CN109648880A - Heat shrink films and its production method and application - Google Patents
Heat shrink films and its production method and application Download PDFInfo
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- CN109648880A CN109648880A CN201811435052.6A CN201811435052A CN109648880A CN 109648880 A CN109648880 A CN 109648880A CN 201811435052 A CN201811435052 A CN 201811435052A CN 109648880 A CN109648880 A CN 109648880A
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- heat shrink
- shrink films
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- film
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/04—Polymers of ethylene
- B29K2023/06—PE, i.e. polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/04—Polymers of ethylene
- B29K2023/08—Copolymers of ethylene
- B29K2023/086—EVOH, i.e. ethylene vinyl alcohol copolymer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2023/00—Tubular articles
- B29L2023/001—Tubular films, sleeves
Landscapes
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
The present invention relates to heat shrink films and its production method and application, the production method includes the following steps: first to mix raw material and auxiliary agent, is heated to molten condition, then it squeezes out, film bubble is obtained, is then water-cooled and is formed and is heated to glass transition temperature or more, carry out secondary inflation stretching；Thin film bubble is subjected to cooling and shaping processing, obtains film cylinder, heats and simultaneously carries out inflation again, then cooling and shaping and winds, obtains heat shrink films.The heat shrink films of the method for the present invention production, are close to packaging more；Corrugationless after thermal contraction bag is heat-shrinked, inner layer material is very fit, eliminates the capillary water absorption phenomenon being generated by it；The infiltration of the effective blocking oxygen of the barrier layer of thermal contraction bag, extends the shelf-life；Thermal contraction bag can effectively stop the loss of moisture content, maintain the original taste of product, while having saved cost for enterprise；The product of heat shrinkable package avoid with extraneous contact, avoid secondary pollution, eat safer.
Description
Technical field
The invention belongs to Material Fields, and in particular to a kind of heat shrink films and its production method and application.
Background technique
Heat shrink films be one kind in process of production in the longitudinally, laterally stretch orientation of film, and in use by
The thermoplastic film of thermal contraction.The heat-shrinkable of film was just applied early in 1936, initially mainly used rubber film
To shrink-wrap putrefactive food.Nowadays, heat shrinkage techniques have evolved to can almost be packed with plastic shrink film
Extensive stock has extensive purposes in food and drink, electronic product, Automobile Products, daily use chemicals, stationery, medicine and other fields.Heat is received
The production technology of contracting film divides the tape casting and blowing by the molding mode of film.The tape casting: with BOPET thermal contractive label
For production technology, production procedure is that first PET copolymer resins are dried, and melting in extruder is then added and squeezes
Out, by die head/cold founding piece, slab is then heated to glass transition temperature or more, melting temperature a certain appropriate temperature below
It spends in range, and under external force, carries out the stretching of one-way or bi-directional certain multiple, usually require that progress lateral 3.5~4.0
Stretching again.The blowing of heat shrink films is generally divided into single bubble method, double bubble process and three bubble methods.Common blown film production technology belongs to list
Bubble method, due to being unable to accurately control film inflation in machine and transverse direction and stretch ratio, and blow-up ratio is generally on 2~3 left sides
The percent thermal shrinkage on the right side, film is not high, therefore the product of bubble method production is mainly used for the packaging in product stream, as beer is drunk
Material, outer packing of daily electronic product etc..Double bubble process is mainly used in the production of POF film.Due to film carried out it is secondary
Inflation, therefore can control the stretch ratio of film in machine and transverse direction, and stretch ratio is high, passes through the control of process recipe
System, the shrinking percentage of film can achieve 70% or more.The main application fields of POF film are in the product of some inner wrappings.With
Heat shrink films in food, application in especially cold fresh meat, three bubble method heat shrink films production technologies are come into being.Due to fresh
Meat products is high to the thermal contraction stability requirement of film packaging, is heat-shrinked and uses temperature low, barrier property is good, and common double bubble process is not
Satisfactory product can be produced.
Summary of the invention
An object of the present invention is to provide a kind of heat shrink films with high obstructing performance and high thermal contraction performance
Production method.
The production method of heat shrink films of the invention, includes the following steps: S101: after raw material and auxiliary agent are mixed first,
According to the melting temperature of different material and auxiliary agent, it is heated to molten condition, is then squeezed out using flat crowded lower blowing method, obtains film
Bubble；S102: the film bubble is water-cooled sizing under vacuum conditions, the film bubble of cooling and shaping is then heated to vitrifying again
More than temperature, secondary inflation stretching is carried out using compressed air；S103: the processed thin film bubble of the step S102 is carried out cold
But setting treatment obtains film cylinder；S104: the processed film cylinder of the step S103 is heated and is blown again
It is swollen, it then cooling and shaping and winds, obtains heat shrink films.
The major advantage of the production method of heat shrink films of the invention, the thermal contraction bag of production is as follows: shrinking and helps to reduce
Outer excess stock is packed, is close to packaging more, bandwagon effect is good, promotes meat sales appeal；Nothing after thermal contraction bag is heat-shrinked
Fold, inner layer material is very fit, eliminates the capillary water absorption phenomenon being generated by it, while lower shrinkage power also farthest subtracts
The exudation of watery blood is lacked；The infiltration of the effective blocking oxygen of the barrier layer of thermal contraction bag, extends the shelf-life of meat products；It is heat-shrinked
Bag can effectively stop the loss of moisture content, maintain the original taste of product, while having saved cost for enterprise；Heat shrinkable package
Product avoid with extraneous contact, avoid secondary pollution, eat safer.
In addition, the production method of above-mentioned heat shrink films of the invention, can also have the following additional technical features:
Further, in the step S102, hot bath or heater box are used when heating.
Further, in the step S101, the temperature of heating is 150 DEG C~250 DEG C.
Further, in the step S102, blow-up ratio and draw ratio are (3~4): 1.
Further, in the step S104, by the processed film cylinder heating of the step S103 and again
Secondary carry out inflation, then cooling and shaping and wind process during, carry out crosslinking Treatment；The crosslinking Treatment includes electron radiation
Crosslinking, the electron radiation crosslinking are one of online crosslinking and offline crosslinking.Heat shrink films are crosslinked toward contact
Processing is generally crosslinked using electron radiation, and online crosslinking and offline crosslinking are divided into.Film by crosslinking can be such that its performance obtains
Significantly improve, not only significantly improves the mechanical property, environmental stress cracking resistance, resistance to corrosive chemicals of film
The comprehensive performances such as energy, creep resistance and electrical property, and be readily apparent that improve temperature resistant grade.
Further, the raw material includes at least polyethylene or ethylene-vinyl acetate copolymer, and the polyethylene includes
Metallocene linear polyethylene.
Further, the raw material also includes at least in polyvinylidene chloride, ethylene-vinyl alcohol copolymer and copolymer nylon
One kind.
It is another object of the present invention to the heat shrink films for proposing the method production.
Another object of the present invention is to propose application of the heat shrink films in product packaging.
It is another object of the present invention to the use steps for proposing the heat shrink films.
The heat shrink films include the following steps: to pack product with the heat shrink films when in use, then with 60 DEG C
Hot water heating 3s~5s of~90 DEG C of temperature；Perhaps with Hot-blast Heating 3s~5s of 60 DEG C~90 DEG C temperature or infrared ray is used
Heat 3s~5s.Since three bubble heat shrink films are using the production technology of downward-blowing water-cooling, raw material generally selects blown film grade
?.During having packed the thermal contraction after product, generally using hot water, wind leaching or infrared heating 3~5 seconds.To reduce
Influence of the temperature to cold fresh meat surface, therefore it is required that the heat shrink temperature of film is low, so should select the polyethylene compared with low-density,
The raw materials such as metallocene linear polyethylene and EVA, so as to can 90 DEG C of even lower temperature realize 40% or more thermal contraction.Together
When be also contemplated that the fit performance of film and to get well, shrinking percentage is big, and convergent force is low, to avoid the extrusion of watery blood.
Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description
Obviously, or practice through the invention is recognized.
Specific embodiment
The embodiment of the present invention is described below in detail, the embodiment is exemplary, it is intended to it is used to explain the present invention, and
It is not considered as limiting the invention.
The invention proposes a kind of heat shrink films, production method includes the following steps:
S101: it after first mixing raw material and auxiliary agent, according to the melting temperature of different material and auxiliary agent, is heated to molten
Melt state, is then squeezed out using flat crowded lower blowing method, obtain film bubble.Embryonic tube is squeezed out using flat crowded lower blowing method, high polymer is at this time
Molten condition.
S102: the film bubble is water-cooled sizing under vacuum conditions, is then again heated to the film bubble of cooling and shaping
More than glass transition temperature, secondary inflation stretching is carried out using compressed air.Embryonic tube passes through at once after multiple layers of molds is coextruded
Vacuum cylinder water jacket is cooling, then into people's hot bath or heater box, is heated to glass transition temperature or more and carries out longitudinal stretching, recycles
Compressed air carries out lateral inflation, and blow-up ratio and draw ratio are 3.5:1 or so.Here there are two important concept: draw ratio and
Blow-up ratio.Draw ratio: refer to the ratio between the hauling speed of film and pipe embryo extruded velocity.Draw ratio is longitudinal stretching times
Number makes film have orientation in lead.Draw ratio increases, then longitudinal tensile strength can also increase accordingly, and thin
The thickness of film is thinning, but if draw ratio is excessive, the thickness of film is difficult to control, it could even be possible to can break film, causes
Film breakage phenomenon.Blow-up ratio: refer to the ratio after inflation between the diameter of film bubble and the embryonic tube diameter of non-inflation.Blow-up ratio is film
Lateral expansion multiple, cross directional stretch actually is carried out to film, stretching can generate a degree of orientation to plastic molecules
Effect, blow-up ratio increases, so that the transverse tensile strength of film be made to improve.But blow-up ratio can neither too greatly can not be too small,
It is easy to cause film bubble unstable greatly very much, and film bubble is easy to appear fold；The shrinking percentage of too small then finished product is inadequate.Therefore, blow-up ratio
It should cooperate with draw ratio suitably.The physical principle of two bubble techniques is: when high polymer is in elastomeric state, stretching and takes to it
To then high polymer being quenched to glass transition temperature hereinafter, molecularly oriented is frozen, when article add in packaging process to it
When hot, since molecular thermalmotion generates stress relaxation, the state that recovery is original divided, has generated contraction.Three bubble method heat shrink films and
The key difference of common heat-shrinkable film production technology is: when a bubble method propels the price of high polymer be carried out more than fusing point it is longitudinal and
Lateral stretching, and three bubble rules be by the control of embryonic tube temperature more than glass transition temperature, fusing point hereinafter, then carry out stretch and
It propels the price of.
S103: the processed thin film bubble of the step S102 is subjected to cooling and shaping processing, obtains film cylinder.Secondary inflation
Film afterwards also needs to carry out shaping processing, then winds.Even if heat shrink films store at normal temperature, contraction can be also generated, therefore
Setting treatment is quite crucial.
S104: the processed film cylinder of the step S103 is heated and carries out inflation again, then cooling and shaping
And wind, obtain heat shrink films.
Embodiment 1
Embodiment 1 proposes a kind of heat shrink films, and production method includes the following steps:
(1) after first mixing raw material and auxiliary agent, it is heated to 225 DEG C of molten condition, is then blown using flat force down
Method squeezes out, and obtains film bubble.The raw material includes metallocene linear polyethylene, ethylene-vinyl alcohol copolymer, low-density linearly poly- second
Alkene is 1:1.5:4 mixing according to weight ratio.The auxiliary agent is slipping agent, opening agent, weight ratio 1:1.
(2) film bubble is water-cooled sizing under vacuum conditions, the film bubble of cooling and shaping is then used into hot water again
Bath or heater box are heated to glass transition temperature or more, carry out secondary inflation stretching using compressed air, wherein blow-up ratio and stretching
Than for 4:1.
(3) the processed thin film bubble of the step (2) is subjected to cooling and shaping processing, obtains film cylinder.
(4) inflation is carried out by the processed film cylinder heating of the step (3) and again, then cooling and shaping and is received
Volume, carries out online electron radiation crosslinking Treatment during this period, obtains heat shrink films.
The heat shrink films of embodiment 1 include the following steps: to pack product with the heat shrink films when in use, then with 75
The hot water heating 4s of DEG C temperature.
Embodiment 2
Embodiment 2 proposes a kind of heat shrink films, and production method includes the following steps:
(1) after first mixing raw material and auxiliary agent, it is heated to 180 DEG C of molten condition, is then blown using flat force down
Method squeezes out, and obtains film bubble.The raw material is ethylene-vinyl acetate copolymer, polyethylene and polyvinylidene chloride according to weight
Than for 1:1:1.The auxiliary agent is slipping agent, opening agent, weight ratio 2:1.
(2) film bubble is water-cooled sizing under vacuum conditions, the film bubble of cooling and shaping is then used into hot water again
Bath or heater box are heated to glass transition temperature or more, carry out secondary inflation stretching using compressed air, wherein blow-up ratio and stretching
Than for 3:1.
(3) the processed thin film bubble of the step (2) is subjected to cooling and shaping processing, obtains film cylinder.
(4) inflation is carried out by the processed film cylinder heating of the step (3) and again, then cooling and shaping and is received
Volume carries out the processing of offline e crosslinking with radiation during this period, obtains heat shrink films.
The heat shrink films of embodiment 2 include the following steps: to pack product with the heat shrink films when in use, then with 75
The Hot-blast Heating 4s of DEG C temperature.
Embodiment 3
Embodiment 3 proposes a kind of heat shrink films, and production method includes the following steps:
(1) after first mixing raw material and auxiliary agent, it is heated to 250 DEG C of molten condition, is then blown using flat force down
Method squeezes out, and obtains film bubble.Wherein, the raw material is metallocene linear polyethylene, ethylene-vinyl acetate copolymer, gathers inclined two
Vinyl chloride, ethylene-vinyl alcohol copolymer and copolymer nylon are 5:3:3:1:1 mixing according to weight ratio.The auxiliary agent be slipping agent,
Opening agent, weight ratio 1:2.
(2) film bubble is water-cooled sizing under vacuum conditions, the film bubble of cooling and shaping is then used into hot water again
Bath or heater box are heated to glass transition temperature or more, carry out secondary inflation stretching using compressed air, wherein blow-up ratio and stretching
Than for 3.5:1.
(3) the processed thin film bubble of the step (2) is subjected to cooling and shaping processing, obtains film cylinder.
(4) inflation is carried out by the processed film cylinder heating of the step (3) and again, then cooling and shaping and is received
Volume, obtains heat shrink films.
The heat shrink films of embodiment 3 include the following steps: to pack product with the heat shrink films when in use, then with red
4s is heated in outside line.
To sum up, the major advantage of the production method of heat shrink films of the invention, the thermal contraction bag of production is as follows: shrinking help
It reduces and packs outer excess stock, be close to packaging more, bandwagon effect is good, promotes meat sales appeal；Thermal contraction bag is heat-shrinked
Corrugationless afterwards, inner layer material is very fit, eliminates the capillary water absorption phenomenon being generated by it, while lower shrinkage power is also utmostly
Ground reduces the exudation of watery blood；The infiltration of the effective blocking oxygen of the barrier layer of thermal contraction bag, extends the shelf-life of meat products；Heat
Contraction bag can effectively stop the loss of moisture content, maintain the original taste of product, while having saved cost for enterprise；It is heat-shrinked
The product of packaging avoid with extraneous contact, avoid secondary pollution, eat safer.
In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", " specifically show
The description of example " or " some examples " etc. means specific features, structure, material or spy described in conjunction with this embodiment or example
Point is included at least one embodiment or example of the invention.In the present specification, schematic expression of the above terms are not
It must be directed to identical embodiment or example.Moreover, particular features, structures, materials, or characteristics described can be in office
It can be combined in any suitable manner in one or more embodiment or examples.In addition, without conflicting with each other, the skill of this field
Art personnel can tie the feature of different embodiments or examples described in this specification and different embodiments or examples
It closes and combines.
Although the embodiments of the present invention has been shown and described above, it is to be understood that above-described embodiment is example
Property, it is not considered as limiting the invention, those skilled in the art within the scope of the invention can be to above-mentioned
Embodiment is changed, modifies, replacement and variant.
Claims (10)
1. a kind of production method of heat shrink films, which comprises the steps of:
S101: it after first mixing raw material and processing aid, according to the melting temperature of different material and auxiliary agent, is heated to molten
Melt state, is then squeezed out using flat crowded lower blowing method, obtain film bubble；
S102: the film bubble is water-cooled sizing under vacuum conditions, the film bubble of cooling and shaping is then heated to glass again
Change temperature or more, carries out secondary inflation stretching using compressed air；
S103: the processed thin film bubble of the step S102 is subjected to cooling and shaping processing, obtains film cylinder；
S104: carrying out inflation by the processed film cylinder heating of the step S103 and again, then cooling and shaping and receives
Volume, obtains heat shrink films.
2. the production method of heat shrink films according to claim 1, which is characterized in that in the step S102, heating
Shi Caiyong hot bath or heater box.
3. the production method of heat shrink films according to claim 1, which is characterized in that in the step S101, heating
Temperature be 150 DEG C~250 DEG C.
4. the production method of heat shrink films according to claim 1, which is characterized in that in the step S102, inflation
Than being (3~4) with draw ratio: 1.
5. the production method of heat shrink films according to claim 1, which is characterized in that in the step S104, inciting somebody to action
The processed film cylinder of step S103 heats and carries out inflation again, then cooling and shaping and the process phase wound
Between, carry out crosslinking Treatment；The crosslinking Treatment includes electron radiation crosslinking, and electron radiation crosslinking is online crosslinking and offline
One of crosslinking.
6. the production method of heat shrink films according to claim 1, which is characterized in that the raw material includes at least polyethylene
Or ethylene-vinyl acetate copolymer, the polyethylene include metallocene linear polyethylene.
7. the production method of heat shrink films according to claim 6, which is characterized in that the raw material also includes at least poly- inclined
One of dichloroethylene, ethylene-vinyl alcohol copolymer and copolymer nylon.
8. the heat shrink films of the described in any item method productions of claim 1-7.
9. application of the described in any item heat shrink films of claim 1-7 in product packaging.
10. the described in any item heat shrink films of claim 1-9 include the following steps: to be packed with the heat shrink films when in use
Product, then with hot water heating 3s~5s of 60 DEG C~90 DEG C temperature；Or with the Hot-blast Heating 3s of 60 DEG C~90 DEG C temperature~
5s, or with infrared heating 3s~5s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811435052.6A CN109648880A (en) | 2018-11-28 | 2018-11-28 | Heat shrink films and its production method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811435052.6A CN109648880A (en) | 2018-11-28 | 2018-11-28 | Heat shrink films and its production method and application |
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| Publication Number | Publication Date |
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| CN109648880A true CN109648880A (en) | 2019-04-19 |
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ID=66111656
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| Application Number | Title | Priority Date | Filing Date |
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| CN201811435052.6A Pending CN109648880A (en) | 2018-11-28 | 2018-11-28 | Heat shrink films and its production method and application |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112793140A (en) * | 2020-12-18 | 2021-05-14 | 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 using double-bubble method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203046247U (en) * | 2012-12-06 | 2013-07-10 | 上海通冷包装材料有限公司 | Film bubble huffing device of film blowing machine |
-
2018
- 2018-11-28 CN CN201811435052.6A patent/CN109648880A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203046247U (en) * | 2012-12-06 | 2013-07-10 | 上海通冷包装材料有限公司 | Film bubble huffing device of film blowing machine |
Non-Patent Citations (1)
| Title |
|---|
| 金伟: ""浅析三泡法热收缩薄膜加工技术"，，", 《全球塑料包装农业》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112793140A (en) * | 2020-12-18 | 2021-05-14 | 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 using double-bubble method |
| 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 |
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Application publication date: 20190419 |