Embossing apparatus having magnetic roller and flexible embossing plates

Abstract

Apparatus for applying a continuous embossing pattern to webs of material such as paper or the like and a method for producing an embossing surface. The apparatus includes rollers which receive a web or webs of such material therebetween and removable embossing plates secured to the surface of the rollers and having an embossing surface for embossing the webs. The rollers are constructed such that they have magnetic properties whereby the embossing plates which are comprised of magnetically attracted material can be held against the roller surface. The plates are positioned in closely adjacent relationship with respect to each other such that they provide a continuous embossing pattern around the surface of the roller. The plates and the rollers also include mutually engaging registering means which permit the plates to be accurately aligned with respect to the roller surface. The plates can thus be readily removed or replaced in the event that they become worn or damaged or in the event that it is desirable to change the embossing pattern frequently. The embossing pattern can be formed in the surface of each of the embossing plates by means of a method of coating the plate surfaces with a photo-chemical resist material, laying a negative of the desired pattern over the photo-chemical coating, directing light through the negative to cause selective deterioration of the coating, and subjecting the plate to a caustic chemical, wash chemical, or etchant to etch the desired pattern into the surface of the plate. The plate may, if necessary, be further machined in order to increase the depth of the etching and to improve the definition and clarity of the embossing pattern.