Fixing systems including contact pre-heater and methods for fixing marking material to substrates

A fixing system, comprising:

• a pre-heating device comprising:
• a first fixing member including a first surface;
• a second fixing member including a second surface forming a first nip with the first surface;
• and
• a first thermal energy source for heating at least one of the first surface and the second surface;
• wherein the first surface and the second surface contact and pre-heat a substrate and marking material comprising toner disposed on the substrate when the substrate is received at the first nip;
• and
• a fixing device disposed downstream from the pre-heating device comprising:
• a third fixing member including a third surface;
• a fourth fixing member including a fourth surface forming a second nip with the third surface at which the pre-heated substrate is received;
• and
• a second thermal energy source for heating at least one of the third surface and fourth surface,
• wherein:
• the third fixing member and forth fixing member apply pressure to the pre-heated substrate and marking material at the second nip to fix the toner to the substrate,
• the first fixing member comprises a first roll including the first surface,
• the second fixing member comprises a second roll including the second surface,
• the third fixing member comprises a third roll including the third surface,
• the fourth fixing member comprises a fourth roll including the fourth surface,
• the first thermal energy source heats at least one of the first surface and the second surface to a temperature from about 50° C. to about 100° C.,
• the second thermal energy source heats the third surface to a temperature of about 70° C. to about 120° C.,
• the first roll and second roll are operable to apply a pressure of about 300 psi to about 2000 psi to the substrate and marking material at the first nip, and
• the third roll and fourth roll are operable to apply a pressure of about 50 psi to about 500 psi to the pre-heated substrate and marking material at the second nip.

A method of fixing toner to a substrate, comprising:

• applying marking material comprising toner to a substrate with a marking device;
• feeding the substrate to a first nip of a pre-heating device, the first nip being formed by a first surface of a first fixing member and a second surface of a second fixing member;
• heating at least one of the first surface and the second surface;
• contacting and pre-heating the substrate and marking material at the first nip to produce the temperature condition:
• Tamb<Tint<Tm, where Tamb is the ambient temperature, Tint is the temperature at an interface between the marking material and the surface of the substrate, and Tm is the melting temperature of the toner, the pre-heated toner adheres to the substrate substantially without adhering to the first surface or the second surface;
• and
• feeding the pre-heated substrate and marking material to a second nip of a fixing device disposed downstream from the pre-heating device, the second nip being formed by a third surface of a third fixing member and a fourth surface of a fourth fixing member;
• and
• applying pressure to the pre-heated substrate and marking material at the second nip to fix the toner to the substrate,
• wherein the fixing device comprises a second thermal energy source for heating at least one of the third surface and fourth surface,
• the first fixing member comprises a first roll including the first surface, the second fixing member comprises a second roll including the second surface,
• the third fixing member comprises a third roll including the third surface,
• the fourth fixing member comprises a fourth roll including the fourth surface,
• the first thermal energy source heats at least one of the first surface and the second surface to a temperature from about 50° C. to about 100° C.,
• the second thermal energy source heats the third surface to a temperature of about 70° C. to about 120° C.,
• the first roll and second roll are operable to apply a pressure of about 300 psi to about 2000 psi to the substrate and marking material at the first nip, and
• the third roll and fourth roll are operable to apply a pressure of about 50 psi to about 500 psi to the pre-heated substrate and marking material at the second nip.

A method of fixing toner to a substrate, comprising:

• applying marking material comprising toner to a substrate with a marking device;
• feeding the substrate to a first nip of a pre-heating device, the first nip being formed by a first surface of a first fixing member and a second surface of a second fixing member;
• heating at least one of the first surface and the second surface;
• contacting and pre-heating the substrate and marking material at the first nip with the first surface and second surface;
• and
• feeding the pre-heated substrate and marking material to a second nip of a fixing device disposed downstream from the pre-heating device, the second nip being formed by a third surface of a third fixing member and a fourth surface of a fourth fixing member;
• heating at least one of the third surface and fourth surface;
• and
• applying thermal energy and pressure to the pre-heated substrate and marking material at the second nip to fix the toner to the substrate,
• wherein the fixing device comprises a second thermal energy source for heating at least one of the third surface and fourth surface,
• the first fixing member comprises a first roll including the first surface, the second fixing member comprises a second roll including the second surface,
• the third fixing member comprises a third roll including the third surface,
• the fourth fixing member comprises a fourth roll including the fourth surface
• the first thermal energy source heats at least one of the first surface and the second surface to a temperature from about 50° C. to about 100° C.,
• the second thermal energy source heats the third surface to a temperature of about 70° C. to about 120° C.,
• the first roll and second roll are operable to apply a pressure of about 300 psi to about 2000 psi to the substrate and marking material at the first nip, and
• the third roll and fourth roll are operable to apply a pressure of about 50 psi to about 500 psi to the pre-heated substrate and marking material at the second nip.