering and design team is here to help you understand these, and to identify the most efficient and affordable strap for your program.
 
 
Thermal Straps Graphite Thermal Straps - PyroFlex HSFL PGS Thermal Straps - TAI - X-Series PGL__X6-501 in Shipping Fixture__NASA Program October 2018 General_Atomics_PGL_thermal_straps_TAI Ball Aerospace PGL Thermal Strap by TAI - In Shipping Fixtures_ X-Series PGL Thermal Strap in Stiffness Test for NASA GTL Thermal Test X-Series PGL Thermal Strap - NASA Thermal Test__October 2018 PGS_Thermal_Straps_TAI X-Series PGL - X6-501__Mylar Sleeve and Shipping Fixture__NASA Program October 2018 Thermal Straps Thermal_Straps_PGS_DLR-TAI PGS Thermal Strap Pyrolytic Graphite Sheet Thermal Strap HSFL Thermal Straps - PGS - TAI - PGL Thermal Strap April 2020 - TAI_ PyroFlex Graphite Thermal Strap in shipping fixture - slider PyroFlex Graphite Thermal Straps with High Conductivity Carbon Fiber End Fittings - slider PyroFlex Graphite Thermal Straps with High Conductivity Carbon Fiber End Fittings - slider website again again PyroFlex Thermal Straps

VISIT THE X-SERIES® THERMAL STRAP DESIGN GALLERY 

 

CUSTOM & STANDARD MODEL X-SERIES® STRAPS

2024 X Series Catalog

PyroFlex™ and GTL™ products are made entirely of NASA approved, low/zero outgassing materials, and are offered in standard and custom configurations.  X-Series® Links/Straps are our standard model line, and can be manufactured with either PGF or Graphene foils (depending on customer preference and performance requirements).  The X-Series® is comprised of 3 standard models with fully customizable end fittings and sheet stack thicknesses (number of sheets), in order to meet your conductance requirement.
 
All PyroFlex™ and GTL™ products come with optional Mylar® or kapton encapsulation sleeves, and chromated end fittings for corrosion mitigation.  Models in our new 2024 Catalog now offer even higher thermal performance, and both products have been qualified by engineers at NIST and medical engineering & instrument companies from 10K - 300K, and multiple companies are now using PyroFlex straps in cryogenic and quantum computing applications ranging from 40K - 115K (either for additional heat transfer, or as passive thermal switches).
 
To learn more about our standard and custom strap offerings, request your copy of the 2024 X-Series® Catalog. To learn more about our other strap products, visit our Thermal Straps page, contact us today.
 

ORDERING YOUR STRAPS

If you have already selected your standard X-Series® model(s) from the catalog, please download and complete the Thermal Strap Design and Ordering Form, and submit the questionnaire to our Director of Business Development at tlink@techapps.com, to receive your quote.

PGL X-Series - X6-501

X-SERIES® STRAPS

  • Available in 3 Fixed Widths
  • Available in 2 Thicknesses
  • Available with Graphite Sheets or Graphene 
  • 6 Models to Choose From
  • 2 Semi-Customizable End Fitting Types Available
  • Length Customizable
  • Bolt Pattern Customizable
  • No NRE or Design Fees
  • Thermal Test(s) - OPTIONAL
  • End Fitting Chromate / Passivation - OPTIONAL
  • Optional Mylar Sleeves for Contamination-Sensitive Applications
  • Typical 8-10 Week Lead Times
Pictured: X6-501 X-Series® with dual aluminum L-fittings.

Custom PGL Thermal Strap

CUSTOM PyroFlex™ STRAPS

  • Available in Nearly any Width 
  • Available in Nearly any Thickness
  • Available with Graphite Sheets or Graphene Foil
  • End Fitting Material Customizable
  • Fully-Customizable End Fittings
  • Length Customizable
  • Bolt Pattern Customizable
  • Prototype/Protoflight Program Required
  • Thermal Test(s) - INCLUDED
  • End Fitting Chromate / Passivation - OPTIONAL
  • Optional Mylar Sleeves for Contamination-Sensitive Applications
  • Typical 8-10 Week Lead Times

Pictured: Custom PGL™ with dual flat aluminum fittings.

 

 

THE INDUSTRY'S HIGHEST THERMAL PERFORMANCE 

Carbon Thermal Strap Material Conductivity Graph
TAI's X-Series® products offer the highest thermal performance available in the industry; providing a material thermal conductivity of 1,350- 2,500 W/(m-K), depending on material, operating temperature, and sheet thickness (though graphene foil/sheet may one day offer even higher thermal performance than the current 1,700 W/(m-K) available in the industry, as the manufacturing technology improves).  However, the materials used are just one aspect that makes our products unique. These materials, when combined with our proprietary design and assembly methods (which minimize resistance losses), result in unrivaled thermal performance. 
 
Though these straps do not have years of spaceflight heritage (like our copper and graphite fiber thermal straps), they are a unique product, offering a particular set of benefits which make them ideal in volume-restricted applications like Xilinx™ electronics boxes, FPGA/chip & PCB cooling applications, and cubesats. 
 
*It should be noted that we do not provide "monolayer graphene straps," as there are no (actual) monolayer graphene sheet thermal straps available in the industry. While a single layer of graphene can achieve a thermal conductivity in excess of 3,500 W/(m-K), it is only 0.35 nm thick.

Graphene Thermal Conductance graph

Specific Thermal Conductivity of Strap Materials

Thermal Strap Conductivity Graph - PGS and Graphene Thermal Conductance

Thermal Conductivity of Strap Materials
 
 

SPACE FLIGHT QUALIFICATION

Thermal Straps

TAI's X-Series® PyroFlex™ products were space-qualified by NASA JPL in 2018, and are now being used on multiple spaceflight programs in both Europe and the United States, by Airbus, Lockheed Martin, the DLR, CNES, General Atomics, NASA, Raytheon, University of Hawaii, and numerous aerospace and commercial spaceflight organizations which cannot be named due to NDA's and/or cybersecurity policies. Testing performed by TAI, NASA, and outside facilities included:
  • Thermal Conductance
  • Thermal Cycling
  • Post-Thermal Cycling Thermal Conductance
  • Stiffness
  • Vibration
  • Post-Vibration Thermal Conductance
  • Particulation Contamination Level (PCL)
  • Outgassing
  • Post-Vibration PCL
This extensive qualification proved that TAI's X-Series® PyroFlex™ products do not require encapsulation sleeves for particulate control, are the cleanest, most efficient, and most flexible carbon sheet strap on the market, and are durable enough to withstand extremely high vibration environments (while at the same time offering the highest thermal performance of any space-qualified strap in the industry).  For test data, please contact us today (TAI provides complete vibration, thermal conductance, stiffness, and PCL/PAC/FPAC reports). 
 

X-Series PGL Thermal Strap - NASA Stiffness Test

Pictured: X6-501 NASA Stiffness Test (October 2018).

X-Series Thermal Strap Vibration Test - NASA

Pictured: Dual X6-501 NASA Vibration Test (November 2018).

 

 
 
 

Graphite Sheet Thermal Straps IMAPPYROFLEX™ SPACE FLIGHT HERITAGE

PyroFlex™ products have now achieved TRL 9 with several DX-rated US Military satellites and NASA programs launched in 2022 - 2024.  The list below details just a handful of the satellite, cubesat, and commercial crew and cargo vehicles using our PyoFlex™ products:
  • NASA Goddard - PROGRAM NAME WITHHELD AT CUSTOMER REQUEST - straps used for waste heat removal of reaction wheel isolation system (RWIS). Expected launch date: 2028.
  • General Atomics - PROGRAM NAME WITHHELD AT CUSTOMER REQUEST - straps used to cool Fast-Steering Mirrors. Expected launch date: 2026.
  • Lockheed Martin - MULTIPLE PROGRAM NAMES WITHHELD (DX-RATED) - several designs with both aluminum and high conductivity carbon fittings for multiple military satellite programs. Launch Dates: 2024 - 2028. 
  • DLR and Aribus DS - MERLIN Program - Straps used to cool optical instruments. Expected launch date: 2028
  • University of Hawaii Space Flight Laboratory / NASA JPL -  Hyperspectral Thermal Imager (HyTI). Straps used to cool instruments on CubeSat. Launched March 21, 2024. 
  • Lockheed Martin - ARTEMIS II & III MISSION (ORION) -  Dozens of straps used to cool DAQ systems. Expected Launch dates 2025 and 2026.
  • Blue Origin - NEW GLENN - Several dozen straps used to cool multiple tanks and other equipment on NG. Expected Launch Date: End of 2024.
  • John's Hopkins Applied Physics Lab - IMAP - 10 straps used to cool an avionics box and the IMAP-LO instrument. Expected Launch Date: February 2025.
  • Planet Labs - PELICAN CONSTELLATION SATELLITES - dozens of straps used to cool reaction wheels on the satellites. Launch Dates: COMING SOON.
  • Numerous CubeSat, NanoSat, military satellites, and Commercial Crew and Cargo Vehicle Customers that are CONFIDENTIAL due to NDA's. Launch Dates: 2022 - 2028.
  • Turion Space - DROID 002 MISSION - multiple flight model straps used on satellite program to clean up orbital debris. Launch date - February 2025. 
 
Pictured: X-Series®  X5-502-LF PyroFlex™ straps with mylar sleeves in shipping fixtures: JHU APL and NASA (February 2024).
 
 
 

CRYOGENIC APPLICATIONS

Several of TAI's customers have tested our graphite sheet and fiber thermal straps for use in cryogenic applications, ranging from cryocoolers, to medical equipment, and quantum computers, and TAI will be releasing cryogenic performance data in late 2023 / early 2024.  Studies have shown that both graphite strap types can be used in place of thermal switches, as they can speed up cool-down times in cryostats and other cold laboratory equipment, but effectively stop transferring heat between 10K and 40K.

 

PYROFLEX™ - THE "ZERO-STIFFNESS THERMAL STRAP"

Thermal Straps - X6-501 for NASA

Perhaps one of the most unique and exciting benefits of our X-Series® PyroFlex™ products, is their inherent "low/zero stiffness" attribute (when assembled and encapsulated using TAI's proprietary process).  Not only does the pyrolytic graphite sheet material used in our products offer superior flexibility to graphene foils and all other strap materials (as a film material, it is far more flexible and durable than graphene foils), but stiffness tests performed on our X6 PyroFlex™ assemblies revealed stiffness measurements in the mN/mm range, and on all 3 axes when installed in curved or S-configurations (with many measurements  ≤3mN/mm).  As a result, our PGL™ products exceeded all expectations and came in well under the most restrictive stiffness requirements ever levied on a thermal strap in NASA's history (making PGL™ straps ideal for highly sensitive optical and photonics applications).
 
For more information and stiffness qualification data and graphs, contact us today.
 
Pictured (Right): X6-501 PyroFlex™ in shipping fixture (October 2018).
 

PyroFlex Graphite Thermal Straps with High Conductivity Carbon Fiber End Fittings - slider website again againHIGH CONDUCTIVITY CARBON FIBER (HCCF) FITTINGS

TAI now offers our exclusive High Conductivity Carbon Fiber (HCCF) End Fittings on PyroFlex™ and Graphene thermal straps. This carbon ply material is far stronger than graphite, and can be used in place of the more commonly used Al 6061 end fittings when material mismatch concerns exclude aluminum and other metals. HCCF Fittings, with an impressive 200 W/m-K at 300K material conductivity (on the X and Y axis; 129 W/m-K on the cross plane/Z-axis), offer superior thermal performance to all other carbon based fitting materials on the market today (or offered by any other strap supplier).  HCCF Fittings also come with a dust-free vapor-deposition coating applied to all outer surfaces to provide contamination control, and PyroFlex™ Straps using HCCF Fittings have now been qualified and used in multiple space flight programs. To learn more about HCCF Fittings and other customization options, contact TAI today.
 
Picture6

Pictured: 3 Flight Model PyroFlex™ Thermal Straps with HCCF Fittings in shipping fixture.

 PyroFlex Graphite Thermal Straps - HCG Fittings 2

Pictured: 2 Flight Model PyroFlex™ Thermal Straps with HCCF Fittings and posts for Sensors.

 

 

WHICH CARBON-BASED STRAP IS BEST FOR YOUR APPLICATION?

Thermal Straps-1TAI offers multiple carbon-based strap products because no single configuration or material is ideal under all operational and environmental conditions. Pictured (left to right): GraFlex I, GraFlex II, Graphene Foils, and Pyrolytic Graphite Film Straps from TAI.

 ADS PGL Strap Thermal Test
Though they have a lower thermal performance, our Graphite Fiber-based straps are typically more durable and lighter than graphite sheet straps, and they do not need to be designed into 180 degree arcs (C/U-shapes), or S-shapes in order to flex on the lateral axis/provide lateral deflection (which is helpful for applications such as battery pack cooling, antenna arrays, optical instruments, and some deployable/moving/rotating instruments and equipment).  Though spaceflight customers most commonly choose GraFlex™ I and II, GraFlex™ III is also ideal for applications with extremely limited volumes, but requiring flexibility on each axis.
 
Graphite/Graphene sheet straps are better-suited to applications with compact envelopes, requiring little to no flexibility/range of motion or repeated flex cycles (such as electronics boxes, chip cooling, etc.), or those with extremely low stiffness requirements.  Because of their higher performance at lower temperatures, PyroFlex™ products are now a superior replacement for aluminum foil thermal links at temperatures as low as 50K, and can be used in place of OFHC copper straps at temperatures as low as 70 - 80K (to reduce mass but offer similar thermal performance). 
 
Pictured (Right): Custom PyroFlex™ pre-thermal conductance test  (May 2018).
 
 
 

Graphene Thermal Links Thermal Cycling GraphLAYERED GRAPHENE FOIL (LGF) AND MICRO-CRACKING

While TAI has extensive experience designing and testing our layered graphene foil-based straps (and our PyroFlex™ & GTL™ products have been tested by NIST researchers), our team will only offer a graphene layered foil solution under extremely limited applications and operating environments, due to issues with commercially-available layered graphene foil thermal links.

As our customers and colleagues at NASA, NIST, the Indian Space Research Organization (ISRO), and the European Space Agency (ESA) have all noted and experienced firsthand (either with graphene foil thermal links/straps, or individual graphene foil sheets), one critical problem plagues all layered graphene foils and composite sheets: "micro-cracking" or stress fractures.  These tiny cracks are caused by flexing/bending the strap assemblies (or sheets), and even occur with the minimal movements associated with minute levels of thermal expansion and contraction.  These fractures can grow over time (in just a matter of a few cycles), and eventually lead to reduced performance, damaged foils, and compromised straps.

Additionally, tests performed by NIST researchers demonstrated that layered graphene foil-based thermal links experienced significant performance degradation after being thermally-cycled (just two additional cycles can result in conductance losses of >15% at 160K). As a result, TAI will not provide layered graphene foil thermal links to any application operating under 200K, and any application with a wide range of motion/deflection requirements. 

 

Graph: Graphene  layered foil-based Thermal Links demonstrated a 10-15% drop (depending on operating temperature), in thermal conductance after two thermal cycles (February 2020).