Paper precoat system and methods thereof
A precoat application system is disclosed. The precoat application system includes a pressure member configured to apply contacting pressure to a hydrophobic compliant member. A precoat solution, disposed on at least a portion of a surface of the hydrophobic compliant member, is delivered to a surface of paper in contact with the hydrophobic compliant member when the paper is passed between the hydrophobic compliant member and the pressure member. A pressure member is configured to apply pressure to the surface of the paper and the precoat solution on the surface of the paper to obtain a uniform coating of the precoat solution on the surface of the paper. The precoat solution may include an aqueous salt solution, such as magnesium chloride, calcium nitrate, barium, or a combination thereof.
1 . A precoat application system, comprising:
a hydrophobic compliant member;
a pressure member configured to apply contacting pressure to the hydrophobic compliant member; and
an aqueous precoat solution, disposed on at least a portion of a surface of the hydrophobic compliant member; and wherein:
the surface of the hydrophobic compliant member has a static water contact angle of greater than 90°;
the precoat application system is configured to deliver a quantity of precoat solution to a first surface of a substrate in contact with the hydrophobic compliant member when the substrate is passed between the hydrophobic compliant member and the pressure member;
the pressure member is configured to apply pressure to the first surface of the substrate and the precoat solution on the first surface of the substrate to obtain a uniform coating of the precoat solution on the first surface of the substrate; and
the aqueous precoat solution has a static surface tension lower than a static surface tension of an ink to be printed onto the substrate.
2 . The precoat application system of claim 1 , wherein the aqueous precoat solution comprises a salt solution.
3 . The precoat application system of claim 1 , wherein the aqueous precoat solution comprises magnesium chloride, calcium nitrate, barium, or a combination thereof.
4 . The precoat application system of claim 1 , wherein the aqueous precoat solution comprises a magnesium chloride solution.
5 . The precoat application system of claim 1 , wherein the aqueous precoat solution comprises 5% wt to 40% wt of a salt in a solution.
6 . The precoat application system of claim 1 , wherein the hydrophobic compliant member comprises a roll.
7 . The precoat application system of claim 1 , wherein the pressure member comprises a roll.
8 . The precoat application system of claim 1 , wherein the precoat application system is combined for use with a digital printer, an offset press, or a combination thereof.
9 . The precoat application system of claim 1 , wherein the substrate comprises an uncoated paper.
10 . The precoat application system of claim 1 , wherein the substrate is in a form of one or more discrete sheets.
11 . The precoat application system of claim 1 , further comprising:
a precoat solution management subsystem comprising:
a precoat solution reservoir containing a quantity of aqueous precoat solution;
a precoat solution metering roll in contact with the precoat solution in the precoat solution reservoir;
a precoat solution metering blade in contact with the precoat solution metering roll; and
a precoat solution donor roll in contact with the precoat solution metering roll and the hydrophobic compliant member; and
wherein the precoat solution management subsystem is configured to dispose a measured quantity of the aqueous precoat solution on a portion of the hydrophobic compliant member prior to the portion of the hydrophobic compliant member contacting the first surface of the substrate.
12 . A precoat application system, comprising:
a hydrophobic compliant roll;
a pressure roll configured to apply pressure to the hydrophobic compliant roll when in contact with the hydrophobic compliant roll; and
an aqueous precoat solution comprising a salt solution, disposed on at least a portion of a surface of the hydrophobic compliant roll; and wherein:
the surface of the hydrophobic compliant roll has a static water contact angle of greater than 90°;
the precoat application system is configured to deliver a quantity of aqueous precoat solution to a first surface of a substrate in contact with the hydrophobic compliant roll when the substrate is passed between the hydrophobic compliant roll and the pressure roll; and
the pressure roll is configured to apply pressure to the first surface of the substrate and the aqueous precoat solution on the first surface of the substrate to obtain a uniform coating of the aqueous precoat solution on the first surface of the substrate; and
the aqueous precoat solution has a static surface tension lower than a static surface tension of an ink to be printed onto the substrate.
13 . A method for improving print quality in a printing system, comprising:
passing a substrate between a hydrophobic compliant member and a pressure member;
applying an aqueous precoat solution comprising a salt solution from the hydrophobic compliant member to a first surface of the substrate; and
applying pressure to the first surface of the substrate to obtain a uniform coating of the aqueous precoat solution on the first surface of the substrate; and
printing an image with an ink on the surface of the substrate wherein:
the surface of the hydrophobic compliant member has a static water contact angle of greater than 90°; and
the aqueous precoat solution has a static surface tension lower than a static surface tension of an ink to be printed onto the substrate.
14 . The method for improving print quality in a printing system of claim 13 , further comprising reacting the aqueous precoat solution with a component of the ink to inhibit the ink from permeating the first surface of the substrate.
15 . The method for improving print quality in a printing system of claim 13 , further comprising applying the aqueous precoat solution from the hydrophobic compliant member to a first surface of the substrate multiple times prior to printing an image with an ink comprising a pigment on the first surface of the substrate.
16 . The method for improving print quality in a printing system of claim 15 , wherein applying the aqueous precoat solution multiple times increases a quantity of salt from the precoat solution on the first surface of the substrate.
17 . The method for improving print quality in a printing system of claim 13 , wherein the aqueous precoat solution comprises magnesium chloride, calcium nitrate, barium, or a combination thereof.
18 . The method for improving print quality in a printing system of claim 13 , wherein the aqueous precoat solution comprises a magnesium chloride solution.
19 . The method for improving print quality in a printing system of claim 13 , wherein the aqueous precoat solution comprises 5% wt to 40% wt of a salt in a solution.
20 . The method for improving print quality in a printing system of claim 13 , wherein the ink comprises a pigment, a dye, or a combination thereof.