A. Field of Invention
The present application relates to a novel coating system which can be used on specific areas of ascent and re-entry vehicles or in any other application in which ablative coatings may be advantageous.
B. Description of Prior Art
Heretofore in the art of forming ablative heat shield coatings, one method utilized expensive pressure molds or dies into which batches of materials were placed and vacuum cured at 300.degree. F. The resultant molded coating was then machined and applied by secondary bonding under a pressure of 1-3 psi to the specific surface for which the mold was intended. This process involves clear and numerous disadvantages, such as the use of expensive molds and dies, high labor costs and the necessity of mixing large batches of materials.
Additionally, U.S. Pat. No. 3,553,002 - Haraway, Jr., et al., teaches a sprayable ablative system which has the distinct disadvantage of producing a coating with a relatively high density of over 35 lbs/ft.sup.3.
The prior art method described in U.S. Pat. No. 3,210,233, Kummer et al., involves a non-metallic honeycomb having a heat insulating and ablative composition in the cells. This arrangement has the disadvantages of difficulty in applying the ablative and in the expense of the honeycomb.
It is an object of this invention, therefore, to provide a method for producing sprayable ablative compositions capable of depositing ablative coatings having lower density than the prior art products and at the same time having increased thermal improved properties of insulation and adherence.
In addition, it is an object of this invention to produce a method of applying such ablative coatings simply, inexpensively and in a manner that allows close control of the coating thickness.