Manufacturing method of cover film for sealing high-temperature cooking aluminum ring

Abstract

The manufacturing method of the cover film for sealing the high-temperature cooking aluminum ring comprises the following steps: S1, printing on the PET film layer; s2, placing the printed PET roll film in a first unwinding unit for unwinding, coating glue on the printing surface of the PET film layer, drying, placing the AL roll in a second unwinding unit for unwinding, and compounding and winding with the printed PET film layer to obtain a first dry compound semi-finished product; s3, placing the first dry-laminated semi-finished product in a first unwinding unit for unwinding, coating glue on the AL layer surface of the first dry-laminated semi-finished product, drying, placing an NY roll in a second unwinding unit for unwinding, and compounding and winding with the first dry-laminated semi-finished product to obtain a second dry-laminated semi-finished product; and S4, placing the second dry-laminated semi-finished product in a first unreeling unit for unreeling, coating glue on the NY layer of the second dry-laminated semi-finished product, drying, placing the PP roll film in a second unreeling unit for unreeling, and compounding and reeling with the second dry-laminated semi-finished product to obtain the cover film with the PET-INK-AL-NY-PP structure. According to the manufacturing method, multi-color complex pattern printing can be achieved, and the production complexity is reduced; the prepared cover film is better in scratch resistance and toughness.

Description

Technical Field

[0001] The invention belongs to the field of production and manufacturing of composite films, and in particular relates to a method for manufacturing a cover film for sealing a high-temperature boiled aluminum ring. Background Art

[0002] POE (Peel Off End) is the abbreviation for the easy-open system for metal containers. POE metal easy-open systems typically consist of two parts: an aluminum ring and a composite film cover. The manufacturer of the metal easy-open system seals the aluminum ring and the composite film cover into a complete easy-open lid. The terminal canning plant then seals the metal container below with the easy-open lid during canning.

[0003] The composite cover film used in the above-mentioned POE metal easy-open system is traditionally produced through an extrusion lamination process, with a structure of "protective varnish-ink-AL-PP". This production method and cover film structure have problems such as a single printing pattern, poor anti-scratch effect, complex production, and poor cover film toughness. Summary of the Invention

[0004] In view of the shortcomings of the traditional production method, the present invention provides another different method for producing a cover film for sealing a high-temperature steamed aluminum ring, which comprises the following steps:

[0005] S1. Perform gravure printing on the PET film layer at a printing speed of 250-300 m / min;

[0006] S2. The printed PET film roll is placed in the first unwinding unit of the dry laminating equipment for unwinding. Glue is applied to the printed surface of the PET film layer and dried in an oven. The AL roll is then placed in the second unwinding unit of the dry laminating equipment for unwinding and rewound with the glued surface of the printed PET film layer to obtain the first dry laminating semi-finished product of "PET film layer-INK ink layer-AL layer";

[0007] S3. The first dry-laminated semi-finished product obtained in step S2 is then re-placed in the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the AL layer of the first dry-laminated semi-finished product and oven-dried. The corona-treated NY roll is then placed in the second unwinding unit of the dry-laminated equipment for unwinding. This roll is then rewound together with the glued surface of the first dry-laminated semi-finished product to produce a second dry-laminated semi-finished product with a structure of "PET film layer - INK ink layer - AL layer - NY layer".

[0008] S4. Repeatedly place the second dry-laminated semi-finished product on the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the NY layer of the second dry-laminated semi-finished product and oven-dried. The corona-treated PP film roll is then placed on the second unwinding unit of the dry-laminated equipment for unwinding. The roll is then rewound together with the glued surface of the second dry-laminated semi-finished product to produce a cover film having a structure of "PET film layer - INK ink layer - AL layer - NY layer - PP film layer."

[0009] S5. The cover film with the complete structure in step S4 is subjected to a curing treatment to obtain the final product.

[0010] Preferably, the ratio of the main agent of the glue: the curing agent: ethyl acetate is 8:1:8, the main agent is polyester resin, and the curing agent is polyisocyanate; the viscosity of the glue is controlled at 20-30S (2# Chan cup), and the amount of glue is controlled at 4-6g / m 2 .

[0011] Preferably, the oven includes three drying zones, the temperature of the first drying zone of the oven is controlled to be 80-90°C, the temperature of the second drying zone of the oven is controlled to be 90-95°C, and the temperature of the third drying zone of the oven is controlled to be 105-115°C.

[0012] Preferably, the unwinding tension of the first unwinding unit of the dry laminating equipment is controlled to be 7-8 kg, the unwinding tension of the second unwinding unit of the dry laminating equipment is controlled to be 17-19 kg, and the composite winding tension is controlled to be 47-49 kg.

[0013] Preferably, in step S5, the aging conditions are 45-55° C. and 4-6 days.

[0014] Preferably, the thickness of the PET film layer is 7-9 μm, the thickness of the INK ink layer is 1-3 μm, the thickness of the AL layer is 58-62 μm, the thickness of the NY layer is 13-17 μm, and the thickness of the PP film layer is 48-52 μm.

[0015] Through the above technical solution, the present invention has at least the following beneficial effects:

[0016] The present application describes a method for producing a cover film for sealing high-temperature retorted aluminum rings. The method combines various layers of material through a dry lamination process, resulting in a cover film having a "PET film layer - INK ink layer - AL layer - NY layer - PP film layer" structure. Compared to the traditional method of flexographic printing on the AL layer, this method prints on the PET film layer first, enabling the printing of multi-color, complex patterns. The PET outer layer of the cover film produced by this method has better scratch resistance than the surface varnish of traditional cover films. Compared to traditional extrusion lamination processes, this dry lamination process reduces production complexity and enables more flexible and convenient production. Furthermore, the present application's dry lamination process successfully introduces a NY layer into the cover film, thereby improving the overall toughness of the cover film and preventing the cover film tab from easily breaking when removed. DETAILED DESCRIPTION

[0017] The technical solution of the invention will be clearly and completely described below through embodiments, and the application of the present invention is not limited to the embodiments given.

[0018] Example 1

[0019] A method for manufacturing a cover film for sealing a high-temperature boiled aluminum ring, comprising the following steps:

[0020] S1. Gravure printing was performed on the PET film layer at a printing speed of 280 m / min;

[0021] S2. The printed PET film roll is placed in the first unwinding unit of the dry laminating equipment for unwinding. Glue is applied to the printed surface of the PET film layer and dried in an oven. The AL roll is then placed in the second unwinding unit of the dry laminating equipment for unwinding and rewound with the glued surface of the printed PET film layer to obtain the first dry laminating semi-finished product of "PET film layer-INK ink layer-AL layer";

[0022] S3. The first dry-laminated semi-finished product obtained in step S2 is then re-placed in the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the AL layer of the first dry-laminated semi-finished product and oven-dried. The corona-treated NY roll is then placed in the second unwinding unit of the dry-laminated equipment for unwinding. This roll is then rewound together with the glued surface of the first dry-laminated semi-finished product to produce a second dry-laminated semi-finished product with a structure of "PET film layer - INK ink layer - AL layer - NY layer".

[0023] S4. Repeatedly place the second dry-laminated semi-finished product on the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the NY layer of the second dry-laminated semi-finished product and oven-dried. The corona-treated PP film roll is then placed on the second unwinding unit of the dry-laminated equipment for unwinding. The roll is then rewound together with the glued surface of the second dry-laminated semi-finished product to produce a cover film having a structure of "PET film layer - INK ink layer - AL layer - NY layer - PP film layer."

[0024] S5. The cover film with the complete structure in step S4 is subjected to a curing treatment at 50°C for 5 days to obtain a final product. In the finished cover film, the thickness of the PET film layer is 8 μm, the thickness of the INK ink layer is 2 μm, the thickness of the AL layer is 60 μm, the thickness of the NY layer is 15 μm, and the thickness of the PP film layer is 50 μm.

[0025] The ratio of the main agent, curing agent and ethyl acetate used in the above-mentioned compounding steps is 8:1:8. The main agent is polyester resin and the curing agent is polyisocyanate. The viscosity of the glue is controlled at 25S (2# Chan cup) and the amount of glue applied is controlled at 5g / m 2 .

[0026] The oven used in the above-mentioned compounding steps includes three drying areas. The temperature of the first drying area of ​​the oven is controlled to be 90°C, the temperature of the second drying area of ​​the oven is controlled to be 95°C, and the temperature of the third drying area of ​​the oven is controlled to be 115°C.

[0027] The unwinding tension of the first unwinding unit of the dry laminating equipment used in the above-mentioned laminating steps is controlled to be 7.5 kg, the unwinding tension of the second unwinding unit of the dry laminating equipment is controlled to be 18 kg, and the composite winding tension is controlled to be 48 kg.

[0028] Example 2

[0029] A method for manufacturing a cover film for sealing a high-temperature boiled aluminum ring, comprising the following steps:

[0030] S1. Perform gravure printing on the PET film layer at a printing speed of 250 m / min;

[0031] S2. The printed PET film roll is placed in the first unwinding unit of the dry laminating equipment for unwinding. Glue is applied to the printed surface of the PET film layer and dried in an oven. The AL roll is then placed in the second unwinding unit of the dry laminating equipment for unwinding and rewound with the glued surface of the printed PET film layer to obtain the first dry laminating semi-finished product of "PET film layer-INK ink layer-AL layer";

[0032] S3. The first dry-laminated semi-finished product obtained in step S2 is then re-placed in the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the AL layer of the first dry-laminated semi-finished product and oven-dried. The corona-treated NY roll is then placed in the second unwinding unit of the dry-laminated equipment for unwinding. This roll is then rewound together with the glued surface of the first dry-laminated semi-finished product to produce a second dry-laminated semi-finished product with a structure of "PET film layer - INK ink layer - AL layer - NY layer".

[0033] S4. Repeatedly place the second dry-laminated semi-finished product on the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the NY layer of the second dry-laminated semi-finished product and oven-dried. The corona-treated PP film roll is then placed on the second unwinding unit of the dry-laminated equipment for unwinding. The roll is then rewound together with the glued surface of the second dry-laminated semi-finished product to produce a cover film having a structure of "PET film layer - INK ink layer - AL layer - NY layer - PP film layer."

[0034] S5. The complete cover film of step S4 is subjected to a curing treatment at 45° C. for 6 days to obtain a final product. In the finished cover film, the thickness of the PET film layer is 9 μm, the thickness of the INK ink layer is 3 μm, the thickness of the AL layer is 58 μm, the thickness of the NY layer is 17 μm, and the thickness of the PP film layer is 48 μm.

[0035] The ratio of the main agent, curing agent and ethyl acetate used in the above-mentioned compounding steps is 8:1:8. The main agent is polyester resin and the curing agent is polyisocyanate. The viscosity of the glue is controlled at 20S (2# Chan cup) and the amount of glue applied is controlled at 6g / m 2 .

[0036] The oven used in the above-mentioned compounding steps includes three drying areas. The temperature of the first drying area of ​​the oven is controlled to be 85°C, the temperature of the second drying area of ​​the oven is controlled to be 92°C, and the temperature of the third drying area of ​​the oven is controlled to be 110°C.

[0037] The unwinding tension of the first unwinding unit of the dry laminating equipment used in the above-mentioned laminating steps is controlled to be 7 kg, the unwinding tension of the second unwinding unit of the dry laminating equipment is controlled to be 17 kg, and the composite winding tension is controlled to be 49 kg.

[0038] Example 3

[0039] A method for manufacturing a cover film for sealing a high-temperature boiled aluminum ring, comprising the following steps:

[0040] S1. Perform gravure printing on the PET film layer at a printing speed of 300 m / min;

[0041] S2. The printed PET film roll is placed in the first unwinding unit of the dry laminating equipment for unwinding. Glue is applied to the printed surface of the PET film layer and dried in an oven. The AL roll is then placed in the second unwinding unit of the dry laminating equipment for unwinding and rewound with the glued surface of the printed PET film layer to obtain the first dry laminating semi-finished product of "PET film layer-INK ink layer-AL layer";

[0042] S3. The first dry-laminated semi-finished product obtained in step S2 is then re-placed in the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the AL layer of the first dry-laminated semi-finished product and oven-dried. The corona-treated NY roll is then placed in the second unwinding unit of the dry-laminated equipment for unwinding. This roll is then rewound together with the glued surface of the first dry-laminated semi-finished product to produce a second dry-laminated semi-finished product with a structure of "PET film layer - INK ink layer - AL layer - NY layer".

[0043] S4. Repeatedly place the second dry-laminated semi-finished product on the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the NY layer of the second dry-laminated semi-finished product and oven-dried. The corona-treated PP film roll is then placed on the second unwinding unit of the dry-laminated equipment for unwinding. The roll is then rewound together with the glued surface of the second dry-laminated semi-finished product to produce a cover film having a structure of "PET film layer - INK ink layer - AL layer - NY layer - PP film layer."

[0044] S5. The cover film with the complete structure in step S4 is subjected to a curing treatment at 55°C for 4 days to obtain a final product. In the finished cover film, the thickness of the PET film layer is 7 μm, the thickness of the INK ink layer is 1 μm, the thickness of the AL layer is 62 μm, the thickness of the NY layer is 13 μm, and the thickness of the PP film layer is 52 μm.

[0045] The ratio of the main agent, curing agent and ethyl acetate used in the above-mentioned compounding steps is 8:1:8. The main agent is polyester resin and the curing agent is polyisocyanate. The viscosity of the glue is controlled at 30S (2# Chan cup) and the amount of glue applied is controlled at 4g / m 2 .

[0046] The oven used in the above-mentioned compounding steps includes three drying areas. The temperature of the first drying area of ​​the oven is controlled to be 80°C, the temperature of the second drying area of ​​the oven is controlled to be 90°C, and the temperature of the third drying area of ​​the oven is controlled to be 105°C.

[0047] The unwinding tension of the first unwinding unit of the dry laminating equipment used in the above-mentioned laminating steps is controlled to be 8 kg, the unwinding tension of the second unwinding unit of the dry laminating equipment is controlled to be 19 kg, and the composite winding tension is controlled to be 47 kg.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Based on the present invention and the above description, relevant personnel can make various changes and modifications without departing from the technical idea of ​​the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for making a cover film for sealing a high-temperature boiled aluminum ring, characterized in that: The following steps are involved: S1. gravure printing on the PET film layer; S2. The printed PET film roll is placed in the first unwinding unit of the dry laminating equipment for unwinding. Glue is applied to the printed surface of the PET film layer and dried in an oven. The AL roll is then placed in the second unwinding unit of the dry laminating equipment for unwinding and rewound with the glued surface of the printed PET film layer to obtain the first dry laminating semi-finished product of "PET film layer - INK ink layer - AL layer"; S3. The first dry-laminated semi-finished product obtained in step S2 is then re-placed in the first unwinding unit of the dry-laminated equipment for unwinding. Glue is applied to the AL layer of the first dry-laminated semi-finished product and oven-dried. The corona-treated NY roll is then placed in the second unwinding unit of the dry-laminated equipment for unwinding. The roll is then rewound together with the glued surface of the first dry-laminated semi-finished product to produce a second dry-laminated semi-finished product with a structure of "PET film layer - INK ink layer - AL layer - NY layer". S4. The second dry-laminated semi-finished product is repeatedly unwound by the first unwinding unit of the dry-laminated equipment. Glue is applied to the NY layer of the second dry-laminated semi-finished product and dried in an oven. The corona-treated PP film roll is then unwound by the second unwinding unit of the dry-laminated equipment and rewound with the glued surface of the second dry-laminated semi-finished product to obtain a cover film having a "PET film layer - INK ink layer - AL layer - NY layer - PP film layer" structure. S5. The cover film with the complete structure in step S4 is subjected to a aging treatment.

2. The method for manufacturing a cover film for sealing a high-temperature boiling aluminum ring according to claim 1, characterized in that: The ratio of the main agent of the glue: curing agent: ethyl acetate is 8:1:8, the main agent is polyester resin, and the curing agent is polyisocyanate; the viscosity of the glue is controlled at 20-30S (2# Chan cup), and the amount of glue is controlled at 4-6g / m 2 .

3. The method for manufacturing a cover film for sealing a high-temperature boiling aluminum ring according to claim 2, characterized in that: The oven includes three drying areas. The temperature of the first drying area is controlled to be 80-90°C, the temperature of the second drying area is controlled to be 90-95°C, and the temperature of the third drying area is controlled to be 105-115°C.

4. The method for manufacturing a cover film for sealing a high-temperature boiling aluminum ring according to claim 3, characterized in that: The unwinding tension of the first unwinding unit of the dry laminating equipment is controlled to be 7-8 kg, the unwinding tension of the second unwinding unit of the dry laminating equipment is controlled to be 17-19 kg, and the composite winding tension is controlled to be 47-49 kg.

5. The method for manufacturing a cover film for sealing a high-temperature boiling aluminum ring according to claim 1, characterized in that: In step S5, the aging conditions are 45-55° C. and 4-6 days.

6. A method for manufacturing a cover film for sealing a high-temperature boiled aluminum ring according to any one of claims 1 to 5, characterized in that: The thickness of the PET film layer is 7-9 μm, the thickness of the INK ink layer is 1-3 μm, the thickness of the AL layer is 58-62 μm, the thickness of the NY layer is 13-17 μm, and the thickness of the PP film layer is 48-52 μm.