Co-extruded plastic film with a foam core and a method for coating the film on a substrate

A composite sheet comprising:

• a paper sheet;
• a plastic adhering layer containing at least 10% by weight of a first non-plastic particulate, the adhering layer being coated onto the paper sheet at a high melt temperature;
• a plastic top layer containing at least 10% by weight of a second non-plastic particulate;
• and
• a plastic foam core layer extruded with and disposed between the adhering and top layers to form a unitary plastic film having dead fold and adhered to the paper sheet.

A process for manufacturing a plastic sheet having dead fold, the process comprising:

• preparing a first plastic extrudate comprising a polyolefin and at least 10% by weight of a first non-plastic particulate;
• preparing a second plastic extrudate comprising a polyolefin and at least 10% by weight of a second non-plastic particulate;
• preparing a third plastic extrudate comprising a polyolefin and a chemical blowing agent;
• co-extruding the first, second, and third plastic extrudates together so that the first plastic extrudate forms a plastic top layer, the second plastic extrudate forms a plastic bottom layer, and the third plastic extrudate forms a plastic foam core layer disposed between the top and bottom layers to form a unitary plastic sheet.

A process for manufacturing a composite sheet having dead fold, the process comprising:

• preparing a first plastic mixture comprising polyethylene and at least 10% by weight of a first non-plastic particulate;
• preparing a second plastic mixture comprising a polyolefin and at least 10% by weight of a second non-plastic particulate;
• preparing a third plastic mixture comprising a polyolefin and a chemical blowing agent;
• corona treating a paper sheet;
• coating the paper sheet with an adhering layer using the first plastic mixture at a coating melt temperature of over 570° F. as to form a coated paper sheet;
• corona treating the coated paper sheet;
• co-extruding the second plastic mixture and the third plastic mixture together, along with the coated paper sheet, so that the first plastic mixture forms the adhering layer, the second plastic mixture forms a plastic top layer, and the third plastic mixture forms a plastic foam core layer extruded with and disposed between the top and adhering layers to form a unitary plastic film adhered to the paper sheet.