Method of making compressible printing roller

Claim 1

A method of making a printing roller comprising the steps of, providing a central support made of a comparatively rigid material, forming a tubular inner layer of a salt-leached microporous rubber material that has voids therein comprising between 30 and 70% of the total volume of said inner layer and defined by cavities interconnected by passages, disposing said tubular inner layer of microporous rubber material around said central support so that said inner layer is under radial expansion and is secured to said central support solely by the resulting friction fit therewith, and placing a polymeric tubular outer layer around said inner layer in such a manner that said inner layer is under compression by said outer layer whereby said outer layer is secured to said inner layer solely by the resulting friction fit therewith, said layers cooperating to define said printing roller and assure said roller provides optimum contact between said roll and material being coated thereby at comparatively small nip pressures, said disposing step comprising the step of forcing said central support within said tubular inner layer upon relatively moving said central support and tubular inner layer towards each other and thereby causing said radial expansion of said tubular inner layer around said central support and the frictionally holding of said inner layer thereagainst, said placing step comprising the step of partially compressing said inner layer radially inwardly and relatively moving said outer layer around said inner layer during said partial compression such that upon release thereof said inner layer expands radially against said outer layer so that said outer layer is held firmly in position against said inner layer solely by the resulting frictional engagement between said inner layer and said outer layer, said partially compressing step being achieved solely by relatively axially moving said outer layer over said inner layer.

Claim 2

A method of making a printing roller comprising the steps of, providing a central support made of a comparatively rigid material, forming a tubular inner layer of a salt-leached microporous rubber material that has voids therein comprising between 30 and 70% of the total volume of said inner layer and defined by cavities interconnected by passages, disposing said tubular inner layer of microporous rubber material around said central support so that said inner layer is under radial expansion and is secured to said central support solely by the resulting friction fit therewith, and placing a polymeric tubular outer layer around said inner layer in such a manner that said inner layer is under compression by said outer layer whereby said outer layer is secured to said inner layer solely by the resulting friction fit therewith, said layers cooperating to define said printing roller and assure said roller provides optimum contact between said roll and material being coated thereby at comparatively small nip pressures, said disposing step comprising the step of forcing said central support within said tubular inner layer upon relatively moving said central support and tubular inner layer towards each other and thereby causing said radial expansion of said tubular inner layer around said central support and the frictionally holding of said inner layer thereagainst, said placing step comprising the step of partially compressing said inner layer radially inwardly and relatively moving said outer layer around said inner layer during said partial compression such that upon release thereof said inner layer expands radially against said outer layer so that said outer layer is held firmly in position against said inner layer solely by the resulting frictional engagement between said inner layer and said outer layer, said partially compressing step being achieved solely by relatively axially moving said outer layer over said inner layer.