What are Thermal Straps?

1 Answer
Can you answer this question?
Oct 3, 2022

Thermal straps or thermal links are heat transfer devices that help dissipate the heat from the source of the application to a heat sink which helps to transfer the heat to a fluid medium like air or a liquid coolant. Thermal straps are made up of conductive materials such as copper cables, aluminum foil & graphite sheets.

Apart from transferring heat, thermal straps are also used to reduce erratic movements that are produced by vibration, shock, mechanical function, and thermal expansion or contraction which occur as a result of events such as a rocket launch.

Thermal straps are highly essential in providing conductive heat transfer, flexibility, and vibration attenuation and can be used to cool anything from batteries to cryocoolers as well as rocket & missile components.

Types of Thermal Straps

Copper Cabled Thermal Straps

Copper-cabled thermal straps are made with copper cablings and fittings. They are primarily used for cryogenic applications for space stations and other space applications.

They provide superior durability over other metallic & carbon-based strap types and are the most affordable type of thermal straps.

Graphite Fiber Thermal

Graphite Fiber Thermal straps are made from high conductivity graphite fibers that are woven together to increase their tensile strength and are connected by aluminum end fittings. They are highly durable and provide extreme vibration damping. However, they are significantly more expensive than the copper cabled thermal straps.

Pyrolytic Graphite Film (PGF)

Pyrolytic Graphite Film (PGF) is made from pyrolytic graphite sheets which are lightweight and highly flexible. PGF offers the highest thermal performance of any other strap product. Though they are more fragile compared to the other copper variants they offer a unique combination of flexibility, low mass, and thermal performance.

There are certain limitations in using the thermal straps in certain space applications and must be used judicially while considering the following points:

  • Limitations in weight: Thermal straps that are used must be lightweight and compact, as the mass of any object is detrimental in deciding the success of a space mission. 
  • Operational environments: Thermal straps to be used in space will be subjected to harsh environments. Hence, the type of strap that will be used must be decided to serve the application depending on the space mission.
  • Vibration transmission limits: Thermal straps have high vibration resistance & can be used to dampen the effect of vibration as well. But, during space launch, the vibrations that are subjected to the straps are too high and hence might cause the thermal strap to degrade and not perform well.