摘要 |
A method for monitoring the quality of a pattern of fluid beads applied to a moving substrate measures time delays between the passage of a reference point on a substrate element and leading and trailing edges of a bead, the quality of which is to be measured. A time delay ratio is generated, and compared to a reference ratio. The result of the comparison is indicative of variations in the quality of the measured bead. The invention has utility in a variety of industries, including industries in which adhesive beads are applied to a substrate, such as the envelope and box industries. An apparatus in accordance with the invention may conveniently utilize non-contact sensors to monitor the passage of the substrate and beads, and further may advantageously monitor the leading edge of the substrate and leading and trailing edges of the beads.
|