Patent ID: 6544382
Filing Date: 2003-04-08
Classification: B29C,Y10T

Abstract:
A heat sealing apparatus comprising:a tube structure having a conductive hollow tube and a conductive strip, the tube being comprised of a first conductive material having a first electrical resistivity and a first coefficient of thermal expansion, the strip being comprised of a second conductive material having a second electrical resistivity less than the first resistivity and a second coefficient of thermal expansion, a difference between said second coefficient of thermal expansion and said first coefficient of thermal expansion being no greater than about 11.3% of said first coefficient of thermal expansion, the strip being connected along its entire length to only a portion of an outer surface of the tube and extending along a length of the tube; and a current source supplying a current to said tube structure, said strip heating to a sealing temperature in response to said current and a temperature of said hollow tube being only minimally increased in response to said current.