Method for producing a substantially continuous, nonporous thermoplastic coating and articles constructed therefrom
View Patent ↗This invention relates to a non-contact coating method for producing a substantially continuous coating and articles constructed therefrom. This invention further relates to a non-contact slot coating method for producing a variety of coatings and laminations. This invention particularly relates to a method of coating a non-porous substrate including film, foil and paper with a molten thermoplastic composition which reduces streaking caused by particles such as impurities, fillers and superabsorbent polymers. This invention further relates to thermoplastic compositions useful in the present non-contact coating method.
1. A method of coating, wherein a thermoplastic material, which has been thermally made flowable, is provided in the form of a substantially continuous nonporous film without contact of the film with a substrate and said film is then coated onto a nonporous substrate, said coating having a complex viscosity of less than about 500 poise at about 1000 radians/sec at the coating temperature,
said method further comprising transferring said continuous film from said first substrate to a second substrate.
2. A method of coating, wherein a thermoplastic material, which has been thermally made flowable, is provided in the form of a substantially continuous nonporous film without contact of the film with a substrate and said film is then coated onto a nonporous substrate, said coating having a complex viscosity of less than about 500 poise at about 1000 radians/sec at the coating temperature, said method further comprising
nipping said coated substrate and
contacting the coating of said nipped substrate with a second substrate.
3. A method of coating, comprising
releasing a hot melt adhesive, which has been thermally made flowable, from a coating device onto a substantially nonporous substrate as a substantially continuous coating without contact between said coating device and said substrate,
subsequently disposing said substantially continuous coating upon the surface of said substrate at a coating weight of less than about 10 g/m 2 ;
nipping said coated substrate between a first roller and a second roller; and
contacting the coating of said nipped substrate with a second substrate.
4. The method of claim 3 , wherein said fist substrate comprises film and said second substrate comprises foil.
5. The method of claim 3 , wherein said first substrate comprises foil and said second substrate comprises film.
6. The method of claim 3 , wherein at least one of said first substrate and said second substrate comprises metallized film.
7. The method of claim 3 , wherein said first substrate comprises film and said second substrate comprises paper.
8. A method of coating a substrate, said method comprising
releasing a hot melt adhesive that has been thermally made flowable from a coating device in the form of a substantially continuous film without contact between said coating device and a substrate; and
contacting the surface of a substrate comprising a substantially nonporous moving web with said continuous film to form a coated substrate having a continuous coating having an area weight less than about 30 g/m 2 ,
said coated substrate being essentially free of entrapped air between the coating and the substrate.
9. The method of claim 8 , wherein said coating has an area weight of less than about 10 g/m 2 .
10. The method of claim 8 , further comprising nipping said continuous film and said substrate between a first roller and a second roller.
11. The method of claim 10 , wherein said contacting and said nipping occur substantially simultaneously.
12. The method of claim 8 , wherein said substrate comprises a polymeric film.
13. The method of claim 8 , wherein said substrate comprises foil.
14. The method of claim 8 , wherein said substrate comprises metallized polymeric film.
15. The method of claim 8 , wherein the substrate of said coated substrate is a fist substrate, said method further comprising contacting the coating of said coated substrate with a second substrate.
16. The method of claim 15 , wherein said second substrate comprises a polymeric film.
17. The method of claim 15 , wherein said second substrate comprises foil.
18. The method of claim 15 , wherein said second substrate comprises metallized polymeric film.
19. The method of claim 15 , wherein said second substrate comprises paper.
20. The method of claim 16 , wherein said first substrate comprises a polymeric film.
21. The method of claim 17 , wherein said first substrate comprises foil.
22. The method of claim 17 , wherein said fist substrate comprises polymeric film.
23. The method of claim 18 , wherein said first substrate comprises metallized polymeric film.
24. The method of claim 8 , wherein said hot melt adhesive has a complex viscosity of less than about 500 poise at 1000 radians/sec at the coating temperature.
25. The method of claim 24 , wherein said hot melt adhesive has a complex viscosity of less than about 1000 poise at 1 radians/sec at the coating temperature.
26. The method of claim 8 , wherein the adhesive composition is released from the coating device at a temperature less than about 177° C.
27. The method of claim 8 , wherein the adhesive composition is released from the coating device at a temperature less than about 160° C.
28. The method of claim 8 , wherein the adhesive composition is released from the coating device at a temperature less than about 125° C.
29. The method of claim 8 , wherein the adhesive composition is released from the device at a temperature less than about 110° C.
30. The method of claim 8 , wherein the distance between the coating device and the substrate is greater than 20 mm.
31. The method of claim 8 , wherein the coating device is a slot nozzle.