Production process of high-performance film

Abstract

The production process of the high-performance thin film comprises the following steps: S1, raw material pretreatment; the preparation method comprises the following steps: selecting polyethylene resin, polypropylene resin and a functional additive as three main raw materials, respectively drying the raw materials, and then mixing through a high-speed mixer to obtain a mixed raw material; wherein the functional additive comprises an antioxidant, an ultraviolet light absorber and a nano blocking agent, and the mass ratio of each component is as follows: 45%-65% of polyethylene resin, 30%-55% of polypropylene resin, 0.5%-2% of the antioxidant, 0.3%-1.5% of the ultraviolet light absorber and 1%-5% of the nano blocking agent; s2, co-extrusion composite molding; s3, gradient stretching orientation; s4, intelligent shaping treatment; and S5, performing a post-treatment process. According to the preparation method, the precision drying and high-speed mixing technologies are adopted, and the optimized raw material ratio is combined, so that the performance stability of the thin film is effectively improved; the functional additives are reasonably matched, especially the surface-modified nano blocking agent is added, so that the oxidation resistance, the ultraviolet resistance and the barrier property of the film are remarkably enhanced.

Description

Technical Field

[0001] This invention relates to the field of plastic film production technology, and in particular to a production process for high-performance films. Background Technology

[0002] Plastic films, due to their advantages such as light weight, transparency, moisture resistance, and adjustable barrier properties, are widely used in packaging across various industries including food, pharmaceuticals, electronics, and chemicals. However, as market demands for packaging material performance continue to rise, traditional film production processes are revealing numerous problems. For example, uneven raw material mixing in traditional processes leads to significant fluctuations in film performance; insufficient temperature control precision during co-extrusion affects the bonding strength between composite film layers; and unreasonable temperature distribution during stretching and orientation results in poor mechanical properties and dimensional stability of the film. Furthermore, traditional production processes are energy-intensive, and some post-processing steps generate pollutants, which is inconsistent with current green and environmentally friendly development trends. Therefore, developing a production process that can produce high-performance films while being environmentally friendly and energy-efficient is of significant practical importance. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a manufacturing process for high-performance thin films.

[0004] One embodiment of the present invention addresses its technical problem by employing a production process for a high-performance thin film, comprising the following steps: S1, Raw material pretreatment: Polyethylene resin, polypropylene resin, and functional additives are selected as the three main raw materials. The raw materials are dried separately and then mixed using a high-speed mixer to obtain a mixed raw material. The functional additives include antioxidants, ultraviolet absorbers, and nano-barriers, with the following mass percentages: polyethylene resin 45%-65%, polypropylene resin 30%-55%, antioxidants 0.5%-2%, ultraviolet absorbers 0.3%-1.5%, and nano-barriers 1%-5%. S2, co-extrusion composite molding: The mixed raw materials are added to three extruders respectively, and the barrel temperature is controlled by the temperature control system of different extruders. The molten raw materials are extruded through the composite die to form a three-layer composite preform. S3, Gradient stretching orientation: The composite film preform is fed into a stretching machine, first longitudinally stretched, then transversely stretched, with gradient temperature control during the stretching process; S4, Intelligent Shaping Process: The stretched film is sent into the shaping box, and the film temperature is monitored in real time by an infrared thermometer to ensure the stability of the film size; S5, Post-processing steps: The shaped film undergoes surface corona treatment, edge trimming, and winding processes to finally obtain a high-performance film product.

[0005] Optionally, in step S1, the nano barrier agent is nano-montmorillonite or nano-silica.

[0006] Optionally, in step S1, the drying temperature is controlled at 80-100℃, the drying time is 2-4 hours, the mixing speed of the high-speed mixer is 800-1200 r / min, and the mixing time is 15-30 minutes.

[0007] Optionally, in step S2, the barrel temperature of the first extruder is 160-180℃, the barrel temperature of the second extruder is 170-190℃, and the barrel temperature of the third extruder is 180-200℃.

[0008] Optionally, in step S3, the longitudinal stretching temperature is 80-100℃ and the stretching ratio is 2.5-4 times; the transverse stretching temperature is 90-110℃ and the stretching ratio is 3-5 times; a gradient temperature control method is adopted during the stretching process, with a temperature gradient of 5-10℃ / segment.

[0009] Optionally, in step S3, the stretching machine is driven by a servo motor, and the control accuracy of the stretching speed is ±0.1m / min.

[0010] Optionally, in step S4, the intelligent temperature control system controls the setting temperature at 110-130℃ and the setting time at 30-60 seconds, while adopting bidirectional synchronous cooling technology with a cooling rate of 10-15℃ / second.

[0011] Optionally, the intelligent temperature control system described in step S4 includes a temperature sensor, a PID controller, and a heating device, with a temperature control accuracy of ±1℃.

[0012] Optionally, in step S5, the corona power of the surface corona treatment is 30-50kW, and the treatment time is 5-10 seconds; the winding speed of the winding treatment is 20-30m / min, and the winding tension is controlled at 50-80N.

[0013] Optionally, in step S5, after surface corona treatment, the surface tension of the film is not less than 38 mN / m.

[0014] The beneficial effects of this invention are: 1. The raw material pretreatment stage adopts precision drying and high-speed mixing technology, combined with optimized raw material ratio, to ensure the uniformity of raw material mixing and effectively improve the stability of film performance; the rational combination of functional additives, especially the addition of surface-modified nano barrier agents, significantly enhances the film's antioxidant, UV resistance and barrier properties.

[0015] 2. During the co-extrusion composite molding process, the temperature of each extruder is precisely controlled according to the characteristics of different film layer raw materials, which improves the bonding force between film layers, avoids delamination, and ensures the overall structural stability of the composite film.

[0016] 3. The application of gradient stretching and orientation technology optimizes the molecular chain arrangement of the film, significantly improving the mechanical properties of the film such as tensile strength and elongation at break; at the same time, the servo motor driven stretching machine ensures precise control of the stretching speed and improves the uniformity of film thickness.

[0017] 4. The intelligent shaping process employs a real-time temperature monitoring and precise temperature control system, combined with bidirectional synchronous cooling technology, which effectively fixes the molecular orientation structure of the film, reduces the thermal shrinkage rate of the film, and improves dimensional stability; the improved temperature control accuracy further ensures the consistency of film performance.

[0018] 5. The optimized surface corona treatment process improves the surface adhesion of the film, meeting the requirements of subsequent processing; the entire production process has low energy consumption and low pollutant emissions, which is in line with the concept of green and environmentally friendly development.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a process flow diagram of the production process of the high-performance thin film of the present invention. Detailed Implementation

[0021] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0022] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integrally formed connection; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0025] Example Reference Figure 1 The present invention proposes a high-performance thin film manufacturing process, comprising the following steps: S1, Raw material pretreatment: Polyethylene resin, polypropylene resin, and functional additives are selected as the three main raw materials. The raw materials are dried separately and then mixed using a high-speed mixer to obtain a mixed raw material. The functional additives include antioxidants, ultraviolet absorbers, and nano-barriers, with the following mass percentages: polyethylene resin 45%-65%, polypropylene resin 30%-55%, antioxidants 0.5%-2%, ultraviolet absorbers 0.3%-1.5%, and nano-barriers 1%-5%. S2, co-extrusion composite molding: The mixed raw materials are added to three extruders respectively, and the barrel temperature is controlled by the temperature control system of different extruders. The molten raw materials are extruded through the composite die to form a three-layer composite preform. S3, Gradient stretching orientation: The composite film preform is fed into a stretching machine, first longitudinally stretched, then transversely stretched, with gradient temperature control during the stretching process; S4, Intelligent Shaping Process: The stretched film is sent into the shaping box, and the film temperature is monitored in real time by an infrared thermometer to ensure the stability of the film size; S5, Post-processing steps: The shaped film undergoes surface corona treatment, edge trimming, and winding processes to finally obtain a high-performance film product.

[0026] The beneficial effects of this invention are: 1. The raw material pretreatment stage adopts precision drying and high-speed mixing technology, combined with optimized raw material ratio, to ensure the uniformity of raw material mixing and effectively improve the stability of film performance; the rational combination of functional additives, especially the addition of surface-modified nano barrier agents, significantly enhances the film's antioxidant, UV resistance and barrier properties.

[0027] 2. During the co-extrusion composite molding process, the temperature of each extruder is precisely controlled according to the characteristics of different film layer raw materials, which improves the bonding force between film layers, avoids delamination, and ensures the overall structural stability of the composite film.

[0028] 3. The application of gradient stretching and orientation technology optimizes the molecular chain arrangement of the film, significantly improving the mechanical properties of the film such as tensile strength and elongation at break; at the same time, the servo motor driven stretching machine ensures precise control of the stretching speed and improves the uniformity of film thickness.

[0029] 4. The intelligent shaping process employs a real-time temperature monitoring and precise temperature control system, combined with bidirectional synchronous cooling technology, which effectively fixes the molecular orientation structure of the film, reduces the thermal shrinkage rate of the film, and improves dimensional stability; the improved temperature control accuracy further ensures the consistency of film performance.

[0030] 5. The optimized surface corona treatment process improves the surface adhesion of the film, meeting the requirements of subsequent processing; the entire production process has low energy consumption and low pollutant emissions, which is in line with the concept of green and environmentally friendly development.

[0031] In this embodiment, the nano-barrier agent in step S1 is nano-montmorillonite or nano-silica. These nanomaterials have high specific surface area and good dispersibility, which can effectively enhance the gas barrier properties (such as oxygen and water vapor), mechanical strength, and thermal stability of the film. Nano-montmorillonite can form intercalation structures to improve barrier efficiency; nano-silica enhances the wear resistance and transparency of the film, thereby improving the application performance of the film in harsh environments.

[0032] Specifically, in step S1, the drying temperature is controlled at 80-100℃ and the drying time is 2-4 hours to ensure that the raw materials are fully dehydrated and to avoid the generation of bubbles or degradation during processing. The mixing speed of the high-speed mixer is 800-1200 r / min and the mixing time is 15-30 minutes to make the additives evenly dispersed, reduce agglomeration, improve the uniformity of film composition and processing stability, thereby reducing performance fluctuations and ensuring batch consistency.

[0033] In this embodiment, in step S2, the barrel temperature of the first extruder is 160-180℃, the barrel temperature of the second extruder is 170-190℃, and the barrel temperature of the third extruder is 180-200℃. This adapts to the melting characteristics of polyethylene, polypropylene, and additives, ensuring consistent melt flow and avoiding overheating degradation or insufficient melting.

[0034] In this embodiment, in step S3, the longitudinal stretching temperature is 80-100℃ and the stretching ratio is 2.5-4 times; the transverse stretching temperature is 90-110℃ and the stretching ratio is 3-5 times; a gradient temperature control method is adopted during the stretching process, with a temperature gradient of 5-10℃ / segment.

[0035] Specifically, in step S3, the stretching machine is driven by a servo motor, and the stretching speed control accuracy is ±0.1m / min. This high-precision control reduces tension fluctuations during the stretching process, lowers the risk of film breakage, and improves production efficiency and yield.

[0036] In this embodiment, in step S4, the intelligent temperature control system controls the setting temperature at 110-130℃ and the setting time at 30-60 seconds, while employing bidirectional synchronous cooling technology with a cooling rate of 10-15℃ / second. This allows the film to quickly set and release internal stress. This improves the dimensional stability, surface smoothness, and thermal properties of the film, while shortening the production cycle and reducing energy consumption.

[0037] Preferably, the intelligent temperature control system in step S4 includes a temperature sensor, a PID controller, and a heating device, with a temperature control accuracy of ±1℃. The PID controller enables rapid response and adjustment, reduces temperature fluctuations, improves the consistency of molding quality, and avoids film defects caused by overheating or insufficient cooling.

[0038] In this embodiment, in step S5, the corona power of the surface corona treatment is 30-50kW, and the treatment time is 5-10 seconds, which effectively improves the surface energy of the film, enhances its wettability and adhesion, and facilitates subsequent printing, coating or lamination processing; the winding speed of the winding treatment is 20-30m / min, and the winding tension is controlled at 50-80N to ensure flat and wrinkle-free winding, improve winding quality and storage stability, and reduce waste.

[0039] Optionally, in step S5, after the surface corona treatment, the surface tension of the film is not less than 38 mN / m, ensuring that the film surface treatment is sufficient and meets the strict requirements of high-end packaging for printing and lamination.

[0040] In one embodiment, a production process for a high-performance thin film includes the following steps: S1, Raw material pretreatment: Select 50kg of polyethylene resin, 45kg of polypropylene resin, 1.5kg of antioxidant, 1kg of ultraviolet absorber, and 2.5kg of nano-montmorillonite (after surface modification treatment with silane coupling agent). Dry each raw material separately at 90℃ for 3 hours, then feed them into a high-speed mixer and mix at 1000r / min for 20 minutes to obtain mixed raw materials.

[0041] S2, Co-extrusion composite molding: The mixed raw materials are added to three extruders respectively. The barrel temperature of the first extruder is controlled at 170℃, the barrel temperature of the second extruder is controlled at 180℃, and the barrel temperature of the third extruder is controlled at 190℃. The molten raw materials are extruded through the composite die to form a three-layer composite preform.

[0042] S3, Gradient stretching orientation: The composite film preform is fed into a stretching machine driven by a servo motor. It is first stretched longitudinally at 90°C with a stretching ratio of 3 times, and then stretched transversely at 100°C with a stretching ratio of 4 times. The temperature gradient during the stretching process is 8°C / segment, and the stretching speed control accuracy is ±0.1m / min.

[0043] S4, Intelligent Shaping Process: The stretched film is sent into the shaping chamber, and the temperature is monitored in real time by an infrared thermometer. The heating device is adjusted by a PID controller to control the shaping temperature at 120℃ and the shaping time is 45 seconds. At the same time, bidirectional synchronous cooling technology is adopted, with a cooling rate of 12℃ / second.

[0044] S5, Post-processing step: The film is subjected to surface corona treatment with a corona power of 40kW and a treatment time of 8 seconds. The surface tension of the film is measured to be 40mN / m. Then, the film is trimmed and wound up at a speed of 25m / min and the winding tension is controlled at 65N to obtain a high-performance film product.

[0045] The performance of the film product produced in this embodiment was tested, and the results showed that: the tensile strength was 25 MPa in the longitudinal direction and 23 MPa in the transverse direction; the elongation at break was 300% in the longitudinal direction and 280% in the transverse direction; the oxygen permeability was 5 cm³ / (m²・24h・0.1 MPa); the water vapor permeability was 3 g / (m²・24h); and the heat shrinkage rate (120℃, 30 minutes) was 1.5% in the longitudinal direction and 1.2% in the transverse direction. All of these properties were superior to those of film products produced by traditional processes.

[0046] In yet another embodiment, a manufacturing process for a high-performance thin film includes the following steps: S1, Raw material pretreatment: Select 45kg of polyethylene resin, 50kg of polypropylene resin, 1kg of antioxidant, 0.8kg of ultraviolet absorber, and 3.2kg of nano-silica (after surface modification treatment with silane coupling agent). Dry each raw material at 85℃ for 3.5 hours, then feed them into a high-speed mixer and mix at 900r / min for 25 minutes to obtain a mixed raw material.

[0047] S2, Co-extrusion composite molding: The mixed raw materials are added to three extruders respectively. The barrel temperature of the first extruder is controlled at 165℃, the barrel temperature of the second extruder is controlled at 175℃, and the barrel temperature of the third extruder is controlled at 185℃. The molten raw materials are extruded through the composite die to form a three-layer composite preform.

[0048] S3, Gradient stretching orientation: The composite film preform is fed into a stretching machine driven by a servo motor. It is first stretched longitudinally at 85°C with a stretching ratio of 3.5 times, and then stretched transversely at 95°C with a stretching ratio of 4.5 times. The temperature gradient during the stretching process is 6°C / segment, and the stretching speed control accuracy is ±0.1m / min.

[0049] S4, Intelligent Shaping Process: The stretched film is sent into the shaping chamber, and the temperature is monitored in real time by an infrared thermometer. The heating device is adjusted by a PID controller to control the shaping temperature at 115℃ and the shaping time is 50 seconds. At the same time, bidirectional synchronous cooling technology is adopted, with a cooling rate of 13℃ / second.

[0050] S5, Post-processing step: The film is subjected to surface corona treatment with a power of 35kW and a treatment time of 9 seconds. The surface tension of the film is measured to be 39mN / m. Then, the film is trimmed and wound up at a speed of 22m / min and the winding tension is controlled at 55N to obtain a high-performance film product.

[0051] Performance test results show that the tensile strength of the film produced in this embodiment is 26 MPa in the longitudinal direction and 24 MPa in the transverse direction; the elongation at break is 310% in the longitudinal direction and 290% in the transverse direction; the oxygen permeability is 4.5 cm³ / (m²・24h・0.1 MPa); the water vapor permeability is 2.8 g / (m²・24h); and the heat shrinkage rate (120℃, 30 minutes) is 1.3% in the longitudinal direction and 1.1% in the transverse direction, which also demonstrates excellent comprehensive performance.

[0052] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. A manufacturing process for a high-performance thin film, characterized in that, Includes the following steps: S1, Raw material pretreatment: Polyethylene resin, polypropylene resin, and functional additives are selected as the three main raw materials. The raw materials are dried separately and then mixed using a high-speed mixer to obtain a mixed raw material. The functional additives include antioxidants, ultraviolet absorbers, and nano-barriers, with the following mass percentages: polyethylene resin 45%-65%, polypropylene resin 30%-55%, antioxidants 0.5%-2%, ultraviolet absorbers 0.3%-1.5%, and nano-barriers 1%-5%. S2, co-extrusion composite molding: The mixed raw materials are added to three extruders respectively, and the barrel temperature is controlled by the temperature control system of different extruders. The molten raw materials are extruded through the composite die to form a three-layer composite preform. S3, Gradient stretching orientation: The composite film preform is fed into a stretching machine, first longitudinally stretched, then transversely stretched, with gradient temperature control during the stretching process; S4, Intelligent Shaping Process: The stretched film is sent into the shaping box, and the film temperature is monitored in real time by an infrared thermometer to ensure the stability of the film size; S5, Post-processing steps: The shaped film undergoes surface corona treatment, edge trimming, and winding processes to finally obtain a high-performance film product.

2. The production process of the high-performance thin film according to claim 1, characterized in that: In step S1, the nano barrier agent is nano-montmorillonite or nano-silica.

3. The production process of the high-performance thin film according to claim 1, characterized in that: In step S1, the drying temperature is controlled at 80-100℃, the drying time is 2-4 hours, the mixing speed of the high-speed mixer is 800-1200 r / min, and the mixing time is 15-30 minutes.

4. The production process of the high-performance thin film according to claim 1, characterized in that: In step S2, among the three extruders, the barrel temperature of the first extruder is 160-180℃, the barrel temperature of the second extruder is 170-190℃, and the barrel temperature of the third extruder is 180-200℃.

5. The production process of the high-performance thin film according to claim 1, characterized in that: In step S3, the longitudinal stretching temperature is 80-100℃ and the stretching ratio is 2.5-4 times; the transverse stretching temperature is 90-110℃ and the stretching ratio is 3-5 times; a gradient temperature control method is adopted during the stretching process, with a temperature gradient of 5-10℃ / segment.

6. The production process of the high-performance thin film according to claim 5, characterized in that: In step S3, the stretching machine is driven by a servo motor, and the control accuracy of the stretching speed is ±0.1m / min.

7. The production process of the high-performance thin film according to claim 1, characterized in that: In step S4, the intelligent temperature control system controls the setting temperature at 110-130℃ and the setting time at 30-60 seconds. At the same time, it adopts bidirectional synchronous cooling technology with a cooling rate of 10-15℃ / second.

8. The production process of the high-performance thin film according to claim 7, characterized in that: The intelligent temperature control system described in step S4 includes a temperature sensor, a PID controller, and a heating device, with a temperature control accuracy of ±1℃.

9. The production process of the high-performance thin film according to claim 1, characterized in that: In step S5, the corona power of the surface corona treatment is 30-50kW, and the treatment time is 5-10 seconds; the winding speed of the winding treatment is 20-30m / min, and the winding tension is controlled at 50-80N.

10. The production process of the high-performance thin film according to claim 9, characterized in that: In step S5, after surface corona treatment, the surface tension of the film is not less than 38 mN / m.

Images