Thermal Mastic
In refrigeration systems such as refrigerators and freezers the foam insulation in contact with the evaporator tubing and condenser tubing is an integral part of the cooling system. refurbished rv refrigerators The mastic is one of the most important parts of the system and affords excellent heat transfer between the two components.
This invention relates to a low cost thermal mastic that does not degrade polyurethane foam insulation in refrigeration systems. It accomplishes this feat by employing low viscosity chlorinated paraffin as a vehicle in combination with fillers and a wetting agent. The present invention can be a pumpable mastic or paste, a squirt or squeeze type or even a spray type, in a formulation containing from about 25 to 40 weight percent of the aforementioned chlorinated paraffin along with a finely divided aluminum silicate clay and/or calcium carbonate filler.
The mastic may have a kinematic viscosity of about 2600 centistokes at room temperature (24 C.). A small amount of a wetting agent such as oleic acid can be included to facilitate the dispersion of the filler in the vehicle and to improve the wetting properties of the composition.
As a side note, the above mastic or paste also has good adhesive properties and can be used to seal a hole or crack in concrete or asphalt pavements that are too wide or deep for hot liquid rubber joint sealants. It can be applied with a finger tip or a “pop sickle” stick.
Using this mastic was a lot easier than the prior generations of mastics that did not have chlorinated paraffin as the vehicle in their formulation.
There was a time when using a mastic containing the aforementioned chlorinated paraffin was considered to be the obvious way to provide a low cost thermal mastic for use in refrigeration systems, and it was indeed the most efficient, or the best that a non-chemist can say for the subject. This mastic also had the smallest possible carbon footprint, as well as being the best heat transfer compound for its application in the refrigeration industry.
