CN110978702B - Heat shrinkable film and preparation method and application thereof - Google Patents

Heat shrinkable film and preparation method and application thereof Download PDF

Info

Publication number
CN110978702B
CN110978702B CN201911198477.4A CN201911198477A CN110978702B CN 110978702 B CN110978702 B CN 110978702B CN 201911198477 A CN201911198477 A CN 201911198477A CN 110978702 B CN110978702 B CN 110978702B
Authority
CN
China
Prior art keywords
film
parts
heat shrinkable
density polyethylene
master batch
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.)
Active
Application number
CN201911198477.4A
Other languages
Chinese (zh)
Other versions
CN110978702A (en
Inventor
文斌森
魏洪媚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangmen Hualong membrane materials Co.,Ltd.
Original Assignee
Jiangmen Hualong Membrane Materials Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jiangmen Hualong Membrane Materials Co ltd filed Critical Jiangmen Hualong Membrane Materials Co ltd
Priority to CN201911198477.4A priority Critical patent/CN110978702B/en
Publication of CN110978702A publication Critical patent/CN110978702A/en
Application granted granted Critical
Publication of CN110978702B publication Critical patent/CN110978702B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D7/00—Producing flat articles, e.g. films or sheets
    • B29D7/01—Films or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B32B27/327—Layered products comprising a layer of synthetic resin comprising polyolefins comprising polyolefins obtained by a metallocene or single-site catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
    • 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
    • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
    • B65D65/02—Wrappers or flexible covers
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2250/00—Layers arrangement
    • B32B2250/03—3 layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2250/00—Layers arrangement
    • B32B2250/24—All layers being polymeric
    • B32B2250/246—All polymers belonging to those covered by groups B32B27/32 and B32B27/30
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/406—Bright, glossy, shiny surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/54—Yield strength; Tensile strength
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/558—Impact strength, toughness
    • 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
    • C08J2323/06—Polyethene
    • 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
    • C08J2400/00—Characterised by the use of unspecified polymers
    • C08J2400/10—Polymers characterised by the presence of specified groups, e.g. terminal or pendant functional groups
    • 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
    • C08J2423/04—Homopolymers or copolymers of ethene
    • C08J2423/08—Copolymers of ethene

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Laminated Bodies (AREA)
  • Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

Abstract

The invention provides a high-performance heat shrinkable film which has the advantages of low shrinkage temperature, high shrinkage speed, low water vapor transmission rate, high transparency and the like. The heat shrinkable film is prepared by adopting a three-layer co-extrusion film blowing method and comprises an outer layer, a middle layer and an inner layer; the outer layer: middle layer: the mass ratio of the inner layer is 1-3: 1-3: 1-3; the outer layer comprises high-pressure low-density polyethylene, ethylene-vinyl acetate copolymer, anti-sticking master batches, smooth master batches and antistatic master batches; the middle layer comprises ethylene-vinyl acetate copolymer and propylene-based elastomer; the inner layer comprises high-pressure low-density polyethylene, metallocene low-density polyethylene, a propylene-based elastomer, an anti-sticking master batch, a smooth master batch and an antistatic master batch. The heat shrinkable film improves the tensile strength and the elastic modulus, and effectively reduces the bag breaking rate; the heat shrinkage rate of the film treated at 130 ℃ for 20 seconds is up to 75%, the light transmittance is more than 90%, and the haze and the glossiness are greatly improved.

Description

Heat shrinkable film and preparation method and application thereof
Technical Field
The invention belongs to the technical field of polymer materials for packaging, relates to a heat shrinkable film, and particularly relates to a heat shrinkable film with good shrinkage efficiency and high transparency, and a preparation method and application thereof.
Background
With the increase of national environmental protection and energy conservation, some products packaged by cartons are increasingly replaced by plastic packages, the improvement of the consumption quantity of plastic packaging products inevitably promotes the technical progress and rapid development of the plastic packaging machinery industry, the economic macro surface and micro surface shape trend of China is good, the social demand is in a stable increase situation, and the increase of the consumption of the plastic products is expected to be stimulated. In order to meet the requirements of the new era, namely, the plastic packaging materials are required to meet the increasingly improved packaging quality and benefit standards of the market, so that the heat shrinkable films are also increasingly applied to various fields, and the current heat shrinkable films in the market are roughly classified into 2 types, one type is a PE (polyethylene) shrink film, and the other type is a POF (polyester oriented polypropylene) shrink film.
Polyethylene PE is transparent thermoplastic plastic, common PE has three main types, namely Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE) and Linear Low Density Polyethylene (LLDPE), the performances of the three materials have larger differences, and the PE heat shrinkable film is widely suitable for the integral assembly packaging of products such as wines, pop-top cans, mineral water, various beverages, cloth and the like. POF is a heat shrinkable film, which is called a multilayer co-extruded polyolefin heat shrinkable film and is prepared by plasticizing and extruding linear low-density polyethylene (LLDPE) serving as an intermediate layer and propylene copolymer (PP) serving as an inner layer and an outer layer by three extruders, and then carrying out die head molding, film bubble blowing and other special processes. However, the 2-type shrink films still have a plurality of problems in the using process, such as poor toughness and easy bag breakage of the POF shrink films; the common PE shrink film has high shrink temperature, slow shrink speed and low efficiency, if the outer layer of the package is the PE film, the fusion adhesion is easy to occur when the PE film passes through a drying channel, the transparency is poor, the label of the packaged product cannot be scanned and identified, the label needs to be additionally printed and pasted outside the film, the working procedures are increased, and the efficiency is reduced.
Disclosure of Invention
In order to solve the technical problems and meet the packaging requirements of more products, the invention aims to provide a high-performance heat shrinkable film which has the advantages of low shrinkage temperature, high shrinkage speed, low water vapor transmission rate, high transparency and the like.
Based on the above purpose, the technical solution adopted by the invention to solve the above technical problems is as follows:
a heat shrinkable film is prepared by adopting a three-layer coextrusion film blowing method and comprises an outer layer, a middle layer and an inner layer;
the outer layer: middle layer: the mass ratio of the inner layer is 1-3: 1-3: 1-3;
the outer layer comprises high-pressure low-density polyethylene, ethylene-vinyl acetate copolymer, anti-sticking master batches, smooth master batches and antistatic master batches;
the middle layer comprises ethylene-vinyl acetate copolymer and propylene-based elastomer;
the inner layer comprises high-pressure low-density polyethylene, metallocene low-density polyethylene, a propylene-based elastomer, an anti-sticking master batch, a smooth master batch and an antistatic master batch.
The heat shrinkable film has a three-layer structure, the outer layer is used for printing, and the adopted material is favorable for corona treatment; the inner layer is used as a heat sealing layer and is required to have smoothness, and the three layers are made of polyethylene and other materials with different functions, so that various requirements of the shrink film are met.
Preferably, the outer layer comprises the following components in parts by weight: 20-80 parts of high-pressure low-density polyethylene, 10-60 parts of ethylene-vinyl acetate copolymer, 0.5-5 parts of anti-sticking master batch, 0.1-3 parts of smooth master batch and 0.3-6 parts of antistatic master batch.
More preferably, the high pressure low density polyethylene in the outer layer component has a melt index of 0.2 to 2.0g/10min and a density of 0.918 to 0.933g/cm3。
More preferably, the ethylene-vinyl acetate copolymer in the outer layer component has a melt index of 0.2 to 2.0g/10min and a density of 0.928 to 0.950g/cm3The content of Vinyl Acetate (VA) is 6-20%.
Preferably, the middle layer comprises the following components in parts by weight: 22-85 parts of ethylene-vinyl acetate copolymer and 10-60 parts of propenyl elastomer.
More preferably, the ethylene-vinyl acetate copolymer in the middle layer component has a melt index of 0.3 to 1.8g/10min and a density of 0.928 to 0.950g/cm3The VA content is 6-20%.
More preferably, the propylene-based elastomer in the middle layer component has a melt index of 0.2 to 3.5g/10min and a density of 0.860 to 0.890g/cm3。
Preferably, the inner layer comprises the following components in parts by weight: 20-80 parts of high-pressure low-density polyethylene, 5-25 parts of metallocene low-density polyethylene, 10-60 parts of propenyl elastomer, 0.8-6 parts of anti-sticking master batch, 0.1-5 parts of smooth master batch and 0.5-6 parts of antistatic master batch.
More preferably, the high pressure low density polyethylene in the inner layer componentThe melt index of the alkene is 0.2-2.0g/10min, and the density is 0.918-0.933g/cm3。
More preferably, the metallocene low density polyethylene in the inner layer component has a melt index of 0.2 to 1.0g/10min and a density of 0.910 to 0.935g/cm3。
More preferably, the propylene-based elastomer in the inner layer component has a melt index of 0.2 to 3.5g/10min and a density of 0.860 to 0.890g/cm3。
Preferably, the anti-sticking master batch is silicate inorganic matter. More preferably, the anti-sticking master batch is one or more of zeolite, natural silica or synthetic silica.
Preferably, the slip concentrate comprises erucamide and/or oleamide.
Preferably, the antistatic master batch is a long-acting antistatic agent. In particular, the long-acting antistatic agent is preferably VLA55 produced by Schleman.
In order to solve the performance defects of low notch sensitivity, low-temperature impact resistance, easy aging, uneven shrinkage and the like of the shrink film in the prior art, in order to modify the shrink film to meet the requirement of high toughness, the prior art often improves the impact resistance by adding a thermoplastic elastomer or a rubber elastomer, the elastomer commonly used at present comprises metallocene Polyethylene (POE), but the POE toughening modified shrink film product also has some defects, namely the transparency and the stress whitening phenomenon of the shrink film are obviously influenced. The applicant found that the shrinkage of the shrink film modified with a propylene-based elastomer is improved by about 30% compared to the shrinkage modified with a conventional low density polyethylene and a metallocene polyethylene, and at the same time, the shrinkage temperature can be reduced and the shrinkage time can be shortened.
In order to reduce the shrinkage temperature, the invention also adds ethylene-vinyl acetate copolymer (EVA) with the melting point of about 70-90 ℃ and the melting point of about 110-125 ℃ for other low-density polyethylene materials. Meanwhile, the high-strength low-temperature-resistant polyurethane has good low-temperature resistance, the thermal decomposition temperature is lower and is about 230 ℃, and the strength, the impact toughness and the environmental stress cracking resistance of the high-strength low-temperature-resistant polyurethane are improved along with the increase of the molecular weight. The properties of EVA are strongly related to the content of Vinyl Acetate (VA), and when the content of VA is increased, the rebound resilience, flexibility, adhesion, transparency, solubility, stress cracking resistance and impact performance of the EVA are improved; when the content of VA is reduced, the rigidity, abrasion resistance and electrical insulation of EVA are increased. Generally, when the VA content is less than 10%, the polyethylene is softer than polyethylene, and the impact strength is good; the transparency is good when the content is within the range of 10-20%, and the paint is cold-resistant and stress-cracking-resistant; and when the VA content exceeds 30%, the material is an elastic material and has good adhesion.
The invention also provides a preparation method of the heat shrinkable film, which comprises the following steps:
respectively melting the components of the three layers, outputting, forming a film blank with the three layers fused into one layer, extruding, and cooling to obtain a film bubble;
and clamping the obtained film bubble into a cylindrical film, flattening the cylindrical film and then cooling to obtain the heat shrinkable film.
Preferably, the three layers of components are respectively added into an outer layer extruder, a middle layer extruder and an inner layer extruder for melting, the three layers of film blanks fused into one layer are output and formed, then the film blanks are extruded through a die orifice, and the film bubbles are obtained after cooling.
More preferably, the extrusion temperature of each zone of the extruder is respectively as follows: the temperature of the first zone is 135-150 ℃, the temperature of the second zone is 145-155 ℃, the temperature of the third zone is 140-160 ℃, the temperature of the fourth zone is 135-155 ℃, the temperature of the fifth zone is 135-145 ℃ and the temperature of the die head is 145-160 ℃.
More preferably, the extruder pressure is 155-335 bar.
Preferably, the specific operation of cooling to obtain the film bubble is to obtain the film bubble by cooling with cooling air of 10-25 ℃ of an automatic air ring.
Preferably, after the film bubble is obtained through cooling, the film bubble is stabilized by using a bubble stabilizing frame, the thickness distribution of the whole film bubble is measured through 360-DEG C rotation of an online thickness gauge, and information is fed back to an automatic air ring for adjustment through a thickness adjusting system so as to obtain the thickness meeting the requirement.
Preferably, the obtained film bubble enters a herringbone row to be clamped into a flat cylindrical film, the cylindrical film enters an upper traction rotating device, the cylindrical film is flattened and then enters a guide roller to be further cooled, and a heat shrinkage film is obtained.
Preferably, the obtained heat shrinkable film is subjected to corona treatment, then trimmed, and separated into single sheets to be packaged.
More preferably, the obtained heat shrinkable film enters a corona treatment device, is subjected to corona treatment and then is subjected to edge cutting, enters a lower traction device and is divided into single sheets, and then enters a front and rear winding device for winding and then is packaged.
Specifically, the preparation method of the heat shrinkable film comprises the following steps:
(1) respectively adding the components of the three layers into an outer layer extruder, a middle layer extruder and an inner layer extruder for melting, outputting and forming a film blank fused into one layer of the three layers, and extruding through a die orifice;
(2) cooling by cooling air of 10-25 ℃ of an automatic air ring to obtain a film bubble;
(3) and (3) enabling the obtained film bubble to enter a herringbone row to be clamped into a flat cylindrical film, enabling the cylindrical film to enter an upper traction rotating device, flattening the cylindrical film, and then enabling the cylindrical film to enter a guide roller for further cooling to obtain a heat shrinkage film.
More specifically, a method for preparing a heat shrinkable film, comprising the steps of:
(1) respectively adding the components of the three layers into an outer layer extruder, a middle layer extruder and an inner layer extruder, carrying out fusion plasticization and then outputting, conveying the materials output by the extruders to a die head, and extruding a film blank formed by fusing the three layers into a layer through the die opening;
(2) cooling the film into required film bubble by cooling air at 10-25 ℃ of an automatic air ring;
(3) after cooling, stabilizing the film bubble by a bubble stabilizing frame, measuring the thickness distribution of the whole film bubble by an online thickness gauge rotating at 360 ℃, feeding back information to an automatic air ring by a thickness adjusting system, and adjusting to obtain the thickness meeting the requirement;
(4) the film bubble enters a herringbone row to be clamped into a flat cylinder film, the flat cylinder film enters an upper traction rotating device, the cylinder film is flattened and then sequentially enters a guide roller to be further cooled, and a heat shrinkage film is obtained;
(5) and (3) enabling the obtained heat shrinkable film to enter a corona treatment device, cutting edges after corona treatment, entering a lower traction device, dividing into single sheets, entering a front winding device and a rear winding device, winding and packaging.
The invention adopts high and new technology equipment and a multilayer co-extrusion process technology to prepare the high-performance heat shrinkable film, promotes the progress and development of a plastic blending technology, a new plastic additive product and an application technology, improves the performance of a plastic packaging material by using a low-cost technology on the premise of ensuring the non-toxicity, sanitation and environmental protection of the plastic packaging material, and realizes the reduction of the packaging material.
The invention also provides application of the heat shrinkable film as a packaging film, and the heat shrinkable film is used for other packages such as tissues, medicines, beverages, daily chemicals and the like. The heat shrinkable film has high shrinkage rate and high shrinkage speed, is suitable for products with faster production line running, is particularly suitable for products which are required to avoid the influence of heat treatment on quality, and is particularly suitable for the markets of tissues, beverages, food packaging and medical drugs.
The invention also provides a method for applying the heat shrinkable film, which comprises the following steps: and wrapping the heat shrinkable film outside the product or the package, and heating to enable the heat shrinkable film to tightly wrap the product or the package.
Preferably, the heat shrink film is wrapped around the product or package using a heat shrink film wrapping machine.
The invention has the beneficial effects that:
(1) the shrinkage temperature of the heat shrinkable film is reduced by improving the formula, the toughness of the heat shrinkable film is greatly improved after the formula is improved, and the heat shrinkable film has the advantages of low shrinkage temperature, high shrinkage speed, low water vapor transmission rate, high transparency and the like, and the tensile strength is 33-38Mpa and the elastic modulus is 87-98Mpa under the film thickness of 50 mu m, so that the bag breaking rate is effectively reduced; the heat shrinkage rate of the product treated at 130 ℃ for 20 seconds is up to 75%, the light transmittance is greater than 90%, the haze and the glossiness are greatly improved, and the product can be directly scanned.
(2) The heat shrinkable film has a three-layer structure, the outer layer is used for printing, and the adopted material is favorable for corona treatment; the inner layer is used as a heat sealing layer, and is required to have lower seal-initiating temperature, higher heat sealing strength, better smoothness and easy packaging; the three layers adopt polyethylene and other materials with different functions, and on the premise of ensuring that the plastic packaging material is nontoxic, sanitary and environment-friendly, the performance of the plastic packaging material is improved by using a low-cost technology, various requirements of the heat shrinkable film are met, the packaging material is reduced, the heat shrinkable film is rapidly packaged, the cost is reduced, and the efficiency is improved.
(3) The heat shrinkable film can be recycled by 100 percent, and simultaneously meets the requirements of food and medicine related safety quality standards of GB/4806.6-2016 (GB/4806.6-2016) plastic resin for food contact and GB/4806.7-2016 (GB 4806.7-2016) plastic materials for food contact, products and the like.
Detailed Description
The invention will now be further illustrated by reference to specific examples, which are intended to be illustrative of the invention and are not intended to be a further limitation of the invention.
Example 1
The heat shrinkable film of the embodiment has three layers of structures, namely an outer layer, a middle layer and an inner layer, wherein the weight percentages of the three layers of materials are respectively as follows: 33% of outer layer, 34% of middle layer and 33% of inner layer; the composition of each layer is shown in table 1 below:
TABLE 1
Figure BDA0002295269460000051
The high-pressure low-density polyethylene in the outer layer component has a melt index of 0.25g/10min and a density of 0.924g/cm3Particularly, 2420D manufactured by zhonghai shell petrochemical company ltd; the ethylene-vinyl acetate copolymer has a melt index of 0.25g/10min and a density of 0.930g/cm3The Vinyl Acetate (VA) content is 12%, and 3135 manufactured by DuPont, USA is particularly preferable.
The ethylene-vinyl acetate copolymer in the middle layer component has a melt index of 1.5g/10min and a density of 0.930g/cm3The VA content is 15%, and particularly preferred is EVA630 manufactured by Tosoh corporation of Japan; the propylene-based elastomer has a melt index of 1.3g/10min and a density of 0.862g/cm3Particularly preferred is Vistamaxx6102FL manufactured by exxon corporation of usa.
The high pressure low density polyethylene in the inner layer component has a melt index of 0.25g/10min, density 0.924g/cm3Particularly, 2420D manufactured by zhonghai shell petrochemical company ltd; the metallocene low density polyethylene in the inner layer component has a melt index of 0.2g/10min and a density of 0.916g/cm3Particularly preferred is XP6026 manufactured by exxon corporation, usa; the propylene-based elastomer in the inner layer component has a melt index of 0.9g/10min and a density of 0.874g/cm3, and is particularly preferably Vistamaxx3020FL manufactured by exxon corporation, usa.
The smooth master batch is preferably SAB-8078 produced by the Huayi scientific and technological development limited company; the antistatic agent is preferably VLA55 from Schelman.
A preparation method of a heat shrinkable film comprises the following steps:
(1) respectively adding the components of the three layers into an outer layer extruder, a middle layer extruder and an inner layer extruder, carrying out fusion plasticization and then outputting, conveying the materials output by the extruders to a die head, and extruding a film blank formed by fusing the three layers into a layer through the die opening;
(2) cooling the film into required film bubble by cooling air at 10-25 ℃ of an automatic air ring;
(3) after cooling, stabilizing the film bubble by a bubble stabilizing frame, measuring the thickness distribution of the whole film bubble by an online thickness gauge rotating at 360 ℃, feeding back information to an automatic air ring by a thickness adjusting system, and adjusting to obtain the thickness meeting the requirement;
(4) the film bubble enters a herringbone row to be clamped into a flat cylinder film, the flat cylinder film enters an upper traction rotating device, the cylinder film is flattened and then sequentially enters a guide roller to be further cooled, and a heat shrinkage film is obtained;
(5) and (3) enabling the obtained heat shrinkable film to enter a corona treatment device, cutting edges after corona treatment, entering a lower traction device, dividing into single sheets, entering a front winding device and a rear winding device, winding and packaging.
The extruder process parameters are shown in table 2:
TABLE 2
Temperature of Region 1 Zone 2 Zone 3 Zone 4 Zone 5 Pressure (bar)
Outer layer 141 145 147 143 142 182-238
Middle layer 135 138 140 136 135 155-236
Inner layer 142 148 151 146 143 201-327
Die head 148 151 155 152
Example 2
The heat shrinkable film of the embodiment has three layers of structures, namely an outer layer, a middle layer and an inner layer, wherein the weight percentages of the three layers of materials are respectively as follows: 33% of an outer layer, 45% of a middle layer and 22% of an inner layer; the composition of each layer is shown in table 3 below:
TABLE 3
Figure BDA0002295269460000071
The melt index, density and manufacturer of each component of the heat shrinkable film of this example are the same as those of example 1, except that the anti-sticking master batch is natural silica. The preparation method of the heat shrinkable film of this example is the same as that of example 1, and the extruder process parameters are shown in table 4:
TABLE 4
Temperature of Region 1 Zone 2 Zone 3 Zone 4 Zone 5 Pressure (bar)
Outer layer 141 145 147 143 142 182-238
Middle layer 135 138 143 141 137 165-256
Inner layer 142 148 151 146 143 178-307
Die head 148 155 158 155
Example 3
The heat shrinkable film of the embodiment has three layers of structures, namely an outer layer, a middle layer and an inner layer, wherein the weight percentages of the three layers of materials are respectively as follows: 25% of outer layer, 50% of middle layer and 25% of inner layer; the composition of each layer is shown in table 5 below:
TABLE 5
Figure BDA0002295269460000072
Figure BDA0002295269460000081
The melt index, density and manufacturer of each component of the heat shrinkable film of this example were the same as those of example 1, except that the anti-sticking master batch was synthetic silica. The preparation method of the heat shrinkable film of this example is the same as that of example 1, and the extruder process parameters are shown in table 6:
TABLE 6
Temperature of Region 1 Zone 2 Zone 3 Zone 4 Zone 5 Pressure (bar)
Outer layer 141 145 147 143 142 172-218
Middle layer 135 138 143 141 137 195-286
Inner layer 142 148 151 146 143 178-277
Die head 148 155 158 155
Example 4
The heat shrinkable film of the embodiment has three layers of structures, namely an outer layer, a middle layer and an inner layer, wherein the weight percentages of the three layers of materials are respectively as follows: 20% of the outer layer, 60% of the middle layer and 20% of the inner layer; the composition of each layer is shown in table 7 below:
TABLE 7
Figure BDA0002295269460000082
Figure BDA0002295269460000091
The melt index, density and manufacturer of each component of the heat shrinkable film of this example were the same as those of example 1, except that the anti-sticking master batch was synthetic silica. The preparation method of the heat shrinkable film of this example is the same as that of example 1, and the process parameters of the extruder are shown in table 8:
TABLE 8
Temperature of Region 1 Zone 2 Zone 3 Zone 4 Zone 5 Pressure (bar)
Outer layer 141 145 147 143 142 172-208
Middle layer 138 141 143 141 138 195-305
Inner layer 142 148 151 146 143 178-237
Die head 148 155 158 155
Comparative example 1
Comparative example 1 is a heat shrinkable film of the prior art having three layers, an outer layer, a middle layer and an inner layer, the weight percentages of the three layers being: 30% of an outer layer, 40% of a middle layer and 30% of an inner layer; the composition of each layer is shown in table 9 below:
TABLE 9
Figure BDA0002295269460000092
Figure BDA0002295269460000101
Comparative example 1 extruder process parameters are shown in table 10:
watch 10
Temperature of Region 1 Zone 2 Zone 3 Zone 4 Zone 5 Pressure (bar)
Outer layer 165 168 172 168 166 286-423
Middle layer 188 195 198 195 193 330-542
Inner layer 177 182 186 185 181 318-528
Die head 198 205 208 203
The heat shrinkable films obtained in examples 1 to 4 and the heat shrinkable film obtained in comparative example 1 were tested for their performance parameters according to GBT 13519-92-polyethylene heat shrinkable film, in which the heat shrinkage was measured by treatment at 130 ℃ for 20 seconds, and the results are shown in Table 11.
TABLE 11 Heat shrink film Performance test
Figure BDA0002295269460000102
The invention reduces the shrinkage temperature of the heat shrinkable film by improving the formula, greatly improves the toughness of the heat shrinkable film after improving the formula, and has the advantages of low shrinkage temperature, high shrinkage speed, low water vapor transmission rate, high transparency and the like. The materials used in the formula of the heat shrinkable film of the comparative example 1 comprise part of metallocene medium-density polyethylene and high-density polyethylene, so that the film has high processing temperature, high shrinkage temperature, high material stiffness, poor flexibility, and very brittle and easy-to-break package after shrinkage; the transparency after shrinkage is worse due to the high crystallinity of the high density polyethylene, which is poor in transparency. As can be seen from table 11, the film thickness is the same, the haze of comparative example 1 is as high as 32, while the haze of 4 examples is below 12, and the two-dimensional code of the inner package can be scanned after the package; the process of sticking labels outside is reduced, and the cost is reduced. The glossiness is more than 85, and the higher glossiness makes the printing pattern more bright-colored, and the goods shelves show the effect better. As can be seen from Table 11, the tensile strength of the examples is 33-38MPa, the elastic modulus is 87-98MPa at a film thickness of 50 μm, the strength is high, the elastic modulus is low, the film has high toughness and puncture resistance, and the percentage of broken bags is effectively reduced. The heat shrinkage rate of the film treated at 130 ℃ for 20 seconds is up to 75 percent in the longitudinal direction and 48 percent in the transverse direction; greatly improves the packaging speed, reduces the contraction time, and ensures that the packaged clamping force is higher and the articles are firmer.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical solutions of the present invention in any way. Any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention still fall within the scope of the technical solution of the present invention.

Claims (5)

1. A heat shrinkable film is characterized in that the heat shrinkable film is prepared by adopting a three-layer coextrusion film blowing method and comprises an outer layer, a middle layer and an inner layer;
the outer layer: middle layer: the mass ratio of the inner layer is 1-3: 1-3: 1-3;
the outer layer comprises high-pressure low-density polyethylene, ethylene-vinyl acetate copolymer, anti-sticking master batches, smooth master batches and antistatic master batches;
the middle layer comprises ethylene-vinyl acetate copolymer and propylene-based elastomer;
the inner layer comprises high-pressure low-density polyethylene, metallocene low-density polyethylene, a propylene-based elastomer, an anti-sticking master batch, a smooth master batch and an antistatic master batch;
the high-pressure low-density polyethylene in the outer layer component has a melt index of 0.2-2.0g/10min and a density of 0.918-0.933g/cm3(ii) a The ethylene-vinyl acetate copolymer in the outer layer component has a melt index of 0.2-2.0g/10min and a density of 0.928-0.950g/cm3The VA content is 6-20%;
the melt index of the ethylene-vinyl acetate copolymer in the middle layer component is 0.3-1.8g/10min, and the density is 0.928-0.950g/cm3The VA content is 6-20%; the melt index of the propylene-based elastomer in the middle layer component is 0.2-3.5g/10min, and the density is 0.860-0.890g/cm3；
The outer layer comprises the following components in parts by weight: 20-80 parts of high-pressure low-density polyethylene, 10-60 parts of ethylene-vinyl acetate copolymer, 0.5-5 parts of anti-sticking master batch, 0.1-3 parts of smooth master batch and 0.3-6 parts of antistatic master batch;
the middle layer comprises the following components in parts by weight: 22-85 parts of ethylene-vinyl acetate copolymer and 10-60 parts of propenyl elastomer;
the inner layer comprises the following components in parts by weight: 20-80 parts of high-pressure low-density polyethylene, 5-25 parts of metallocene low-density polyethylene, 10-60 parts of propenyl elastomer, 0.8-6 parts of anti-sticking master batch, 0.1-5 parts of smooth master batch and 0.5-6 parts of antistatic master batch.
2. The heat shrinkable film of claim 1, wherein the high pressure low density polyethylene in the inner layer component has a melt index of 0.2 to 2.0g/10min and a density of 0.918 to 0.933g/cm3(ii) a The metallocene low-density polyethylene in the inner layer component has a melt index of 0.2-1.0g/10min and a density of 0.910-0.935g/cm3(ii) a The propylene-based elastomer in the inner layer component has a melt index of 0.2-3.5g/10min and a density of 0.860-0.890g/cm3。
3. The method for producing a heat shrinkable film of any one of claims 1 to 2, comprising the steps of:
respectively melting the components of the three layers, outputting, forming a film blank with the three layers fused into one layer, extruding, and cooling to obtain a film bubble;
and clamping the obtained film bubble into a cylindrical film, flattening the cylindrical film and then cooling to obtain the heat shrinkable film.
4. The preparation method of claim 3, wherein after the bubble is obtained by cooling, the bubble is stabilized by using a bubble stabilizing frame, the thickness distribution of the whole bubble is measured by an online thickness gauge rotating at 360 ℃, and information is fed back to an automatic air ring by a thickness adjusting system to be adjusted so as to obtain the thickness meeting the requirement.
5. Use of the heat shrinkable film of any one of claims 1-2 as a packaging film.
CN201911198477.4A 2019-11-29 2019-11-29 Heat shrinkable film and preparation method and application thereof Active CN110978702B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911198477.4A CN110978702B (en) 2019-11-29 2019-11-29 Heat shrinkable film and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911198477.4A CN110978702B (en) 2019-11-29 2019-11-29 Heat shrinkable film and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN110978702A CN110978702A (en) 2020-04-10
CN110978702B true CN110978702B (en) 2021-12-21

Family

ID=70088334

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911198477.4A Active CN110978702B (en) 2019-11-29 2019-11-29 Heat shrinkable film and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN110978702B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111925580A (en) * 2020-07-16 2020-11-13 江阴市德惠热收缩包装材料有限公司 Easy-to-uncover cover film and preparation method thereof
CN112373157A (en) * 2020-10-21 2021-02-19 永生运佳(宣城)薄膜科技有限公司 Ultrathin EVA vacuum casting film
CN112793140B (en) * 2020-12-18 2023-09-22 汕头市明佳热收缩膜有限公司 Process for preparing non-crosslinked biaxially oriented PE (polyethylene) heat-shrinkable film by double-bubble method
CN114619739B (en) * 2022-03-11 2023-12-19 揭阳市千田塑胶有限公司 Rainproof reflective film for trucks and preparation method thereof
CN114734701A (en) * 2022-05-10 2022-07-12 江门市华龙膜材股份有限公司 Stainless steel deep-drawing protective film and preparation method thereof
CN115195246A (en) * 2022-08-26 2022-10-18 深圳市致新包装有限公司 POF high-performance film and preparation method thereof

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1193052A1 (en) * 2000-09-29 2002-04-03 Cryovac, Inc. New heat-shrinkable multi-layer thermoplastic film and container obtained therefrom
JP4644946B2 (en) * 2001-02-02 2011-03-09 株式会社プライムポリマー Olefin-based multilayer shrink film and packaging material
WO2012058789A1 (en) * 2010-11-05 2012-05-10 Exxonmobil Chemical Patents Inc. Polymeric films and methods to manufacture the same
CN103331969B (en) * 2013-06-09 2017-02-15 南通环球塑料工程有限公司 Multi-layer co-extruded two-way stretching poultry meat packaging shrink film and preparation method thereof

Also Published As

Publication number Publication date
CN110978702A (en) 2020-04-10

Similar Documents

Publication Publication Date Title
CN110978702B (en) Heat shrinkable film and preparation method and application thereof
CN103029388B (en) Three-layer coextrusion heavy packaging membrane and fabrication method thereof
CN104691071B (en) A kind of packaging film of puncture-resistant and preparation method thereof
CN103770422B (en) High-stiffness puncture-resistant low-friction coefficient composite membrane and preparation method thereof
CN103264553B (en) Shrink package color film and production method thereof
CN101475074B (en) Self-lubricating polyethylene membrane
CN107696623B (en) Heat shrinkage film suitable for automatic quick packaging of production line
CN102196908A (en) Multilayer shrink, films, labels made therefrom and use thereof
CN112356543B (en) High-gloss high-transparency polyethylene casting film and preparation method thereof
CN109532177A (en) A kind of three-layer co-extruded polyethylene label film and preparation method thereof
CN103009761B (en) Polyolefin heat-shrinkable film with high shrinking percentage and manufacturing method thereof
CN102765190B (en) Method for producing biaxially oriented multilayer co-extruded polyolefin shrink film by flat film process
CN106626654B (en) Polyolefin biaxial stretching film and preparation method thereof
CN111070611A (en) Preparation method of anti-aging polyolefin heat-shrinkable film
CN103753825A (en) Production method of multilayer co-extruded low-temperature shrinkable polyolefin heat-shrinkable film
CN105881923A (en) PET (Polyethylene Terephthalate) sheet production technology
CN115635750A (en) Low-temperature-resistant three-layer co-extrusion heavy packaging film
CN106626655A (en) Polyolefin bidirectional stretching surface hanging film and preparation method thereof
CN102729463A (en) Preparation method of high-transparency nylon composite film
CN114454579B (en) FFS film for thinned heavy packaging and preparation method thereof
CN115838487A (en) Biaxially oriented polypropylene film, method of making and use thereof, thermoforming process and products thereof
EP3326809A1 (en) Unidirectional oriented polyethylene-based heat shrinkable polymeric label
CN103481620B (en) PE (Poly Ethylene) liquid packaging film and preparation method thereof
CN106585013B (en) Polyolefin biaxial tension electrostatic film and preparation method thereof
CN111204093A (en) Logistics protective 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
TA01 Transfer of patent application right

Effective date of registration: 20211201

Address after: 529075 Building 8, No.3, Huagui 2nd Road, durian Town, Pengjiang district, Jiangmen City, Guangdong Province

Applicant after: Jiangmen Hualong membrane materials Co.,Ltd.

Address before: 529000 one of the first floor of Building 1, No. 10, Yinghua Road, Duruan Town, Pengjiang district, Jiangmen City, Guangdong Province (self compiled)

Applicant before: JIANGMEN PENGJIANG HUALONG PACKING MATERIAL Co.,Ltd.

TA01 Transfer of patent application right
GR01 Patent grant
GR01 Patent grant