Preparation process of high-barrier steaming-resistant anti-UV (ultraviolet) film

Abstract

The invention belongs to the technical field of preparation of high-barrier films, and particularly relates to a preparation process of a high-barrier steaming-resistant anti-UV (ultraviolet) film, which comprises the following steps: step 1, preparing resin raw materials including the following raw materials: PA, TIE, PP, TIE, PA, EVOH, PA, TIE and a propenyl ultraviolet light absorber, drying the raw materials by using drying equipment, setting proper temperature and time, and preparing the resin raw materials for later use; 2, setting the process temperature of the raw materials, namely setting the process temperature of PP (Polypropylene) to be 180-230 DEG C, setting the process temperature of TIE (Tungsten Inert Extraction) to be 200-220 DEG C, setting the process temperature of EVOH (Ethylene Vinyl Alcohol) to be 180-220 DEG C and setting the process temperature of PA (Polyamide) to be 220-260 DEG C. The high-barrier steaming-resistant anti-UV film can be produced, prepared and formed, the prepared high-barrier steaming-resistant anti-UV film can be kept stable in the high-temperature steaming process, invasion of ultraviolet rays and water is blocked, and therefore the shelf life and the service life of products in a package are prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of high-barrier film preparation, and in particular to a process for preparing a high-barrier, cooking-resistant and UV-resistant film. Background Art

[0002] High barrier film is a multi-layer film made by simultaneously extruding a material with strong gas barrier properties and a polyolefin with strong heat-sealing and moisture barrier properties. In the packaging field, EVOH is made into a composite film as an intermediate barrier layer and is used in all hard and soft packaging. In the food industry, it is used for aseptic packaging, hot cans and retort bags, and for packaging dairy products, meat, canned juice and condiments. In the non-food field, it is used for packaging solvents, chemicals, air-conditioning structural parts, gasoline barrel liners, electronic components, etc.

[0003] Existing packaging materials are prone to degradation, aging and performance degradation under the influence of high-temperature cooking, ultraviolet radiation, gas, moisture and other environmental factors. Especially in the field of food and drug packaging, traditional materials are difficult to simultaneously meet the requirements of high barrier, high temperature resistance and ultraviolet resistance, resulting in shortened product shelf life and reduced quality. To this end, the present invention provides a process for preparing a high-barrier cooking-resistant and UV-resistant film. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a process for preparing a high-barrier, retort-resistant and UV-resistant film, which solves the problem that existing packaging materials are prone to degradation, aging and performance degradation under the influence of high-temperature retort, ultraviolet irradiation, gas, moisture and other environmental factors. Especially in the field of food and drug packaging, traditional materials are difficult to simultaneously meet the requirements of high barrier, high temperature resistance and UV resistance, resulting in shortened product shelf life and deteriorated quality.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: A process for preparing a high-barrier, cooking-resistant and UV-resistant film, comprising the following steps: Step 1: Preparation of resin raw materials, including the following raw materials PA, TIE, PP, TIE, PA, EVOH, PA, TIE and propylene-based ultraviolet absorber, and drying the raw materials with drying equipment, setting appropriate temperature and time to ensure that the moisture in the raw materials is completely removed so that they are in the best processing state.

[0006] Step 2: Set the process temperature of raw materials. The process temperature of PP is set between 180-230℃, the process temperature of TIE is set at 200-220℃, the process temperature of EVOH is set at 180-220℃, and the process temperature of PA is set at 220-260℃.

[0007] Step 3: Equipment process settings, the cold roller temperature is set to 30°C, the fixed edge voltage is set to 15KV, and the air knife pressure is set to 5bar.

[0008] Step 4: The equipment is running to extrude the film. Start the extruder screw, set the screw speed to 7rpm, use the traction rope to pull the film from the cold roller position to the winding device, start the online thickness gauge, and start the winding device.

[0009] As a preferred technical solution of the present invention, the PA refers to polyamide resin, the TIE refers to adhesive resin, the PP is polypropylene resin, and the EVOH is ethylene-vinyl alcohol copolymer.

[0010] As a preferred technical solution of the present invention, the TIE is a mixture of PP resin and propylene-modified adhesive resin, the PP used in the inner layer is a mixture of copolymer PP and PP elastomer, the EVOH is a high-temperature resistant ethylene-vinyl alcohol copolymer with an ethylene content of 29%, the propylene-based UV absorber is a mixture of PP resin and propylene-based UV absorber, the PA and EVOH resins used need to be dried in advance, and the layer thicknesses of each layer are 9%, 5%, 16%, 5%, 9%, 4%, 9%, 5%, 24%, and 14%, respectively.

[0011] As a preferred technical solution of the present invention, the TIE is formed by mixing PP resin and propylene-modified adhesive resin. When preparing TIE, the mixing ratio of PP resin and propylene-modified adhesive resin must be accurately controlled. The EVOH is a high-temperature resistant ethylene and vinyl alcohol copolymer with an ethylene content of 29%, and the propylene-based ultraviolet absorber is a mixture of PP resin and propylene-based ultraviolet absorber.

[0012] As a preferred technical solution of the present invention, the PP process temperature is set between 180-230°C. Within this temperature range, the PP resin can gradually soften and achieve suitable fluidity, which is convenient for subsequent processing and molding through an extruder. The process temperature of TIE is set at 200-220°C. At this temperature, its bonding performance can be fully exerted so that when it contacts with other layers of resin, it can quickly and firmly form a bonding interface. The process temperature of EVOH is set at 180-220°C. This temperature range can ensure its normal processing and maintain its excellent barrier properties. The process temperature of PA is set at 220-260°C. Within this temperature range, PA6 resin can be fully melted and have good fluidity, which is convenient for extrusion through an extruder to form a uniform film layer.

[0013] As a preferred technical solution of the present invention, the low temperature of 30°C of the cold roller can quickly cool and solidify the diaphragm, helping the diaphragm to maintain its shape and dimensional stability. The application of a 15KV fixed edge voltage can form a stable electric field at the edge of the diaphragm, so that the resin molecules at the edge of the diaphragm are arranged neatly under the action of the electric field force, thereby effectively ensuring the flatness and stability of the diaphragm edge. The airflow of the wind knife with a pressure of 5 bar will blow toward the diaphragm to dry the water vapor on the surface of the diaphragm, and at the same time, it will also make certain adjustments to the surface shape of the diaphragm to make it smoother.

[0014] As a preferred technical solution of the present invention, the extruder screw can extrude various preheated resin raw materials from the hopper in a set ratio and sequence, and through the shearing and extrusion action of the screw, the raw materials gradually form a uniform melt flow.

[0015] As a preferred technical solution of the present invention, the traction rope can pull the film from the cold roller position to the winding device. After the film is cooled and solidified from the cold roller, it needs to be smoothly pulled to the winding device by the traction rope.

[0016] As a preferred technical solution of the present invention, the online thickness measuring instrument can monitor the thickness change of the film in the production process in real time. Once the thickness abnormality is found, the operator can take timely measures.

[0017] As a preferred technical solution of the present invention, the winding device is responsible for neatly winding up the produced film. During the winding process, attention should be paid to adjusting the winding tension to ensure that the film does not become loose or too tight during the winding process, and to ensure that the film can be wound up evenly and neatly.

[0018] Compared with the prior art, the present invention provides a high barrier, boiling-resistant and UV-resistant film preparation process, which has the following beneficial effects: The high-barrier retort-resistant UV-resistant film preparation process adopts raw materials such as PA, TIE, PP, TIE, PA, EVOH, PA, TIE and propylene-based UV absorbers, and utilizes the setting of the raw material process temperature and the equipment process to produce and prepare high-barrier retort-resistant UV-resistant film. The prepared high-barrier retort-resistant UV-resistant film will be able to remain stable during high-temperature retort, block the intrusion of ultraviolet rays, oxygen and moisture, thereby extending the shelf life and service life of the product in the package. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a process flow chart of the preparation process. DETAILED DESCRIPTION

[0020] 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.

[0021] Example See also Figure 1 , In this embodiment: A high barrier cooking resistant UV resistant film preparation process comprises the following steps: Step 1: Preparation of resin raw materials, including the following raw materials PA, TIE, PP, TIE, PA, EVOH, PA, TIE and propylene-based UV absorber, and drying the raw materials with drying equipment, setting appropriate temperature and time to ensure that the moisture in the raw materials is completely removed so that they are in the best processing state; Step 2: Set the process temperature of raw materials. The process temperature of PP is set between 180-230℃, the process temperature of TIE is set between 200-220℃, the process temperature of EVOH is set between 180-220℃, and the process temperature of PA is set between 220-260℃. Step 3: Equipment process settings, the cold roll temperature is set to 30°C, the fixed edge voltage is set to 15KV, and the air knife pressure is set to 5bar; Step 4: The equipment is running to extrude the film. Start the extruder screw, set the screw speed to 7rpm, use the traction rope to pull the film from the cold roller position to the winding device, start the online thickness gauge, and start the winding device.

[0022] In this embodiment, the PA refers to a polyamide resin, the TIE refers to an adhesive resin, the PP is a polypropylene resin, the EVOH is an ethylene-vinyl alcohol copolymer, the TIE is a mixture of PP resin and a propylene-based modified adhesive resin, the PP used in the inner layer is a mixture of copolymerized PP and PP elastomer, the EVOH is a high-temperature resistant ethylene-vinyl alcohol copolymer with an ethylene content of 29%, the propylene-based UV absorber is a mixture of PP resin and a propylene-based UV absorber, the PA and EVOH resins used need to be dried in advance, and the thickness of each layer is 9%, 5%, 16%, 5%, 9%, 4%, 9%, 5%, 24%, and 14%, respectively; the TIE is a mixture of PP resin and a propylene-based modified adhesive resin, and when preparing TIE, the mixing ratio of PP resin and propylene-based modified adhesive resin must be precisely controlled; the EVOH is a high-temperature resistant ethylene-vinyl alcohol copolymer with an ethylene content of 29%. The propylene-based UV absorber is a mixture of PP resin and propylene-based UV absorber. The process temperature of PP is set between 180-230°C. Within this temperature range, the PP resin can gradually soften and achieve suitable fluidity, which is convenient for subsequent processing and molding through an extruder. The process temperature of TIE is set at 200-220°C. At this temperature, its bonding performance can be fully exerted, so that when it contacts with other layers of resin, it can quickly and firmly form a bonding interface. The process temperature of EVOH is set at 180-220°C. This temperature range can ensure its normal processing and maintain its excellent barrier properties. The process temperature of PA is set at 220-260°C. Within this temperature range, PA6 resin can be fully melted and have good fluidity, which is convenient for extrusion through an extruder to form a uniform film layer.

[0023] In this embodiment, the low temperature of 30°C of the cold roller can quickly cool and solidify the diaphragm, helping the diaphragm to maintain its shape and dimensional stability. The application of the 15KV fixed edge voltage can form a stable electric field at the edge of the diaphragm, so that the resin molecules at the edge of the diaphragm are arranged neatly under the action of the electric field force, thereby effectively ensuring the flatness and stability of the edge of the diaphragm. The airflow of the 5bar pressure of the wind knife will blow toward the diaphragm to dry the water vapor on the surface of the diaphragm, and at the same time, it will also adjust the surface shape of the diaphragm to make it smoother. The extruder screw can extrude various preheated resin raw materials from the hopper in a set proportion and order. , and through the shearing and extrusion of the screw, the raw materials gradually form a uniform melt flow. The traction rope can pull the film from the cold roller position to the winding device. After the film is cooled and solidified from the cold roller, it needs to be smoothly pulled to the winding device by the traction rope. The online thickness measuring instrument can monitor the thickness change of the film during the production process in real time. Once the thickness is abnormal, the operator can take timely measures. The winding device is responsible for winding the produced film neatly. During the winding process, pay attention to adjusting the winding tension to ensure that the film is not loose or too tight during the winding process, and to ensure that the film can be wound up uniformly and neatly.

[0024] The working principle and preparation process of the present invention are as follows: first, resin raw materials are prepared, and then the process temperature of the raw materials is set. The process temperature of PP is set between 180-230°C, the process temperature of TIE is set to 200-220°C, the process temperature of EVOH is set to 180-220°C, and the process temperature of PA is set to 220-260°C. Then, the equipment process is set, the cold roller temperature is set to 30°C, the fixed edge voltage is set to 15KV, and the air knife pressure is set to 5bar. Then, the equipment is started, and the film is extruded through the extruder, and the film is pulled from the cold roller position to the winding device by a traction rope, and then the online thickness measuring instrument is started for detection, and finally the winding device is wound.

[0025] In the description of the present invention, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprising a reference structure" do not exclude the presence of other identical elements in the process, method, article or device comprising the elements. It should be noted that, in this article, relational terms such as "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0026] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for preparing a high barrier, boiling-resistant and UV-resistant film, characterized in that: The method comprises the following steps: Step 1: preparing resin raw materials, including the following raw materials PA, TIE, PP, TIE, PA, EVOH, PA, TIE and propylene-based ultraviolet absorber, and drying the raw materials with drying equipment, setting appropriate temperature and time to ensure that the moisture in the raw materials is completely removed so that the raw materials are in the best processing state; Step 2: Set the process temperature of raw materials. The process temperature of PP is set between 180-230℃, the process temperature of TIE is set between 200-220℃, the process temperature of EVOH is set between 180-220℃, and the process temperature of PA is set between 220-260℃. Step 3: Equipment process settings, the cold roll temperature is set to 30°C, the fixed edge voltage is set to 15KV, and the air knife pressure is set to 5bar; Step 4: The equipment is running to extrude the film. Start the extruder screw, set the screw speed to 7rpm, use the traction rope to pull the film from the cold roller position to the winding device, start the online thickness gauge, and start the winding device.

2. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The PA refers to a polyamide resin, the TIE refers to an adhesive resin, the PP refers to a polypropylene resin, and the EVOH refers to an ethylene-vinyl alcohol copolymer.

3. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The TIE is a mixture of PP resin and propylene-modified adhesive resin, the PP used in the inner layer is a mixture of copolymer PP and PP elastomer, the EVOH is a high-temperature resistant ethylene-vinyl alcohol copolymer with an ethylene content of 29%, and the propylene-based UV absorber is a mixture of PP resin and propylene-based UV absorber. The PA and EVOH resins used need to be dried in advance, and the layer thicknesses are 9%, 5%, 16%, 5%, 9%, 4%, 9%, 5%, 24%, and 14%, respectively.

4. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The TIE is a mixture of PP resin and propylene-modified adhesive resin. When preparing TIE, the mixing ratio of PP resin and propylene-modified adhesive resin must be accurately controlled. The EVOH is a high-temperature resistant ethylene and vinyl alcohol copolymer with an ethylene content of 29%. The propylene-based ultraviolet absorber is a mixture of PP resin and propylene-based ultraviolet absorber.

5. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The process temperature of PP is set between 180-230°C. Within this temperature range, the PP resin can gradually soften and achieve suitable fluidity, which is convenient for subsequent processing and molding through an extruder. The process temperature of TIE is set at 200-220°C. At this temperature, its bonding performance can be fully exerted, so that when it contacts with other layers of resin, it can quickly and firmly form a bonding interface. The process temperature of EVOH is set at 180-220°C. This temperature range can ensure its normal processing and maintain its excellent barrier properties. The process temperature of PA is set at 220-260°C. Within this temperature range, PA6 resin can be fully melted and have good fluidity, which is convenient for extrusion through an extruder to form a uniform film layer.

6. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The low temperature of 30°C of the cold roller can quickly cool and solidify the diaphragm, helping the diaphragm to maintain its shape and dimensional stability. The application of 15KV fixed edge voltage can form a stable electric field at the edge of the diaphragm, so that the resin molecules at the edge of the diaphragm are arranged neatly under the action of the electric field force, thereby effectively ensuring the flatness and stability of the edge of the diaphragm. The airflow of the wind knife with a pressure of 5 bar will blow towards the diaphragm to dry the water vapor on the surface of the diaphragm, and at the same time, it will also make certain adjustments to the surface shape of the diaphragm to make it smoother.

7. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The extruder screw can extrude various preheated resin raw materials from the hopper in a set ratio and sequence, and through the shearing and extrusion action of the screw, the raw materials gradually form a uniform melt flow.

8. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The traction rope can pull the film from the cold roller to the winding device. After the film is cooled and solidified from the cold roller, it needs to be smoothly pulled to the winding device by the traction rope.

9. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The online thickness measuring instrument can monitor the thickness change of the film in the production process in real time. Once the thickness abnormality is found, the operator can take timely measures.

10. The process for preparing a high barrier, boiling-resistant and UV-resistant film according to claim 1, characterized in that: The winding device is responsible for winding up the produced film neatly. During the winding process, attention should be paid to adjusting the winding tension to ensure that the film is not loose or too tight during the winding process, and to ensure that the film can be wound up uniformly and neatly.

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