Paper Transport Simulation Technology

Multifunction devices use various types of paper such as coated paper, postcards and labels, as well as plain paper. The characteristics of paper also vary significantly depending on the paper storage environment. Therefore, our evaluation of paper transportability on an actual multifunction device requires many man-hours as the conditions of evaluation tend to be complex. And when developing a new paper transport system, we cannot test paper transportability for the new system until the test system is completed after the early stage of development. To work on these problems, Fuji Xerox has utilized paper transport simulation technology to efficiently test the paper transportability of multifunction devices from the early stage of development.

Here, we introduce an example of paper transport simulation for high-speed production printers. High-speed production printers have a long paper path and use a vacuum transport system (as shown in Fig. 1) to transport various types of paper in a fast and stable manner.

Fig. 1: Overview of the vacuum transport system

The vacuum transport system transports paper while holding paper firmly on the belt by attracting paper toward the belt with suction force. Therefore, unlike a normal system that transports paper by sending paper with rolls, the suction force that attracts paper toward the belt is an important parameter in simulating paper transport. For simulation, we first create a model that calculates suction force from the performance of the fan used for attracting paper toward the belt, as well as the shapes and sizes of openings for suction on the paper transport belt. Then we input the suction force calculated by using the model, the properties of paper, and transport parameters into the paper transport simulator to check the behavior of paper on the paper path.

Fig. 2: An example of paper transport simulation (two-dimensional analysis)

Figure 2 is a still image simulating the transport of paper to the fusing unit through the vacuum transport system. By simulating paper transport in chronological order, we check whether paper is transported while being firmly held on the paper transport belt, check for any paper jam between parts on the paper path, check whether paper properly enters the fusing unit, and make other checks. If we find any problem, we reconsider the suction force applied to paper, optimize the length of vacuum transport and the shape of the guide around the fusing unit, and make other necessary corrections.

Fig. 3: An example of paper transport simulation (three-dimensional analysis)

Figure 3 shows an example of the three-dimensional simulation of paper transport. As it is possible to check how paper is transported in the depth direction in three-dimensional simulation, we can evaluate the distribution of stress on the entire area of paper. In accordance with the purpose of analysis, we can select two-dimensional or three-dimensional analysis for efficient and accurate simulation.