Patent ID: 9651500
Date: 2017-05-16
CPC Classifications: B32B,G01N

Claim:
1. A system for detecting glue-joint failure, which is provided on a gypsum board production apparatus and which detects the glue-joint failure at a glue joint section of upper and lower sheets of paper for gypsum board liner with use of optical detection means, wherein the gypsum board production apparatus is arranged to glue edge portions of the sheets with gypsum slurry being fed between the sheets, thereby forming a continuous layered formation, which is formed with a cross-section of an edge portion of a gypsum board and which is conveyed by a forming belt, comprising: a light emission part which is located on one side of said continuous layered formation on said forming belt and which projects a laser light toward an edge portion of said formation, the laser light extending in a direction intersecting a conveyance direction of the forming belt and said formation being in a drying and setting process of the slurry; a light receiving part which is opposed to the light emission part and located on the opposite side of said formation and which receives the laser light of the light emission part; and a control device for determining occurrence of the glue-joint failure when a height of said laser light blocked by said formation exceeds a predetermined value or a predetermined rate, wherein said laser light is so positioned that the laser light at least partially passes through an area above an upper surface of said formation and is partially blocked by rising of the edge portion of the formation.