Anti-fog easy-to-uncover film

Abstract

The invention discloses an anti-fog easy-to-uncover film which comprises a surface layer, a bonding layer and an inner layer, the inner layer takes a polyethylene glycol terephthalate film as a base material, and an anti-fog coating and a heat-seal coating are sequentially coated on a single surface of the base material; the surface layer is arranged on the single face of the side, away from the anti-fog coating, of the base material through the bonding layer. The surface layer is made of one or more of a polyethylene glycol terephthalate film, a polyamide film or a polypropylene film. The prepared cover film has the anti-fog characteristic, water drops condensed on the inner wall of the cover film can be effectively avoided, visible transparent packaging is provided for consumers, and meanwhile the packaging cost of products is saved.

Description

Technical Field

[0001] The invention relates to the technical field of cover films, and in particular to an anti-fog easy-to-remove cover film. Background Art

[0002] Existing fresh vegetables, fruits and other products usually contain a lot of water. If they are packaged with ordinary film materials, the water will condense inside the packaging film to form water droplets, making the contents unclear, greatly reducing the beauty of the product and reducing its attractiveness to consumers. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects in the prior art and provide an anti-fog easy-to-peel cover film, which can effectively solve the above problems in the prior art.

[0004] To achieve the above object, the technical solution of the present invention is to design an anti-fog easy-to-peel cover film, which includes a surface layer, an adhesive layer and an inner layer. The inner layer is based on polyethylene terephthalate film, and an anti-fog coating and a heat-sealing coating are sequentially coated on one side of the substrate; The surface layer is arranged on a single surface of the substrate away from the anti-fog coating through an adhesive layer; The surface layer is made of one or more of polyethylene terephthalate (PET) film, polyamide (NY) film or polypropylene (PP) film.

[0005] Furthermore, the adhesive layer adopts a two-component solvent-based adhesive or a solvent-free adhesive, and the thickness of the adhesive layer is 1-5 μm.

[0006] Furthermore, it also includes an ink layer, which is arranged on the side of the surface layer close to the inner layer.

[0007] Furthermore, it also includes an intermediate layer, which is a functional coating, and the functional coating is coated on the side of the substrate away from the anti-fog coating.

[0008] Furthermore, the functional coating is a barrier layer.

[0009] Furthermore, the thickness of the surface layer is 10-30 μm.

[0010] Furthermore, the thickness of the inner layer is 25-40 μm.

[0011] Furthermore, the thickness of the intermediate layer is 1-5 μm.

[0012] Furthermore, the thickness of the anti-fog coating is 1-5 μm; the thickness of the heat-sealing coating is 10-20 μm.

[0013] A method for preparing a high barrier anti-fog packaging film, wherein the packaging film material structure is PET / INK / PET, and the composite finished product is used as a cover film. The specific preparation process is as follows: Step 1, coating anti-fog and heat-sealing coatings: using PET as a substrate, coating an anti-fog coating and a heat-sealing coating on one side of the PET by a coating machine to obtain a semi-finished heat-sealable PET anti-fog film; the heat-sealing coating uses acrylic acid; the anti-fog coating uses sorbitol; Step 2, applying a barrier coating: coating the non-heat-sealed surface of the PET anti-fog film obtained in step 1 with a PVA coating to obtain a PVA-PET40 semi-finished product; Step 3, printing: preparation of PET / INK layer, placing the PET film on the unwinding rack of the unwinding unit of the printing machine, pouring the ink (INK) into the ink tanks of different ink units, mixing it according to the color requirements of the sample, and adjusting the printing tension, pressure and other process parameters at the same time, printing the PET film through the printing unit of the printing machine, passing through the drying unit online to dry the ink, and obtaining the printed PET / INK semi-finished product in the rewinding unit; Step 4, dry lamination: put the PET / INK printed semi-finished product on the first unwinding rack of the unwinding unit of the dry laminating machine and unwind it, and apply the solvent-based adhesive on the PET / INK printed semi-finished product through the gluing unit, and at the same time put the PVA-PET on the second unwinding rack and unwind it, and set the first unwinding tension, the second unwinding tension and the winding tension adapted to the material according to the material, and use the guide roller to send the first substrate and the second substrate coated with the solvent-based glue to the laminating device for lamination, so as to obtain the PET / INK / PVA-PET (including anti-fog) composite roll film; Step 5, aging: aging the PET / INK / PVA-PET (including anti-fog) composite roll film, the aging temperature is controlled at 25-30°C, and the aging time is controlled at 36-48 hours; Step 6, cutting: cut the cured PET / INK / PET (including anti-fog) composite roll film into small rolls of required width; Step 7: Pass the CPET400 sheet through a thermoforming machine, preheat it three times, and form it into a CPET400 tray. Fill the contents into the tray, put the PET / INK / PVA-PET40 (including anti-fog) composite roll film on the unwinding rack, set the first unwinding tension, the second unwinding tension and the winding tension that are suitable for the material, and heat-seal it with the formed and filled CPET tray to obtain the final packaging product.

[0014] Specifically, in step 3, the material width is 400 mm-1000 mm, the unwinding tension is controlled at 85-140 N, the oven temperature is 50-85 ° C, the winding tension is controlled at 55-95 N, and the printing speed is controlled at 100-350 m / min; Specifically, in step 4, the material width is 400mm-1000mm, the first release tension is set to 5-12 kgf, the second release tension is set to 2-7 kgf, the winding tension is set to 3-20 kgf, the winding taper is set to 60-85%, the oven tension is set to 2-16 kgf, the composite temperature is set to 35-65°C, the oven temperature is set to 55-90°C, and the glue amount is set to 2.8-3.5g / m 2 The pressure of the composite roller is 2.5~7 bar, the gluing pressure is 1.5~4 bar, and the composite speed is 90~200 m / min.

[0015] The advantages and beneficial effects of the present invention are that the cover film prepared by the present invention has anti-fogging properties, can effectively avoid water droplets condensed on the inner wall of the cover film, provide consumers with visible transparent packaging, and at the same time save product packaging costs and meet the development of a single material structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an anti-fog easy-to-peel cover film according to the present invention; In the figure: 1-surface layer, 2-adhesive layer, 3-inner layer, 4-anti-fog coating, 5-heat-seal coating, 6-ink layer, 7-middle layer. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0018] like Figure 1 As shown, an anti-fog easy-to-peel cover film comprises a surface layer 1, an adhesive layer 2 and an inner layer 3. The inner layer 3 is based on polyethylene terephthalate film, and an anti-fog coating 4 and a heat-seal coating 5 are sequentially coated on one side of the substrate; the heat-seal coating is made of acrylic acid; and the anti-fog coating is made of polyols. Preferably, the anti-fog coating is made of long-chain fatty acid lipids, and specifically sorbitol can be used;

[0019] The surface layer 1 is provided on a single surface of the substrate away from the anti-fog coating 4 through an adhesive layer; The surface layer 1 is made of one or more of polyethylene terephthalate (PET) film, polyamide (NY) film or polypropylene (PP) film.

[0020] As a preferred embodiment of the above technical solution, the adhesive layer 2 adopts a two-component solvent-based adhesive or a solvent-free adhesive, and the thickness of the adhesive layer 2 is 1-5 μm.

[0021] As a preferred embodiment of the above technical solution, it further includes an ink layer 6 , and the ink layer 6 is arranged on a side of the surface layer 1 close to the inner layer 3 .

[0022] As a preferred embodiment of the above technical solution, it further includes an intermediate layer 7 , wherein the intermediate layer 7 is a functional coating, and the functional coating is coated on a side of the substrate away from the anti-fog coating 4 .

[0023] As a preferred embodiment of the above technical solution, the functional coating is a barrier layer, and the barrier layer is a PVA coating.

[0024] As a preferred embodiment of the above technical solution, the thickness of the surface layer 1 is 10-30 μm.

[0025] As a preferred embodiment of the above technical solution, the thickness of the inner layer 3 is 25-40 μm.

[0026] As a preferred embodiment of the above technical solution, the thickness of the intermediate layer 7 is 1-5 μm.

[0027] As a preferred embodiment of the above technical solution, the thickness of the anti-fog coating 4 is 1-5 μm; the thickness of the heat-sealing coating 5 is 10-20 μm.

[0028] Embodiment 1: A preparation method and application of a high barrier anti-fog packaging film, wherein the packaging film material structure is PET12 / INK / PET40, and the composite finished product is used as a cover film. The value represents the film thickness in μm, such as PET12 represents a PET layer with a thickness of 12 μm. The specific preparation process is as follows: Step 1, coating anti-fog and heat-sealing coating: Preparation of PET40 anti-fog film, using PET40 as substrate, coating anti-fog coating and heat-sealing coating on one side of PET40 by a coating machine to obtain a heat-sealable PET40 anti-fog film semi-finished product; the heat-sealing coating adopts acrylic acid; the anti-fog coating adopts sorbitol; the thickness of the anti-fog coating 4 is 2 μm; the thickness of the heat-sealing coating 5 is 12 μm; Step 2, applying a barrier coating: coating the non-thermal surface of the PET40 anti-fog film obtained in step 1 with a PVA coating to obtain a PVA-PET40 semi-finished product; the thickness of the PVA coating is 2 μm; Step 3, printing: preparation of PET12 / INK layer, placing PET12 film on the unwinding rack of the unwinding unit of the printing press, pouring ink (INK) into the ink tanks of different ink units, mixing according to the color requirements of the sample, and adjusting the printing tension, pressure and other process parameters, printing the PET film through the printing unit of the printing press, passing through the oven unit online to dry the ink, and obtaining the printed PET12 / INK semi-finished product in the rewinding unit; Step 4, dry lamination: Place the PET12 / INK printed semi-finished product on the first unwinding rack of the unwinding unit of the dry laminating machine and unfold it, and apply the solvent-based adhesive on the PET12 / INK printed semi-finished product through the gluing unit, and at the same time place the PVA-PET40 on the second unwinding rack and unfold it, and set the first unwinding tension, the second unwinding tension and the winding tension adapted to the material according to the material, and use the guide roller to send the first substrate and the second substrate coated with the solvent-based glue to the laminating device for lamination, so as to obtain a PET12 / INK / PVA-PET40 (including anti-fog) composite roll film; the thickness of the adhesive layer (2) is 2 μm; Step 5, aging: aging the PET12 / INK / PVA-PET40 (including anti-fog) composite roll film, the aging temperature is controlled at 25-30°C, and the aging time is controlled at 36-48 hours; Step 6, slitting: slitting the cured composite roll film into small rolls of required width; Step 7: Pass the CPET400 sheet through a thermoforming machine, preheat it three times, and form it into a CPET400 tray. Fill the contents into the tray, put the PET12 / INK / PVA-PET40 (including anti-fog) composite roll film on the unwinding rack, set the first unwinding tension, the second unwinding tension and the winding tension that are suitable for the material according to the material, and heat-seal it with the formed and filled CPET tray to obtain the final packaging product.

[0029] Specifically, in step 3, the material width is 400 mm-1000 mm, the unwinding tension is controlled at 85-140 N, the oven temperature is 50-85 ° C, the winding tension is controlled at 55-95 N, and the printing speed is controlled at 100-350 m / min; Specifically, in step 4, the material width is 400mm-1000mm, the first release tension is set to 5-12 kgf, the second release tension is set to 2-7 kgf, the winding tension is set to 3-20 kgf, the winding taper is set to 60-85%, the oven tension is set to 2-16 kgf, the composite temperature is set to 35-65°C, the oven temperature is set to 55-90°C, and the glue amount is set to 2.8-3.5g / m 2 , the pressure of the composite roller is 2.5~7 bar, the gluing pressure is 1.5~4 bar, and the composite speed is 90~200 m / min; Embodiment 2: A preparation method and application of a high barrier anti-fog packaging film, wherein the packaging film material structure is BOPP18 / INK / PVA-PET35 (including anti-fog), the value represents the film layer thickness, the unit is μm, such as BOPP18 represents a BOPP layer with a thickness of 18 μm, and the specific preparation process is as follows: Step 1, printing: preparation of BOPP18 / INK layer, placing BOPP18 film on the unwinding rack of the unwinding unit of the printing press, pouring ink (INK) into the ink tanks of different ink units, mixing according to the color requirements of the sample, and adjusting the printing tension, pressure and other process parameters, printing the BOPP film through the printing unit of the printing press, passing through the drying unit online to dry the ink, and obtaining the printed BOPP18 / INK semi-finished product in the rewinding unit; Step 2, coating anti-fog and heat-sealing coatings: using PET35 as a substrate, coating an anti-fog coating and a heat-sealing coating on one side of PET35 by a coating machine, to obtain a heat-sealable PET35 anti-fog film semi-finished product; the heat-sealing coating adopts acrylic acid; the anti-fog coating adopts sorbitol; the thickness of the anti-fog coating 4 is 2 μm; the thickness of the heat-sealing coating 5 is 12 μm; Step 3, applying a barrier coating: coating the non-heat-sealable PET35 anti-fog film obtained in step 2 with a PVA coating to obtain a PVA-PET35 semi-finished product; the thickness of the PVA coating is 2 μm; Step 4, solvent-free lamination: placing the BOPP18 / INK printed semi-finished product as the second substrate on the first unwinding rack of the unwinding unit of the solvent-free laminating machine and unfolding it, coating the solvent-free adhesive on the BOPP18 / INK printed semi-finished product through the gluing unit, and placing the first substrate PVA-PET35 (including anti-fog) film on the second unwinding rack and unfolding it, setting the first unwinding tension, the second unwinding tension and the winding tension adapted to the material according to the material, and using the guide roller to send the first substrate and the second substrate coated with the solvent-free glue to the laminating device for lamination, so as to obtain a BOPP18 / INK / PVA-PET35 (including anti-fog) composite film; the thickness of the adhesive layer (2) is 2 μm; Step 5, aging: put the BOPP18 / INK / PVA-PET35 (including anti-fog) composite film into the aging chamber for aging, the aging temperature is controlled at 20-30℃, and the aging time is controlled at 36-48H; Step 6, slitting: slitting the cured BOPP18 / INK / PVA-PET35 (including anti-fog) composite film into small rolls of required width; Step 7, bag making: Place the cut BOPP18 / INK / PVA-PET35 (including anti-fog) composite film on the unwinding rack of the bag making machine and unfold it. After the guide roller, longitudinal sealing, transverse sealing and cooling, the required bag shape is obtained, such as: three-side sealing, self-supporting bag, special-shaped bag, square bottom bag, etc.

[0030] Specifically, in step 1, the material width is 400mm-1000mm, the unwinding tension is controlled at 90-140N, the oven temperature is 50-80°C, the winding tension is controlled at 75-100N, the winding taper is 30-50%, and the printing speed is controlled at 100-350m / min; Specifically, in step 4, the material width is 400mm-1000mm, the first release tension is set to 5-12 kgf, the second release tension is set to 2-7 kgf, the winding tension is set to 3-20 kgf, the winding taper is set to 60-85%, the oven tension is set to 2-16 kgf, the composite temperature is set to 35-65°C, the oven temperature is set to 55-90°C, and the glue amount is set to 2.8-3.5g / m 2 The pressure of the composite roller is 2.5~7 bar, the gluing pressure is 1.5~4 bar, and the composite speed is 90~200 m / min.

[0031] The anti-fog easy-peel film prepared by Examples 1 and 2 has an anti-fog performance that meets national standard level 1-2; according to product characteristics, the low easy-peel strength is 7-12N, and the high easy-peel strength is about 20N; the barrier performance OTR≤4.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An anti-fog easy-to-peel cover film, characterized in that: It comprises a surface layer (1), an adhesive layer (2) and an inner layer (3). The inner layer (3) is based on a polyethylene terephthalate film, and an anti-fog coating (4) and a heat-sealing coating (5) are sequentially coated on one side of the substrate; The surface layer (1) is provided on a single surface of the substrate facing away from the anti-fog coating (4) via an adhesive layer; The surface layer (1) is made of one or more of polyethylene terephthalate (PET) film, polyamide (NY) film or polypropylene (PP) film.

2. The anti-fog easy-to-peel cover film according to claim 1, characterized in that: The adhesive layer (2) is made of a two-component solvent-based adhesive or a solvent-free adhesive, and the thickness of the adhesive layer (2) is 1-5 μm.

3. The anti-fog easy-to-peel cover film according to claim 2, characterized in that: It also includes an ink layer (6), wherein the ink layer (6) is arranged on the side of the surface layer (1) close to the inner layer (3).

4. The anti-fog easy-to-peel cover film according to claim 3, characterized in that: It also includes an intermediate layer (7), wherein the intermediate layer (7) is a functional coating, and the functional coating is coated on the side of the substrate away from the anti-fog coating (4).

5. The anti-fog easy-to-peel cover film according to claim 4, characterized in that: The functional coating is a barrier layer.

6. The anti-fog easy-to-peel cover film according to claim 4, characterized in that: The thickness of the surface layer (1) is 10-30 μm.

7. The anti-fog easy-to-peel cover film according to claim 5, characterized in that: The thickness of the inner layer (3) is 25-40 μm.

8. The anti-fog easy-to-peel cover film according to claim 4, characterized in that: The thickness of the intermediate layer (7) is 1-5 μm.

9. The anti-fog easy-to-peel cover film according to claim 1, characterized in that: The thickness of the anti-fog coating (4) is 1-5 μm; the thickness of the heat-sealing coating (5) is 10-20 μm.

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