A paper laminating process

Abstract

The present invention discloses a laminating process for paper, including step 1, material preparation; step 2, material processing; step 3, gluing processing; step 4, laminating processing; step 5, drying processing; step 6, shaping processing; step 7, post-processing. The present invention controls the drying temperature to 40°C to 60°C, and the drying time to 30 to 40h for low-temperature drying, which can effectively remove the solvent in the adhesive, retain the solid content of the adhesive, and make the main agent and the curing agent fully react within a certain period of time to achieve the best bonding strength. The dryness of the adhesive layer is generally controlled at 90% to 95%. At this time, the bonding force is large, and the paper film is most firmly bonded, which solves the problem that too much residual solvent will produce air isolation in the film, making the film unable to be pasted, and improves the bonding degree of the polyethylene oxide adhesive to the paper and the film, ensuring that the material is flat and free of bubbles, and the paper and the laminating material are tightly attached.

Description

Technical Field

[0001] The invention relates to the technical field of paper lamination, in particular to a paper lamination process. Background Art

[0002] Lamination is a major process in post-printing processing. It is a process of gluing, heating, and pressurizing plastic film and paper printed materials together to form a paper-plastic integrated product. It is one of the most common post-printing processing technologies for paper printed materials. The surface of laminated paper printed materials is smoother and brighter due to the addition of a thin and transparent plastic film. Lamination can also increase the concentration and brightness of colors, improve color contrast, and be waterproof and will not get dirty. At the same time, the paper's tension value, smoothness, anti-aging, tear resistance, puncture resistance and other physical properties are generally improved, reducing the deformation and damage of paper products caused by the influence of moisture, improving the rigidity and molding stability of the paper, and greatly increasing the added value of printed materials.

[0003] The existing paper laminating process cannot control the concentration of adhesive. The solvent dilution adhesive concentration is too high, resulting in excessive moisture content and humidity, which will also affect the volatilization of the solvent in the adhesive. Too much residual solvent will produce air isolation in the film, making the film unable to stick. During pressurized lamination, air bubbles are prone to appear, followed by peeling and falling off problems. Summary of the invention

[0004] The purpose of the present invention is to provide a paper laminating process to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a paper laminating process, comprising step one, material preparation; step two, material processing; step three, gluing processing; step four, laminating processing; step five, drying processing; step six, shaping processing; step seven, post-processing;

[0006] In the above step 1, the material preparation includes paper rewinding, preparation of degradable coating film, and compounding of polyethylene oxide adhesive;

[0007] In the above step 2, the paper rewound in step 1 is subjected to surface treatment, the surface of the paper is subjected to dust removal treatment by a vacuum cleaner, the surface of the paper is subjected to static electricity removal by an electrostatic stripper, and the paper is preheated and humidified by a preheating humidifier, and the degradable film prepared in step 1 is cut into appropriate sizes according to the size of the paper by a slitting machine;

[0008] In the above step 3, the paper that has completed the surface treatment in step 2 is continuously output to the coating mechanism through the unwinding mechanism, the polyethylene oxide adhesive in step 1 is heated and activated by the coating mechanism, and the activated polyethylene oxide adhesive is evenly coated on the paper bonding surface by the coating mechanism;

[0009] In the above step 4, the film of suitable size in step 2 is installed on the unwinding device of the laminating machine, and then the paper coated with glue in step 3 is conveyed to the laminating machine so that the glued surface of the paper is in contact with the film, and hot pressing laminating is performed;

[0010] In the above step 5, the coated paper in step 4 is transported to a dryer, and the coated paper is dried and solidified by adjusting the drying temperature and drying time of the dryer;

[0011] In the above step 6, the coated paper dried in step 5 is transported to a setting machine, and the coated paper first passes through a double hot roller in the setting machine for hot pressing and setting, and then passes through a cooling roller to cool the set coated paper before winding it up;

[0012] In the above step 7, the coated paper in step 6 is first rewound and placed for 24 hours, and then cut and trimmed by a slitting machine at a slitting speed of 200-250 m / min.

[0013] Preferably, in the step 1, a degradable film is prepared: polylactic acid (PLA) is used as a base material, a butyl acrylate-methyl methacrylate modifier (GACR) grafted with glycidyl methacrylate (GMA) is synthesized by a core-shell emulsion polymerization method, polylactic acid (PLA) is modified with GACR having a core-shell ratio of 80 / 20, and a film is prepared by a melt blending method and an extrusion blown film process; a polyethylene oxide adhesive is compounded: polyethylene oxide is dissolved in a non-aqueous solvent miscible with water and dispersed to prepare an 18-25% (mass fraction) aqueous solution adhesive;

[0014] Preferably, in step three, the coating thickness of the polyethylene oxide adhesive is 5 μm, the temperature of the activated polyethylene oxide adhesive is controlled at 30° C. to 45° C., and the glue output of the coating mechanism is adjusted to 3.0 to 3.5 g / m 2 .

[0015] Preferably, in step four, the winding tension of the laminating machine is 10.0-10.5 kg*m / s2, the compounding speed is 120-125 m / min, the pressure between rollers is 19-23 mPa, the temperature of the internal heating rubber roller of the laminating machine is controlled at 55°C-60°C, and the temperature of the laminating machine is controlled at 45°C-50°C in zone one, 50°C-55°C in zone two, and 55°C-60°C in zone three.

[0016] Preferably, in step five, the drying temperature of the dryer is controlled at 40° C. to 60° C., and the drying time is controlled at 30 to 40 hours.

[0017] Preferably, in step six, the temperature of the double hot rollers is controlled at 60°C to 80°C, the machine speed is controlled at 6 to 10 m / min, and the temperature of the cooling roller is controlled at 0°C to 5°C.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention sets three temperature zones with increasing temperatures in a laminating machine. The laminating paper passes through the first zone at 45°C to 50°C, the second zone at 50°C to 55°C, and the third zone at 55°C to 60°C. The polyethylene oxide adhesive can be activated incrementally by using different temperature zones, so that the polyethylene oxide adhesive can be fully penetrated and diffused, thereby improving the adhesion of the polyethylene oxide adhesive to the paper and the film, and effectively avoiding the quality problems of delamination and blistering.

[0020] By controlling the drying temperature at 40℃~60℃ and the drying time at 30~40h for low-temperature drying, the solvent in the adhesive can be effectively removed, the solid content of the adhesive can be retained, and the main agent and the curing agent can fully react within a certain period of time to achieve the best bonding strength. The dryness of the adhesive layer is generally controlled at 90%~95%. At this time, the bonding force is strong and the paper film is most firmly bonded. The problem of too much residual solvent causing air isolation in the film and making the film unable to be pasted is solved, and the bonding degree of the polyethylene oxide adhesive to the paper and the film is improved, ensuring that the material is flat and free of bubbles, and the paper and the coating material are tightly fitted;

[0021] The elongation at break and tear strength of PLA film after adding GACR are greatly improved. The longitudinal and transverse tear strengths are 1.85 and 1.73 times of those of pure PLA, respectively, indicating that the modified film has tear resistance. The addition of GACR reduces the spherulite size and improves the adhesion of PLA film. The reduction of spherulite size can reduce scattering, thereby improving transparency and ensuring good adhesion and transparency with paper.

[0022] Moreover, polylactic acid (PLA) is an ideal green and environmentally friendly polymer material with the advantages of renewability, good transparency, high tensile strength, flexural strength and modulus. Polylactic acid (PLA) is polymerized from lactide monomers extracted from plant sugars and can be completely degraded into water and carbon dioxide under industrial composting, so that the coated paper can be recycled, degraded, and recycled for reuse, thereby maximizing the added value of the coated paper, solving the economic losses caused by the inability to recycle the coated paper, avoiding waste of resources, achieving environmentally friendly coating, and rationally developing the coating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A process flow chart of a paper laminating process of the present invention;

[0024] Figure 2 A process flow chart of a paper laminating process of the present invention;

[0025] Figure 3 A material preparation process guide diagram for a paper laminating process of the present invention;

[0026] Figure 4 The present invention is a paper surface treatment process guide diagram in a paper laminating process. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1-4 , an embodiment provided by the present invention:

[0029] To achieve the above object, the present invention provides the following technical solution: a paper laminating process, comprising step one, material preparation; step two, material processing; step three, gluing processing; step four, laminating processing; step five, drying processing; step six, shaping processing; step seven, post-processing;

[0030] In the above step 1, the material preparation includes paper rewinding, preparation of degradable coating film, and compounding of polyethylene oxide adhesive;

[0031] In the above step 2, the paper rewound in step 1 is subjected to surface treatment, the surface of the paper is subjected to dust removal treatment by a vacuum cleaner, the surface of the paper is subjected to static electricity removal by an electrostatic stripper, and then the paper is preheated and humidified by a preheating humidifier, and the degradable film prepared in step 1 is cut into appropriate sizes according to the size of the paper by a slitting machine, and the slitting machine speed is 200-250 m / min;

[0032] In the above step 3, the paper that has completed the surface treatment in step 2 is continuously output to the coating mechanism through the unwinding mechanism, and the polyethylene oxide adhesive in step 1 is heated and activated by the coating mechanism, and the activation temperature is controlled at 30°C to 45°C. The activated polyethylene oxide adhesive is evenly coated on the paper bonding surface by the coating mechanism to ensure that the glue forms a uniform coating on the paper bonding surface. The coating thickness is 5 μm, the coating mechanism temperature is controlled at 30°C to 45°C, and the glue output of the coating mechanism is adjusted to 3.0 to 3.5 g / m2;

[0033] In the above step 4, the film of suitable size in step 2 is installed on the unwinding device of the laminating machine, and then the paper coated with glue in step 3 is transported to the laminating machine, and the winding tension is 10.0-10.5 kg*m / s2, the speed is 120-125 m / min, the pressure between the rollers is 19-23 mPa, and the temperature of the internal hot rubber roller of the laminating machine is controlled at 55°C-60°C, and hot pressing laminating is performed, so that the glue-coated surface of the paper is attached to the film, and the laminated paper is obtained;

[0034] In the above step 5, the coated paper in step 4 is conveyed to a dryer, and low-temperature drying is performed by controlling the drying temperature at 40°C to 60°C and the drying time at 30 to 40 hours. Accurately controlling the drying temperature and time can effectively remove the solvent in the adhesive, retain the solid content of the adhesive, and allow the main agent and the curing agent to fully react within a certain period of time to achieve the best composite strength. The dryness of the adhesive layer is generally controlled at 90% to 95%, at which time the bonding force is large and the paper film is most firmly bonded;

[0035] In the above step 6, the coated paper dried in step 5 is conveyed to a setting machine, and the coated paper first passes through a double hot roller in the setting machine, the temperature of the double hot roller is 60°C to 80°C, and the machine speed is controlled at 6 to 10 m / min for hot pressing and setting processing. Hot pressing can ensure that the paper and the coating material are tightly combined to ensure no gaps, and also make the surface tension of both sides of the coated paper the same. Then, the shaped coated paper is cooled by a cooling roller, and the temperature of the cooling roller is controlled at 0°C to 5°C. The coated paper is cooled, and the cooling eliminates the internal stress formed by the heating shrinkage of the film, so as to achieve the purpose of cooling and setting, and then the shaped coated paper is rolled up;

[0036] In the above step 7, the coated paper in step 6 is first rewound and placed for 24 hours, and then the paper is cut and trimmed by a slitting machine at a slitting speed of 200-250 m / min. Rewinding can improve the bonding strength and prevent the single paper from curling.

[0037] Further, in step 1, a degradable film is prepared: polylactic acid (PLA) is used as the base material, glycidyl methacrylate (GMA) has a highly active acrylate double bond, which can be grafted onto the polymer, and the epoxy group carried by GMA can react with a variety of other functional groups to form a functionalized polymer, therefore, a core-shell emulsion polymerization method is used to synthesize butyl acrylate (BA)-methyl methacrylate modifier (GACR) grafted with glycidyl methacrylate (GMA), polylactic acid (PLA) is modified with GACR with a core-shell ratio of 80 / 20, and a degradable film is prepared by melt blending and extrusion film blowing process;

[0038] Furthermore, in step 1, a polyethylene oxide adhesive is compounded: polyethylene oxide is dissolved in a non-aqueous solvent miscible with water and dispersed to prepare an aqueous solution adhesive of 18 to 25% (mass fraction), and the concentration of the adhesive is precisely controlled to have good water solubility to improve the quality of the film;

[0039] Furthermore, in step 4, the laminating machine uses an internal hot glue roller to press the film, and the film is fed up and down, which increases the heating time of the film and the polyethylene oxide adhesive, and the heat is balanced, so that the coated film is flat and bright, and the laminating machine is set with three temperature zones with increasing temperatures. The coated paper passes through zone 1 at 45°C to 50°C, zone 2 at 50°C to 55°C, and zone 3 at 55°C to 60°C. The polyethylene oxide adhesive can be activated incrementally by using different temperature zones. Under the action of incremental activation, the thermal motion of the molecules in the polyethylene oxide adhesive is in the Brownian motion state of the chain segment, and the polyethylene oxide adhesive The adhesive molecules move to the surface of the film and the paper, and the molecules in the polyethylene oxide adhesive diffuse with the film molecules to form a strong bonding joint. The bonding strength increases with time, and the polyethylene oxide adhesive molecules penetrate into the gaps in the paper. The contact surface between the polyethylene oxide adhesive and the paper is increased through penetration, so that a good mechanical structural force is generated between the polyethylene oxide adhesive and the paper. The polyethylene oxide adhesive penetration is the process of pressing into the pores of the paper under the action of the external force of the hot rubber roller, so that the polyethylene oxide adhesive can be fully penetrated and diffused.

[0040] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

[0041] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified and replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A paper laminating process, comprising step 1, material preparation; step 2, material processing; step 3, gluing process; step 4, laminating process; step 5, drying process; step 6, shaping process; step 7, post-processing; characterized in that: In the above step 1, the material preparation includes paper rewinding, preparation of degradable coating film, and compounding of polyethylene oxide adhesive; In the above step 2, the paper rewound in step 1 is subjected to surface treatment, the surface of the paper is subjected to dust removal treatment by a vacuum cleaner, the surface of the paper is subjected to static electricity removal by an electrostatic stripper, and the paper is preheated and humidified by a preheating humidifier, and the degradable film prepared in step 1 is cut into appropriate sizes according to the size of the paper by a slitting machine; In the above step 3, the paper that has completed the surface treatment in step 2 is continuously output to the coating mechanism through the unwinding mechanism, the polyethylene oxide adhesive in step 1 is heated and activated by the coating mechanism, and the activated polyethylene oxide adhesive is evenly coated on the paper bonding surface by the coating mechanism; In the above step 4, the film of suitable size in step 2 is installed on the unwinding device of the laminating machine, and then the paper coated with glue in step 3 is conveyed to the laminating machine so that the glued surface of the paper is in contact with the film, and hot pressing laminating is performed; In the above step 5, the coated paper in step 4 is transported to a dryer, and the coated paper is dried and solidified by adjusting the drying temperature and drying time of the dryer; In the above step 6, the coated paper dried in step 5 is transported to a setting machine, and the coated paper first passes through a double hot roller in the setting machine for hot pressing and setting, and then passes through a cooling roller to cool the set coated paper before winding it up; In the above step 7, the coated paper rolled up in step 6 is first rewound and placed for 24 hours, and then cut and trimmed by a slitting machine at a slitting speed of 200 to 250 m / min; In the step 1, a degradable film is prepared: polylactic acid (PLA) is used as a base material, a butyl acrylate-methyl methacrylate modifier (GACR) grafted with glycidyl methacrylate (GMA) is synthesized by a core-shell emulsion polymerization method, polylactic acid (PLA) is modified with GACR with a core-shell ratio of 80 / 20, and a film is prepared by a melt blending method and an extrusion blown film process; a polyethylene oxide adhesive is compounded: polyethylene oxide is dissolved in a non-aqueous solvent miscible with water and dispersed to prepare an 18-25% (mass fraction) aqueous solution adhesive.

2. The paper laminating process according to claim 1, characterized in that: In step 3, the coating thickness of the polyethylene oxide adhesive is 5 μm, the temperature of the activated polyethylene oxide adhesive is controlled at 30°C to 45°C, and the glue output of the coating mechanism is adjusted to 3.0 to 3.5 g / m 2 .

3. The paper laminating process according to claim 1, characterized in that: In step 4, the winding tension of the laminating machine is 10.0-10.5 kg*m / s 2 The compounding speed is 120-125 m / min, the pressure between rollers is 19-23 mPa, the temperature of the internal heating rubber roller of the laminating machine is controlled at 55°C-60°C, and the temperature of the laminating machine is controlled at 45°C-50°C in zone one, 50°C-55°C in zone two, and 55°C-60°C in zone three.

4. The paper laminating process according to claim 1, characterized in that: In step five, the drying temperature of the dryer is controlled at 40° C. to 60° C., and the drying time is controlled at 30 to 40 hours.

5. The paper laminating process according to claim 1, characterized in that: In step six, the temperature of the double hot rollers is controlled at 60°C to 80°C, the machine speed is controlled at 6 to 10 m / min, and the temperature of the cooling roller is controlled at 0°C to 5°C.

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