Process and apparatus for applying adhesive points to a web or sheet in a desired pattern

Abstract

Abstract A PROCESS IS PROVIDED FOR APPLYING A DESIRED PATTERN OF ADHESIVE AREAS OR POINTS TO A MOVING WEB BY ARRANGING A LAYER OF POWDERED THERMOSETTING PLASTIC ADHESIVE MATERIAL ON THE MOVING WEB AND THEREAFTER CONTACTING A PATTERN OF HEATED PROJECTIONS WITH THE ADHESIVE TO MELT OR SINTER THE SAME AT THE POINTS OF CONTACT. THE EXCESS AND UNHEATED POWDERED ADHESIVE IS REMOVED BY SUCTION. THE RESULT IS A PATTERN, SUCH AS A SCREEN-LIKE ARRANGEMENT, OF ADHESIVE POINTS ON THE WEB SO THAT IT MAY BE BONDED TO ANOTHER WEB OR SHEET BY COMPRESSION. THE PATTERN IS FORMED BY A ROTATING HEATED ROLLER HAVING PROJECTIONS ON ITS PERIPHERY, THE ENDS OF THE PROJECTIONS SUCCESSIVELY CONTACTING THE ADHESIVE LAYER ON THE MOVING WEB. THE ADHESIVE IN CONTACT WITH THE ENDS MELTS AND THE REMAINING UNHEATED POWDERED ADHESIVE IS REMOVED BY SUCTION NOZZLE MEANS TO THEREBY PROVIDE THE WEB WITH A SCREEN-LIKE PATTERN OF ADHESIVE POINTS. TO APPLY A SIMILAR PATTERN TO THE UNDERSIDE OF THE WEB, THE ADHESIVE LAYER IS FORMED ON AND ENDLESS CONVEYOR BELT BELOW THE WEB. THE ROTATING HEATED ROLLER WITH THE PROJECTIONS IS LOCATED BETWEEN THE CONVEYOR BELT AND THE BOTTOM OF THE MOVING WEB. AS THE ROLLER ROTATES, THE ENDS OF THE PROJECTIONS CONTACT AND MELT THE ADHESIVE MATERIAL AND THEREAFTER TRANSFER THE MOLTEN GLUBULES OF ADHESIVE TO THE BOTTOM OF THE WEB TO THEREBY FORM A SCREEN-LIKE PATTERN OF ADHESIVE POINTS ON THE BOTTOM OR UNDERSIDE OF THE WEB.

Inventors

• 👤 Wilhelm Uhrig

Bibliographic Details