CN113968413A - Milk storage bag and preparation method thereof - Google Patents
Milk storage bag and preparation method thereof Download PDFInfo
- Publication number
- CN113968413A CN113968413A CN202111253133.6A CN202111253133A CN113968413A CN 113968413 A CN113968413 A CN 113968413A CN 202111253133 A CN202111253133 A CN 202111253133A CN 113968413 A CN113968413 A CN 113968413A
- Authority
- CN
- China
- Prior art keywords
- storage bag
- milk storage
- ethylene
- polypropylene
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D29/00—Sacks or like containers made of fabrics; Flexible containers of open-work, e.g. net-like construction
- B65D29/02—Sacks with laminated or multiple walls
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D33/00—Details of, or accessories for, sacks or bags
- B65D33/16—End- or aperture-closing arrangements or devices
- B65D33/25—Riveting; Dovetailing; Screwing; using press buttons or slide fasteners
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2323/04—Homopolymers or copolymers of ethene
- C08J2323/08—Copolymers of ethene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2323/16—Ethene-propene or ethene-propene-diene copolymers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2423/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2423/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2423/16—Ethene-propene or ethene-propene-diene copolymers
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Materials Engineering (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Bag Frames (AREA)
- Laminated Bodies (AREA)
- Wrappers (AREA)
Abstract
The invention discloses a milk storage bag and a preparation method thereof. The milk storage bag body is made of a polypropylene multilayer composite film, and the polypropylene multilayer composite film at least comprises an outer layer, a middle layer and an inner layer; the outer layer is made of homopolymerized polypropylene; the middle layer is formed by blending an ethylene-propylene copolymer with the ethylene content of more than 5 wt.%, an ethylene-propylene copolymer with the ethylene content of less than 5 wt.% and a metallocene-catalyzed ethylene-octene hydrocarbon copolymer; the inner layer is made of random copolymer polypropylene. The temperature in the preparation process is lower than 180 ℃, and no small molecular additives such as antioxidant, light stabilizer, nucleating agent and the like are added in the whole process. The milk storage bag has no peculiar smell after being unsealed, has no peculiar smell after being irradiated for sterilization, has good flexibility and low temperature resistance, does not leak liquid and break the bag under the freezing condition after containing breast milk, and can be widely applied to the packaging of liquid foods and medicines which need refrigeration and freezing.
Description
Technical Field
The invention relates to the field of plastic packaging, in particular to a milk storage bag and a preparation method thereof.
Background
The plastic package and the plastic package products occupy more and more share in the market, particularly the composite plastic flexible package is widely applied to the fields of food, medicine, chemical industry and the like, and the products bring great convenience to the life of people. Along with the improvement of the substance and living standard of people, people pay more and more attention to the quality of packaging materials, in particular to the aspects of food safety, medical treatment and health and the like.
At present, a class of plastic packages on the market is called milk storage bags, also known as breast milk fresh-keeping bags. The breast milk bag is a plastic product for food package, and is mainly used for storing breast milk. Mothers can squeeze out milk when the breast milk is sufficient, and the milk is stored in a milk storage bag for refrigeration or freezing so as to be used when the milk is insufficient or the milk cannot be fed to children on time due to work and the like. The milk storage bag is made of polyethylene, so called PE, which is the most widely used plastic. Some milk storage bags also adopt PE composite PET to improve the barrier property of the bags. The commercially available milk storage bags are basically manufactured by welding a zipper made of PE on a cast polyethylene film (CPE) or a CPE/PET composite film through a bag making machine. After the milk storage bag is made, the milk storage bag can be sold after being irradiated and sterilized to reach a sterile state.
The breast milk packaged by the milk storage bag can be directly drunk by babies after being warmed, so that the food safety performance of the milk storage bag is a project which is focused on by industries and mothers. At present, the milk storage bag made of CPE or CPE/PET matching with PE zipper has a more pungent smell after being unsealed, and the smell generally comes from the plastic smell of the film material polyethylene, the smell of low molecular degradation products generated in the CPE film processing process, the smell of CPE and PET composite glue, and the smell of oligomers generated by the film material and the zipper in the milk storage bag irradiation process. This taste affects the mouthfeel of breast milk and may seriously affect the food safety of breast milk. Therefore, how to reduce or eliminate the peculiar smell of the milk storage bag becomes an urgent problem to be solved. In order to reduce the odor of the milk storage bag, the temperature resistance or the irradiation resistance of the CPE or the CPE/PET composite film needs to be improved, the most direct way is to add various stabilizers in the film preparation process or in the raw materials, for example, patent applications CN 109306100A and CN 106751158A are to add composite antioxidants, hindered amine light stabilizers, uvioresistant agents and the like to improve the heat resistance and the irradiation resistance of PE.
However, the above measures improve the heat resistance and radiation resistance of the film material to some extent, and may reduce the taste of the milk storage bag; however, various micromolecule additives are added into the modified membrane material, and the micromolecules are easy to migrate into the breast milk in the long-term contact process, so that the potential safety hazard of food is brought on the other hand.
Disclosure of Invention
The invention aims to provide a milk storage bag and a preparation method thereof. The milk storage bag body is prepared from the polypropylene multilayer composite film, has no peculiar smell after being unsealed, has no peculiar smell after being irradiated for sterilization, has good flexibility and low-temperature resistance, cannot leak liquid and break the bag under the freezing condition after containing breast milk, and can be widely applied to the packaging of liquid foods and medicines which need to be refrigerated and frozen.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a milk storage bag, which comprises a milk storage bag body and a sealing zipper; the milk storage bag body is made of a polypropylene multilayer composite film;
the polypropylene multilayer composite film at least comprises an outer layer, a middle layer and an inner layer;
the outer layer is made of homopolymerized polypropylene; the middle layer is formed by blending an ethylene-propylene copolymer with the ethylene content of more than 5 wt.%, an ethylene-propylene copolymer with the ethylene content of less than 5 wt.% and a metallocene-catalyzed ethylene-octene hydrocarbon copolymer; the inner layer is made of random copolymer polypropylene.
According to the milk storage bag of the present invention, preferably, the sealing zipper is a PP zipper.
In the polypropylene multilayer composite film, preferably, in the middle layer, the ethylene-propylene copolymer having an ethylene content of more than 5 wt.% has a mass content of 20% to 40% (preferably 20% to 30%), the ethylene-propylene copolymer having an ethylene content of less than 5 wt.% has a mass content of 20% to 40% (preferably 35% to 40%), and the metallocene-catalyzed ethylene-octene hydrocarbon copolymer has a mass content of 20% to 60% (preferably 30% to 45%). The ethylene propylene copolymer having an ethylene content of more than 5 wt.%, such as an ethylene propylene copolymer having an ethylene content of 7 wt.%, and the ethylene propylene copolymer having an ethylene content of less than 5 wt.%, such as an ethylene propylene copolymer having an ethylene content of 2 wt.% or 3 wt.%.
In the polypropylene multilayer composite film, preferably, the random copolymer polypropylene does not contain an antioxidant, has a melting point of less than 145 ℃, and has a friction coefficient of less than 0.5.
In the polypropylene multilayer composite film, preferably, the homo-polypropylene, the ethylene-propylene copolymer having an ethylene content of more than 5 wt.%, the ethylene-propylene copolymer having an ethylene content of less than 5 wt.%, the metallocene-catalyzed ethylene-octene hydrocarbon copolymer and the random copolymer polypropylene each have a molecular weight distribution dispersion coefficient of less than 5; the melt index of the homopolymerized polypropylene, the mixture of the copolymers in the middle layer and the random copolymerized polypropylene is 2-6g/10 min.
In the polypropylene multilayer composite film used by the milk storage bag, the outer layer material has good temperature resistance, rigidity and smoothness, and the polypropylene multilayer composite film used as the non-composite PET directly used for the milk storage bag can improve the bag making efficiency. The ethylene-propylene copolymer with two ethylene contents in the middle layer and the metallocene ethylene-octene copolymer can achieve good co-melting in the designed proportion range, and can ensure that a uniform, transparent and crystal-point-free film is blown in a lower processing temperature range; the metallocene ethylene-octene copolymer ensures the flexibility and low temperature resistance of the film material. The inner layer is made of a single material and does not contain an antioxidant so as to ensure that no low-molecular antioxidant is separated out in the processing and using processes; the low coefficient of friction ensures good openability after the bag is made; a melting point below 145 ℃ ensures good welding of the film to the polypropylene containment zipper at lower temperatures. The dispersion coefficient of the molecular weight distribution of all polymers is less than 5, the low molecular weight distribution ensures that the content of oligomers in the polymers is low, easily degradable components are few in the processing process, the proportion of higher molecular weight is small, and higher processing temperature is not needed; meanwhile, the irradiation resistance of the film is further improved due to less oligomers, and the film does not yellow and has no pungent smell caused by degradation products after irradiation; the melt index is between 2 and 6g/10min, which can ensure the best film blowing effect. And all polymers used are food-contactable grade materials, so that food safety is met.
The multilayer co-extruded polypropylene film for the milk storage bag does not contain any small molecular additives such as an antioxidant, a light stabilizer, a nucleating agent and the like in the preparation process, and the total content of the additives in the polymer raw material is not more than 0.3 percent. The strictly controlled additive content and the food safety level of the polymer raw material are optimized, so that small molecules are effectively prevented from migrating to inclusions in the production process, the irradiation process and the use process of the film, and the precipitation amount is ensured to be far lower than a food safety threshold value, so that the safety of food or inclusions is ensured; in addition, the possibility of generating decomposition products to cause pungent odor due to low-molecular irradiation in the process of irradiation sterilization of the milk storage bag is greatly reduced by the low-molecular additive content.
In the polypropylene multilayer composite film, preferably, the thickness of the polypropylene multilayer composite film is 40 to 100 micrometers; wherein the thickness of the outer layer is 5% -35% (preferably 20% -25%), the thickness of the middle layer is 30% -90% (preferably 50% -60%), and the thickness of the inner layer is 5% -35% (preferably 20% -25%).
According to the milk storage bag of the present invention, preferably, after dry-mixing raw materials of each layer of the polypropylene multilayer composite film, the raw materials are melted and plasticized at a temperature lower than 180 ℃ by a screw extruder, the mixture is extruded downwards through a multilayer co-extrusion die head and blown, a film bubble is formed through a water cooling process, and then the formed film is drawn and rolled to obtain the polypropylene multilayer composite film.
The low-temperature film blowing process avoids the problems that the raw materials are degraded at an overhigh temperature to generate oligomers, which cause film material peculiar smell and radiation-intolerance color change, and the oligomers are further degraded in the radiation process to generate pungent smell and the like.
According to the milk storage bag of the present invention, preferably, the polypropylene multilayer composite film further comprises a PET film connected to the outer layer by glue. After the PET is compounded, the oxygen barrier property of the milk storage bag film can be improved, and the long-term storage of the milk products is guaranteed.
According to the milk storage bag of the present invention, preferably, the thickness of the PET film is 8 to 20 micrometers.
According to the milk storage bag of the present invention, preferably, the glue is a polyurethane glue, preferably a polyurethane glue of an aliphatic curing system (such as Adcote 811A-EA + CATALYST 9L10 from Dow), which does not generate primary aromatic amine (carcinogenic substance) and does not generate yellowing during use.
The invention also provides a preparation method of the milk storage bag, which comprises the following steps: and preparing the milk storage bag on a bag making machine by using the polypropylene multilayer composite film and the sealing zipper.
The multilayer co-extruded polypropylene (PP) film can be independently used as a film material for preparing a milk storage bag body, and can also be prepared into a composite film material by using polyurethane glue and PET for preparing the milk storage bag. In the whole preparation process of the film material, the adopted raw materials are food-contactable grade materials, and the total content of additives in the polymer raw material is not more than 0.3 wt.%; the temperature of each extruder and the die head in the process preparation process is lower than 180 ℃, and no small molecular additives such as an antioxidant, a light stabilizer, a nucleating agent and the like are added in the whole process. The milk storage bag prepared by the polypropylene multilayer composite film has no peculiar smell after being unsealed, has no peculiar smell after being irradiated for sterilization, has good flexibility and low temperature resistance, does not leak liquid and break the bag under the freezing condition after containing breast milk, and can be widely applied to the packaging of liquid foods and medicines which need refrigeration and freezing.
Detailed Description
In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.
All numerical designations of the invention (e.g., temperature, time, concentration, weight, and the like, including ranges for each) may generally be approximations that vary (+) or (-) in increments of 0.1 or 1.0 as appropriate. All numerical designations should be understood as preceded by the term "about".
Example 1
In the embodiment, a multi-layer co-extruded polypropylene film is prepared and used for preparing a milk storage bag; the method comprises the following steps:
adopting homopolymerized polypropylene with the melt index of 2.5g/10min and the molecular weight distribution dispersion coefficient of 4 as an outer layer raw material; blending 20 wt.% of ethylene-propylene copolymer with ethylene content of 7 wt.% (molecular weight distribution dispersion coefficient of 2.8), 35 wt.% of ethylene-propylene copolymer with ethylene content of 2 wt.% (molecular weight distribution dispersion coefficient of 3.6) and 45 wt.% of metallocene-catalyzed ethylene-octene hydrocarbon copolymer (molecular weight distribution dispersion coefficient of 1.6), wherein the melt index of the mixture is 4.3g/10min, and the mixture is used as a middle layer raw material; adopting random copolymerization polypropylene which does not contain an antioxidant, has a melting point of 142 ℃, a melt index of 4, a friction coefficient of 0.4 and a molecular weight distribution dispersion coefficient of 1.9 as an inner layer raw material; the raw materials of each layer are fed in proportion by a metering hopper according to the weight percentage of 25:50:25, and are melted and plasticized by a screw extruder, the temperature of the extruder is between 150 and 180 ℃, the raw materials are extruded downwards by a multilayer coextrusion die head with the set temperature of 175 ℃ and are blown up, the blowing-up ratio is 1.3, film bubbles are formed by a water cooling process, and then the film is prepared by traction, rolling and the like, wherein the whole thickness of the film is 60 micrometers, the thickness of a middle layer is 15 micrometers, the thickness of a middle layer is 30 micrometers, and the thickness of an inner layer is 15 micrometers.
The milk storage bag is prepared on a bag making machine by adopting the film and a PP zipper, and relevant tests are carried out, and specific data are shown in table 1.
Comparative example 1
The comparative example prepared a multilayer co-extruded polypropylene film and used to make a milk storage bag; the method comprises the following steps:
homo-polypropylene with a melt index of 4g/10min and a molecular weight distribution dispersion coefficient of 7.2 is used as an outer layer raw material; blending 20 wt.% of ethylene-propylene copolymer with ethylene content of 7 wt.% (molecular weight distribution dispersion coefficient of 9.2), 35 wt.% of ethylene-propylene copolymer with ethylene content of 2 wt.% (molecular weight distribution dispersion coefficient of 8.6) and 45 wt.% of metallocene-catalyzed ethylene-octene hydrocarbon copolymer (molecular weight distribution dispersion coefficient of 6.3), wherein the melt index of the mixture is 5.4g/10min, and the mixture is used as a middle layer raw material; adopting random copolymerization polypropylene which does not contain an antioxidant, has a melting point of 142 ℃, a melt index of 4, a friction coefficient of 0.4 and a molecular weight distribution dispersion coefficient of 6.6 as an inner layer raw material; the raw materials of each layer are fed in proportion by a metering hopper according to the weight percentage of 25:50:25, and are melted and plasticized by a screw extruder, the temperature of the extruder is between 150 and 180 ℃, the raw materials are extruded downwards by a multilayer coextrusion die head with the set temperature of 175 ℃ and are blown up, the blowing-up ratio is 1.3, film bubbles are formed by a water cooling process, and then the film is prepared by traction, rolling and the like, wherein the whole thickness of the film is 60 micrometers, the thickness of a middle layer is 15 micrometers, the thickness of a middle layer is 30 micrometers, and the thickness of an inner layer is 15 micrometers.
The milk storage bag is prepared on a bag making machine by adopting the film and a PP zipper, and relevant tests are carried out, and specific data are shown in table 1.
As can be seen by comparing example 1 with comparative example 1, the high dispersion coefficient of the polymer in comparative example 1 means that there is an oligomer and there is a taste even in low temperature processing.
Example 2
In the embodiment, a multi-layer co-extruded polypropylene film is prepared and used for preparing a milk storage bag; the method comprises the following steps:
adopting homopolymerized polypropylene with 4g/10min of melt index and 1.4 of molecular weight distribution dispersion coefficient as an outer layer raw material; blending 30 wt.% of ethylene-propylene copolymer with ethylene content of 7 wt.% (molecular weight distribution dispersion coefficient of 1.8), 40 wt.% of ethylene-propylene copolymer with ethylene content of 3 wt.% (molecular weight distribution dispersion coefficient of 2.6) and 30 wt.% of metallocene-catalyzed ethylene-octene hydrocarbon copolymer (molecular weight distribution dispersion coefficient of 2.3), wherein the melt index of the mixture is 3.4g/10min, and the mixture is used as a middle layer raw material; adopting random copolymerization polypropylene which does not contain antioxidant, has a melting point of 142 ℃, a melt index of 5, a friction coefficient of 0.4 and a molecular weight distribution dispersion coefficient of 2.6 as an inner layer raw material; the raw materials of each layer are fed in proportion by a metering hopper according to the weight percentage of 20:60:20, and are melted and plasticized by a screw extruder, the temperature of the extruder is between 150 and 180 ℃, the raw materials are extruded downwards by a multilayer coextrusion die head with the set temperature of 175 ℃ and are blown up, the blowing-up ratio is 1.3, film bubbles are formed by a water cooling process, and then the film is prepared by traction, rolling and the like, wherein the whole thickness of the film is 80 micrometers, the thickness of a middle layer is 16 micrometers, the thickness of a middle layer is 48 micrometers, and the thickness of an inner layer is 16 micrometers. The milk storage bag is prepared on a bag making machine by adopting the film and a PP zipper, and relevant tests are carried out, and specific data are shown in table 1.
From the test results of the milk storage bags in the embodiments 1 and 2, the molecular weight distribution of the polymer, the characteristics of the copolymer, the material ratio and the processing technology of the film material defined by the invention can ensure that the film material has no crystal point after being formed, high transparency, no peculiar smell before and after irradiation and good anti-falling performance, thereby comprehensively ensuring the use safety and functionality of the milk storage bag.
Comparative example 2
The comparative example prepared a multilayer co-extruded polypropylene film and used to make a milk storage bag; the method comprises the following steps:
adopting homopolymerized polypropylene with 4g/10min of melt index and 1.4 of molecular weight distribution dispersion coefficient as an outer layer raw material; the ethylene-propylene copolymer with the ethylene content of 50 wt% (the molecular weight distribution dispersion coefficient is 2.4), the ethylene-propylene copolymer with the ethylene content of 15 wt% (the molecular weight distribution dispersion coefficient is 2.6) and the metallocene-catalyzed ethylene-octene hydrocarbon copolymer with the ethylene content of 35 wt% (the molecular weight distribution dispersion coefficient is 2.3) are blended, and the melt index of the mixture is 4.4g/10min, so that the mixture is used as a middle layer raw material; adopting random copolymerization polypropylene which does not contain antioxidant, has a melting point of 142 ℃, a melt index of 5, a friction coefficient of 0.4 and a molecular weight distribution dispersion coefficient of 2.6 as an inner layer raw material; the raw materials of each layer are fed in proportion by a metering hopper according to the weight percentage of 20:60:20, and are melted and plasticized by a screw extruder, the temperature of the extruder is between 150 ℃ and 180 ℃, the raw materials are extruded downwards by a multilayer coextrusion die head with the set temperature of 175 ℃ and are blown up, the blowing-up ratio is 1.3, film bubbles are formed by a water cooling process, and then a film material is prepared by traction, rolling and the like, wherein the thickness of the film material is uneven and is between 80 and 100 micrometers.
The temperature of an extruder is changed to be between 170 and 200 ℃, the mixture is extruded downwards through a multilayer coextrusion die head with the set temperature of 195 ℃ and is blown, the blow-up ratio is 1.3, the film bubble is formed through a water cooling process, and then a film material is prepared through traction, rolling and the like, wherein the thickness of the film material is 80 microns. The films prepared at different temperatures and the PP zipper are prepared into milk storage bags on a bag making machine, and relevant tests are carried out, and specific data are shown in table 1.
Comparing example 2 with comparative example 2, it can be seen that the middle layer material has improper mixture ratio, the ethylene-propylene copolymer with high/low ethylene content is not properly matched, the blow molding effect of the film material is poor, the required processing temperature is high, and the odor of the film material can be caused.
Comparative example 3:
the comparative example prepared a multilayer co-extruded polypropylene film and used to make a milk storage bag; the method comprises the following steps:
the preparation method comprises the steps of preparing a film material on casting film equipment by adopting the completely same raw materials and proportion in the embodiment 2, feeding the raw materials of each layer in a metering hopper according to the weight percentage of 20:60:20 in proportion, melting and plasticizing by a screw extruder, wherein the temperature of the extruder is between 150 ℃ and 180 ℃, and preparing the film by adopting a casting process through a multilayer co-extrusion T-shaped die head with the set temperature of 175 ℃, wherein the material is in a shark skin shape which is not completely plasticized at a die, has no drafting performance and cannot form the film; the film forming property is improved when the temperature is increased to 210 ℃ and 235 ℃, but the film is not bright, and a film with the thickness of 80 microns is prepared, wherein the thickness of the outer layer is 16 microns, the thickness of the middle layer is 48 microns, and the thickness of the inner layer is 16 microns. And preparing a milk storage bag on a bag making machine together with a PP zipper, and performing related tests, wherein specific data are shown in a table 1.
Comparing example 2 with comparative example 3, it can be seen that the casting process requires higher processing temperature to form the film material because the raw material has better fluidity, even if the molecular weight distribution is narrow, and the raw material with optimized proportion still degrades due to high temperature, and generates pungent smell.
Example 3
In this example, the polypropylene multilayer film prepared in example 1 is solvent-free compounded with 12 μm PET film dow aliphatic polyurethane glue Adcote 811A-EA + CATALYST 9L10, and after curing for 72h, the polypropylene multilayer film and a PP zipper are prepared into a milk storage bag on a bag making machine, and relevant tests are performed, and specific data are shown in table 1.
Example 4
In this example, the polypropylene multilayer film prepared in example 2 is solvent-free compounded with a 15 μm PET film using dow aliphatic polyurethane adhesive Adcote 811A-EA + CATALYST 9L10, and after curing for 72h, the resultant is combined with a PP zipper to prepare a milk storage bag on a bag making machine, and relevant tests are performed, and specific data are shown in table 1.
From the examples 3 and 4, it is known that the oxygen barrier property of the milk storage bag film can be increased after the polypropylene multilayer film is compounded with the PET film, and the long-term storage of the milk products is guaranteed.
TABLE 1 results of the Performance test of the milk storage bags obtained in the examples and comparative examples
It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.
Claims (10)
1. A milk storage bag is characterized by comprising a milk storage bag body and a sealing zipper; the milk storage bag body is made of a polypropylene multilayer composite film;
the polypropylene multilayer composite film at least comprises an outer layer, a middle layer and an inner layer; the outer layer is made of homopolymerized polypropylene; the middle layer is formed by blending an ethylene-propylene copolymer with the ethylene content of more than 5 wt.%, an ethylene-propylene copolymer with the ethylene content of less than 5 wt.% and a metallocene-catalyzed ethylene-octene hydrocarbon copolymer; the inner layer is made of random copolymer polypropylene.
2. The milk storage bag of claim 1, wherein the containment zipper is a PP zipper.
3. The milk storage bag according to claim 1, wherein in the middle layer, the ethylene-propylene copolymer having an ethylene content of more than 5 wt.% is 20 to 40 wt.%, the ethylene-propylene copolymer having an ethylene content of less than 5 wt.% is 20 to 40 wt.%, and the metallocene-catalyzed ethylene-octene hydrocarbon copolymer is 20 to 60 wt.%.
4. The milk storage bag of claim 1, wherein the random copolymer polypropylene is free of antioxidants, has a melting point of less than 145 ℃, and has a coefficient of friction of less than 0.5;
preferably, the homopolypropylene, the ethylene propylene copolymer having an ethylene content greater than 5 wt.%, the ethylene propylene copolymer having an ethylene content less than 5 wt.%, the metallocene catalyzed ethylene-octene hydrocarbon copolymer, and the random copolymerized polypropylene all have a molecular weight distribution dispersion coefficient less than 5;
the melt index of the homopolymerized polypropylene, the mixture of the copolymers in the middle layer and the random copolymerized polypropylene is 2-6g/10 min.
5. The milk storage bag according to claim 1, wherein the polypropylene multilayer composite film has a thickness of 40-100 microns; wherein the thickness of the outer layer accounts for 5-35%, the thickness of the middle layer accounts for 30-90%, and the thickness of the inner layer accounts for 5-35%.
6. The milk storage bag according to claim 1, wherein the polypropylene multilayer composite film is obtained by dry-blending raw materials of each layer, melting and plasticizing at a temperature lower than 180 ℃ by a screw extruder, extruding and blowing the mixture downwards through a multilayer coextrusion die head, forming a film bubble by a water cooling process, and then drawing and rolling the formed film to form a film material.
7. The milk storage bag according to any of claims 1-6, wherein the polypropylene multilayer composite film further comprises a PET film connected to the outer layer by glue.
8. The milk storage bag of claim 7, wherein the PET film has a thickness of 8-20 microns.
9. The milk storage bag of claim 7, wherein the glue is a polyurethane glue.
10. A method of making a milk storage bag according to any of claims 1-9, comprising: and preparing the milk storage bag on a bag making machine by using the polypropylene multilayer composite film and the sealing zipper.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111253133.6A CN113968413B (en) | 2021-10-27 | 2021-10-27 | Milk storage bag and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111253133.6A CN113968413B (en) | 2021-10-27 | 2021-10-27 | Milk storage bag and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113968413A true CN113968413A (en) | 2022-01-25 |
| CN113968413B CN113968413B (en) | 2023-03-10 |
Family
ID=79588581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111253133.6A Active CN113968413B (en) | 2021-10-27 | 2021-10-27 | Milk storage bag and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113968413B (en) |
Citations (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09207294A (en) * | 1996-02-07 | 1997-08-12 | Tonen Chem Corp | Low temperature heat-sealable polypropylene multilayered film |
| JPH115891A (en) * | 1997-06-19 | 1999-01-12 | Mitsui Chem Inc | Polyester resin composition |
| US6187402B1 (en) * | 1996-03-04 | 2001-02-13 | Borealis A/S | Multilayer pipe |
| US20040043239A1 (en) * | 2001-01-15 | 2004-03-04 | Toshiharu Iwasaki | Laminate and container |
| JP2005111874A (en) * | 2003-10-09 | 2005-04-28 | Japan Polypropylene Corp | Laminate and medical bag using laminate |
| TW200528268A (en) * | 2004-02-27 | 2005-09-01 | David Lin | Method for manufacturing a self-venting composite film for heating food package |
| JP2006001055A (en) * | 2004-06-15 | 2006-01-05 | Dainippon Printing Co Ltd | Multilayered laminated film, laminated material using it and packaging bag |
| CN101306593A (en) * | 2008-07-07 | 2008-11-19 | 苏州天加新材料有限公司 | Multilayer coextruding pyrocondensation film |
| JP2009051167A (en) * | 2007-08-29 | 2009-03-12 | Toppan Printing Co Ltd | Decorative sheet |
| JP2011201032A (en) * | 2010-03-24 | 2011-10-13 | Dic Corp | Coextruded multilayer film and packaging material composed of the same |
| CN104086905A (en) * | 2014-07-25 | 2014-10-08 | 北京奥星医药耗材有限公司 | Modified polypropylene soft bottle material, as well as preparation method and applications thereof |
| CN104520103A (en) * | 2012-05-15 | 2015-04-15 | 大冢科技株式会社 | Multilayer film, drug solution container and process for production thereof |
| CN107210008A (en) * | 2014-11-18 | 2017-09-26 | Upm拉弗拉塔克公司 | A kind of label facestock |
| CN108162534A (en) * | 2017-12-29 | 2018-06-15 | 雷诺丽特朗活医药耗材（北京）有限公司 | A kind of three-layer co-extruded blown polypropylene film and preparation method and application |
| CN108367551A (en) * | 2015-12-03 | 2018-08-03 | 克里奥瓦克公司 | Deodorizing multilayer packaging film and package made therefrom |
| CN109306100A (en) * | 2018-07-26 | 2019-02-05 | 北京化工大学 | A kind of resistance to electron beam irradiation polythene material and its preparation and use |
| CN110626034A (en) * | 2019-10-10 | 2019-12-31 | 雷诺丽特朗活医药耗材（北京）有限公司 | Co-extruded shrinkable film and preparation and application thereof |
| CN112721372A (en) * | 2020-11-23 | 2021-04-30 | 上海若祎新材料科技有限公司 | Modified polyolefin composite membrane composition, modified polyolefin composite membrane, and preparation method and application thereof |
-
2021
- 2021-10-27 CN CN202111253133.6A patent/CN113968413B/en active Active
Patent Citations (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09207294A (en) * | 1996-02-07 | 1997-08-12 | Tonen Chem Corp | Low temperature heat-sealable polypropylene multilayered film |
| US6187402B1 (en) * | 1996-03-04 | 2001-02-13 | Borealis A/S | Multilayer pipe |
| JPH115891A (en) * | 1997-06-19 | 1999-01-12 | Mitsui Chem Inc | Polyester resin composition |
| US20040043239A1 (en) * | 2001-01-15 | 2004-03-04 | Toshiharu Iwasaki | Laminate and container |
| JP2005111874A (en) * | 2003-10-09 | 2005-04-28 | Japan Polypropylene Corp | Laminate and medical bag using laminate |
| TW200528268A (en) * | 2004-02-27 | 2005-09-01 | David Lin | Method for manufacturing a self-venting composite film for heating food package |
| JP2006001055A (en) * | 2004-06-15 | 2006-01-05 | Dainippon Printing Co Ltd | Multilayered laminated film, laminated material using it and packaging bag |
| JP2009051167A (en) * | 2007-08-29 | 2009-03-12 | Toppan Printing Co Ltd | Decorative sheet |
| CN101306593A (en) * | 2008-07-07 | 2008-11-19 | 苏州天加新材料有限公司 | Multilayer coextruding pyrocondensation film |
| JP2011201032A (en) * | 2010-03-24 | 2011-10-13 | Dic Corp | Coextruded multilayer film and packaging material composed of the same |
| CN104520103A (en) * | 2012-05-15 | 2015-04-15 | 大冢科技株式会社 | Multilayer film, drug solution container and process for production thereof |
| CN104086905A (en) * | 2014-07-25 | 2014-10-08 | 北京奥星医药耗材有限公司 | Modified polypropylene soft bottle material, as well as preparation method and applications thereof |
| CN107210008A (en) * | 2014-11-18 | 2017-09-26 | Upm拉弗拉塔克公司 | A kind of label facestock |
| CN108367551A (en) * | 2015-12-03 | 2018-08-03 | 克里奥瓦克公司 | Deodorizing multilayer packaging film and package made therefrom |
| CN108162534A (en) * | 2017-12-29 | 2018-06-15 | 雷诺丽特朗活医药耗材（北京）有限公司 | A kind of three-layer co-extruded blown polypropylene film and preparation method and application |
| CN109306100A (en) * | 2018-07-26 | 2019-02-05 | 北京化工大学 | A kind of resistance to electron beam irradiation polythene material and its preparation and use |
| CN110626034A (en) * | 2019-10-10 | 2019-12-31 | 雷诺丽特朗活医药耗材（北京）有限公司 | Co-extruded shrinkable film and preparation and application thereof |
| CN112721372A (en) * | 2020-11-23 | 2021-04-30 | 上海若祎新材料科技有限公司 | Modified polyolefin composite membrane composition, modified polyolefin composite membrane, and preparation method and application thereof |
Non-Patent Citations (2)
| Title |
|---|
| 许平飞等: "罐藏食品多层共挤阻隔包装共挤技术工艺发展情况", 《轻工科技》 * |
| 高学文: "PVDC多层共挤出薄膜的加工技术及应用", 《塑料包装》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113968413B (en) | 2023-03-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101367283B (en) | Antimicrobial polyethylene film and preparing technique thereof | |
| JP6694613B2 (en) | Polypropylene sealant film for retort packaging and laminate using the same | |
| US4528220A (en) | Plastic bags for medical solutions and blood | |
| JPH06254946A (en) | Preparation of polypropyrene resin sheet or film | |
| JP7411454B2 (en) | Polypropylene composite film and laminate using the same | |
| EP1842872A2 (en) | Polypropylene blown film | |
| JP3052398B2 (en) | Medical bag | |
| CN113968413B (en) | Milk storage bag and preparation method thereof | |
| CN111055565A (en) | Low-temperature-resistant outer-bag multilayer co-extrusion film for cooking sterilization and preparation method thereof | |
| CN113278211A (en) | Polyethylene master batch and preparation method and application thereof | |
| CN113997666B (en) | Polypropylene multilayer composite film for milk storage bag and preparation method thereof | |
| WO2014181696A1 (en) | Synthetic resin-based stretched film | |
| EP3347413B1 (en) | Polyolefin compositions | |
| JP2017222844A (en) | Resin composition for heat seal and film using the same | |
| CN108340647B (en) | Five-layer co-extrusion infusion film for liquid-liquid multi-chamber bag and preparation method thereof | |
| CN104098829B (en) | A kind of moisture vapor permeable polyethylene film and preparation method thereof | |
| CN113861567B (en) | Modified polypropylene zipper material for liquid packaging and preparation method thereof | |
| CN110588114A (en) | High-breathability co-extruded film for seafood packaging and production process thereof | |
| CN113896993B (en) | Polypropylene zipper for liquid packaging and preparation method thereof | |
| JP3162736B2 (en) | Antibacterial stretch film for food packaging | |
| JP2022145664A (en) | Method for manufacturing multi-chamber container | |
| JPH0655613A (en) | Manufacture of thermoplastic resin sheet or film | |
| JP7551283B2 (en) | Polypropylene Composition for Retort Packaging Applications | |
| JP3774973B2 (en) | Blow bag and manufacturing method thereof | |
| JP2007137968A (en) | Film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |