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WO2001036194A1 - Feuille d'emballage polymere composite pour produits carnes et vegetaux frais - Google Patents

Feuille d'emballage polymere composite pour produits carnes et vegetaux frais Download PDF

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Publication number
WO2001036194A1
WO2001036194A1 PCT/US2000/031545 US0031545W WO0136194A1 WO 2001036194 A1 WO2001036194 A1 WO 2001036194A1 US 0031545 W US0031545 W US 0031545W WO 0136194 A1 WO0136194 A1 WO 0136194A1
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WO
WIPO (PCT)
Prior art keywords
film
composite film
polymer composite
polymer
layer
Prior art date
Application number
PCT/US2000/031545
Other languages
English (en)
Inventor
Carl M. Sullivan
Thomas E. Hopton
Original Assignee
Pliant Corporation
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 Pliant Corporation filed Critical Pliant Corporation
Priority to AU19211/01A priority Critical patent/AU1921101A/en
Publication of WO2001036194A1 publication Critical patent/WO2001036194A1/fr

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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
    • B32B27/06—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
    • 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
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (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
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/304—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
    • 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
    • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
    • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
    • B32B37/15—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
    • B32B37/153—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state at least one layer is extruded and immediately laminated while in semi-molten state
    • 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
    • B32B38/00—Ancillary operations in connection with laminating processes
    • B32B38/0036—Heat treatment
    • 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
    • B32B38/00—Ancillary operations in connection with laminating processes
    • B32B38/0012—Mechanical treatment, e.g. roughening, deforming, stretching
    • B32B2038/0028—Stretching, elongating
    • 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
    • B32B2307/412—Transparent
    • 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
    • B32B2307/70—Other properties
    • B32B2307/724—Permeability to gases, adsorption
    • 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
    • B32B2327/00—Polyvinylhalogenides
    • B32B2327/06—PVC, i.e. polyvinylchloride
    • 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
    • B32B2439/00—Containers; Receptacles
    • B32B2439/70—Food packaging
    • 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
    • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
    • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
    • C08J2327/04—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing chlorine atoms
    • C08J2327/06—Homopolymers or copolymers of vinyl chloride

Definitions

  • This invention relates to packaging films for fresh meat and vegetable produce and, in particular, a polymer composite packaging film that is formulated to have a film surface with anti-fog properties and a controlled gas permeability rate.
  • Optically transparent films useful for covering food product containers and packaging food products are ideally formulated to provide consumers with a clear view of the packaged food product while maintaining its appearance and freshness.
  • Films with oxygen transmission rate (OTR) control properties extend the shelf life of refrigerated freshly cut produce and fresh meat since the presence of either too much or too little oxygen in the package lowers shelf life.
  • OTR oxygen transmission rate
  • In the packaging of lettuce excessive oxygen in the package results in enzymatic browning of cut surfaces of the lettuce.
  • insufficient oxygen in the package results in lettuce spoilage caused by anaerobiosis.
  • fresh meat packaging denies delivery of excessive oxygen to the meat to minimize bacterial growth and simultaneously permits delivery of sufficient oxygen to the myoglobin contained within the meat to maintain its natural red color and thus achieve the fresh looking product preferred by consumers.
  • Optically transparent films with anti-fog properties provide a clear, unobstructed view of a food product. Fog arises in the presence of surface moisture on the packaging film. Sources of such moisture include ambient moisture in the atmosphere and latent moisture in the packaged product.
  • Packaging films made from poly vinyl chloride (PVC) have been used for decades to wrap red meat and produce.
  • PVC films include VitafilmTM packaging film sold by Pliant Corporation, Uniontown, Ohio and ResiniteTM packaging film sold by AEP, Inc., Hackensack, New Jersey.
  • PVC films possess a sparkling clear view of the packaged product, and, when formulated with tackifier plasticizers, exhibits superb cling properties.
  • packaging films made from olefmic materials can be formulated to control OTR, they are susceptible to surface moisture buildup in the form of small beads that obscure a consumer's view of the product contained in the package.
  • An example of such an olefin film includes CryovacTM packaging film sold by Sealed Air Corporation, Hartford, Connecticut.
  • An object of the present invention is to provide a visually clear atmospheric packaging film for refrigerated fresh meat and freshly cut produce to prolong their states of freshness.
  • the present invention is a polymer composite film for packaging fresh meat and vegetable produce.
  • the composite film is of a particular thickness and is compounded to have a film surface with visual clarity and gas permeability rate (specifically OTR) control.
  • a monolayer composite film includes a polymer film substrate, e.g., PVC, into which one or more surface active agents are incorporated to provide the composite film with anti- fog properties.
  • PVC film substrate readily absorbs the surface active agents, which have an affinity for moisture.
  • the surface active agents evenly spread minuscule beads of any moisture coating the inner surface of the package and thereby present a visually clear surface through which a customer can inspect the packaged product.
  • one or more plasticizer active ingredients are incorporated into the PVC film substrate.
  • the amount and type of plasticizer dictate the degree of stiffness of the composite film, and, for a given thickness or gauge of the composite film, an increase in plasticizer provides an increase in OTR.
  • Control of OTR is governed not only by the amount and type of plasticizer but also by the orientation of the molecular chain order of the PVC film substrate used in the composite film. Applying heat and/or imparting stretch forces to the composite film affects the OTR because heat and stretching affect the molecular chain orientation. OTR preservation of a monolayer composite film is, therefore, maintained by sealing without shrinking or stretching the composite film as it is applied to a container or formed into a package container.
  • a multilayer lamination or extrusion of PVC films provides OTR control at a fixed composite film gauge.
  • at least two layers of PVC films having different OTR properties are separated by an adhesive layer and fused together.
  • multiple layers of PVC film having different OTR properties are extruded together in a molten state without an adhesive.
  • multiple layers of PVC film having different OTR properties are laminated together under high temperature and pressure.
  • Each of the three implementations provides a multilayer composite film having a specified overall OTR at a prescribed overall film thickness.
  • a multilayer lamination or extrusion can be formulated using layer distribution to provide a differential heat seal.
  • Fig. 1 is a graph showing the relationship between OTR and plasticizer material concentration for a monolayer composite PVC film of a specified thickness.
  • Fig. 2 is a graph demonstrating the effect of the orientation of the molecular chain order of the PVC film on the plasticizer concentration versus OTR @ 1.0 mil curve.
  • Fig. 3 is a table showing certain properties of exemplary monolayer PVC films implemented in accordance with the present invention.
  • Fig. 4 is a table showing trial test data representing 11 two-layer sample laminations of different gauges and film layer component types, as identified in Fig. 3.
  • Fig. 5 is a set of two curves showing OTR @ 1.0 mil thickness expressed as a function of di(2-ethyl-hexyl adipate) (DEHA) equivalents for monolayer composite films made with high and low concentrations of epoxidized soya oil (ESO) in accordance with the present invention.
  • DEHA di(2-ethyl-hexyl adipate)
  • Fig. 6 is a table showing the formulation of a preferred monolayer PVC film made in accordance with the present invention for fresh cut produce. Detailed Description of Preferred Embodiments
  • a first preferred embodiment of the invention is a monolayer polymer composite film that comprises a PVC substrate into which a surface active agent and a plasticizer material are incorporated.
  • a PVC material in powder form, one or more surface active agents in liquid or solid form, and a plasticizer material in solid or liquid form are dry blended.
  • the resultant blend is extruded into a film sheet or into pellets that are then extruded into a film sheet.
  • the surface active agent is thereby homogeneously mixed in the polymer matrix.
  • the homogeneous mixture promotes uniform spreading of any surface moisture present on the composite film when in use and thereby maintains its visual clarity.
  • the amount of surface active agent preferably ranges from between about 0.001 and 5 parts/hundred resin, the higher proportion of surface active agent providing a slippery surface to the composite film.
  • PVC material which is a polar compound, readily absorbs surface active agents, skilled persons will appreciate that there is an upper limit to the amount of surface active agent that PVC can accept.
  • Preferred surface active agents include surfactant, antistat, antiblock, and slip agents.
  • the amount of plasticizer material or materials preferably ranges from between about 5 and 60 parts/hundred resin.
  • an increase in the amount of plasticizer increases the OTR.
  • Fig. 1 shows the relationship between plasticizer material concentration, expressed in DEHA equivalents, and OTR for a 1.0 mil thick monolayer composite PVC film.
  • Equivalent DEHA is a measure of the amount of plasticizer or plasticizer blend required to give the same amount of stiffness as that provided by a unit measure of DEHA.
  • the diamond-shaped symbols indicate experimental data points.
  • the x and y variables represent equivalent DEHA and OTR @ 1.0 mil thickness, respectively, and the parameter R 2 represents a statistical measure of confidence that the equation fits the data presented.
  • the OTR selected for commercial use depends in part on the type of product that is to be packaged. A higher OTR (e.g., 600 and greater cc/100 in 2 /day) is preferable to maintain the redness of red meat, and a lower OTR (e.g., 120 and below cc/100 in 2 /day for romaine lettuce; 120-210 cc/100 in 2 /day for fresh cut salad; and 240-360 cc/100 in 2 /day for coleslaw salad) is preferable to maintain crisp, fresh salad.
  • Preferred plasticizer materials include di(2-ethyl-hexyl) adipate (DEHA) and epoxidized soya bean oil (ESO).
  • ESO is a secondary plasticizer used in flexible systems at low levels to add stability and to produce a cost-effective film.
  • Other factors affecting OTR include the gauge (i.e., thickness) of, molecular orientation of, and temperature applied to the composite film.
  • Fig. 2 is a set of two curves 20 and 22 showing that the orientation of the molecular chain comprising the PVC film substrate shifts the plasticizer concentration versus OTR curve along the ordinate axis.
  • curves 20 and 22 represent composite films having the same range of plasticizer composition but with different molecular orientations.
  • Orienting a monolayer PVC composite film can be achieved by prestretching the composite film and thereby increasing the order of the molecules in the molecular chain. The amount and direction of the recovery of the prestretching imparted to the composite film may be tested by measuring shrinkage at high temperature. The shrinkage data points are used to derive curve 20.
  • OTR control and its preservation for a PVC-oriented composite film may be achieved by refraining from shrinking or stretching the composite film when using it to cover a container or forming it into a package container.
  • Temperature also affects the OTR of the composite film. An increase or decrease in temperature applied to the composite film causes a consequent increase or decrease in its OTR.
  • Non-resin additives are added to the film composite to change the physical characteristics of the resin.
  • plasticizers have a dual effect on the PVC resin; by intimately associating themselves with the PVC resin powder, they (1) change the consistency of the melted and cast PVC film from a stiff, hard, brittle thermoplastic film resembling glass to a soft, rubbery, tough, stretchable film and
  • non-resin additives include polyoxyethylene sorbitan monooleate (POE-SMO), an anti-fog agent; glycerol monooleate (GMO), an anti-fog agent; and sorbitan monostearate (SMS), a slip agent.
  • POE-SMO polyoxyethylene sorbitan monooleate
  • GMO glycerol monooleate
  • SMS sorbitan monostearate
  • Process aids and copolymers may also be introduced into the PVC resin film, as is commonly known to those skilled in the art. Process aids improve the machinability of the film by acting as external and/or internal lubricants that modify the polymer melt. External lubricants allow the film to slide over without sticking to the hot metal components of the film manufacturing equipment.
  • Internal lubricants provide lubrication between the individual polymer chains to allow internal slippage that promotes heat stabilization and thereby prevents tearing of the polymer chains and melt fracturing of the film.
  • external lubricants include polyethylene wax, erucamide, and ethylene bis-oleamide (EBO).
  • Stearic acid is an example of an internal lubricant.
  • Calcium/zinc heat stabilizer soaps are process aids that may act as internal and external lubricants. The amount of process aid material or materials preferably ranges from between about 0.001 to about 5 parts/hundred resin. Copolymers can be used to modify the existing properties of the polymer to allow maximization of its beneficial characteristics.
  • copolymer functions include increasing the strength and modulus of the film while increasing its softness. Further, copolymers can act as surface active agents, aid in heat sealing, or function as a process aid by affecting viscosity, as is commonly known to those skilled in the art. Skilled persons will recognize that use of copolymers does not appreciably affect OTR and thus does not materially affect the method of determining a plasticizer equivalent described in Fig. 5 below.
  • Exemplary commonly known copolymers include polyvinyl chloride polyvinyl acetate (PVCPVA) and polyester adipate.
  • PVCPVA polyvinyl chloride polyvinyl acetate
  • polyester adipate polyester adipate
  • Fig. 3 is a table showing certain properties of exemplary monolayer PVC films in which the invention has been implemented.
  • Fig. 3 presents values of certain properties for different gauges of different base film types.
  • Film styles identified as CBIX, BIX, FTX, MX, LGS, LG, and PS are VitafilmTM packaging film products.
  • CBIX and BIX indicate, respectively, Canadian- and German- produced biaxially oriented general purpose films;
  • FTX indicates biaxially oriented shrink films; LG and LGS indicate delicatessen food style wrapping films; LG also indicates laundry bundling wrapping films;
  • OmnifilmTM indicates meat wrapping films; MX indicates oriented meat wrapping; and PS indicates print films.
  • Film styles identified as AV are VitafilmTM variants that are not currently commercially available.
  • the films described in Fig. 3 were made in accordance with the following procedure.
  • PVC resin powder was dry blended in a high intensity blender, e.g., a "Henschel blender" made by Henschel Corp., at high speed at a temperature sufficient to allow absorption of the non-resin additives into the PVC resin particles.
  • Non-resin additives e.g., plasticizers, process aids, slip agents, anti-fog agents, and surface active agents, were added gradually to the highly porous PVC resin powder during dry blending. Spraying the non-resin additives onto the PVC resin as the resin warms in the high intensity blender constitutes one method of performing this addition.
  • the resulting dry blend was placed into a cooling blender that feeds into an extruder having controlled temperature and speed. While in the extruder, the dry blend melted and became a visco-elastic melt. The melt was then forced into a die producing pellets that were fed into a second extruder with a die that produced a thin film.
  • the use of two extruders resulted in more complete mixing, permitted increased control of production rates, and allowed reworking of scrap trim remnants, thereby increasing cost-effective and efficient manufacture.
  • This production process resulted in a thin film of specified thickness that was wound onto cylindrical cores as rolls of specified length and width.
  • An alternative process commonly known to those skilled in the art involves forcing the visco-elastic melt into a first extruder with a die producing a thin film.
  • the nominal gauge is expressed in mils (0.001 in.).
  • Equivalent DEHA is a measure of the degree of stiffness of the film and is expressed relative to the amount of plasticization by DEHA. In Fig. 3, the greater the plasticizer concentration, the softer the resulting film.
  • Molecular Orientation refers to the degree of order imparted to the composite film. Slip, anti-block, anti-fog, surface active agents, and plasticizers are all non-resin additives that were added to the PVC resin as described above.
  • a second embodiment of the invention is a multilayer lamination of PVC films having different OTR properties to give a specified overall OTR for a multilayer composite PVC film at a specified thickness.
  • This embodiment accommodates a need for a predictable OTR when the film gauge is a fixed parameter.
  • the adjacent surfaces of the PVC layers can be separated by a material, which may be either a tie adhesive or barrier adhesive with minimal effect on OTR, or air. Air may be considered an adhesive because PVC adheres to itself due to the magnitude of its binding attractive force.
  • Fig. 4 is a table showing trial test data representing 11 two-layer sample laminations of different gauges and film layer component types, such types identified in Fig. 3.
  • the adhesive type Liofol No. 7980 used for trials A, B, C, D, E, F, G, H, I, J, and K is a solid adhesive with minimal effect on OTR.
  • the 2-ply Nominal Gauge refers to the thickness of the two-layer laminations, expressed in mils.
  • Fig. 4 shows that two-layer PVC films of approximately the same nominal thickness can be produced with different OTR values.
  • the films represented by trials D and E are each 2.00 mils thick but have respective OTR values of about 75.2 cc/100 in 2 /24 hours and about 138.4 cc/100 in 2 /24 hours.
  • the 11 two-layer sample laminations described in Fig. 4 were made in accordance with the following procedure. Each individual film was produced using the procedure described above. One film was designated as the primary web and the other the secondary web. The primary and secondary webs constituted, respectively, the back side and the seal side of the two-layer packaging film. Skilled persons will appreciate that either film could constitute the primary or secondary web.
  • the primary web constitutes the seal side and the secondary web constitutes the back side in the production of a printed two-layer packaging film.
  • the primary web was covered with an adhesive, and the secondary web was laminated to the adhesive-coated primary web.
  • the primary web could be coated with adhesive, and the secondary web could be joined to the primary web using a pinch roller.
  • additives were introduced to begin a curing process, as is known to those skilled in the art.
  • the curing process reached completion upon winding of the packaging film around a cylindrical cord to achieve a specified length and width.
  • the conventional lamination method used entails dissolving the adhesive in water or a solvent and then coating the primary web with the liquid adhesive mixture. The coated film is then dried to remove the solvent. Once substantially all of the solvent has been removed, the secondary web is joined to the coated primary web.
  • various laminators and adhesives are known to those skilled in the art including UtecoTM laminating manufacturing equipment and LyofolTMadhesive.
  • the packaging film of the present invention has sufficient binding attractive force to allow use of solventless laminators known to those skilled in the art. Solventless laminators offer the benefits of increased production rate, because no drying time is required, and decreased manufacturing cost, because no fumes are released.
  • Fig. 5 is a set of two curves showing the OTR @ 1.0 mil thickness expressed in DEHA equivalents for the base film laminants set out in Fig. 6.
  • Curves 50 and 52 represent OTR @ 1.0 mil thickness trendlines for monolayer films with, respectively, high and low ESO relative concentrations as a function of DEHA.
  • An ESO/DEHA ratio of greater than 0.5 is considered to be a low ESO concentration, while a ratio of greater than 0.5 is considered to be a high ESO concentration.
  • Fig. 5 also presents exponential equations from which curves 50 and 52 are derived.
  • the x and y variables represent equivalent DEHA and OTR @ 1.0 mil thickness, respectively, and the parameter R 2 represents a statistical measure of confidence that the equation fits the data presented.
  • the square- and diamond-shaped symbols indicate actual data points.
  • Fig. 5 demonstrates that a change in Equivalent DEHA results in a corresponding change in OTR.
  • Fig. 5 suggests that an amount of ESO and an equivalent amount of DEHA that provide a specified film stiffness have different corresponding OTRs.
  • a skilled person can use Fig. 5 by selecting a desired OTR for an equivalent film thickness of either a high or low ESO concentration to achieve an equivalent DEHA.
  • a desired OTR for an equivalent film thickness of either a high or low ESO concentration could determine the required amount of plasticizer to be about 28.8 DEHA equivalent.
  • Fig. 5 presented herein provides OTR data curves for a 1.0 mil film, but similar changes in OTR versus Equivalent DEHA would arise with different gauge films.
  • Fig. 6 is a table showing the proportional formulation of a preferred monolayer PVC film expressed in parts per hundred resin (pphr). Fig. 6 also states the function performed by each component and provides the OTRs at 1.0 mil for each film style.
  • a preferred two-layer PVC composite film is formulated with 100 pphr of each of the commercially available PVC films, BIX 44-XT and LGS, the properties of which appear in the table of Fig. 3.
  • the formulations of BIX 44-XT and LGS films are either compounded and extruded separately and laminated together with an adhesive or compounded separately and coextruded together.
  • a third preferred embodiment of the invention is a multilayer lamination or extrusion of PVC films formed to implement layer distribution, which provides differential heat seal capability. This is achieved by forming a composite film that includes a first, inner PVC layer having a lower melting point and a second, outer PVC layer having a higher melting point. Thus there are two layers that have different sealing temperatures. So when a set of seal jaws come together, only the inner layers are melted, rather than both the inner and outer layers, due to the differing melt temperatures of the two layers. This embodiment is especially useful when one is using a stiff and brittle film that will not seal in the absence of a softer inner sealing layer.
  • the VitafilmTM BIX 44XT/LGS film constituting the preferred second embodiment of the present invention benefits from this differential heat seal capacity since the BIX film is stiffer, with a higher melting point, whereas the LGS film is softer, with a lower melting point.
  • a differential heat seal is a laminated or coextruded structure in which the inner layer of the film structure functions as a sealant layer and the outer layer functions as a heat transfer layer.
  • the inner layer is the softer, more-susceptible-to- melting layer that seals together the stiffer, less-susceptible-to-melting outer layer.
  • the outer layer therefore gives support to the inner layer and permits application of heat to the multiple-layer structure without necessarily melting the outer surfaces.
  • a common example of the implementation of a differential heat seal is a bag for snacks (e.g., peanuts, potato chips, or pretzels).
  • the stiffer outer layer of the bag seals shut because the less stiff inner layer with a lower melting point melts together at a sealing seam.
  • the two-layer composite film can be formed by conventional multilayer coextrusion or lamination techniques, or a combination of them.
  • the composite film provides different heat sealability and displays the structural integrity of low temperature PVC materials but also has a controllable OTR.

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  • Manufacturing & Machinery (AREA)
  • Medicinal Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
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  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
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  • Laminated Bodies (AREA)

Abstract

L'invention concerne une feuille composite formulée de manière à présenter une surface optiquement transparente et à assurer une régulation de la perméabilité au gaz (en particulier du taux de transmission d'oxygène). Une première forme de réalisation préférée comprend une feuille composite monocouche composée d'un substrat constitué d'une feuille en polymère PVC. Pour conférer à cette feuille composite des propriétés anti-buée et des propriétés de régulation du taux de transmission d'oxygène, on a respectivement incorporé au substrat polymère un ou plusieurs agents de surface et des plastifiants. L'orientation de la chaîne moléculaire du PVC détermine également le taux de transmission d'oxygène. Etant donnée que la chaleur et l'étirage influencent l'orientation de la chaîne moléculaire du substrat, l'application de chaleur et/ou d'une force d'étirage sur la feuille composite modifie le taux de transmission d'oxygène. Une seconde forme de réalisation préférée comprend une feuille de PVC multicouche laminée ou extrudée qui permet une régulation du taux de transmission d'oxygène à une épaisseur déterminée la feuille composite. Une troisième forme de réalisation préférée concerne une feuille multicouche laminée ou extrudée dont la répartition des couches est formulée de manière à de produire un thermoscellage différentiel.
PCT/US2000/031545 1999-11-19 2000-11-17 Feuille d'emballage polymere composite pour produits carnes et vegetaux frais WO2001036194A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU19211/01A AU1921101A (en) 1999-11-19 2000-11-17 Polymer composite packaging film for fresh meat and vegetable produce

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US16665999P 1999-11-19 1999-11-19
US60/166,659 1999-11-19

Publications (1)

Publication Number Publication Date
WO2001036194A1 true WO2001036194A1 (fr) 2001-05-25

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PCT/US2000/031545 WO2001036194A1 (fr) 1999-11-19 2000-11-17 Feuille d'emballage polymere composite pour produits carnes et vegetaux frais

Country Status (2)

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AU (1) AU1921101A (fr)
WO (1) WO2001036194A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8697164B2 (en) 2011-04-18 2014-04-15 Dole Fresh Vegetables, Inc. Commercial lettuce packaging in the field
EP3490798B1 (fr) * 2016-11-25 2022-07-13 Waldemar Vladimir Schmidt Feuille d'emballage d'aliments à base de pvc co-extrudée et son procédé de fabrication

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4042549A (en) * 1975-09-30 1977-08-16 Emery Industries, Inc. Improve stabilizers for vinyl halide resins containing a metal halide and an ethoxylated alkylphenol
US4774146A (en) * 1986-07-11 1988-09-27 Solvay & Cie Flexible thermoplastic structures with multiple coextruded polymeric layers comprising a vinylidene chloride copolymer layer bonded to a plasticized vinyl chloride polymer layer
US5149724A (en) * 1989-10-23 1992-09-22 Lonza Inc. Anti-static and anti-fogging compositions for use in polyvinyl chloride and polyolefin films
US5248546A (en) * 1991-08-30 1993-09-28 The B. F. Goodrich Company Vinyl based articles in contact with chloro-fluoro chemicals
US5698621A (en) * 1992-03-06 1997-12-16 Achilles Usa, Inc. Printable self-clinging polyvinyl chloride film and methods relating thereto
US5914194A (en) * 1992-12-17 1999-06-22 Cryovac, Inc. Extrudable vinylidene chloride polymeric film
US5929133A (en) * 1996-02-16 1999-07-27 Hitachi Chemical Filtec, Inc. Anti-bacterial film suitable for food packaging
US5962092A (en) * 1994-03-28 1999-10-05 Cryovac, Inc. Oxygen-permeable multilayer film containing antifog agent and package made therefrom

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4042549A (en) * 1975-09-30 1977-08-16 Emery Industries, Inc. Improve stabilizers for vinyl halide resins containing a metal halide and an ethoxylated alkylphenol
US4774146A (en) * 1986-07-11 1988-09-27 Solvay & Cie Flexible thermoplastic structures with multiple coextruded polymeric layers comprising a vinylidene chloride copolymer layer bonded to a plasticized vinyl chloride polymer layer
US5149724A (en) * 1989-10-23 1992-09-22 Lonza Inc. Anti-static and anti-fogging compositions for use in polyvinyl chloride and polyolefin films
US5248546A (en) * 1991-08-30 1993-09-28 The B. F. Goodrich Company Vinyl based articles in contact with chloro-fluoro chemicals
US5698621A (en) * 1992-03-06 1997-12-16 Achilles Usa, Inc. Printable self-clinging polyvinyl chloride film and methods relating thereto
US5914194A (en) * 1992-12-17 1999-06-22 Cryovac, Inc. Extrudable vinylidene chloride polymeric film
US5962092A (en) * 1994-03-28 1999-10-05 Cryovac, Inc. Oxygen-permeable multilayer film containing antifog agent and package made therefrom
US5929133A (en) * 1996-02-16 1999-07-27 Hitachi Chemical Filtec, Inc. Anti-bacterial film suitable for food packaging

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8697164B2 (en) 2011-04-18 2014-04-15 Dole Fresh Vegetables, Inc. Commercial lettuce packaging in the field
EP3490798B1 (fr) * 2016-11-25 2022-07-13 Waldemar Vladimir Schmidt Feuille d'emballage d'aliments à base de pvc co-extrudée et son procédé de fabrication
US11447315B2 (en) * 2016-11-25 2022-09-20 Waldemar Vladimir SCHMIDT Co-extruded plasticized PVC-based packaging films and method for its production

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