A high-temperature resistant composite oven film and its preparation method

Abstract

This invention relates to a high-temperature resistant composite oven film and its preparation method, which not only meets the requirements for high-temperature food heating and diverse bag manufacturing needs, but also complies with food bag hygiene and safety requirements, controls production costs, and facilitates recycling. The composite oven film body is formed by laminating a first composite film and a second composite film together with a high-temperature resistant adhesive. The first composite film is a heat-sealable PET film, and the second composite film is a high-temperature resistant PET film or PA film. The high-temperature resistant adhesive includes a polyester polyol containing aromatic polyester segments. Advantages: This high-temperature resistant composite oven film and its preparation method not only meet the requirements for high-temperature food heating and diverse bag manufacturing needs, but also comply with food bag hygiene and safety requirements, control production costs, and facilitate recycling.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of food packaging bag film manufacturing, and particularly relates to a high-temperature-resistant composite oven film and a preparation method thereof. BACKGROUND

[0002] The global oven bag market is expected to grow at a CAGR of 4.5% over the next five years, reaching US$1.2 billion by 2030, driven by increasing demand for convenience foods, improved awareness of healthy eating habits, and the increasing popularity of cooking shows. The global oven bag market is divided into many types according to the material, among which PET oven bags are expected to dominate the global oven bag market during the forecast period, as they not only have high durability but also have low production costs.

[0003] The existing oven bags are basically three-edge sealed bags made of single-layer materials, such as CN 203111770 U, a convenient oven food packaging bag with easy bundling and opening, which includes a bag body, an open edge at the top of the bag body, and side sealing edges or folded edges on the left and right sides formed by a folding process. At least one narrow strip is provided on the bag body near the open edge, and at least one fusion seal is formed on the narrow strip to form a fusion seal. The length of the narrow strip is equal to the length of the open edge. The narrow strip is located at the lower part of the open edge and is parallel to the open edge. The length of the narrow strip is equal to the length of the open edge, and the left and right ends of the narrow strip are fused to the left and right sides of the bag body to form two fusion seals. The area between the two fusion seals on the narrow strip is provided with a longitudinal tear opening. The tear opening is a tear or a virtual line. The front and back of the bag body each have a narrow strip. The bag body is made of PET film, PA66 film, PA6 film, or a mixed film of PA66 and PA6. This type of oven bag is used for roasting meat and seafood. For roasted meat and seafood, the existing oven bag can basically meet the use requirements. It is the main source of income for oven bags. However, with the increasing demand for convenience foods in various regions around the world, the application of other foods such as baked bread is also becoming more and more popular. The existing oven bags made of single-layer materials (such as single-layer PET film oven bags) cannot meet the application requirements of other foods such as baked bread, and the existing oven bags cannot be used for other foods such as baked bread.

[0004] The thin thickness and single form have been difficult to meet the needs of other food such as baked bread, and if other types of oven bags (such as eight-edge sealed bags) are to be developed, the thickness of the single layer film needs to be increased, which will multiply the production cost. In addition, the existing synthetic film made of oven bags also has some problems, such as some synthetic films, the glue in the film cannot withstand the heating temperature of the oven, so the oven bag made of it is easy to break when used, and some synthetic films, the glue in the film can withstand the heating temperature of the oven, but the glue will migrate out of the excessive harmful substances to the human body when the oven is heated at high temperature. SUMMARY

[0005] Design purpose: In order to avoid the shortcomings in the background art, a kind of high-temperature-resistant composite oven film and its preparation method are designed, which not only can meet the needs of high-temperature heating of food, but also can meet the needs of bag making diversity, at the same time meet the sanitary and safety requirements of food bag, at the same time control the production cost, and at the same time facilitate recycling.

[0006] Design scheme: In order to realize the above design purpose.

[0007] 1. The composite oven film body is composed of a first composite film and a second composite film by high-temperature-resistant glue, the first composite film is a heat-sealable PET film, the second composite film is a high-temperature-resistant PET film or PA film, the high-temperature-resistant glue includes polyester polyol and the polyester polyol contains aromatic polyester segment, which is one of the technical features of the application. The purpose of such design is that the composite oven film body is composed of a first composite film and a second composite film by high-temperature-resistant glue, the first composite film is a heat-sealable PET film, the second composite film is a high-temperature-resistant PET film or PA film, the high-temperature-resistant glue includes polyester polyol and the polyester polyol contains aromatic polyester segment, so that the composite oven film of the application has the following advantages: first, the application combines the functional heat-sealable PET (which also has high-temperature-resistant properties) with the high-temperature-resistant PA film or PET film through high-temperature-resistant glue, which increases the thickness of the film under the premise of controlling production cost, so that the composite film can be processed into various different bag types (a variety of different oven bags can be developed to adapt to different sizes of ovens, air fryers, microwaves, and also to different types of contents, such as poultry, ordinary meat, seafood, vegetables, and different products), meeting the diversified needs of the market; second, the high-temperature-resistant composite oven film can withstand a temperature of up to 204℃, so that the oven bag made of it can be used in the oven; third, the high-temperature-resistant glue includes polyester polyol and the polyester polyol contains aromatic polyester segment, which meets the food bag hygiene and safety requirements; fourth, when the first composite film and the second composite film are both PET films, the composite oven film is a single material film, which is more convenient to recycle.

[0008] 2. The high-temperature-resistant glue is made of the following components by weight percentage: 20%-20.5% adipic acid, 33.5-34.5% 2,2-dimethyl-1,3-propanediol, 8%-8.4% ethylene glycol, 0.085%-0.089% butyl titanate, 0.025%-0.027% triethyl phosphate, and the rest is terephthalic acid, which is the second technical feature of the application. The purpose of such design is that the high-temperature-resistant glue is made of the following components by weight percentage: 20%-20.5% adipic acid, 33.5-34.5% 2,2-dimethyl-1,3-propanediol, 8%-8.4% ethylene glycol, 0.085%-0.089% butyl titanate, 0.025%-0.027% triethyl phosphate, and the rest is terephthalic acid, which can withstand a temperature of up to 220℃, and its properties can meet the requirements of oven bags for high-temperature resistance. In addition, the glue of this formula not only meets the food bag hygiene and safety requirements, but also has a low migration amount of harmful substances when heated in the oven.

[0009] 3. The design of the high-temperature resistant adhesive application amount being 3.8g / ㎡-4.2g / ㎡ is the third technical feature of this invention. The purpose of this design is that the application amount of the high-temperature resistant adhesive is 3.8g / ㎡-4.2g / ㎡, which ensures the bonding strength between the first and second composite films while effectively controlling the production cost of the oven film.

[0010] 4. Step 1: First, the first composite film located in the first unwinding mechanism and the second composite film located in the second unwinding mechanism are unwound respectively. Then, the composite surfaces of the unwound first composite film and the second composite film are subjected to online corona treatment. After that, the composite surfaces of the corona-treated first composite film or the second composite film are coated with adhesive online. Then, the first composite film and the second composite film are pressed together online by hot press rollers. After pressing, the first composite film and the second composite film are dried online and then wound up by the winding mechanism to form a composite film. Step 2: Then, the wound composite film is placed in a curing chamber for curing treatment. The temperature of the curing chamber is 50℃-60℃ and the curing time is not less than 96 hours, forming the design of a high-temperature resistant composite oven film, which is the fourth technical feature of this invention.The purpose of this design is to ensure that when a high-temperature resistant adhesive (composed of the following components by weight percentage: 37.41408% terephthalic acid, 20.36022% adipic acid, 33.93370% 2,2-dimethyl-1,3-propanediol, 8.17889% ethylene glycol, 0.08701% tetrabutyl titanate, and 0.02610% triethyl phosphate) is applied using the above method (step one: firstly, the first composite film located in the first unwinding mechanism and the second composite film located in the second unwinding mechanism are unwound respectively; then, the composite surfaces of the unwound first composite film and the second composite film are subjected to online corona treatment respectively; and then, the composite surfaces of the corona-treated first composite film or the second composite film are...) In the first step, the adhesive is applied online, and then the first and second composite films are pressed together online by hot press rollers. After pressing, the first and second composite films are dried online and then wound up by a winding mechanism to form a composite film. In the second step, the wound composite film is placed in a curing chamber for curing treatment. The temperature of the curing chamber is 50℃-60℃ and the curing time is not less than 96 hours to form a high-temperature resistant composite oven film. (This involves laminating a 0.023mm thick high-temperature resistant PET film with a 0.015mm thick heat-sealable PET film (HSPET).) The resulting high-temperature resistant composite oven film (applied at 4 g / m² during lamination) is made of 0.023 mm PET film and 0.015 mm HSPET film bonded together with high-temperature resistant adhesive. When used to make a high-temperature resistant oven composite bag, it exhibits excellent physical properties (heat-sealing strength 6.1 N / 15 mm; 5% tensile strain stress: 84 MPa longitudinally, 96 MPa transversely; tensile strength: 198 MPa longitudinally, 226 MPa transversely; elongation at break: 133% longitudinally, 1...). 0.07%; its heat shrinkage rate (150, 15min): longitudinal is 1.3%, transverse is -0.3%; haze is 3.8%); and the harmful substances are far below the requirements of the national standards (in terms of specific chemical substances, its cadmium and cadmium compounds are less than 2.5mg / kg; its lead and lead compounds are less than 5.0mg / kg; its mercury and mercury compounds are less than 1.5mg / kg; hexavalent chromium compounds are less than 2.0mg / kg; in terms of polybrominated biphenyls, none from monobrominated biphenyls to decabrominated biphenyls were detected; in terms of polybrominated diphenyl ethers, none from monobrominated diphenyl ethers to decabrominated diphenyl ethers were detected).

[0011] 5. The first and second composite films after lamination are dried online through a set of online drying chambers. The set of online drying chambers consists of a first drying chamber, a second drying chamber, and a third drying chamber. The design that the temperature of the first drying chamber is 70°C, the temperature of the second drying chamber is 80°C, and the temperature of the third drying chamber is 90°C is the fifth technical feature of the present invention. The purpose of this design is that the first and second composite films, after being pressed together, are dried online through a set of online drying chambers. This set of online drying chambers consists of a first drying chamber, a second drying chamber, and a third drying chamber. The temperature of the first drying chamber is 70°C, the temperature of the second drying chamber is 80°C, and the temperature of the third drying chamber is 90°C. This allows for the production of composite oven films with stable performance even during the plum rain season in Hangzhou. In addition, after the composite oven film passes through the first drying chamber at 70°C, the second drying chamber at 80°C, and the third drying chamber at 90°C in sequence, the residual solvent in the adhesive can be completely evaporated (in the case of oven bags made of a high-temperature resistant composite oven film, no residual solvent was detected upon testing).

[0012] Technical Solution 1: A high-temperature resistant composite oven film, comprising a composite oven film body, wherein the composite oven film body is formed by bonding a first composite film and a second composite film together with a high-temperature resistant adhesive, wherein the first composite film is a heat-sealable PET film, and the second composite film is a high-temperature resistant PET film or PA film, and the high-temperature resistant adhesive comprises a polyester polyol and the polyester polyol contains an aromatic polyester segment.

[0013] Technical Solution 2: A method for preparing a high-temperature resistant composite oven film, characterized by the following steps: Step 1, firstly, a first composite film located in a first unwinding mechanism and a second composite film located in a second unwinding mechanism are unwound respectively. Then, the composite surfaces of the unwound first composite film and the second composite film are subjected to online corona treatment respectively. After that, the composite surfaces of the corona-treated first composite film or the composite surfaces of the second composite film are coated with adhesive online. Then, the first composite film and the second composite film are pressed together online by hot press rollers. After pressing, the first composite film and the second composite film are dried online and then wound up by a winding mechanism to form a composite film. Step 2, the wound composite film is then placed in a curing chamber for curing treatment. The temperature of the curing chamber is 50℃-60℃ and the curing time is not less than 96 hours, thus forming the high-temperature resistant composite oven film.

[0014] Compared with the prior art, the present invention provides a high-temperature resistant composite oven film and its preparation method, which can not only meet the needs of high-temperature heating of food, but also meet the diverse needs of bag making, while complying with the hygiene and safety requirements of food bags, controlling production costs, and facilitating recycling. Attached Figure Description

[0015] Figure 1 This is a cross-sectional structural diagram of a high-temperature resistant composite oven film.

[0016] Figure 2 It is a test report Figure One .

[0017] Figure 3 It is a test report Figure Two .

[0018] Figure 4 It is a test report Figure Three .

[0019] Figure 5 It is a test report Figure Four .

[0020] Figure 6 It is a test report Figure Four . Detailed Implementation

[0021] Example 1: Refer to Appendix Figures 1-6 A high-temperature resistant composite oven film includes a composite oven film body 1, which is formed by laminating a first composite film 2 and a second composite film 3 with a high-temperature resistant adhesive. The first composite film 2 is a heat-sealable PET film, and the second composite film 3 is a high-temperature resistant PET film or PA film. The high-temperature resistant adhesive 4 includes a polyester polyol, and the polyester polyol contains an aromatic polyester segment. The aromatic polyester is obtained by esterifying an aromatic polyacid containing at least one benzene ring with an aliphatic or aromatic polyol. The polyacid is a dibasic acid or a tribasic acid; the aliphatic polyol is ethylene glycol or neopentyl glycol; the aromatic polyol is hydroquinone bis(hydroxyethyl) ether or resorcinol bis(hydroxyethyl) ether.

[0022] A high-temperature resistant adhesive, by weight, comprises the following components in the following weight percentages: 20%-20.5% adipic acid, 33.5-34.5% 2,2-dimethyl-1,3-propanediol, 8%-8.4% ethylene glycol, 0.085%-0.089% tetrabutyl titanate, 0.025%-0.027% triethyl phosphate, with the remainder being terephthalic acid. The application weight of the high-temperature resistant adhesive is 3.8 g / m²-4.2 g / m².

[0023] Preferably, the application rate of the high-temperature resistant adhesive is 4.0 g / m².

[0024] Example 2: Based on Example 1. A high-temperature resistant adhesive, based on the total weight of the high-temperature resistant adhesive, is made of the following components in weight percentages: 37.41408% terephthalic acid, 20.36022% adipic acid, 33.93370% 2,2-dimethyl-1,3-propanediol, 8.17889% ethylene glycol, 0.08701% tetrabutyl titanate, and 0.02610% triethyl phosphate. The high-temperature resistant PET film has a thickness of 0.023 mm, and the heat-sealed PET film (HSPET) has a thickness of 0.015 mm. That is, the high-temperature resistant composite oven film is formed by laminating 0.023 mm PET film and 0.015 mm HSPET film with high-temperature resistant adhesive. A high-temperature resistant oven composite bag is formed by heat-sealing the high-temperature resistant composite oven film. The high-temperature resistant oven composite bag, after testing, exhibits the following physical properties: heat seal strength of 6.1 N / 15 mm; 5% tensile strain stress: 84 MPa longitudinally, 96 MPa transversely; tensile strength: 198 MPa longitudinally, 226 MPa transversely; elongation at break: 133% longitudinally, 107% transversely; heat shrinkage rate (150, 15 min): 1.3% longitudinally, -0.3% transversely; haze of 3.8. Regarding specific chemical substances, cadmium and cadmium compounds were less than 2.5 mg / kg; lead and lead compounds were less than 5.0 mg / kg; mercury and mercury compounds were less than 1.5 mg / kg; hexavalent chromium compounds were less than 2.0 mg / kg; in terms of polybrominated biphenyls, none were detected from monobrominated biphenyls to decabrominated biphenyls; in terms of polybrominated diphenyl ethers, none were detected from monobrominated diphenyl ethers to decabrominated diphenyl ethers; in terms of physicochemical indicators, toluene diamine (4% acetic acid) was less than 0.001 mg / L; its evaporation residue - 4% acetic acid was 3 mg / L; its evaporation residue - n-hexane, at room temperature, 2h was 5 mg / L; its evaporation residue - 65% ethanol, at room temperature, 2h was 3 mg / L; potassium permanganate consumption (water) was 1 mg / L; heavy metals (calculated as Pb) in 4% acetic acid were less than 1 mg / L; in terms of solvent residue, none were detected.

[0025] Example 3: Based on Example 1. A high-temperature resistant adhesive, based on the total weight of the high-temperature resistant adhesive, is made of the following components in weight percentages: 38.89% terephthalic acid, 20% adipic acid, 33% 2,2-dimethyl-1,3-propanediol, 8% ethylene glycol, 0.085% tetrabutyl titanate, and 0.025% triethyl phosphate.

[0026] Example 4: Based on Example 1. A high-temperature resistant adhesive, based on the total weight of the high-temperature resistant adhesive, is made of the following components in weight percentages: 36.484% terephthalic acid, 20.5% adipic acid, 34.5% 2,2-dimethyl-1,3-propanediol, 8.4% ethylene glycol, 0.089% tetrabutyl titanate, and 0.027% triethyl phosphate.

[0027] Example 5: Based on Examples 1-4. A method for preparing a high-temperature resistant composite oven film includes the following steps: Step 1, firstly, a first composite film 2 located in a first unwinding mechanism and a second composite film 3 located in a second unwinding mechanism are unwound respectively. Then, the composite surfaces of the unwound first composite film 2 and the second composite film 3 are subjected to online corona treatment respectively. After that, the composite surfaces of the corona-treated first composite film 2 or the second composite film 3 are coated with adhesive online. Then, the first composite film 2 and the second composite film 3 are pressed together online by hot press rollers. After pressing, the first composite film 2 and the second composite film 3 are dried online and then wound up by a winding mechanism to form a composite film. Step 2, the wound composite film is then placed in a curing chamber for curing treatment. The temperature of the curing chamber is 50℃-60℃ and the curing time is not less than 96 hours (so that residual volatiles can be effectively and fully volatilized), forming any one of the high-temperature resistant composite oven films as described in claims 1-6.

[0028] The first composite film 2 and the second composite film 3, after lamination, are dried online through a set of online drying chambers. This set of online drying chambers consists of a first drying chamber, a second drying chamber, and a third drying chamber. The temperature of the first drying chamber is 70°C, the temperature of the second drying chamber is 80°C, and the temperature of the third drying chamber is 90°C. The pressure of the hot press roller during online lamination is 0.4 MPa, and the temperature of the hot press roller is 55°C-65°C. Preferably, the temperature of the hot press roller is 60°C. The online adhesive coating pressure is 0.4 MPa, and the adhesive application amount is 3.8 g / m²-4.2 g / m²; preferably, the adhesive application amount is 4.0 g / m².

[0029] When a high-temperature resistant adhesive (based on the total weight of the high-temperature resistant adhesive, it is composed of the following components in weight percentage: 37.41408% terephthalic acid, 20.36022% adipic acid, 33.93370% 2,2-dimethyl-1,3-propanediol, 8.17889% ethylene glycol, 0.08701% tetrabutyl titanate, and 0.02610% triethyl phosphate) is applied using the above method (step one: firstly, the first composite film located in the first unwinding mechanism and the second composite film located in the second unwinding mechanism are unwound respectively; then, the composite surfaces of the unwound first composite film and the second composite film are subjected to online corona treatment respectively; then, the composite surfaces of the corona-treated first composite film or the second composite film are subjected to...) In the first step, the adhesive is applied online, and then the first and second composite films are pressed together online by hot press rollers. After pressing, the first and second composite films are dried online and then wound up by a winding mechanism to form a composite film. In the second step, the wound composite film is placed in a curing chamber for curing treatment. The temperature of the curing chamber is 50℃-60℃ and the curing time is not less than 96 hours to form a high-temperature resistant composite oven film. (This involves laminating a 0.023mm thick high-temperature resistant PET film with a 0.015mm thick heat-sealable PET film (HSPET).) The resulting high-temperature resistant composite oven film (applied at 4 g / m² during lamination) is made of 0.023 mm PET film and 0.015 mm HSPET film bonded together with high-temperature resistant adhesive. When used to make a high-temperature resistant oven composite bag, it exhibits excellent physical properties (heat-sealing strength 6.1 N / 15 mm; 5% tensile strain stress: 84 MPa longitudinally, 96 MPa transversely; tensile strength: 198 MPa longitudinally, 226 MPa transversely; elongation at break: 133% longitudinally, 1...). 0.07%; its heat shrinkage rate (150, 15min): longitudinal 1.3%, transverse -0.3%; haze 3.8%); and the harmful substances are far below the requirements of the national standards (in terms of specific chemical substances, its cadmium and cadmium compounds are less than 2.5 mg / kg; its lead and lead compounds are less than 5.0 mg / kg; its mercury and mercury compounds are less than 1.5 mg / kg; hexavalent chromium compounds are less than 2.0 mg / kg; in terms of polybrominated biphenyls, none from monobrominated biphenyls to decabrominated biphenyls were detected; in terms of polybrominated diphenyl ethers, none from monobrominated diphenyl ethers to decabrominated diphenyl ethers were detected).

[0030] It should be understood that although the above embodiments provide a relatively detailed textual description of the design concept of the present invention, these textual descriptions are merely simple textual descriptions of the design concept of the present invention, and not limitations on the design concept of the present invention. Any combination, addition, or modification that does not exceed the design concept of the present invention falls within the protection scope of the present invention.

Claims

1. A high temperature resistant composite oven membrane comprising a composite oven membrane body (1) characterized by: The composite oven film body (1) is composed of a first composite film (2) and a second composite film (3) by high-temperature-resistant glue, the first composite film (2) is a PET film capable of heat sealing, the second composite film (3) is a PET film or a PA film capable of resisting high temperature, the high-temperature-resistant glue (4) includes polyester polyol, and the polyester polyol contains aromatic polyester segments; made of the following weight percentage components: 20%-20.5% of adipic acid, 33.5-34.5% of 2,2-dimethyl-1,3-propanediol, 8%-8.4% of ethylene glycol, 0.085%-0.089% of butyl titanate, 0.025%-0.027% of triethyl phosphate, and the rest is terephthalic acid; the glue amount of the high-temperature-resistant glue is 3.8g / ㎡-4.2g / ㎡; a high-temperature-resistant composite oven film is prepared by the following steps: step one, first, the first composite film (2) in the first unwinding mechanism and the second composite film (3) in the second unwinding mechanism are unwound respectively, then the composite surfaces of the first composite film (2) and the second composite film (3) after unwinding are respectively subjected to online corona treatment, then the composite surface of the first composite film (2) or the composite surface of the second composite film (3) after corona treatment is subjected to online gluing, then the first composite film (2) and the second composite film (3) are subjected to online pressing by a hot pressing roller, and the first composite film (2) and the second composite film (3) after pressing are subjected to online drying by a winding mechanism to form a composite film; step two, the wound composite film is put into a curing chamber for curing treatment, the temperature of the curing chamber is 50℃-60℃, and the curing time is not less than 96 hours.

2. The high temperature resistant composite oven film according to claim 1, characterized in that: The glue amount of the high-temperature-resistant glue is 4.0g / ㎡.

3. The high temperature resistant composite oven film according to claim 1, wherein: The first composite film (2) and the second composite film (3) after pressing are subjected to online drying by a group of online drying chambers, the group of online drying chambers is composed of a first drying chamber, a second drying chamber and a third drying chamber, the temperature of the first drying chamber is 70℃, the temperature of the second drying chamber is 80℃, and the temperature of the third drying chamber is 90℃.

4. The high temperature resistant composite oven film according to claim 1, wherein: The pressure of the hot pressing roller for online pressing is 0.4Mpa, and the temperature of the hot pressing roller is 55℃-65℃.

5. The high temperature resistant composite oven film according to claim 1, wherein: The coating pressure of the online gluing is 0.4Mpa, and the glue amount is 3.8g / ㎡-4.2g / ㎡.

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