Patent ID: 7141768

Claim:
A reversible, induction activatable fastening device for promoting the assembly and disassembly of associated pieces upon exposure to electromagnetic energy in the range of from 1.0 to 1000 kHz, said fastening device comprising a susceptor sheet having a thickness of no greater than about 2 mils and a thermoplastic adhesive whose softening temperature is at least 60° C. on at least one surface of said susceptor, (i) wherein the thermoplastic adhesive, as applied to said at least one surface, contacts from about 1% to about 65% of the surface area of said susceptor and has a pattern such that at least about 75% of the area of surface contact between the adhesive and said susceptor can have inscribed within it circles having a diameter of from about ½″ to about 0.001″ and (ii) wherein the thermoplastic adhesive on said at least one surface of the susceptor is applied in such a manner that a) when in touch contact with a substrate congruent in shape to the susceptor, a Test Surface, from about 1% to about 65% of the surface area of the Test Surface is in contact with the thermoplastic adhesive and at least about 75% of that contact area can have inscribed within it circles having a diameter of from about ½″ to about 0.001″ and b) when in bonded relationship with said Test Surface, from about 1% to about 65% of the surface area of the Test Surface is in contact with the adhesive: the bonded relationship having been established by mating the adhesive device and the Test Surface under a force of about 5 psi and heating the same to a temperature that is about 10° C. above the melt temperature of the thermoplastic adhesive for a sufficient time to allow the thermoplastic adhesive to melt and subsequently allowing the adhesive to cool.