Printer and copier rollers are used for handling paper media within printing and copy machines. They create an electrical charge or transfer thermal energy so that ink or toner is transferred to the paper and permanently fused. Typically, the paper travels through a fuser assembly that includes both a fuser roll and a pressure roll. Each roll is coated with silicone rubber, a polymeric substance that retains its flexibility resilience and tensile strength over a wide temperature range.
Used in varying degrees of hardness, silicones provide a large contact area or nip while allowing a specific period of contact between the toner and the fuser assembly. Printer and copier rollers are designed for use with printer toner and/or copier toner, both of which are made of carbon powder that is melt-mixed with a polymer.
There are several basic types of printer and copier rollers. In addition to fuser rollers and pressure rollers, product categories include thermally conductive rollers and electrically conductive rollers. With thermally conductive rollers, the fuser roller transfers thermal energy both to the toner and to the paper. For best results, the silicone elastomer must have high thermal conductivity. Electrically conductive printer and copier rollers are also available. With these printer and copier rollers electrically-charged toner particles are transported to and then fused with the paper.
Typically, electrically conductive silicone rubber is used in several areas of the printer or copying machine. Transfer rollers and cleaning rollers are also available. Printer and copier rollers are designed for use with specific types of computer printers, imagers and imaging units, and copying machines. Laser printers contain a hollow tube called the heat roller and a rubber-backed cylinder called the pressure roller. A radiant heat lamp in the center of the hollow roller uses infrared (IR) energy to heat the unit from the inside. The backing roller provides the necessary pressure and tension. In addition to laser printer rollers, inkjet printer rollers and thermal printer rollers are available. Printer and copier rollers include photocopy rollers and photographic imaging rollers, currency dispensing rollers, film and microfilm rollers, medical chart recorder rollers and medical imaging rollers, high-speed mail sorting rollers, and sticky rollers or cleaning rollers.