Fenner Precision have a dedicated Global Engineering team with a vast range of experience and specialisms, one of which is Polyurethane Tyres and Rollers.
On an automatic document feeder (ADF), it is necessary to ensure only 1 piece of paper advances through the machine at a time. When there is a stack of papers present, while one page is advancing through the device the remaining pages need to stay in place. Fenner Precision currently supplies many of the industry leaders in printers/copiers with rollers and tyres to meet their specific needs.
There are two different options to use, a roller or tire. A roller is a component which has a hub or shaft which is then over molded with urethane. A tire is a urethane component that does not contain a hub or shaft. In order to ensure there is only 1 sheet of paper fed at a time the system should use a feed roller/tire which will drive the sheet you want to feed through the system and a retard roller/tire to ensure the remainder of the stack stays in place. In order to accomplish this you want the feed roller/tire to have a different hardness and coefficient of friction (COF) than the retard roller/tire while maintaining similar life with respect to the media you are using.
There are 3 COF relationships that exist in an ADF. There is the Feed roller/tire to the paper, paper to paper and retard roller/tire to paper. In order for the ADF to function properly the COF of the feed roller/tire against paper needs to be greater than the COF of paper to paper. The retard roller/tire COF then needs to be less than the feed roller/tyre to paper however greater than the paper to paper COF. This will ensure the feed roller can only move 1 sheet at a time.
The part hardness will define how much of the roller/tire will contact the media which has a direct impact on wear. Ideally the hardness of the feed and retard roller/tires should be matched in a manner that ensures the wear characteristics are similar.
Due to the many urethane options Fenner Precision offers, we can choose a material that will fit the customers’ ideal hardness and COF. This in addition to Fenner Precision’s understanding of Media Transport allows us to choose a material that will provide the critical performance characteristics such as COF and hardness resulting in optimum equipment operation with better life and reduced down time.