Method and apparatus for applying barrier coating substances to sheet materials

Abstract

Abstract A BARRIER COATING OF THE HIGH VISCOSITY "HOT MELT" CLASS IS APPLIED WITH HIGH UNIFORMITY TO A MOVING WEB BY MEANS OF A COATING APPARATUS WHICH IS CAPABLE OF OPERATING AT SPEEDS AS HIGH AS 1,500 FEET PER MINUTE UTILIZING "HOT MELT" COMPOUNDS OF VISCOSITIES RANGING AS HIGH AS 100,000 CPS. THE COATING FLUID IN A HEATED CONDITION IS APPLIED FROM A COATING HEAD CONSISTING OF A TUBULAR BODY FORMED WITH AN ELONGATED APERTURE OVER WHICH THE WEB IS PASSED. THE COATING FLUID IS UNDER RELATIVELY HIGH PRESSURES OF VARYING INTENSITY. PRESSURE DROPS TOWARDS THE CENTER OF THE COATING TUBE, INDUCED BY FRICTION OF HIGH VISCOSITY MATERIALS AND INCREASINGLY HIGH FLOW RATES, IS CONTROLLED BY REGULATING WEB PRESSURE. MULTIPLE TENSIONING MEANS ARE ARRANGED AT TWO OPPOSITE SIDES OF THE COATING TUBE. ONE TENSIONING DEVICE ENGAGES THE WEB AS IT APPROACHES THE COATING HEAD AND ACTS INITIALLY TO EXERT CROSS TENSION AND STRETCH THE WEB SUFFICIENTLY TO OVER- COME VARIATIONS IN CAPIPER AND WEB LENGTH. A SECOND TENSIONING DEVICE EXERTS LINEAR TENSION TO FORCE THE TRANSVERSELY STRETCHED WEB UNIFORMLY AGAINST THE COATING TUBE WITH SUFFICIENT WEB PRESSURE TO EQUALIZE AND BALANCE PUMPING PRESSURE OF FLUID ALL ALONG THE COATING APERTURE. REQUIRED WEB PRESSURES OF A MAGNITUDE NECESSITATING LINEAR TENSION IN EXCESS OF THE TENSILE STRENGTH OF ANY GIVEN WEB IS PROVIDED BY MEANS OF A WEB PRESS ROLL SUPPORTED IN ROLLING CONTACT WITH THE WEB IMMEDIATELY ABOVE THE ELONGATED TUBE APERTURE. A VARIABLE SPEED POWER DRIVEN WINDING ROLL MEANS FOR THE WEB IS INTERLOCKED WITH A VARIABLE SPEED PUMP MECHANISM FOR SYNCHRONIZING WEB SPEED AND PUMPING RATE. A DUAL READING INDICATOR CONSTANTLY INDICATES RESPECTIVE WEB SPEEDS AND PUMPING RATES TO THE MACNINE OPERATOR.

Inventors

• 👤 George C Park

Bibliographic Details