Patent ID: 6471799
Filing Date: 2002-10-29
Classification: B28B

Abstract:
A process for producing gypsum board by holding a gypsum slurry at upper and lower surfaces thereof with an overlay paper and an underlay paper, respectively, and then causing a resulting perform to travel between and lower forming units, which are composed in combination of plated and/or forming rolls as an upper forming unit and a lower forming unit, while pressing said preform with said upper forming unit, which comprises: forming an electric circuit at least one of between said upper forming unit and said lower forming unit, between a part of said overlay paper, said part being located in an advancing direction of said production of said gypsum boards as viewed from said upper forming unit, and said upper forming unit, and between a part of said underlay paper, said part being located in said advancing direction of said production of said gypsum boards as viewed from said lower forming unit, and said lower forming unit, applying a voltage across said electric circuit, widening a spacing between said upper forming unit and said lower forming unit when a current has flowed through said electric circuit during production of said gypsum boards, and subsequent to elimination of a cause for said flow of said current, narrowing said widened spacing back to said spacing before said widening.