Details:
Summary:
A rational procedure for identifying the source of horizontal printing streaks is presented in the form of a troubleshooting flow diagram. As a prelude to explaining the logic underlying the diagram, various methods for categorizing streaks are identified and the three basic mechanisms by which streaks are generated are described. Although the construction of the flow diagram was simulated by the authors' firsthand experience in troubleshooting horizontal streaks on sheetfed presses, the final form given in the paper also encompasses like problems on web presses. The flow diagram itself is in the form of a decision tree wherein a question is posed at each node. Progress along the many possible diagram paths is governed by the investigator's answers to the node questions. Each path ends at a node which identifies the most likely location in the press where the particular streak originates. Much of the paper is devoted to explaining the rationale behind the multitude of questions which constitute the troubleshooting flow diagram. In addition to the specific directions provided by the troubleshooting guide, the paper also includes some general advice and suggestions on the subject as well as a discussion of various potential causes of streaks.