PABST program

FM 73 Cytec Engineered Materials 60-90 min at 121°C Toughened epoxy film preferred system on the PABST program for primary bonding of aluminum... 

At the end of the PABST program, there were several questions unanswered about (1) the ease and cost of maintaining the adhesive-bonded structures, (2) the durability in actual service environments where temperature cycles and moisture attack could reduce the life of the bonded joints, and (3) the feasibility and cost of curing an immense primary-bonded structure in an autoclave. 

The studies on adhesives, surface preparation, test specimen preparation, and design of bonded joints reported for the PABST Program gave much more credibUity to the concept of a bonded aircraft and provided reliable methods of transferring loads between composites and metals or other composites. 

During the PABST program, the supplier of one candidate adhesive tried to create the impression that their product was superior to that of their competitors by submitting durability tests performed on aluminum adherends twice as thick as... 

For the PABST program, far more generous acceptance limits were established than are customary even today. Flaws up to 0.25 inch in diameter would be left unrepaired if they had occurred within 0.5 inches of an edge of the bonded members and voids up to 0.5 inch in diameter would be left alone in the interior. The manufacturing techniques were good enough that there were few flaws to assess but, actually, far larger flaws could have been tolerated structurally. 

Thrall, E. W. (1980) The primary adhesively bonded structure technology (PABST) program. Adhesion 4, AUen, K. W., Ed., Appl. Sci. Publ., London,... 

Today with the advance of structural and high temperature adhesives, aircraft, spacecraft, and missies (109) are built with secondary-bonded and some primary-bonded structures. The PABST (Primary Adhesive Bonding Structures Technology) program (110) was carried out at the Air Force Materials Laboratory between 1976 and 1981. That project led to the construction of a totally adhesive-bonded 42-foot-long circumferential fuselage section of a... 

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