CN1078160C - Pouches for packaging flowable materials - Google Patents

Pouches for packaging flowable materials Download PDF

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Publication number
CN1078160C
CN1078160C CN97181758.8A CN97181758A CN1078160C CN 1078160 C CN1078160 C CN 1078160C CN 97181758 A CN97181758 A CN 97181758A CN 1078160 C CN1078160 C CN 1078160C
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bag
weight
copolymer
melt index
gram
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CN1246099A (en
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D·J·法拉
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Dow Chemical Co
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Dow Chemical Co
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    • 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
    • B65D65/38—Packaging materials of special type or form

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Wrappers (AREA)
  • Laminated Bodies (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Bag Frames (AREA)

Abstract

The present invention discloses a polymer filmbag which is made from a polyethylene film and is friendly to environment. The present invention can be used for packing fluid material, such as milk. The bag has a single-layer or multiple-layer film structure, for example, a bag is made from double-layer or three-layer coextrusion films. The film structure comprises at least one sealing layer made from a composition of linetype ethylene copolymer and high-pressure low-density polyethylene. The present invention also discloses a method for preparing a bag for packing fluid material. In the method, the film structure made from the composition of the linetype ethylene copolymer and the high-pressure low-density polyethylene is used.

Description

The bag that is used for packaging flowable materials
The present invention relates to a kind of bag of being made by some membrane structure that is used for consumer package, it can be used for packaging flowable materials, as the liquid of milk and so on.
U.S. Pat 4,503,102,4,521,437 and 5,288,531 disclose the preparation method of polyethylene film, and this film can be used for making the used disposable bags of class I liquid I of packing milk.U.S. Pat 4,503,102 disclose a kind of bag, by ethene and C 4-C 10The blend of linear ethylene copolymer that alpha-olefin copolymer obtains and the ethane-acetic acid ethyenyl ester poly-mer that obtained by ethene and vinyl acetate copolymerization is made.The density of Hi-fax copolymer is the 0.916-0.930 gram per centimeter 3And melt index (MI) is 0.3-2.0 gram/10 minutes.In the ethane-acetic acid ethyenyl ester poly-mer, the weight ratio of ethene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.In U.S. Pat 4,503, in the 102 disclosed this blends, the weight ratio of linear low density polyethylene (LLDPE) and ethane-acetic acid ethyenyl ester poly-mer is 1.2: 1-4: 1.U.S. Pat 4,503,102 also disclose and have comprised the laminated product of above-mentioned blend as diaphragm seal.
U.S. Pat 4,521,437 have described the bag of being made by diaphragm seal, and (density is the 0.916-0.930 gram per centimeter wherein to comprise the ethene of 50-100 part and the linear copolymers of 1-octene 3And melt index (MI) is 0.3-2.0 gram/10 minutes); With the 0-50 weight portion be selected from ethene and C 4-C 10(density is the 0.916-0.930 gram per centimeter to the linear copolymers of-alpha-olefin 3And melt index (MI) is 0.3-2.0 gram/10 minutes), (density is the 0.916-0.924 gram per centimeter to high pressure polyethylene 3And melt index (MI) is 1-10 gram/10 minutes) and at least a poly-mer of blend.U.S. Pat 4,521,437 disclosed this diaphragm seals can have following performance through selection: (a) under identical thickness, compared with by 85 parts of ethene/1-butylene linear copolymers (about 0.919 gram per centimeter of density 3And melt index (MI) is 0.75 gram/10 minutes) (density is 0.918 gram per centimeter with 15 parts of high pressure polyethylenees 3And melt index (MI) is 8.5 grams/10 minutes) the bag made of blend membrane, its bag has less M-trial value, or (b) is the bag that 1.3-5 rises for volume, and M (2)-trial value is lower than 12%, or (c) be the bag that 0.1-1.3 rises for volume, M (1.3)-trial value is lower than 5%.As the bag dip test, U.S. Pat 4,521,437 have defined M, M (2) and M (1.3)-test.Bag also can be made by the complex film that diaphragm seal forms internal layer thereon at least.But U.S. Pat 4,521, the high pressure polyethylene of describing in 437 is not described has high melt strength, and the melt index (MI) that all high pressure polyethylene resins that use among the embodiment have all restrains/10 minutes greater than 1.In addition, U.S. Pat 4,521, also instruction in 437, it doesn't matter for the melt strength of ethylene polymer blends and hot sticky intensity or seepage property.
U.S. Pat 5,288,531 disclose the bag of being made by membrane structure, and this structure has the blend of following material: (a) at least a polymeric seal layer of the extremely-low density linear ethylene copolymer of 10-100% weight, this copolymer is by ethene and at least a C 3-C 10Alpha-olefin copolymer is made, and density is the 0.89-0.915 gram per centimeter 3(b) at least a poly-mer of 0-90% weight is selected from ethene and C 3-C 18(density is greater than 0.916 gram per centimeter for the linear copolymers of-alpha-olefin 3And melt index (MI) is 0.1-10 gram/10 minutes), (density is the 0.916-0.930 gram per centimeter to hp-ldpe 3And melt index (MI) is 0.1-10 gram/10 minutes) or vinyl-vinyl acetate copolymer (wherein, the weight ratio of ethene and vinyl acetate is 2.2: 1-24: 1, and melt index (MI) is 0.2-10 gram/10 minutes).U.S. Pat 5,288, the heat sealing layer in 531 two-layerly or three-layer co-extruded go out multi-layer film structure for what wherein describe, and improved hot sticky intensity and lower heat seal initiation temperature are provided.
Polythene Bag known in the prior art comes with some shortcomings.The problem relevant with Polythene Bag known in the prior art relates to the sealing property and the in-use performance of the film that is used to prepare bag.Especially, the prior art film of making bag generally has the high accident rate of " seepage ", i.e. seal defect, as sealing part or near the aperture that produced, therefore, the flowable materials of milk and so on can be missed from bag by these holes.Though the sealing of prior art film and in-use performance are generally satisfactory, industrial, still need the film of better sealing and operating characteristic, be used for the sealing bag of packaging flowable materials with manufacturing.More particularly, need to improve the sealing property of film,, also improve the bag of making by this film with the processing characteristics of improving film as hot sticky intensity and melt strength.
For example, be used to produce the known package equipment of bag, limited to by the sealing property of the used film of machine as the line speed of moulding, can and capper.The melt strength of prior art polyethylene film is low.Therefore, the speed of moulding, can and capper production bag is restricted, and the bag number that moulding simultaneously, can and capper are produced also just is restricted.If the raising melt strength, the speed of moulding so, can and capper can be improved, and the bag number of therefore being produced also just increases.Till the present invention, carried out many trials and be used for the sealing property of the polymer composition of bag film, but do not had success with raising.
A kind of polyethylene film structure that is used for packaging bag need be provided, and it has with known prior art bag film improves melt strength and in-use performance equally or better.
Also need to provide a kind of membrane structure that is used for packaging bag, it can be processed into monofilm by moulding, can and capper.
Also need to provide a kind of bag of being made by above-mentioned membrane structure, this bag has lower damage rate.
Therefore, an object of the present invention is to provide the bag that flowable materials is housed, they have improved melt strength and sealing property, therefore have lower damage rate.
Another object of the present invention provides a kind of membrane structure that is used to pack, and bag prepared therefrom has improved melt strength and sealing property.
A further object of the present invention provides the above-mentioned method that the bag of flowable materials is housed of preparation.
The invention provides a kind of packing has the bag of flowable materials, this bag made by the membrane structure with at least one polymer composition sealing layer, described composite contains: (a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; (b) based at least a copolymer that is selected from vinyl-vinyl acetate copolymer of the 0-90% weight of said composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.
One embodiment of the invention are a kind of bags that flowable materials is housed, and described bag is made by multi-layer film structure, and described membrane structure comprises:
(I) a polymer composition layer wherein comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based on the vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes; With
(II) at least one layer line type ethylene copolymer, described linear ethylene copolymer is by ethene and at least a C 3-C 18Alpha-olefin copolymer is made, and its density is the 0.916-0.940 gram per centimeter 3And melt index (MI) is the 0.1-10 gram/minute.
Another embodiment of the present invention is the membrane structure of the polymer composition that is used to pack, wherein comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based on the vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.
One embodiment of the invention are methods that the bag of flowable materials is equipped with in a kind of preparation, comprising, form membrane structure by blown tube extrusion molding or the flat extrusion molding that squeezes, membrane structure is shaped to tubular part, the two ends of transversal heat seal tubular part then, described tubular part comprises the membrane structure of the packaging bag that is used to have at least one polymer composition sealing layer, and described polymer composition comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based at least a copolymer that is selected from vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.
Another embodiment of the present invention is the method that the bag of flowable materials is equipped with in a kind of preparation, comprising, form membrane structure by blown tube extrusion molding or the flat extrusion molding that squeezes, membrane structure is shaped to tubular part, the two ends of transversal heat seal tubular part then, described tubular part comprises:
(I) a polymer composition layer wherein comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based at least a copolymer that is selected from vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes; With
(II) at least one layer line type ethylene copolymer, described linear ethylene copolymer is by ethene and at least a C 3-C 18Alpha-olefin copolymer is made, and its density is the 0.916-0.940 gram per centimeter 3And melt index (MI) is the 0.1-10 gram/minute.
One embodiment of the invention are, by containing the bag that linear low density polyethylene (LLDPE) two-layer co-extruded films outer and aforementioned polymer composite inner sealant layer is made.
Another embodiment of the invention is, by containing the bag that linear low density polyethylene (LLDPE) three-layer co-extruded membrane outer and core layer and aforementioned polymer composite inner sealant layer is made.
Another aspect of the present invention is the method for the aforementioned bag of preparation.
Another embodiment of the invention is, by containing the bag that hp-ldpe three-layer co-extruded membrane outer and core layer and aforementioned polymer composite inner sealant layer is made.
The membrane structure that has been found that bag of the present invention has improved melt strength and heat seal strength, especially final sealing intensity.By using these films to make bag of the present invention in moulding, can and capper, the speed of machine is than using the obtained existing speed height of commercial membrane.
Brief description of the drawings
Fig. 1 is the transparent view of packaging bag of the present invention.
Fig. 2 is the transparent view of another packaging bag of the present invention.
Fig. 3 is that the part of the membrane structure of bag of the present invention is amplified cross sectional drawing.
Fig. 4 is that another part of the membrane structure of bag of the present invention amplifies cross sectional drawing.
Fig. 5 is that the another part of the membrane structure of bag of the present invention is amplified cross sectional drawing.
Fig. 6 is the figure of the relative melt strength of final sealing intensity.
As illustrated in fig. 1 and 2, the bag of the present invention that is used for packaging flowable materials is made by the polymeric seal layer of single-layer membrane structure, and the sealing layer is the blend of linear low density polyethylene (LLDPE) and hp-ldpe, has high fondant-strength.This blend also can comprise ethylene vinyl acetate copolymer.
" melt strength " is also referred to as " melt tension " in association area, represent by definition and quantification in this article, on fusing point, when melt extruding thing through the time, with certain specific speed stretch its required stress or power (applying) by the rolling cylinder that strain gauge element is housed as the die head of standard plasticgraph as described in the ASTM D1238-E.Melt strength values is come record with a li newton number (cN) in this article, measures down at 190 ℃ with Gottfert Rheotens.In general, for ethylene alpha-olefin interpolymers and high pressure ethylene polymer, melt strength is along with the raising of mol wt, or improves along with the expansion of molecular weight distribution and/or along with the raising of melt flows ratio.When measuring with Gottfert Rheotens devices down for 190 ℃, the melt strength of hp-ldpe of the present invention is greater than 10cN, preferred 13-40cN, most preferably 15-25cN.In addition, when measuring with Gottfert Rheotens devices down for 190 ℃, the melt strength of polymer composition of the present invention is greater than 10cN, preferred 15-70cN, and 15-50cN most preferably.
A kind of component of polymer composition of the present invention is a kind of polyethylene that hereinafter is called " linear low density polyethylene (LLDPE) " (" LLDPE ").The example of commercially available LLDPE is DOWLEXTM2045 (trade mark of Dow chemical company and by its sale).LLDPE generally is ethene and has 3-18 carbon atom, preferred 4-10 carbon atom, the most preferably linear copolymers of a small amount of alpha-olefin of 8 carbon atoms.The density of LLDPE that is used for polymer composition of the present invention is greater than 0.916 gram per centimeter 3, more preferably 0.916-0.940 gram per centimeter 3, 0.918-0.926 gram per centimeter most preferably 3In general, its melt index (MI) is less than 10 grams/10 minutes, preferred 0.1-10 gram/10 minutes, most preferably 0.5-2 gram/10 minutes, and I 10/ I 2Than being generally 0.1-20, preferred 5-20,7-20 most preferably.
LLDPE can be in the presence of conventional ziegler natta catalyst, by ethene and one or more optional alpha-olefin comonomer continuously, intermittently or semibatch solution, slurry or gas phase polymerization prepare, the U.S. Pat 4 by people such as Anderson for example, 076,698 disclosed methods are incorporated it into the present invention as a reference at this.
The alpha-olefin that is suitable for LLDPE of the present invention is expressed from the next:
CH 2＝CHR
Wherein R is the alkyl with 1-20 carbon atom.The copolyreaction method can be solution, slurry or gaseous techniques or its combination.Be suitable for the alpha-olefin of making comonomer and comprise 1-propylene, 1-butylene, 1-isobutylene, 1-amylene, 1-hexene, 4-methyl-1-pentene, 1-heptene and 1-octene, and other monomer type, the styrene, tetrafluoroethylene, the vinyl benzo tetramethylene, 1 that replace of styrene, halo or alkyl for example, 4-hexadiene, 1, the 7-octadiene, and cycloolefin, for example cyclopentene, cyclohexene and cyclooctene.The preferred 1-butylene of alpha-olefin, 1-amylene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, or its compound.Alpha-olefin is 1-hexene, 1-heptene, 1-octene more preferably, or its compound, because if use these high alpha-olefins as comonomer, coating, section bar and the film made by the gained extruding composition have improved especially in-use performance.Alpha-olefin is the 1-octene, and polymerization is preferably the successive soln method yet most preferably.
The molecular weight distribution of ethylene alpha-olefin interpolymers composite and high pressure ethylene polymer composite is measured on the Water 150 type high temperature chromatogram arrangements that are equipped with differential refractometer and three mixing porosity posts by gel permeation chromatography (GPC).These posts are provided and generally be filled to the aperture by PolymerLaboratories be 10 3, 10 4, 10 5With 10 6Dust.Solvent is 1,2, the 4-trichloro-benzenes, and the sample solution for preparing 0.3% weight thus is used for injection.Flow velocity is 1.0 ml/min, and the service temperature of device is 140 ℃, and injection volume is 100 microlitres.
For the molecular weight determination of main polymer chain, infer by using Narrow Molecular Weight Distribution polystyrene standard (from Polymer Laboratories) and their elution volume.The suitable Mark-Houwink coefficient of equivalent molecular weight of polyethylene by using polyethylene and polystyrene is (as Williams and Ward at Journal of Polymer Science (polymer science magazine), Polymer Letters, Vol.6, p.621,1968 is described), measure by following equation:
M Polyethylene=a* (M Polystyrene) b
In this equation, a=0.4316 and b=1.0.Weight average molecular weight Mw adopts common mode to calculate according to following formula: Mw=∑ w i* M i, w wherein iAnd M iBe respectively the parts by weight and the mol wt of I the fraction that wash-out goes out from the GPC post.
For LLDPE, the preferred 2-7 of Mw/Mn, especially 4.
Can believe, by in the membrane structure of bag of the present invention, using LDPE with high fondant-strength, can reach following effect: (1) provides the bag of producing fast through moulding, can and capper, (2) provide packaging bag, particularly when bag of the present invention is compared with the bag that uses linear low density polyethylene (LLDPE), low density polyethylene (LDPE) or its compound to make with low seepage.
About Fig. 3-5, the membrane structure of bag of the present invention also comprises multilayer or structure of composite membrane 30, wherein preferably contains above-mentioned polymeric seal layer as the bag internal layer.
The one skilled in the art can understand that the multi-layer film structure of bag of the present invention can contain the rete of various combining forms, as long as sealing layer forms the part of final membrane structure.The multi-layer film structure that is used for bag of the present invention can be co-extruded films, coated film or laminated film.Except sealing layer, membrane structure also comprises antiseepage film, as polyester, nylon, EVOH, polyvinylidene chloride (PVDC) as SARAN TM(trade mark of Dow chemical company) and metalized film.The final use of bag has been determined the selection to other one or more materials that use with the sealing tunic to a great extent.Bag described herein is meant, uses the bag of sealing layer at least in the inboard of bag.
As shown in Figure 3, an embodiment that is used for the membrane structure 30 of bag of the present invention comprises, the sealing layer of being made up of the blend of LLDPE of the present invention and high fondant-strength LDPE 31 and by at least one polymeric outer layer 32.This polymeric outer layer 32 preferably polyethylene rete, more preferably LLDPE.The example of commercially available LLDPE is DOWLEX TM(trade mark is sold by Dow chemical company).Outer 32 thickness can be any thickness, as long as sealing layer 31 has minimum thickness 0.1 mil (2.5 microns).
As shown in Figure 4, another embodiment that is used for the membrane structure 30 of bag of the present invention comprises, is clipped in the polymeric layer 32 in the middle of the two layers of polymers sealing layer 31.
As shown in Figure 5, the another embodiment that is used for the membrane structure 30 of bag of the present invention comprises, at least one core polymer layer 33 between at least one polymeric outer layer 32 and at least one polymeric seal layer 31.Polymeric layer 33 can be LLDPE rete or the preferred different LLDPE identical with outer 32, and the more preferably high LLDPE of its density ratio outer 32 is as DOWLEX TM204S (trade mark of Dow chemical company and by its sale).The thickness of sandwich layer 33 can be any thickness, as long as sealing layer 31 has minimum thickness 0.1 mil (2.5 microns).
The final thickness that is used to make the telolemma product of bag of the present invention is 0.5 mil (12.7 microns)-10 mils (254 microns), preferred 1 mil (25.4 microns)-5 mils (127 microns), more preferably 2 mils (50.8 microns)-4 mils (100 microns).
The various additives that those skilled in the art know can add the poly-mer that is used for preparing bag of the present invention as antiblocking agent, slip aids, UV stabilizer, pigment and processing aid.
As can be seen, the membrane structure that is used for bag of the present invention has design flexibility from the different embodiments of the present invention shown in Fig. 3-5.Skin can use different LLDPE to optimize specific film properties, as membrane rigidity with sandwich layer.Therefore, can be according to application-specific, as optimizing film properties for vertical forming, can and capper.
The polyethylene film structure that is used to prepare bag of the present invention can be made by blown tube extrusion molding known in the art or the flat extrusion molding that squeezes.For example, in Modern Plastics (modern plastics), Mid-October 1989 Encyclopedia Issue, Volume 66, and Number 11, described the blown tube extrusion molding in the 264-266 page or leaf.For example, in ModernPlastics (modern plastics), Mid-October 1989 Encyclopedia Issue, Volume 66, and Number 11, described the flat extrusion molding that squeezes in the 256-257 page or leaf.
As illustrated in fig. 1 and 2, the embodiment of bag of the present invention is the airtight container of packing " flowable materials "." flowable materials " is meant the flowable under gravity material that maybe can aspirate.Term " flowable materials " does not comprise gas material.Flowable materials comprises liquid, as milk, water, fruit juice, oil; Emulsion, as ice cream mix, soft margarine; Lotion is stuck with paste peanut butter as meat; Preserved food products, as jam, sweet cake filling jam; Colloid; Dough/pasta; Meat mincing are as sausage meat; Powder is as gelatin powder, washer solvent; Granular solids, as nut, sugar; And similar substance.Bag of the present invention is particularly useful for aqueous liquid foodstuff, as milk.Flowable materials also can comprise oily liquid, as cooks oil or machine oil.
After making the membrane structure that is used for bag of the present invention, membrane structure is cut into required width to be used for conventional bag forming machine.The embodiment of bag of the present invention is as illustrated in fig. 1 and 2 carried out on so-called moulding known in the art, can and capper.About Fig. 1, provided bag 10 as a kind of tubular part 11, it has longitudinal lap joint and seals 12 and horizontal envelope 13, can form " pincushion " bag when going into flowable materials when this is packed like this.
About Fig. 2, provided bag 20 as a kind of tubular part 11, this bag has along 21 3 directions of tubular part, i.e. the peripheral wing envelope 22 of top envelope 22a, vertical banding 22b and 22c; With the bottom 23 that is spill or " bowl-type " basically of sealing tubular part 21 bottoms, when this bag packaging flowable materials, its cross section of longitudinal 2 observation forms semicircle or " arc " bottom basically like this.The bag that Fig. 2 shows is the example of what is called known in the art " Enviro-Pak " bag.
Bag produced according to the invention is preferably bag shown in Figure 1, produces in so-called vertical forming known in the art, filling and sealing (VFFS) machine.The example of commercially available VFFS machine comprises by Hayssen, Thimonnier, Tetra Pak, or Prepac produce those.Following data has been described VSSF machine: F.C.Lewis, " Form-Fill-Seal ", Packaging Encyclopedia, the 180th page, 1980.
In the VFFS packing method, the sheet material that will have plastic film structure described herein adds in the VFFS machine, and wherein sheet material is shaped to continuous pipe at the pipe moulding section.Tubular part is sealed by the vertical limit with film and makes--and by adopting the inside/outside envelope, the overlap joint plastic film seals these films then; Or, plastic film is carried out wing sealing by adopting interior/interior envelope.Then, sealing band, pours in " bag " as milk then with fill material laterally sealing this pipe as an end of " bag " bottom.Sealing band is sealed the upper end of bag then, and burns plastic film or cutting film, can isolate the complete bag of moulding like this from pipe.U.S. Pat 4,503,102 and US4,521,437 have summarized the method for producing bag with the VFFS machine, incorporate it into the present invention as a reference at this.
The volume of bag of the present invention can change.In general, bag can contain 5 milliliters-10 liters, and preferred 1 milliliter-8 liters, more preferably 1 milliliter-5 liters flowable materials.
But accuracy control is used for the intensity of the membrane structure of bag of the present invention.By membrane structure of the present invention being used for produce bag, can obtain more crash-resistant bag, therefore, the seepage phenomenon that the more preferably less appearance of this bag is relevant with use.In two-layer or three-layer co-extruded membrane product, can be used for producing fast bag in the VFFS method by LLDPE and LDPE blend being used for the membrane structure that sealing layer of the present invention obtains, and the bag of being produced has less seepage.
Provide the packing more friendly to environment along with current consumer package industry tends to be the customer, Polythene Bag of the present invention is exactly a kind of good substitute.Be used for consumer products packaged liquid, as this Polythene Bag of milk relatively in the past employed container (glass bottle, carton and high density polyethylene (HDPE) jar) have various advantages.Used in the past container consumes a large amount of natural resource in its production process, need a large amount of spaces of burying, and takies a large amount of storage areas, and uses higher energy (because heat transfer performance of container) in the temperature control of product.
Polythene Bag of the present invention is made by thin polyethylene film, compares with employed container of past to have various advantages when being used for flexible package punch.This Polythene Bag (1) consumes less natural resource, (2) need the less space of burying, (3) can reclaim, (4) processing easily, (5) need less storage area, and (6) use less energy to be used for storing (heat transfer performance of packing), (7) can incinerate safely, (8) reusable, can be used for other occasion as empty bag, as deep freezer bag, bread bag and general reservoir bag.
The fluoropolymer resin of describing in the following Table I is used for preparing the sample of the blown film that embodiment and Comparative Examples provide.
Table I: resin property
The resin title Kind Melt index (MI) dg/ minute Density g/cc Melt strength cN
?AFFINITY?PL?1880 ?SLEP 1.0 0.903 3.9
DOWLEX?2045 ?LLDPE 1.0 0.920 6
LDPE?1351 LDPE (pipe) 0.22 0.923 19
XU?60021.62 LDPE (autoclave) 0.5 0.919 25
LDPE?609C LDPE (pipe) 0.88 0.924 10
LDPE?5261 LDPE (pipe) 1.0 0.903 ？
The composition of various LDPE and LLDPE blend and their melt strength are listed in the table below among the II.
Table II: the melt strength of resin blend
Blend number (*) is described Melt strength (cN)
1 ?DOWLEX?2045 6.4
2 ?AFFINITY?PL?1880 3.9
3 ?LDPE?5261 12.1
4 ?LDPE1351 19.5
5 ?LDPE?609C 12.1
6 ?LDPE?XU60021.62 24.3
7 ?DOWLEX?2045/10％1351 10.4
8 ?DOWLEX?2045/20％1351 16.0
9 ?DOWLEX?2045/30％1351 19.7
10 ?DOWLEX?2045/10％609C 9.5
11 ?DOWLEX?2045/20％609C 11.7
12 ?DOWLEX?2045/30％609C 13.4
13 ?DOWLEX?2045/10％XU60021.62 11.5
14 ?DOWLEX?2045/20％XU60021.62 24.2
15 ?DOWLEX?2045/30％XU60021.62 30.4
16 ?AFFINITY?PL?10％1880 5.9
17 ?AFFINITY?PL?20％1351 9.4
18 ?AFFINITY?PL?30％1351 9.7
19 ?AFFINITY?PL?10％5261 4.9
20 ?AFFINITY?PL?20％5261 5.8
21 ?AFFINITY?PL?30％5261 6.6
22 ?AFFINITY?PL?10％XU60021.62 8.4
23 ?AFFINITY?PL?20％XU60021.62 12.3
24 ?AFFINITY?PL?30％XU60021.62 14.7
(*) be meant the percent by weight of LDPE in blend
5 kilograms of samples of every kind of blend shown in the Table II are processed through the Leistritz double screw extrusion machine.Use Gottfert Rheotoens device to measure the melt strength of blend.
With erucyl amide, slip aids; SiO 2, antiblocking agent; Add described in the Table I in every kind of resin with processing aid, make that the additive-treated oil ultimate density is as follows: the 1200ppm erucyl amide; 2500ppm SiO 2
The membrane structure of gained is carried out physical testing with definite its various performances, comprising:
(1) ASTM D3763 method is used in puncture test;
(2) drop-dart impact test uses ASTM D1709, method A;
(3) Elmendorf tearing test uses ASTM D1922;
(4) tensile test uses ASTM D882;
ASTM D882 is used in the test of (5) 1% and 2% secant modulus;
(6) following method is used in hot sticky strength test; With
(7) heat seal strength uses following method;
Use " DTC thermal viscosity test method " to measure the hot sticky intensity of sample film, this method is determined at seals fully that cooling (crystallization) preceding heat of dissociation seals required power.This simulation is filled into material in the bag before sealing cooling.
" DTC hot sticky test method " is according to following condition, uses the test method of DTC Hot TackTester Model#52D:
Sample width: 25.4 millimeters
The sealing time: 0.5 second
Sealing load: 0.27N/ millimeter/millimeter
Dead time: 0.5 second
Peeling rate: 150 mm/second
Sample number/temperature 5
Temperature increment: 5 ℃
Range of temperatures: 75 ℃-150 ℃
Use " DTC heat seal strength test method " to measure the heat seal strength of sample film, to be design test separate the required power of sealing after material cooled to 23 ℃ for this.Before test, membrane sample exposes minimum 24 hours down for 23 ℃ in relative humidity 50% and temperature.
" DTC heat seal strength test method " uses DTC Hot TackTester Model#52D according to following condition, wherein used the heat seal lands of tester:
Sample width: 25.4 millimeters
The sealing time: 0.5 second
Sealing load: 0.27N/ millimeter/millimeter
Sample number/temperature 5
Temperature increment: 5 ℃
Range of temperatures: 80 ℃-150 ℃
Use Instron Tensile Tester Model#1122,, measure the sealing intensity of film sample according to following test condition:
Direction of draw: be 90 ° with sealing
Crosshead speed: 500 mm/min
Full load: 5 kilograms
1% of sample number/critical value: FSL
Fracture standard: 80%
Gauge length: 2.0 inches (50.8 millimeters)
Sample width: 1.0 inches (25.4 millimeters)
Table III: multilayer (A/B/A) film that carries out the physical property test
Embodiment number Resin blend among the layer A Resin blend among the layer B Total gauge length (mil)
1A * AFFINITY?PL?1880＋20％ LDPE?1351 ?DOWLEX?2045＋20％ LDPE?1351 2.46
1B ?AFFINITY?PL?1880＋20％ LDPE?1351 ?DOWLEX?2045＋80％ LDPE?1351 2.49
2 ?AFFINITY?PL?1880＋20％ LDPE?5031 ?DOWLEX?2045＋20％ LDPE?5031 2.50
3 ?AFFINITY?PL?1880＋20％ LDPE?5261 ?DOWLEX?2045＋20％ LDPE?5261 2.10
4 ?AFFINITY?PL?1880＋20％ XU60021.621 DOWLEX?2045＋20％XU 60021.62 2.50
The comparative example A ?AFFINITY?PL?1880 ？ 2.54
(*) be meant the percent by weight of LDPE in blend
The physical property of film shown in the Table III is providing in the Table IV down, and hot sticky intensity and heat seal strength then provide in Table V.
Table IV: the physical property of multilayer film
AFF AFF?1880 AFF AFF?1880 AFF AFF AFFIN
1880＋20％ ＋20％ 1880＋ ＋20％XU 1880＋20 1880＋20 ITY
1351 80％ 1351 20％ 60021.62 ％5031 ％5261 1880
1d IN nuclear) 3 mils, 1351 gauge length mils, 2.49 3.18 2.46 2.50 2.50 2.10 2.54Elmendorf f M253D tear Table VI: the hot sticky intensity of hot sticky intensity/heat seal strength, N/in
DOWLEX?2045?DOWLEX?2045＋20％ DOWLEX?2045＋20％ DOWLEX?2045＋20％
LDPE 1351 LDPE 609C XU60021.62 temperature ℃ 90 0.23 0.14 0.22 0.19 95 0.17 0.21 0.15 0.19 100 0.64 0.62 0.66 0.68 105 1.91 1.91 1.85 1.79 110 2.47 2.86 2.55 2.83 115 3.28 3.47 3.30 3.59 120 2.64 3.04 2.73 3.17 125 2.51 2.96 2.63 3.16 130 2.38 2.86 2.56 3.13 135 2.35 2.73 2.32 2.89 140 2.27 2.48 2.16 2.62 145 2.17 2.35 2.14 2.39 150 1.96 2.21 2.09 2.12 155 1.99 1.91 1.85 1.89 160 1.65 1.78 1.80 1.84 Table VII: heat seal strength, lb/in
DOWLEX?2045 DOWLEX?2045＋20％ DOWLEX?2045＋20％ DOWLEX?2045＋20％
LDPE 1351 LDPE 609C XU60021.62 temperature ℃ 100 0.26 0.20 0.19 0.26 105 0.51 0.72 0.51 0.71 110 4.28 4.88 4.10 4.95 115 4.71 5.76 5.15 6.14 120 5.52 7.09 6.00 7.83 125 5.71 7.01 6.50 7.79 130 6.02 7.07 6.60 7.82 135 5.33 7.37 5.90 7.70 140 6.11 7.50 6.75 8.00 145 5.56 7.01 6.06 7.75 150 5.27 7.53 6.33 7.70 155 4.86 7.74 6.48 8.25 160 5.68 7.75 6.50 8.69
The present invention can describe by following examples, but is not limited to these embodiment.
Embodiment 1-3 and comparative example A
Use the Macro membrane blowing production line, the described membrane sample of Table III is made individual layer.The extruder diameter is 2-1/2 inch (6.4 centimetres), and the L/D ratio is 24: 1, and has a barrier-type screw rod, is with a Maddock mixing head.Use the die head of 6 inches (15.2 centimetres) diameters to come the manufacturing test film, wherein die gap is 60 mils (1524 microns).The working condition of blown film is: blow-up ratio 2.5, and 220 ℃ of melt temperatures.
Embodiment 4-6 and Comparative Examples B
Become 15 inches (38.1cm) wide the described film rip cutting of Table III, use Prepac IS6 vertical forming, filling and the sealer that is arranged on the commercialization dairy then, make 2 liters of milk bags.Under the routine operation condition, this device is equipped with the bag of 2 liters of milk with the speed of 30 bags of each fill head of per minute.For each test membrane, collect about 16-20 the bag that milk is housed.Check their initial sealing integrity.The heat seal strength of on-the-spot test 6-8 bag, and 10 bag emptyings, cleaning and dryings are used for further assessment.
Use Instron Tensile Tester Model#1122 to measure sealing intensity.Before test, sample is exposed 24-48 hour down 50% relative humidity and 23 ℃.The Instron test condition is as follows:
Direction of draw: be 90 ° with sealing
Crosshead speed: 500 mm/min
Full load: 5 kilograms
1% of critical value: FSL
Fracture standard: 80%
Gauge length: 2.0 inches (50.8 millimeters)
Sample width: 1.0 inches (25.4 millimeters)
Initial inspection to the end sealing integrity comprises three steps:
I) mensuration of online seepage
Ii) subjective sealing intensity test
The iii) end range estimation of sealing
Online seepage
Only on the bag of making by DOWLEX 2045, observe online seepage.Other film is not observed seepage.
Subjective sealing intensity
Subjective sealing intensity test comprises, fails up to bag surrender or sealing from an end squeeze bag.Table VIII shows, does not observe the sealing failure on the bag of being made by 20%135 I or XU 60021.62.
The range estimation that seal the end
DOWLEX 2045 films are found to have and are significantly sealed attenuation and wire drawing is sealed in the end, as shown in Table VIII.The bag of making by 20%609C find to a certain degree seal attenuation and some end seal wire drawings.For 20%135 I and XU 60021.62 films, do not find to seal attenuation or wire drawing.
End seal intensity
With the said determination heat seal strength time, under the identical condition, use Instron TensileTester Model#4206, measure the end seal intensity of 2 liters of milk bags.
Sealing intensity is shown in the Table X.Found that sealing intensity improves along with the raising of blend melt intensity.This discovery illustrates in Fig. 6, wherein uses the blend of the LDPE of the LLDPE of 80% weight and 20% weight, and just melt strength is that first data point of 6.4cN does not comprise LDPE.Do not find out any relation between LDPE melt index (MI) and the sealing intensity.
The micro-detection of end seal
The wire drawing zone and the fringe region of low temperature cutting bag make then with the light microtechnic and detect.Table X I has summed up these results.
The bag of being made by 20%135 I and XU 60021.62 has the very little attenuation effect of sealing, but does not have end seal wire drawing (from the thin polymer filaments of sealing area), and the bag that contains 100%DOWLEX 2045 has and significantly seals attenuation and wire drawing.
The film attenuation of sealing area
The poorest part of excellent sealing generally is proper film before strip of paper used for sealing.Any attenuation of this film all causes lower sealing intensity, because this is the zone of failing when sealing pressurized.The melt strength (Table II) of resin blend is compared with the film attenuation amount (Table X I) of the bag of producing by commercial VFFS device, and as can be seen, along with the raising of resin blend melt strength, film attenuation amount reduces.It doesn't matter between the melt index (MI) (Table I) of LDPE in film attenuation (Table X I) and the resin blend.
Strip of paper used for sealing
Relatively strip of paper used for sealing thickness (Table X I) and resin blend melt strength (Table II) and LDPE melt index (MI) (Table I) as can be seen, between melt strength and the strip of paper used for sealing thickness much relations are arranged, and it doesn't matter between LDPE melt index (MI) and the strip of paper used for sealing thickness.Higher melt strength obtains thicker strip of paper used for sealing.
Table VIII: Liconsa Dairy Prepac VFFS assessment
Subjective sealing intensity
Test # LLDPE ?LDPE ％LDPE The # bag number of test # seals failure
1 ?DOWLEX?2045 0 7 3
2 ?DOWLEX?2045 ?609C 20 8 2
3 ?DOWLEX?2045 ?1351 20 6 0
4 ?DOWLEX?2045 XU.62 20 7 0
Table I X:Liconsa Dairy Prepac VFFS assessment
The range estimation of end seal
Test # LLDPE LDPE ％LDPE The range estimation of sealing
1 ?DOWLEX?2045 - 0 Attenuation is sealed in serious wire drawing
2 ?DOWLEX?2045 609C 20 Attenuation is sealed in serious wire drawing
3 ?DOWLEX?2045 1351 20 No wire drawing
4 ?DOWLEX?2045 XU.62 20 No wire drawing
Table X: Prepac VFFS bag end seal intensity
Test # ?LLDPE?MI ?LDPE?MI ％LDPE Sealing intensity, lb/in
1 ?DOWLEX?2045 - 0 5.31
2 ?DOWLEX?2045 609C 20 5.78
3 ?DOWLEX?2045 135C 20 6.79
4 ?DOWLEX?2045 XU.62 20 7.01
Table X I:Prepac VFFS micro-analysis is summed up
Test # Explanation Estimate Strip of paper used for sealing thickness micron * thickness micron Thickness micron before the * sealing The thickness drop-out value, %
1 DOWLEX Serious attenuation of sealing area and stretching, many wire drawings 139 ?65.5 43.1 34
2 DOWLEX 2045＋20％ LDPE?609C An attenuation is arranged, some wire drawing 130 63.2 50.0 21
3 DOWLEX 2045＋20％ LDPE?1351 Well, do not have attenuation, do not have wire drawing 176 60.8 56.9 6
4 DOWLEX ?2045＋20％XU ?60021.62 Well, do not have attenuation, do not have wire drawing 228 ?61.3 60.2 2
* locate to measure from sealing 650 microns
* is before sealing, and the thinnest part of film carries out section gauge
Following polymeric resin blends provides in Table X II, is used to further specify advantage of the present invention:
Table X II: resin blend
The blend explanation Blend is described
1 DOWLEX?2045
2 DOWLEX＋10％LDPE?XU?60021.62
3 DOWLEX＋20％LDPE?XU?60021.62
4 DOWLEX＋30％LDPE?XU?60021.62
5 DOWLEX＋40％LDPE?XU?60021.62
6 DOWLEX＋50％LDPE?XU?60021.62
7 DOWLEX＋60％LDPE?XU?60021.62
8 DOWLEX＋70％LDPE?XU?60021.62
9 DOWLEX＋80％LDPE?XU?60021.62
10 DOWLEX＋90％LDPE?XU?60021.62
(*) be meant the percent by weight of LDPE in various blends
Use has the Macro membrane blowing production line of barrier-type screw rod (diameter is 2 1/2 inches (63.5 millimeters), and the L/D ratio is 24: 1) and Maddock mixing head, and the resin blend of Table X II is made the thick film of 2.8 mils (71 microns).Using die gap is 6 inches (15.2 centimetres) die heads of 60 mils (1524 microns).The Macro lips vane that use is produced by cold air.Every kind of mixed with resin is reached the erucyl amide slip aids of 1200ppm and the SiO of 2500ppm 2Anti-caking agent.Test the hot sticky intensity and the heat seal strength of every kind of film, Table X III and Table X IV have provided these numerical value respectively.
The hot sticky intensity (N/IN) of Table X III:DOWLEX 2045/LDPE XU 60021.62 blends
90％XU.62＋ 10％2045 ?80XU.62＋ 20％2045 ?70％XU.62＋ 30％2045 ?60％XU.62＋ 40％2045 ?50％XU.62＋ 50％2045 ?40％XU.62＋ 60％2045 ?30％XU.62＋ 70％2045 ?20％XU.62＋ 80％2045 ?10％XU.62＋ 90％2045 ?D0WLEX 2045
Temperature ℃
95 0.24 0.30 0.23 0.23 0.27 0.32 0.28 0.21 0.27 0.29
100 0.37 0.36 0.41 0.38 0.35 0.29 0.32 0.59 0.70 0.45
105 0.96 0.90 0.96 1.02 0.97 1.12 1.24 1.53 1.62 1.76
110 2.06 2.00 2.17 2.11 2.19 2.28 2.47 2.61 2.58 2.40
115 2.83 2.95 3.25 3.30 3.18 3.15 2.88 3.00 3.03 2.82
120 2.76 3.01 3.35 3.50 3.41 3.33 2.95 3.01 3.00 2.96
125 2.68 2.93 3.29 3.33 3.54 3.29 3.04 2.99 2.97 2.77
130 2.45 2.70 3.03 3.34 3.34 3.30 2.90 2.96 2.92 2.54
135 2.30 2.59 3.01 3.17 3.10 3.10 2.82 2.88 2.89 2.40
140 2.18 2.28 2.75 2.92 3.05 3.01 2.79 2.80 2.69 2.31
145 2.09 2.14 2.47 2.85 2.87 2.87 2.64 2.59 2.61 2.32
150 1.83 2.03 2.27 2.68 2.74 2.64 2.57 2.41 2.40 2.18
155 1.76 1.88 2.28 2.47 2.57 2.44 2.44 2.28 2.17 2.17
160 1.66 1.85 2.10 2.35 2.44 2.49 2.08 2.22 2.03 2.10
The heat seal strength (LB/IN) of Table X IV:DOWLEX 2045/LDPE XU 60021.62 blends
90％XU.62＋ 10％2045 80XU.62＋ 20％2045 70％XU.62＋ 30％2045 60％XU.62＋ 40％2045 50％XU.62＋ 50％2045 40％XU.62＋ 60％2045 30％XU.62＋ 70％2045 20％XU.62＋ 80％2045 10％XU.62＋ 90％2045 DOWLEX 2045
Temperature ℃
95 0.30 0.25 0.23 0.22 0.22 0.22 0.22 0.23 0.24 0.24
100 1.07 1.00 0.79 0.40 0.33 0.32 0.28 0.31 0.30 0.31
105 2.58 4.05 3.18 1.71 0.95 0.96 0.80 0.64 0.67 0.63
110 7.73 7.12 6.90 6.44 5.86 6.35 6.11 5.68 5.33 4.66
115 9.55 9.37 9.26 9.13 8.74 8.55 7.37 6.69 6.55 5.42
120 9.66 9.50 9.59 10.41 11.24 10.86 9.96 9.08 8.73 6.61
125 9.62 9.61 9.92 10.63 11.19 10.67 10.08 9.09 8.79 6.79
130 9.63 9.53 9.86 10.43 11.41 10.84 10.16 9.06 8.86 6.60
135 9.79 9.57 9.63 10.25 11.73 10.81 10.14 9.13 9.02 6.74
140 9.55 9.91 9.66 10.18 11.81 10.94 10.45 9.16 9.07 6.78
145 9.91 9.74 9.79 10.55 11.70 10.90 10.36 9.25 9.14 6.70
150 9.68 9.61 9.92 10.87 11.85 11.03 10.48 9.67 8.85 7.04
155 9.83 9.57 9.83 11.03 12.19 11.02 10.72 9.58 9.25 7.01
160 9.94 9.54 9.62 11.32 11.24 11.27 10.99 10.11 9.72 6.94
Use DTC Hottack Tester Model#D52D, measure hot sticky intensity subject to the foregoing.Use DTC Hottack Tester Model#D52D that these test membranes are sealed subject to the foregoing.Use Instron Tensile Tester Model#1122 to measure sealing intensity.Before test, specimen exposes 24-48 hour down for 23 ℃ in relative humidity 50% and temperature.The Instron test condition as hereinbefore.
From Table X III and the given hot sticky result who tests with heat-sealing of Table X IV, as can be seen, 50%DOWLEX 2045/50%XU 60021.62 blends can reach maximum hot sticky intensity.Can find out that also 50%DOWLEX 2045/50%XU 60021.62 blends can reach high heat-sealing strength.
The hot sticky calculation of strength of expection is as follows:
Hot sticky intensity=(the hot sticky intensity of 0.5 * LLDPE)+(the hot sticky intensity of 0.5 * LDPE)
Table X V: expect hot sticky intensity and actual hot sticky intensity
DOWLEX LDPE DOWLEX?2045＋20％ DOWLEX?2045＋20％
2045 135I LDPE 135I LDPE 135I temperature (℃) the anticipated value actual value
95 0.29 0.18 0.24 0.27
100 0.45 0.22 0.33 0.35
105 1.76 0.56 1.16 0.97
110 2.40 0.81 1.60 2.19
115 2.82 0.86 1.84 3.18
120 2.96 0.74 1.85 3.41
125 2.77 0.69 1.73 3.54
130 2.54 0.69 1.62 3.34
135 2.40 0.64 1.52 3.10
140 2.31 0.64 1.47 3.05
145 2.32 0.60 1.46 2.87
150 2.18 0.56 1.37 2.74
Expect that the result of the actual relatively hot sticky intensity of hot sticky intensity provides in Table X V.As can be seen, the hot sticky intensity of reality of the present invention is apparently higher than anticipated value, and this shows a kind of obvious synergistic effect.

Claims (27)

1, a kind of bag that flowable materials is housed, described bag is made by the membrane structure with at least one polymer composition sealing layer, and described composite contains:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based on the vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.
2, a kind of bag that flowable materials is housed, described bag is made by multi-layer film structure, and described membrane structure comprises:
(I) a polymer composition layer wherein comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based on the vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes; With
(II) at least one layer line type ethylene copolymer, described linear ethylene copolymer is by ethene and at least a C 3-C 18Alpha-olefin copolymer is made, and its density is the 0.916-0.940 gram per centimeter 3And melt index (MI) is the 0.1-10 gram/minute.
3, according to the bag of claim 1, wherein said membrane structure is that bag tubulose and described has the transverse heat seal end.
4, according to the bag of claim 2, it has (III) one deck high pressure polyethylene, and its density is the 0.916-0.930 gram per centimeter 3And melt index (MI) is the 0.1-10 gram/minute.
5, according to the bag of claim 2, its middle level (I) is sealing layer.
6, according to the bag of claim 2, its middle level (II) is outer and layer (I) is sealing layer.
7, according to the bag of claim 4, its middle level (II) is that skin, layer (III) are that sandwich layer and layer (I) are sealing layer.
8, according to the bag of claim 2, the melt index (MI) of wherein said linear ethylene copolymer is less than 10 gram/minute.
9, according to the bag of claim 1, wherein said bag holds 5-10,000 milliliter.
10, according to the bag of claim 1, wherein said flowable materials is a milk.
11, according to claim 1 the bag, the molecular weight distributing index (I of wherein said ethylene copolymer 10/ I 2) be 0.1-20.
12, according to the bag of claim 1, wherein said membrane structure contains slip aids, antiblocking agent and optional processing aid.
13, according to the bag of claim 1, wherein said membrane structure contains pigment so that membrane structure is light tight.
14, according to the bag of claim 1, wherein said membrane structure contains ultraviolet absorbent.
15, according to the bag of claim 1, the alpha-olefin of wherein said membrane structure is the 1-octene.
16, according to the bag of claim 1, the melt strength of wherein said hp-ldpe is 10-40cN.
17, according to the bag of claim 1, the melt strength of wherein said hp-ldpe is 13-25cN.
18, according to the bag of claim 1, the melt strength of wherein said polymer composition is 10-70cN.
19, according to the bag of claim 1, wherein the attenuation value of fringe region reduces below 25%.
20, be used to the membrane structure of the polymer composition packed, wherein comprise:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based on the vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.
21, according to the film of claim 20, the density of wherein said linear ethylene copolymer is the 0.916-0.940 gram per centimeter 3
22, according to the film of claim 20, the concentration of wherein said vinyl-vinyl acetate copolymer is based on the 5-85% of described composition total weight.
23, according to the film of claim 20, the concentration of wherein said vinyl-vinyl acetate copolymer is based on the 5-25% of described composition total weight.
24, according to the film of claim 20, the melt strength of wherein said polymer composition is 10-70cN.
25, the method for the bag of flowable materials is equipped with in a kind of preparation, comprising, form membrane structure by blown tube extrusion molding or the flat extrusion molding that squeezes, membrane structure is shaped to tubular part, the two ends of transversal heat seal tubular part then, described tubular part comprises the membrane structure of the packaging bag that is used to have at least one polymer composition sealing layer, and described polymer composition comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based at least a copolymer that is selected from vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes.
26, the method for the bag of flowable materials is equipped with in a kind of preparation, comprising, form membrane structure by blown tube extrusion molding or the flat extrusion molding that squeezes, membrane structure is shaped to tubular part, the two ends of transversal heat seal tubular part then, described tubular part comprises:
(I) a polymer composition layer wherein comprises:
(a) based on the compound of (1) and (2) of the 10-100% weight of said composition total weight: (1) based on the described compound of 100 weight portions, 5-95% weight by ethene and at least a C 3-C 18The linear ethylene copolymer that alpha-olefin copolymer is made, the density of this copolymer are the 0.916-0.940 gram per centimeter 3And melt index (MI) restrains/10 minutes less than 10, the molecular weight distribution mw/mn ratio is greater than 4.0, and the peak value fusing point of being measured by differential scanning calorimeter is greater than 100 ℃, (2) based on the described compound of 100 weight portions, the hp-ldpe of 5-95% weight, its density are the 0.916-0.930 gram per centimeter 3, melt index (MI) restrains/10 minutes less than 1, and the melt strengths of measuring with Gottfert Rheotens device under 190 ℃ are greater than 10cN; With
(b) based at least a copolymer that is selected from vinyl-vinyl acetate copolymer of the 0-90% weight of described composition total weight, the weight ratio of therein ethylene and vinyl acetate is 2.2: 1-24: 1 and melt index (MI) be 0.2-10 gram/10 minutes; With
(II) at least one layer line type ethylene copolymer, described linear ethylene copolymer is by ethene and at least a C 3-C 18Alpha-olefin copolymer is made, and its density is the 0.916-0.940 gram per centimeter 3And melt index (MI) is the 0.1-10 gram/minute.
27, according to the method for claim 26, wherein said membrane structure comprises:
(III) at least one floor height pressure polyethylene, its density is the 0.916-0.930 gram per centimeter 3And melt index (MI) is the 0.1-10 gram/minute.
CN97181758.8A 1997-02-11 1997-02-11 Pouches for packaging flowable materials Expired - Fee Related CN1078160C (en)

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DE69737571T2 (en) 2007-12-20
EP0998388A1 (en) 2000-05-10
ES2284182T3 (en) 2007-11-01
DE69737571D1 (en) 2007-05-16
WO1998034844A1 (en) 1998-08-13
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CN1246099A (en) 2000-03-01
CA2280910A1 (en) 1998-08-13
AU742162B2 (en) 2001-12-20

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