A high-temperature-resistant cooking easy-to-peel film for teflon and a preparation method and application thereof
Patent Information
- Application Number
- CN202610995226.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-03
- Publication Date
- 2026-08-21
AI Technical Summary
[0003]然而，目前现有技术中用于封特卫强的易揭膜，普遍存在耐高温蒸煮性能不足的缺陷，无法耐受121℃及以上的高温蒸煮灭菌，仅能采用环氧乙烷灭菌和伽马射线辐照灭菌两种方式
[0015]This invention provides a high-temperature resistant, easy-to-peel film for sealing Tyvek, comprising an outer layer, a middle layer, and an inner layer arranged sequentially. By weight, the outer layer comprises: 10-40 parts copolymer polypropylene, 15-50 parts high-density polyethylene, 10-40 parts metallocene medium-density polyethylene, and 0.5-1 parts processing aid. By weight, the middle layer comprises: 15-50 parts copolymer polypropylene, 10-30 parts homopolymer polypropylene, 20-60 parts metallocene medium-density polyethylene, and 0.5-1 parts processing aid. By weight, the inner layer comprises: 15-35 parts easy-to-peel material, 10-30 parts low-density polyethylene, 15-40 parts metallocene medium-density polyethylene, 20-50 parts high-density polyethylene, and 0.5-1 parts processing aid. This invention selects copolymer polypropylene, homopolymer polypropylene, and high-density polyethylene with excellent temperature resistance for the outer and middle layers. Simultaneously, it adds an easy-peeling material with good temperature resistance and stable peelability, along with high-density polyethylene with good temperature resistance, to the inner layer. This improves the film's high-temperature retortability while ensuring its easy-peelability. Furthermore, the metallocene medium-density polyethylene added to the outer, middle, and inner layers of this invention has good toughness, processability, and compatibility with polypropylene, while the low-density polyethylene added to the inner layer has fewer crystal points and good processability, further ensuring the film's performance. In summary, this invention strictly controls the types and proportions of raw materials used in the outer, middle, and inner layers to obtain an easy-peeling film with good high-temperature retortability and excellent mechanical properties, showing broad application prospects in the field of medical device packaging. Example results show that the high-temperature retortable easy-peeling film of this invention does not stick or wrinkle after being boiled at 121°C for 30 minutes, and the peel force before and after boiling can be controlled between 2.5 and 6 N/15 mm, without stringing, delamination, exudation, or leakage.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of protective film technology, and in particular to a high-temperature resistant, easy-to-peel film for sealing Tyvek, its preparation method, and its application. Background Technology
[0002] Tyvek, a high-density polyethylene nonwoven fabric, possesses excellent microbial barrier properties, breathability, and mechanical strength. It is widely used in the aseptic packaging of medical devices, providing reliable aseptic protection for surgical instruments and diagnostic consumables. In practical applications of Tyvek packaging, an easy-open film is required for heat sealing. The peel force at the heat-sealed interface must be between 2.5 and 6 N / 15 mm, and the film should not produce any stringing, residue, or delamination upon opening, thus preventing contamination of the medical device while also meeting the needs of healthcare personnel for convenient opening.
[0003] However, current easy-open films used for sealing Tyvek generally suffer from insufficient high-temperature retort resistance, unable to withstand high-temperature sterilization at 121°C and above. They can only be sterilized using ethylene oxide or gamma irradiation. However, ethylene oxide is toxic, and sterilization using this method requires post-treatment residue analysis, which is time-consuming and incurs high equipment and environmental costs. Gamma irradiation sterilization causes the film material to become brittle and yellow, significantly reducing its mechanical properties and ultimately compromising the sealing integrity and structural stability of the packaging. Summary of the Invention
[0004] In view of this, the present invention provides a high-temperature retort-resistant easy-peel film for sealing Tyvek and its preparation method. When used to seal Tyvek, the high-temperature retort-resistant easy-peel film provided by the present invention meets both the standard of peel strength between 2.5 and 6 N / 15 mm and the requirements of high-temperature retort sterilization.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A high-temperature resistant, easy-to-remove film for sealing Tyvek, comprising an outer layer, a middle layer, and an inner layer arranged sequentially. The raw materials for preparing the outer layer, by weight, include: 10-40 parts of copolymer polypropylene, 15-50 parts of high-density polyethylene, 10-40 parts of metallocene medium-density polyethylene, and 0.5-1 parts of processing aids. The raw materials for preparing the middle layer, by weight, include: 15-50 parts of copolymer polypropylene, 10-30 parts of homopolymer polypropylene, 20-60 parts of metallocene medium-density polyethylene, and 0.5-1 parts of processing aids. By weight, the raw materials for preparing the inner layer include: 15-35 parts of easy-to-remove material, 10-30 parts of low-density polyethylene, 15-40 parts of metallocene medium-density polyethylene, 20-50 parts of high-density polyethylene, and 0.5-1 parts of processing aids.
[0006] Preferably, the outer and middle layers are made of copolymer polypropylene with a melt index of 1.0~2.0 g / 10 min and a density of 0.900~0.910 g / cm³. 3 ; The outer layer is made of high-density polyethylene with a melt index of 0.5~1.2 g / 10 min and a density of 0.950~0.970 g / cm³. 3 ; The outer, middle, and inner layers are made of metallocene medium-density polyethylene with a melt index of 0.1~1.0 g / 10 min and a density of 0.925~0.940 g / cm³. 3 .
[0007] Preferably, the homopolymer polypropylene has a melt index of 7.0~9.0 g / 10 min and a density of 0.890~0.910 g / cm³. 3 .
[0008] Preferably, the melt index of the easy-to-remove material is 0.1~1.0 g / 10min, and the density is 0.905~0.925 g / cm³. 3 ; The low-density polyethylene has a melt index of 0.2~1.2 g / 10min and a density of 0.918~0.930 g / cm³. 3 ; The inner layer is made of high-density polyethylene with a melt index of 3.3~4.5 g / 10min and a density of 0.940~0.960 g / cm³. 3 .
[0009] Preferably, the processing aids used in the outer, middle, and inner layers have a melt index of 1.5~3.0 g / 10 min and a density of 0.900~0.925 g / cm³. 3 .
[0010] Preferably, the copolymer polypropylene is grade RB707CF; the high-density polyethylene used for the outer layer is grade LO6003P. The outer, middle, and inner layers are made of metallocene medium-density polyethylene of grade 3505MC. The homopolymer polypropylene is graded HP510M; The grade of the easy-to-remove material is PB0110M; The grade of the low-density polyethylene is 2420F; The inner layer uses high-density polyethylene of grade C912A; The processing aids used in the outer, middle and inner layers are designated PA0895LD.
[0011] The present invention also provides a method for preparing the high-temperature resistant, easy-to-peel film for sealing Tyvek as described above, comprising the following steps: The raw materials for the preparation of the outer, middle and inner layers are co-extruded and blown into a film to obtain a high-temperature resistant, easy-to-peel film for sealing Tyvek.
[0012] Preferably, the raw materials for preparing the outer layer, middle layer and inner layer are melted and plasticized by the outer layer extruder, the middle layer extruder and the inner layer extruder, respectively, and the resulting adhesive liquid is transported to the die head for extrusion blown film.
[0013] Preferably, the outer, middle, and inner extruders are each equipped with five heating zones, designated as zones 1 to 5 according to the order in which the raw materials pass through. The outer extruder has zone 1 temperatures of 190-200°C, zone 2 temperatures of 195-205°C, zone 3 temperatures of 200-210°C, zone 4 temperatures of 205-215°C, and zone 5 temperatures of 198-208°C. The middle extruder has zone 1 temperatures of 200-210°C, zone 2 temperatures of 205-215°C, zone 3 temperatures of 203-213°C, and zone 4 temperatures of 200-215°C. The inner extruder has four heating zones, numbered 1 to 4 according to the order in which the raw materials pass through. The temperature of zone 1 is 200-210℃, zone 2 is 205-215℃, zone 3 is 210-220℃, and zone 4 is 203-213℃.
[0014] The present invention also provides the application of the high-temperature retortable easy-open film for sealing Tyvek as described in the above-described scheme or the high-temperature retortable easy-open film for sealing Tyvek prepared by the preparation method described in the above-described scheme in medical device packaging.
[0015] This invention provides a high-temperature resistant, easy-to-peel film for sealing Tyvek, comprising an outer layer, a middle layer, and an inner layer arranged sequentially. By weight, the outer layer comprises: 10-40 parts copolymer polypropylene, 15-50 parts high-density polyethylene, 10-40 parts metallocene medium-density polyethylene, and 0.5-1 parts processing aid. By weight, the middle layer comprises: 15-50 parts copolymer polypropylene, 10-30 parts homopolymer polypropylene, 20-60 parts metallocene medium-density polyethylene, and 0.5-1 parts processing aid. By weight, the inner layer comprises: 15-35 parts easy-to-peel material, 10-30 parts low-density polyethylene, 15-40 parts metallocene medium-density polyethylene, 20-50 parts high-density polyethylene, and 0.5-1 parts processing aid. This invention selects copolymer polypropylene, homopolymer polypropylene, and high-density polyethylene with excellent temperature resistance for the outer and middle layers. Simultaneously, it adds an easy-peeling material with good temperature resistance and stable peelability, along with high-density polyethylene with good temperature resistance, to the inner layer. This improves the film's high-temperature retortability while ensuring its easy-peelability. Furthermore, the metallocene medium-density polyethylene added to the outer, middle, and inner layers of this invention has good toughness, processability, and compatibility with polypropylene, while the low-density polyethylene added to the inner layer has fewer crystal points and good processability, further ensuring the film's performance. In summary, this invention strictly controls the types and proportions of raw materials used in the outer, middle, and inner layers to obtain an easy-peeling film with good high-temperature retortability and excellent mechanical properties, showing broad application prospects in the field of medical device packaging. Example results show that the high-temperature retortable easy-peeling film of this invention does not stick or wrinkle after being boiled at 121°C for 30 minutes, and the peel force before and after boiling can be controlled between 2.5 and 6 N / 15 mm, without stringing, delamination, exudation, or leakage. Detailed Implementation
[0016] This invention provides a high-temperature resistant, easy-to-remove film for sealing Tyvek, comprising an outer layer, a middle layer, and an inner layer arranged sequentially. The raw materials for preparing the outer layer, by weight, include: 10-40 parts of copolymer polypropylene, 15-50 parts of high-density polyethylene, 10-40 parts of metallocene medium-density polyethylene, and 0.5-1 parts of processing aids. The raw materials for preparing the middle layer, by weight, include: 15-50 parts of copolymer polypropylene, 10-30 parts of homopolymer polypropylene, 20-60 parts of metallocene medium-density polyethylene, and 0.5-1 parts of processing aids. By weight, the raw materials for preparing the inner layer include: 15-35 parts of easy-to-remove material, 10-30 parts of low-density polyethylene, 15-40 parts of metallocene medium-density polyethylene, 20-50 parts of high-density polyethylene, and 0.5-1 parts of processing aids.
[0017] Unless otherwise specified, all raw materials used in this invention are commercially available products.
[0018] The outer layer is prepared from 10 to 40 parts by weight of copolymer polypropylene, specifically 15, 20, 25, 28, 35, or 40 parts; the melt index of the copolymer polypropylene is preferably 1.0 to 2.0 g / 10 min, more preferably 1.4 to 1.6 g / 10 min, and the density is preferably 0.900 to 0.910 g / cm³. 3 More preferably, it is 0.902~0.906 g / cm³. 3 In a specific embodiment of the present invention, the copolymer polypropylene is grade RB707CF, manufactured by Boluer Chemicals, with a melt index of 1.5 g / 10 min and a density of 0.905 g / cm³. 3 Specifically, it is a copolymerized upblown polypropylene; the copolymerized polypropylene used in this invention has the characteristics of high tensile strength, high stiffness, good temperature resistance, and easy processing.
[0019] Based on the mass fraction of the copolymer polypropylene used in the outer layer, the raw materials for preparing the outer layer include 15 to 50 parts of high-density polyethylene, specifically 25, 28, 35, 38, 45, or 50 parts; the melt index of the high-density polyethylene used in the outer layer is preferably 0.5 to 1.2 g / 10 min, more preferably 0.8 to 1.0 g / 10 min, and the density is preferably 0.950 to 0.970 g / cm³. 3 More preferably, it is 0.96~0.965 g / cm³. 3 In a specific embodiment of the present invention, the outer layer uses high-density polyethylene of grade LO6003P, manufactured by LG Chem, with a melt index of 0.85 g / 10 min and a density of 0.962 g / cm³. 3 The high-density polyethylene used in this invention has the characteristics of good temperature resistance, few crystal points, little precipitation, and easy processing.
[0020] Based on the mass fraction of the copolymer polypropylene used in the outer layer, the raw materials for preparing the outer layer include 10-40 parts of metallocene medium-density polyethylene, specifically 12, 25, 30, 35, 38, or 40 parts; the melt index of the metallocene medium-density polyethylene used in the outer layer is preferably 0.1-1.0 g / 10 min, more preferably 0.4-0.6 g / 10 min, and the density is preferably 0.925-0.940 g / cm³. 3 More preferably, it is 0.93~0.94 g / cm³. 3 In a specific embodiment of the present invention, the metallocene medium-density polyethylene is grade 3505MC, manufactured by ExxonMobil, with a melt index of 0.5 g / 10 min and a density of 0.935 g / cm³. 3 The metallocene medium-density polyethylene used in this invention has the characteristics of good toughness, easy processing, and good compatibility with polypropylene.
[0021] Based on the mass fraction of the copolymer polypropylene used in the outer layer, the raw materials for preparing the outer layer include 0.5 to 1 part of processing aids, specifically 0.6 parts; the melt index of the processing aids is preferably 1.5 to 3.0 g / 10 min, more preferably 2 to 2.5 g / 10 min, and the density is preferably 0.900 to 0.925 g / cm³. 3 More preferably, it is 0.91~0.92 g / cm³. 3 In a specific embodiment of the present invention, the processing aid is designated PA0895LD, manufactured by Suzhou Constance Engineering Plastics Co., Ltd., with a melt index of 2.1 g / 10 min and a density of 0.915 g / cm³. 3 The processing aids used in this invention can effectively reduce die buildup, reduce crystal points, lower extrusion pressure, and improve production efficiency.
[0022] By mass, the raw materials for preparing the middle layer include 15 to 50 parts of copolymer polypropylene, specifically 15, 22, 26, 33, 45, or 50 parts; the melt index, density, and grade of the copolymer polypropylene used in the middle layer are the same as those used in the outer layer, and will not be repeated here.
[0023] Based on the mass of the copolymer polypropylene used in the middle layer, the raw materials for preparing the middle layer include 10-30 parts of homopolymer polypropylene, specifically 10, 15, 17, 20, 25, or 30 parts; the melt index of the homopolymer polypropylene is preferably 7.0-9.0 g / 10 min, more preferably 8-8.5 g / 10 min, and the density is preferably 0.890-0.910 g / cm³. 3 More preferably, it is 0.895~0.905 g / cm³. 3 In a specific embodiment of the present invention, the homopolymer polypropylene is grade HP510M, manufactured by CNOOC Shell, with a melt index of 8.0 g / 10 min and a density of 0.900 g / cm³. 3 The homopolymer polypropylene used in this invention has excellent heat resistance, few crystal points, and high stiffness.
[0024] Based on the mass of the copolymer polypropylene used in the middle layer, the raw materials for preparing the middle layer include 20 to 60 parts of metallocene medium-density polyethylene, specifically 20, 28, 38, 43, 50, or 58 parts; the melt index, density, and grade of the metallocene medium-density polyethylene used in the middle layer are the same as those used in the outer layer, and will not be repeated here.
[0025] Based on the mass of the copolymer polypropylene used in the middle layer, the raw materials for preparing the middle layer include 0.5 to 1 part of processing aids, specifically 0.8 parts; the melt index, density and grade of the processing aids used in the middle layer are the same as those used in the outer layer, and will not be repeated here.
[0026] The inner layer is prepared from 15 to 35 parts by weight of an easy-to-peel material, specifically 15, 18, 20, 25, 28, or 35 parts; the easy-to-peel material has a melt index of 0.1 to 1.0 g / 10 min, more preferably 0.3 to 0.5 g / 10 min, and a density of 0.905 to 0.925 g / cm³. 3 More preferably, it is 0.91~0.915 g / cm³. 3 In a specific embodiment of the present invention, the easy-to-remove material is designated PB0110M, manufactured by Basel, with a melt index of 0.4 g / 10min and a density of 0.914 g / cm³. 3 The easy-to-remove material used in this invention has the characteristics of good temperature resistance and easy and stable removal.
[0027] Based on the mass fraction of the easily removable material, the raw materials for preparing the inner layer include 10-30 parts of low-density polyethylene, specifically 10, 15, 20, 25, 28, or 30 parts; the melt index of the low-density polyethylene is preferably 0.2-1.2 g / 10min, more preferably 0.7-0.8 g / 10min, and the density is preferably 0.918-0.930 g / cm³. 3 More preferably, it is 0.92~0.925 g / cm³. 3 In a specific embodiment of the present invention, the low-density polyethylene is grade 2420F, manufactured by CNOOC Shell, with a melt index of 0.75 g / 10min and a density of 0.923 g / cm³. 3 Specifically, it is a high-pressure low-density polyethylene. The low-density polyethylene used in this invention has the characteristics of few crystal points and good processability.
[0028] Based on the mass fraction of the easily removable material, the raw materials for preparing the inner layer include 15 to 40 parts of metallocene medium-density polyethylene, specifically 15, 20, 26, 30, 35, or 40 parts; the melt index, density, and grade of the metallocene medium-density polyethylene used in the middle layer are the same as those used in the outer layer, and will not be repeated here.
[0029] Based on the mass fraction of the easily removable material, the raw materials for preparing the inner layer include 20-50 parts of high-density polyethylene, specifically 22, 25, 30, 38, 42, or 48 parts; the high-density polyethylene has a melt index of 3.3-4.5 g / 10min, preferably 3.9-4 g / 10min, and a density of 0.940-0.960 g / cm³.3 The preferred value is 0.95~0.955 g / cm³. 3 In a specific embodiment of the present invention, the inner layer uses high-density polyethylene of grade C912A, manufactured by Hanwha Total, with a melt index of 3.9 g / 10 min and a density of 0.954 g / cm³. 3 The high-density polyethylene used in this invention has the characteristics of good temperature resistance, few crystal points, and easy processing.
[0030] Based on the mass fraction of the easily removable material, the raw materials for preparing the inner layer include 0.5 to 1 part of processing aids. Specifically, it can be 1 part. The melt index, density, and grade of the processing aids used in the inner layer are the same as those used in the outer layer, and will not be repeated here.
[0031] In this invention, taking the total mass of the raw materials for the preparation of the outer layer, middle layer and inner layer as 100%, the mass fraction of the raw materials for the preparation of the outer layer is 20% to 30%, specifically 20%, 25%, 28% and 30%; the mass fraction of the raw materials for the preparation of the middle layer is preferably 40% to 60%, specifically 40%, 50%, 52%, 55% and 60%; and the mass fraction of the raw materials for the preparation of the inner layer is preferably 15% to 30%, specifically 18%, 20%, 22%, 25% and 30%.
[0032] In this invention, the thickness of the heat-resistant retort easy-peel film used for sealing Tyvek is 30-80 micrometers, specifically 50 micrometers; the longitudinal tensile strength of the heat-resistant retort easy-peel film used for sealing Tyvek is preferably 32-35 MPa, the transverse tensile strength is preferably 30-33 MPa, the longitudinal elongation at break is preferably 620-640%, the transverse elongation at break is preferably 715-730%, the longitudinal modulus of elasticity is preferably 420-435 MPa, the transverse modulus of elasticity is preferably 430-460 MPa, and the heat-sealing strength is 2.5-6 N / 15 mm, specifically 4-5 N / 15 mm.
[0033] In this invention, the melt index test conditions for copolymer polypropylene and homopolymer polypropylene are: 230℃ / 2.16kg, and the melt index test conditions for high-density polyethylene (including high-density polyethylene used in the outer layer and high-density polyethylene used in the inner layer), metallocene medium-density polyethylene, low-density polyethylene and processing aids are: 190℃ / 2.16kg.
[0034] The high-temperature resistant, easy-to-remove film provided by this invention maintains essentially the same heat-sealing strength before and after cooking, and does not exhibit stringing, delamination, exudation, or leakage. It is suitable for heat-sealing Tyvek products and has broad application prospects.
[0035] The present invention also provides a method for preparing the high-temperature resistant, easy-to-peel film for sealing Tyvek as described above, comprising the following steps: The raw materials for the preparation of the outer, middle and inner layers are co-extruded and blown into a film to obtain a high-temperature resistant, easy-to-peel film for sealing Tyvek.
[0036] In this invention, the co-extrusion blown film preferably includes: the raw materials for preparing the outer layer, middle layer and inner layer are melted and plasticized by the outer layer extruder, the middle layer extruder and the inner layer extruder respectively, and the resulting adhesive liquid is transported to the die head for extrusion blown film.
[0037] In this invention, the outer extruder, middle extruder, and inner extruder are preferably each provided with five heating zones, which are sequentially designated as zones 1 to 5 according to the order in which the raw materials pass through. The temperature of zone 1 of the outer extruder is preferably 190-200℃, specifically 200℃; the temperature of zone 2 is preferably 195-205℃, specifically 200℃; the temperature of zone 3 is preferably 200-210℃, specifically 205℃; the temperature of zone 4 is preferably 205-215℃, specifically 210℃; and the temperature of zone 5 is preferably 198-208℃, specifically 203℃. Similarly, the temperature of zone 1 of the middle extruder is preferably 200-210℃, specifically 205℃; and the temperature of zone 2 is preferably... The temperature of zone 3 is preferably 203~213℃, specifically 208℃; the temperature of zone 4 is preferably 200~210℃, specifically 205℃; and the temperature of zone 5 is preferably 190~210℃, specifically 195℃. The temperature of zone 1 of the inner extruder is preferably 180~190℃, specifically 185℃; the temperature of zone 2 is preferably 185~195℃, specifically 190℃; the temperature of zone 3 is preferably 190~200℃, specifically 195℃; the temperature of zone 4 is preferably 185~195℃, specifically 190℃; and the temperature of zone 5 is preferably 185~195℃, specifically 190℃.
[0038] In this invention, the extrusion pressure of the outer extruder is preferably 285~380 bar, the extrusion pressure of the middle extruder is preferably 290~360 bar, and the extrusion pressure of the inner extruder is preferably 265~375 bar.
[0039] In this invention, the die head is provided with four heating zones, which are numbered 1 to 4 according to the order in which the raw materials pass through. The temperature of zone 1 of the die head is preferably 200 to 210°C, specifically 205°C; the temperature of zone 2 is preferably 205 to 215°C, specifically 210°C; the temperature of zone 3 is preferably 210 to 220°C, specifically 215°C; and the temperature of zone 4 is preferably 203 to 213°C, specifically 208°C.
[0040] In this invention, the extrusion blown film is used to obtain a film bubble. The film bubble is preferably cooled by air cooling and then traction and rotation by a stabilizing ring and a herringbone pattern. After flattening the film bubble, it is subjected to corona treatment, edge trimming, lower traction and winding to obtain the high-temperature resistant and easy-to-peel film for sealing Tyvek.
[0041] This invention also provides the application of the high-temperature retortable easy-open film for sealing Tyvek as described in the above-described scheme, or the high-temperature retortable easy-open film for sealing Tyvek prepared by the preparation method described in the above-described scheme, in medical device packaging. In a specific embodiment of this invention, the high-temperature retortable easy-open film is mainly used for sealing Tyvek, and can also be used for sealing PE.
[0042] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0043] The sources, melt index, and density of the raw materials used in the examples are shown in Table 1.
[0044] Table 1. Raw material source, melt index, and density
[0045] Example 1 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 30%, 40%, and 30%, respectively. The raw material ratios of each layer are shown in Table 2. The film thickness is 50 μm.
[0046] The preparation method is as follows: The raw materials for the outer, middle, and inner layers are mixed in proportion using an automatic batching system and then fed into the outer, middle, and inner layer extruders. After melting and plasticizing, the raw materials are fed into the die head, where an upward blowing process is used. Following air cooling, the material passes through a stabilizing ring and a herringbone pattern, then is traction-driven and rotated to flatten the cylinder. It then enters a corona treatment device via guide rollers for corona treatment. After edge trimming, the material passes through lower traction clamping rollers and enters a front and rear winding device for front and rear winding, thus obtaining the high-temperature resistant, easy-to-peel film for sealing Tyvek. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the die head temperature, are shown in Table 3.
[0047] Table 2 Raw material ratios (parts by mass) for Examples 1-6
[0048] Table 3. Temperature and pressure of the extruder and temperature of the die head
[0049] Example 2 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 20%, 55%, and 25%, respectively. The raw material ratios of each layer are shown in Table 2. The film thickness is 50 μm.
[0050] The preparation method is the same as in Example 1. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the die temperature, are shown in Table 4.
[0051] Table 4. Temperature and pressure of the extruder and temperature of the die head
[0052] Example 3 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 25% for the outer layer, 50% for the middle layer, and 25% for the inner layer. The raw material ratios for each layer are shown in Table 2. The film thickness is 50 μm.
[0053] The preparation method is the same as in Example 1. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the die temperature, are shown in Table 5.
[0054] Table 5. Temperature and pressure of the extruder and temperature of the die head
[0055] Example 4 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 28%, 50%, and 22%, respectively. The raw material ratios of each layer are shown in Table 2. The film thickness is 50 μm.
[0056] The preparation method is the same as in Example 1. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the die temperature, are shown in Table 6.
[0057] Table 6. Temperature and pressure of the extruder and temperature of the die.
[0058] Example 5 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 30%, 52%, and 18%, respectively. The raw material ratios of each layer are shown in Table 2. The film thickness is 50 μm.
[0059] The preparation method is the same as in Example 1. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the die temperature, are shown in Table 7.
[0060] Table 7. Temperature and pressure of the extruder and temperature of the die.
[0061] Example 6 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 20%, 60%, and 20%, respectively. The raw material ratios of each layer are shown in Table 2. The film thickness is 50 μm.
[0062] The preparation method is the same as in Example 1. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the die temperature, are shown in Table 8.
[0063] Table 8. Temperature and pressure of the extruder and temperature of the die head
[0064] Comparative Example 1 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 25% for the outer layer, 50% for the middle layer, and 25% for the inner layer. The raw material ratios for each layer are shown in Table 9. The film thickness is 50 μm.
[0065] Table 9 Raw material ratios for each layer in Comparative Example 1
[0066] In Table 1, 2426H is high-density polyethylene (HDPE), 201XV is linear low-density polyethylene (LLDPE), 7042 is linear LLDPE, and 1002BU is linear LLDPE. PB8640M is an easy-to-remove material.
[0067] The preparation method is the same as in Example 1. The temperatures and pressures of the outer, middle, and inner layer extruders, as well as the temperature of the die head, are shown in Table 10.
[0068] Table 10 Extruder Temperature and Pressure, and Die Temperature
[0069] Comparative Example 2 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, which are co-extruded and blown together. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 30%, 40%, and 30%, respectively. The raw material ratios of each layer are shown in Table 11. The film thickness is 50 μm.
[0070] The preparation method and the setting conditions of each extruder are the same as in Example 1.
[0071] Comparative Example 3 A high-temperature resistant, easy-to-peel film for sealing Tyvek is made of three layers: an outer layer, a middle layer, and an inner layer, by co-extrusion blown film. The total mass of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer is 100%. The mass fractions of the raw materials used in the preparation of the outer layer, the middle layer, and the inner layer are 30%, 52%, and 10%, respectively. The raw material ratios of each layer are shown in Table 11. The film thickness is 50 μm.
[0072] The preparation method and the setting conditions of each extruder are the same as in Example 1.
[0073] Table 11 Raw material ratios for each layer in Comparative Examples 2 and 3
[0074] Performance testing The tensile strength, elongation at break, elastic modulus, wetting tension, heat seal strength, and retort resistance of the high-temperature resistant retort films prepared in Examples 1 to 6 and Comparative Examples 1 to 3 were tested. The test methods and test results are shown in Table 12.
[0075] Table 12 Performance Test Results
[0076] As can be seen from the test results in Table 12, the high-temperature resistant retortable easy-peel film prepared by this invention has excellent mechanical properties and good high-temperature retortability. The heat seal strength with Tyvek before and after retort is within 4~5 N / 15 mm. It also has good opening reliability before and after retort, which meets the requirements for easy peeling. In Comparative Example 1, the traditional formula was used, and the resulting film had poor easy peeling and high peel strength. At the same time, it had poor high-temperature retortability. After retort, the film melted together and was easy to tear the Tyvek film. In Comparative Example 2, the amount of inner easy-peel material was small, and the resulting film had high heat seal strength, but did not meet the requirements for easy peeling. Moreover, the seal was leaking and was easy to tear. In Comparative Example 3, the amount of inner easy-peel material was large, and the resulting film had low heat seal strength and leaking seal.
[0077] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A high-temperature resistant, easy-to-remove film for sealing Tyvek, characterized in that, This includes an outer layer, a middle layer, and an inner layer arranged sequentially. The raw materials for preparing the outer layer, by weight, include: 10-40 parts of copolymer polypropylene, 15-50 parts of high-density polyethylene, 10-40 parts of metallocene medium-density polyethylene, and 0.5-1 parts of processing aids. The raw materials for preparing the middle layer, by weight, include: 15-50 parts of copolymer polypropylene, 10-30 parts of homopolymer polypropylene, 20-60 parts of metallocene medium-density polyethylene, and 0.5-1 parts of processing aids. By weight, the raw materials for preparing the inner layer include: 15-35 parts of easy-to-remove material, 10-30 parts of low-density polyethylene, 15-40 parts of metallocene medium-density polyethylene, 20-50 parts of high-density polyethylene, and 0.5-1 parts of processing aids.
2. The high-temperature resistant, easy-to-remove film for sealing Tyvek as described in claim 1, characterized in that, The outer and middle layers use copolymer polypropylene with a melt index of 1.0~2.0 g / 10 min and a density of 0.900~0.910 g / cm³. 3 ; The outer layer is made of high-density polyethylene with a melt index of 0.5~1.2 g / 10 min and a density of 0.950~0.970 g / cm³. 3 ; The outer, middle, and inner layers are made of metallocene medium-density polyethylene with a melt index of 0.1~1.0 g / 10 min and a density of 0.925~0.940 g / cm³. 3 .
3. The high-temperature resistant, easy-to-peel film for sealing Tyvek as described in claim 1, characterized in that, The homopolymer polypropylene has a melt index of 7.0~9.0 g / 10 min and a density of 0.890~0.910 g / cm³. 3 .
4. The high-temperature resistant, easy-to-peel film for sealing Tyvek as described in claim 1, characterized in that, The easily removable material has a melt index of 0.1~1.0 g / 10min and a density of 0.905~0.925 g / cm³. 3 ; The low-density polyethylene has a melt index of 0.2~1.2 g / 10min and a density of 0.918~0.930 g / cm³. 3 ; The inner layer is made of high-density polyethylene with a melt index of 3.3~4.5 g / 10min and a density of 0.940~0.960 g / cm³. 3 .
5. The high-temperature resistant, easy-to-peel film for sealing Tyvek as described in claim 1, characterized in that, The processing aids used in the outer, middle, and inner layers have a melt index of 1.5~3.0 g / 10 min and a density of 0.900~0.925 g / cm³. 3 .
6. The high-temperature resistant, easy-to-peel film for sealing Tyvek as described in claim 1, characterized in that, The copolymer polypropylene is graded RB707CF; the high-density polyethylene used for the outer layer is graded LO6003P. The outer, middle, and inner layers are made of metallocene medium-density polyethylene of grade 3505MC. The homopolymer polypropylene is graded HP510M; The grade of the easy-to-remove material is PB0110M; The grade of the low-density polyethylene is 2420F; The inner layer uses high-density polyethylene of grade C912A; The processing aids used in the outer, middle and inner layers are designated PA0895LD.
7. The method for preparing the high-temperature resistant, easy-to-peel film for sealing Tyvek as described in any one of claims 1 to 6, characterized in that, Includes the following steps: The raw materials for the preparation of the outer, middle and inner layers are co-extruded and blown into a film to obtain a high-temperature resistant, easy-to-peel film for sealing Tyvek.
8. The preparation method according to claim 7, characterized in that, The raw materials for the preparation of the outer, middle and inner layers are melted and plasticized by the outer layer extruder, the middle layer extruder and the inner layer extruder, respectively, and the resulting adhesive liquid is transported to the die head for extrusion blown film.
9. The preparation method according to claim 7, characterized in that, The outer, middle, and inner extruders are each equipped with five heating zones, numbered 1 to 5 according to the order in which the raw materials pass through. The outer extruder has zone 1 with temperatures of 190-200℃, zone 2 with 195-205℃, zone 3 with 200-210℃, zone 4 with 205-215℃, and zone 5 with 198-208℃. The middle extruder has zone 1 with temperatures of 200-210℃, zone 2 with 205-215℃, zone 3 with 203-213℃, and zone 4 with 200-210℃. The temperature of zone 1 is 180~190℃, and the temperature of zone 2 is 185~195℃, the temperature of zone 3 is 190~200℃, the temperature of zone 4 is 185~195℃, and the temperature of zone 5 is 185~195℃. The die head is provided with 4 heating zones, which are numbered 1 to 4 according to the order of raw material passage. The temperature of zone 1 of the die head is 200~210℃, the temperature of zone 2 is 205~215℃, the temperature of zone 3 is 210~220℃, and the temperature of zone 4 is 203~213℃.
10. The application of the high-temperature retortable easy-open film for sealing Tyvek as described in any one of claims 1 to 6, or the high-temperature retortable easy-open film for sealing Tyvek prepared by the preparation method described in any one of claims 7 to 9, in medical device packaging.