Process for in-line extrusion coatings onto roofing shingles during manufacturing and roofing shingles made by the process
A process for in-line extrusion of polymeric coatings onto roofing shingles during manufacturing includes moving a web of shingle substrate material in a downstream direction and extruding a liquefied coating of polymeric material onto at least one surface of the moving web to form a thin film. The liquefied coating may be a molten polymeric material that forms a thin film on a back surface of the shingle material to prevent sticking and eliminate the need for a traditional back dusting with material such as powdered stone. The polymeric film further may be applied to the substrate material in lieu of a saturation coating of asphalt, thus reducing cost and weight while providing a comparable moisture barrier and a lighter more flexible shingle.
1. An apparatus comprising:
a processing line configured to allow a mat of substrate material having a first surface and a second surface to be conveyed in a downstream direction;
a die positioned along the processing line and configured to eject a stream of molten polymeric material onto the first surface of the mat of substrate material as the mat is conveyed in the downstream direction to deposit a film of polymeric material on the first surface of the mat of substrate material;
a supply apparatus for supplying the molten polymeric material to the die;
a cooling apparatus configured to cool the film of polymeric material;
a coater positioned downstream from the cooling apparatus and configured to apply a coating of bituminous material in molten form to the second surface of the mat of substrate material;
wherein the coating of bituminous material is applied after cooling the film of polymeric material;
a granule applicator configured to apply granules to the coating of bituminous material;
a cutting station configured to cut the finished mat into individual shingles; and
a packaging station configured to bundle the individual shingles and package the bundles.
2. The apparatus of claim 1 wherein the die comprises a slot die.
3. The apparatus of claim 1 wherein the supply apparatus comprises a source of molten polymeric material and a pump configured to deliver the polymeric material from the source to the die.
4. The apparatus of claim 1 wherein the supply apparatus comprises an extruder.
5. The apparatus of claim 1 wherein the cooling apparatus comprises a chilled air blower.
6. The apparatus of claim 1 wherein the cooling apparatus comprises chilled rollers.
7. An apparatus comprising:
a processing line configured to convey a mat of substrate material having a first surface and a second surface along a processing path;
a die positioned along the processing line and configured to eject a stream of molten polymeric material onto the first surface of the mat of substrate material as the mat is conveyed in the downstream direction to deposit a film of polymeric material on the first surface of the mat of substrate material;
a supply apparatus for supplying molten polymeric material to the die;
a cooling apparatus configured to cool the film of polymeric material;
a coater positioned downstream from the cooling apparatus and configured to apply a coating of bituminous material in molten form to the second surface of the mat of substrate material; and
wherein the coating of bituminous material is applied after cooling the film of polymeric material:
a granule applicator configured to apply granules to the coating of bituminous material.
8. The apparatus of claim 7 wherein the cooling apparatus comprises chilled rollers.
9. The apparatus of claim 7 wherein the cooling apparatus comprises a chilled air blower.
10. The apparatus of claim 7 wherein the supply apparatus comprises a source of molten polymeric material and a pump configured to deliver the polymeric material from the source of molten polymeric material to the die.
11. The apparatus of claim 7 wherein the supply apparatus comprises an extruder.
12. The apparatus of claim 7 wherein the die comprises a slot die.