Patent ID: 6119369
Filing Date: 2000-09-19
Classification: B31F,F26B

Abstract:
A vacuum-assisted hot plate for preheating and drying a traveling web comprising:a stationary web supporting and heating surface having high thermal conductivity, the web supporting and heating surface comprising at least an upstream section and a downstream section wherein a web traveling longitudinally in a machine direction travels over the upstream section of the web supporting and heating surface before it travels over the downstream section of the web supporting and heating surface, a transverse cross-section of the upstream section of the web supporting and heating surface taken perpendicular to the machine direction being convex at least in part, and a transverse cross-section of the downstream section of the web supporting and heating surface taken perpendicular to the machine direction also being convex at least in part;the upstream section and the downstream section of the web supporting and heating surface being separated by an open vacuum channel, wherein the upstream section is arranged such that a middle portion of the upstream section is located outward towards the path of the web farther than a portion of the upstream section adjacent the open vacuum channel, and the downstream section is arranged such that a middle portion of the downstream section is located outward towards the path of the web farther than a portion of the downstream section adjacent the open vacuum channel;means for heating the web supporting and heating surface; anda vacuum chamber attached to the underside of the hot plate and communicating with the open vacuum channel located between the upstream section and the downstream section of the web supporting and heating surface;wherein the traveling web is drawn towards the open vacuum channel and against the web supporting and heating surface when a vacuum is applied to the vacuum chamber and the web is traveling over the web supporting and heating surface.