Process and apparatus for embossing precise microstructures and embossing tool for making same
AssigneeAvery Dennison Corporation
InventorsW. Scott Thielman, Robert M. Pricone
Life of this patent
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Abstract
A process and apparatus for embossing thermoplastic products having precise microstructured surfaces including using a continuous press having upper and lower belts with the embossing pattern(s); feeding thermoplastic material through the press where heat and pressure are applied to form the embossed pressure microstructure, and cooling the embossed material, all while maintaining pressure. A continuous embossing tool is provided by welding segments together, the welds including interface material at the weld joint which is of a different material than the segment material to increase the tensile strength.
Claims48
An apparatus for continuously forming thermoplastic products having precision microstructured surfaces thereon, comprising:
- a continuous double band press having upper and lower primary bands providing a substantially planar region therebetween, at least one of said bands being provided with a tool surface having the inverse topography of the precision microstructured surface to be formed, the inverse topography being sized to provide embossing depth of less than 1000 microns;
- means for continuously feeding a thermoplastic material through said press and between said bands;
- means for heating said material to its embossing temperature Te;
- means for applying sufficient pressure to said bands to cause the precise engagement of said heated thermoplastic material with said bands and said tool surface to emboss said material with said precise microstructured pattern;
- and
- means for cooling said material while maintaining pressure on said material, and while said material is moving through said press.
An apparatus for continuously forming thermoplastic products having precision microstructured surfaces thereon, comprising:
- a continuous double band press having upper and lower primary bands providing a substantially planar region therebetween, at least one of said bands being provided with a tool surface having the inverse topography of the precision microstructured surface to be formed;
- means for continuously feeding a thermoplastic material through said press and between said bands;
- means for heating said material to its embossing temperature Te;
- means for applying sufficient pressure to said bands to cause the precise engagement of said heated thermoplastic material with said bands and said tool surface to emboss said material with said precise microstructured pattern;
- and
- means for cooling said material while maintaining pressure on said material, and while said material is moving through said press;
- wherein said tool surface is provided on an overlay band and said overlay band is positioned on one of said upper or lower primary bands;
- and
- further including tracking/steering means for said overlay band to keep said, overlay band in alignment with said primary band.
An apparatus for continuously forming thermoplastic products having precision microstructured surfaces thereon, comprising a continuous double band press having upper and lower bands providing a substantially planar region therebetween, at least one of said bands being provided with a tool surface having the inverse topography of the precision microstructured surface to be formed, the inverse topography being sized to provide embossing depths of less than 1000 micron.
An apparatus for continuously forming thermoplastic products having precision microstructured surfaces, said apparatus comprising:
- a continuous double band press having an upper belt and a lower belt defining a substantially planar region therebetween through which the thermoplastic material travels;
- a reaction zone within the substantially planar region including an upstream heated section whereat the thermoplastic material is heated to its embossing temperature Te as pressure is applied and a downstream heated section whereat the thermoplastic material is cooled as pressure is applied;
- and
- an overlay with a tool surface having inverse topography of the precision microstructured surface to be formed, the inverse topography being sized to provide embossing depths of less than 1000 microns;
- wherein the overlay travels through the reaction zone with the thermoplastic material so that, in the upstream heated section, the tool surface precisely engages the thermoplastic material to emboss it with the precision microstructured surface.
An apparatus for continuously forming thermoplastic products having precision microstructured surfaces, said apparatus comprising:
- a continuous double band press having an endless upper belt and an endless lower belt defining a substantially planar region therebetween through which the thermoplastic material travels;
- a reaction zone within the substantially planar region including an upstream heated section whereat the thermoplastic material is heated to its embossing temperature Te as pressure is applied and a downstream heated section whereat the thermoplastic material is cooled as pressure is applied;
- an overlay with a tool surface having inverse topography of the precision microstructured surface to be formed, the overlay traveling through the reaction zone with the thermoplastic material so that, in the upstream heated section, the tool surface precisely engages the thermoplastic material to emboss it with the precision microstructured surface;
- and
- tracking/steering rollers for keeping the overlay in alignment with the upper belt and/or the lower belt.
Dependencies are inferred from the claim text.