Abstract:
The present invention relates to a paper or paperboard comprising a polymeric coating, said polymeric coating comprising: a first coating layer attached to the paper or paperboard surface, said first coating layer comprising a blend of: a high density polyethylene (HDPE), medium density polyethylene (MDPE) or linear low density polyethylene (LLDPE), or a mixture thereof, and a low density polyethylene (LDPE); and a second coating layer attached to the first coating layer, said second coating layer consisting essentially of a low density polyethylene (LDPE); wherein the first and second coating layers have a combined grammage of less than 12 g/m2. The present invention relates to a method for manufacturing a polyethylene (PE) coated paper or paperboard substrate.
Abstract:
A biodegradable packaging material, a method of manufacturing the same, as well as products made of the material wherein a multilayer coating coextruded onto a fibrous substrate the multilayer coating comprising innermost and outermost layers of a blend comprising 20-95 wt-% of a higher melt index polylactide and 5-80 wt-% of another biodegradable polymer such as polybutylene succinate, and a middle layer containing a lower melt index polylactide alone. The goal is to increase machine speed in coextrusion while maintaining good adhesiveness to the substrate and good heat-sealability of the coating. The products include disposable drinking cups and board trays, as well as sealed carton packages for solids and liquids.
Abstract:
A method for improving the heat sealability of a packaging material and a method for manufacturing a heat-sealed container or package are described. The material can be polymer-coated packaging paper or cardboard, or a polymeric packaging film. The material includes a polymer layer that contains polyester, particularly polylactide, the heat sealability of which is improved by ultraviolet radiation. Polylactide is useful as such or when blended, for example, with other biodegradable polyester. The containers and packages thus manufactured include disposable drinking cups and cardboard carton and box packages.
Abstract:
A biodegradable packaging material, a method of manufacturing the same, as well as products made of the material wherein a multilayer coating coextruded onto a fibrous substrate the multilayer coating comprising innermost and outermost layers of a blend comprising 20-95 wt-% of a higher melt index polylactide and 5-80 wt-% of another biodegradable polymer such as polybutylene succinate, and a middle layer containing a lower melt index polylactide alone. The goal is to increase machine speed in coextrusion while maintaining good adhesiveness to the substrate and good heat-sealability of the coating. The products include disposable drinking cups and board trays, as well as sealed carton packages for solids and liquids.
Abstract:
The invention relates to methods for lowering the melt viscosity and thereby improving heat-sealability of a polyester. The invention also relates to a method for manufacturing a heat-sealed container or package from fibrous- based, polyester-coated packaging material, and a method for heat-sealing polyester. The solution according to the invention is subjecting polyester to electron beam (EB) radiation. The lowered melt viscosity allows a lower heat-sealing temperature, and permits sealing of polyester to an uncoated fibrous surface. The preferred polyester for the invention is polylactide, as such or as blended with another polyester.