External heater member and methods for fusing toner images

A fusing apparatus for fusing toner images on a receiver medium, the receiver medium having a first side and a second side for receiving toner images thereon, the apparatus comprising:

• a fuser member having a contact surface comprised of a first elastomeric composition;
• a pressure member having a contact surface comprised of a second elastomeric composition and positioned adjacent the fuser member thereby forming a fusing nip there between to receive the receiver medium;
• a first heater member comprised of a first core, a conformable first base cushion layer comprised of a first elastomeric composition overlying said core, and a first outer polymeric layer disposed over said first base cushion layer, said first outer polymeric layer including a cured fluorocarbon thermoplastic random copolymer which is the reaction product of a mixture comprising a fluorocarbon thermoplastic random copolymer, a curing agent having a bisphenol residue, a particulate filler containing zinc oxide, and an aminosiloxane, the cured fluorocarbon thermoplastic random copolymer having subunits of:
• —(CH2CF2)x—, —(CF2CF(CF3))y—, and —(CF2CF2)z—;
• wherein
• x is from 1 to 50 or 60 to 80 mole percent;
• y is from 10 to 90 mole percent;
• z is from 10 to 90 mole percent;
• x+y+z equals 100 mole percent;
• said first outer polymeric layer having a first outer contact surface thereon, the first outer contact surface of the first heater member being positioned adjacent to and in contact with the fuser member and external thereto such that a first contact nip with a first nip width is formed therebetween, the first heater member being adapted to controllably exert pressure on the fuser member such that the first nip width can be adjusted during operation of the fusing apparatus and the amount of heat transferred to the fuser member through the first contact nip is controlled thereby;
• a first radiant heat assembly positioned externally of the first heater member to provide heat to the first outer contact surface of the first heater member;
• a second heater member comprised of a second core, a conformable second base cushion layer comprised of a second elastomeric composition overlying said second core, and a second outer polymeric layer disposed over said second base cushion layer;
• said second outer polymeric layer having a second outer contact surface thereon, the second outer contact surface of the second heater member being positioned adjacent to and in contact with the pressure member and external thereto such that a second contact nip with a second nip width is formed therebetween, the second heater member being adapted to controllably exert pressure on the pressure member such that the second nip width can be adjusted during operation of the fusing apparatus and the amount of heat transferred to the pressure member through the second contact nip is controlled thereby;
• and
• a second radiant heat assembly positioned externally of the second heater member to provide heat to the second outer contact surface of the second heater member, the fuser member heating the toner images on the first side of the receiver medium within the fusing nip and thereby fusing the toner images thereon to the receiver medium, and the pressure member heating the toner images on the second side of the receiver medium within the fusing nip and thereby fusing the toner images thereon to the receiver medium.