EP1725395A1 - Multilayer sheet or liner for packing hot foods - Google Patents
Multilayer sheet or liner for packing hot foodsInfo
- Publication number
- EP1725395A1 EP1725395A1 EP05725615A EP05725615A EP1725395A1 EP 1725395 A1 EP1725395 A1 EP 1725395A1 EP 05725615 A EP05725615 A EP 05725615A EP 05725615 A EP05725615 A EP 05725615A EP 1725395 A1 EP1725395 A1 EP 1725395A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- layer
- multilayer sheet
- article
- liner
- produced
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
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- 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
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- 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
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
-
- 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
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
- B32B5/022—Non-woven fabric
-
- 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
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
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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
- B65D65/42—Applications of coated or impregnated materials
-
- 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
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0276—Polyester fibres
-
- 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
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/06—Vegetal fibres
- B32B2262/062—Cellulose fibres, e.g. cotton
- B32B2262/067—Wood fibres
-
- 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
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/14—Mixture of at least two fibres made of different materials
-
- 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
- B32B2307/30—Properties of the layers or laminate having particular thermal properties
- B32B2307/306—Resistant to heat
-
- 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
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/726—Permeability to liquids, absorption
-
- 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
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/1362—Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
Definitions
- the invention relates to a multilayer sheet or liner for use in wrapping and/or packaging foods such as hot foods.
- Composite or multilayer sheets or wraps have long been used for packaging foods. Such sheets aim to keep freshly-made food hot from the time it is prepared until it is consumed.
- Current commercial sheets or wraps include polyethylene-coated paper or tissue, hot-melt coated paper, foil/tissue laminations, tissue/aluminum foil/polyethylene film, dry wax, etc. These wrap materials are of high moisture resistance to maximize heat retention. Liquid water from condensation is often still left in contact with food, which can leave the food undesirably soggy. Most of the known sheets or wraps involve an absorbent layer and an impermeable layer.
- the invention includes an article comprising or produced from at least two layers including a first layer, a second layer, and optionally a third layer wherein the article is a multilayer sheet or a liner; the first layer comprises or is produced from a water-wicking material; the second layer comprises or is produced from an absorbent and insulating material; and the third layer comprises or is produced from a structural material.
- the invention also includes a process for making the multilayer sheet, which can comprise (1) interposing a layer of thermoplastic adhesive scrim between the first inner layer and second layer and laminating the first inner layer to the second layer under suitable heat and pressure; or (2) coating the first inner layer with a suitable pattern-applied adhesive on one side to produce a coated side and contacting the coated side with the second layer prior to lamination.
- a process for making the multilayer sheet can comprise (1) interposing a layer of thermoplastic adhesive scrim between the first inner layer and second layer and laminating the first inner layer to the second layer under suitable heat and pressure; or (2) coating the first inner layer with a suitable pattern-applied adhesive on one side to produce a coated side and contacting the coated side with the second layer prior to lamination.
- FIG. 1 is a cross-sectional view of a specific embodiment of the multilayer sheet illustrating a fiberfill batt as the insulating and absorbent material of the second layer, positioned between and adhesively bonded to a film, as the structural material of the outermost layer, and a water- wicking material, as the inner layer, via two separate adhesive layers.
- FIG. 2 is a cross-sectional view of another embodiment of the multilayer sheet illustrating a fiberfill batt as the insulating and absorbent material of the second layer, again positioned between a film, as the structural material of the outermost layer, and a water-wicking material, as the inner layer, employing an adhesive layer between the fiberfill batt and inner water-wicking material.
- a multilayer sheet or liner for packaging hot foods comprises a first inner layer comprising a water-wicking material with a second layer comprising an absorbent and highly-thermally insulating material.
- the multilayer sheet provides improved moisture control while maintaining heat retention.
- Freshly-cooked food quality can be maintained (e.g., "crispness” especially in fried or baked foods) for time periods of at least about 30 minutes under ambient conditions, and the food quality is judged to be "excellent”.
- the first inner layer of the multilayer sheet or liner can comprise a water-wicking material. This layer is the innermost layer of the sheet, and is the layer in direct contact with the hot food or interior of the package containing the hot food.
- the water-wicking capability prevents the build-up of moisture in the package as the hot food cools, thereby avoiding undesirably soggy food.
- the first layer facilitates the passage of water and moisture vapor (i.e., wicks) from the interior of the package to the second layer of the multilayer sheet.
- the water-wicking material can have a non- condensable surface and preferably demonstrate a moisture-vapor transmission rate of at least about 20,000 g/m 2 /day, at least about 100,000 g/m 2 /day at least about 150,000 g/m 2 /day, or at least about 170,000 g/m 2 /day, as tested by ASTM D-6701 as well as a hydrostatic head pressure of less than about 5 cm H 2 0 or less than about 2 cm H 2 0, as tested under AATCC Method 127-1989.
- the first layer preferably comprises a nonwoven fabric, preferably a "spunlaced" or "hydroentangled" fabric.
- spunlaced fabric or "hydroentangled fabric” refers to a nonwoven fabric that is produced by entangling fibers in the web to provide a strong fabric that is free of binders.
- spunlaced fabrics can be prepared by supporting a nonwoven web of fibers on a porous support such as a mesh screen and passing the supported web underneath water jets, such as in a hydraulic needling process.
- the fibers can be entangled in a repeating pattern.
- the nonwoven fabric can be made out of fibers such as polyester, nylon 6,6, or, preferably, a combination of wood pulp and staple poly(ethylene terephthalate) fibers.
- Such fabrics are available from E. I.
- the starting nonwoven layer comprises a thin, supple web of staple fibers, continuous filaments, plexifilamentary strands or the like.
- the fibers may be natural fibers, e.g., cellulosic, or may be formed from synthetic organic polymers.
- Preferably the fibers are not bonded to each other.
- Suitable starting nonwoven fibrous layers can be selected based on the desired end-use for the nonwoven fabric that is to be produced.
- the starting nonwoven fibrous layer is preferably substantially not bonded, and composed of fibers that inherently can absorb or wick liquid, e.g., polyester and wood pulp, or rayon and wood pulp.
- the first layer may also comprise paper, preferably with sufficient porosity to function as a water-wicking material as described herein.
- the second layer comprising an absorbent and insulating material. This layer may be highly thermally insulating and somewhat absorbent. The high thermal insulating capability effectively retains heat, slows condensation and thereby reduces liquid moisture formation within a given package. At the same time, any condensate that is produced is wicked through the first layer and absorbed by the second layer.
- the multilayer sheet or liner may work successfully because the absorbent and insulating material in the second layer aims to keep the temperature within a given package above the dew point, preventing condensation from forming within the package. If the temperature falls just below the dew point, the water-wicking material of the first layer wicks the liquid from the package interior to the second layer. Hence, the interior of the package is warm but free of liquid moisture that can cause crisp food to turn soggy.
- the second layer preferably has a thermal resistance, as measured in units of insulation, or CLO, of at least about 0.05, or at least about 0.1 , or about 0.1 to about 2.5, or 0.1 to 0.5.
- the CLO unit is defined as a unit of thermal resistance of a garment.
- the SI unit of thermal resistance is the square-meter kelvin per watt (m 2 « K/W) (See “Textile Terms and Definitions", Tenth Edition, The Textile Institute, (1995), pp. 66, 350).
- the range of thermal resistance in SI units of the absorbent and insulating material of the present invention is at least about 0.0077, preferably at least about 0.0154 m 2» K/W .
- CLO is defined in terms of a garment, this measurement can be used to describe the thermal resistance of any textile system, and is used herein to describe the thermal resistance of the absorbent and insulating material of the present invention.
- CLO values depend on the material used for the layer and its thickness.
- the level of thermal resistance preferably is high enough to maintain the temperature within the package above the dew point for at least about 30 minutes when the package is exposed to ambient conditions. It is expected that the water- wicking material of the first layer also contributes some thermal resistance.
- the second layer also has some absorbency, though high levels may not be necessary due to the high efficiency of the insulating capability, and the resulting minimization of condensation formation.
- the absorbency in terms of water pressure resistance, can be less than about 50 cm H 2 0.
- the second layer may comprise an organic thermoplastic fiber- based material comprising, e.g., polyester, polyethylene or polypropylene.
- the thermal insulating layer is a fiberfill batt comprising polyester.
- a fiberfill batt sold as Thermolite ® Active Original by DuPont is especially suitable for use.
- the fiberfill batt useful for the present invention generally has an areal weight in the range of 10 gm/m 2 to 200 gm/m 2 , and a bulk density of less than 0.3 gm/cm 3 .
- the thermal insulating layer may comprise melt-blown fibers, such as melt- blown polyolefins, sold as THINSULATE ® , by 3M.
- melt-blown fibers such as melt- blown polyolefins, sold as THINSULATE ® , by 3M.
- the absorbent and insulating material may possibly comprise an inorganic thermoplastic fiber-based material comprising glass wool, borosilicate glass or rockwool.
- the absorbent and insulating material may comprise a knit fabric, made, for example from a tetrachannel or scalloped oval fiber, sold under the trademark Coolmax ® by DuPont.
- the absorbent and insulating material may be a woven or fleece material.
- the absorbent and insulating material could also comprise some sort of nonwoven, such as felt, or a highloft nonwoven or needled nonwoven fabric.
- the thickness of the second layer may vary and depend on the desired level of insulating capability, i.e., thermal resistance. As more thermal resistance is required, the thickness of the layer increases. Generally, the thickness can fall in the range of about 10 to about 500 mils, or about 10 to about 200 mils, or about 10 to about 50 mils.
- the multilayer sheet or liner may comprise an optional third, outermost layer comprising a structural material.
- the structural material may comprise film, foil, paper and/or fabric.
- a film may be made of a thermoplastic material comprising, e.g., polyester, polyethylene or polypropylene.
- films of oriented polypropylene or oriented polyester are especially preferred. Films of oriented polyester are available from DuPont Teijin Films under the trade names Mylar ® and Melinex ® .
- the choice of material for the optional third layer may depend on how the multilayer sheet or liner is used in the packaging, e.g., what type of package will be used and what type of food product will be packaged. For example, if the desired packaging is a bag or pouch, then paper, foil or a film may be useful. If the multilayer sheet or liner of the invention herein is used as a liner in a package, then it may be helpful to have the structural material contain an adhesive layer to adhere the multilayer sheet or liner to the inside of the package. A peelable backing can also be useful.
- a film that is suitable for use as a structural material is Melinex ® 854, commercially available from DuPont Teijin Films of Wilmington, Delaware.
- Melinex ® 854 is a multilayered film, one layer being heat-sealable, allowing for heat-sealing between the second and third layers.
- Melinex ® 854 is a 120 gauge (0.0012 inch, or 0.0030 cm.) thick co-extruded biaxially oriented polyester film.
- the first layer of the film is made from a standard polyester homopolymer, intrinsic viscosity of about 0.590, containing 2500 ppm of inorganic slip additive particles. This layer comprises approximately 65% of the total film thickness.
- a co- polyester resin comprised of 18 weight % isophthalic acid, intrinsic viscosity of about 0.635, containing 2300 ppm inorganic slip additive particles, is co-extruded to form the heat-sealable layer and comprises 35% of the total film thickness (15-40% preferred).
- the surface of the first layer opposite the heat sealable layer is coated in-line by a gravure coater (during the film manufacturing process) with a print primer coating based on an aqueous polyester dispersion at a dry coat-weight of 0.03 g/m 2 .
- the multilayer sheet or liner can further comprise an additive.
- the additive can be a desiccant such as silica, thermal and ultraviolet (UV) stabilizers, UV absorbers, antistatic agents, processing aids, fluorescent whitening agents, pigments, lubricants, etc. These additives may be present in the compositions used in this invention in quantities that are generally from 0.01 to 20, or 0.1 to 15, weight.
- the structural material may be modified on the surface facing away from the second layer to facilitate printing thereon by a corona discharge treatment.
- surface modification i.e., coating or corona discharge treatment
- an adhesive primer layer is applied to the untreated surface of the structural material or to the corona discharge treated surface.
- This adhesive primer layer is pressure sensitive to enable application of the multilayer sheet or liner to a container to function as a package liner.
- the layers of the multilayer sheet or liner of the invention may be joined by various methods known in the art, one such method being lamination, i.e., uniting layers of material by an adhesive or other means.
- the adhesive can be applied in various ways, e.g., pattern- application or spray application, or through the use of an adhesive layer, e.g., a thermoplastic adhesive scrim, which is a web-like layer of adhesive.
- pattern-application adhesive or an adhesive scrim achieves a similar effect within the multilayer sheet or liner of the invention herein, i.e., there is no complete barrier to moisture transport due to the abundance of free space or holes within the adhesive layer which allows moisture to flow through. This is especially desirable when laminating the first and second layers of the invention herein.
- Other means of joining the layers may include pinpoint embossing, needling and quilting, among others known to those of skill in the art. These methods may allow for the free transport of moisture between layers.
- the adhesive may be a heat-sealable coating on one of the layers to be joined, e.g., on the structural material as discussed above.
- the multilayer sheet or liner may optionally be sealed, such as with a hot knife, at its edges so that fluid cannot penetrate the edges.
- a flexible, impermeable layer may be used to prevent leakage of moisture from the food to the consumer.
- the multilayer sheet or liner can be used in sheet form to act as liner within a package (e.g., take-out tray, box, bag, etc.), or even on the exterior of a package (e.g., covering perforations in a take-out tray lid).
- the multilayer sheet or liner of the invention herein may be used in various ways to package hot foods. One specific embodiment is simply to use the multilayer sheet or liner in sheet form as a packaging wrap to directly wrap hot foods.
- the multilayer sheet or liner may be formed into a pouch or bag for wrapping hot foods, e.g., hot sandwiches.
- the pouches or bags may be manufactured according to any well-known method.
- a "pouch” means an enclosure sealed on at least two of four sides, though generally sealed on three of four sides with the fourth side being an opening.
- a pouch is typically made from a flat web of film by forming a tubular film therefrom with a longitudinal seal and subsequently flattening the tubular film at a first position and transversely heat-sealing said tubular film at the flattened position.
- a “bag” may be a pouch, but can also include a “stand-up pouch", similar to the commonly-known paper lunch bag, comprising four sides and a rectangular bottom opposite an opening. After inserting the hot food into a pouch or bag of the invention herein, the pouch or bag can be sealed or closed in various ways known to those of skill in the art.
- the closing means may be mechanical, such as flaps or tabs that can be folded over and/or tucked in; and/or adhesive, such as pressure sensitive adhesive, among others.
- adhesive such as pressure sensitive adhesive, among others.
- a flexible, impermeable layer may be chosen to prevent leakage of moisture from the food to the consumer.
- the multilayer sheet or liner when used in sheet form to act as liner within a package (e.g., take-out tray, box, bag, etc.), or even possibly on the exterior of a package (e.g., covering perforations in a take-out tray lid), then the third optional layer would not be absolutely necessary.
- significant improvement in food temperature and food quality can be attained by affixing the liner to the inside, top of a package. It is possible that extending the duration of desired temperature and moisture levels within the package could also be attained by affixing the liner to other areas within a package, such as the inside, bottom, of the package.
- the method involves the step of laminating a first inner layer to a second inner layer under suitable pressure and heat.
- the suitable amount of pressure and heat may depend upon the type of adhesive method chosen. Suitable adhesives may be activated by chemical reaction, or be activated by heat, i.e. heat-sealable. Depending on the materials chosen for the first and second layers, other methods known in the art for laminating the layers may also be used, e.g., pinpoint embossing, as disclosed above. Pressure may be useful when laminating two layers to facilitate even bonding across the layers, at least enough to ensure contact between the two layers to be joined, e.g., for adhesives that are activated by chemical reaction.
- the application of heat may be necessary for heat- activated adhesives, such as the thermoplastic adhesive scrim described in Examples 1 and 2.
- the first inner layer may be coated with a suitable pattern-applied adhesive on one side, which is the side placed in contact with the second layer prior to lamination.
- a thermoplastic adhesive scrim is interposed between the first inner layer and second layer prior to lamination.
- Thermal Resistance - CLO Measurement For measurement of insulating capability, CLO was measured on a "Thermolabo II", which is an instrument with a refrigerated bath, commercially available from Kato Tekko Co. L.T.D., of Kato Japan, and the bath is available from Allied Fisher Scientific of Pittsburgh, Pennsylvania. Lab conditions were 21 °C and 65% relative humidity. Each sample was a one-piece sample measuring 10.5 cm x 10.5 cm. The thickness of the sample (in inches) at 6 gm/cm 2 was determined using a Frazier Compressometer, commercially available from Frazier Precision Instrument Company, Inc., of Gaithersburg, Maryland.
- the BT box measured 3.3 inch x 3.3 inch (8.4 cm x 8.4 cm).
- a heat plate measuring 2" x 2" was in the center of the box, and was surrounded by styrofoam.
- Room temperature water was circulated through a metal water box to maintain a constant temperature.
- a sample was placed on the water box, and the BT box was placed on the sample.
- the amount of energy (in watts) required for the BT box to maintain its temperature for one minute was recorded.
- EXAMPLE 1 Preparation of Multilayer Sheet A multilayer sheet or liner for hot food packaging was made according to the process described above and as illustrated in FIG. 1 wherein the first layer, 1 , is a water-wicking material, second layer, 2, is an absorbent and insulating material, and a third layer, 3, is a structural layer.
- the first layer, 1 is a water-wicking material
- second layer, 2 is an absorbent and insulating material
- a third layer, 3, is a structural layer.
- interposed between these layers are porous, thermoplastic adhesive scrims, 4.
- These adhesive scrims, 4 are constructed of polyester materials that are spunlaced. They provide a web-like layer, with an abundance of holes, through which water vapor or condensed water can easily pass through.
- the adhesive layers, 4 were activated at temperatures 240-350°F (116-177 C).
- the structural layer, 1 was a film of the type sold by DuPont-Teijin under the trade name Mylar ® .
- the film was 1.2 mils (0.0012 inch or 0.0030 cm) thick.
- the absorbent and insulating material, 2, was a fiberfill batt of the type sold by DuPont under the trademark Thermolite ® Active Original.
- the fiberfill batt, 2 had an areal weight of 80 g/m 2 at a specified thickness of 0.25 inch (0.63 cm) or a bulk density of 0.013 g/cm 3 .
- the water-wicking material, 3, was a nonwoven fabric available from DuPont under the trademark Sontara ® .
- the Sontara ® comprised hydroentangled, white fibers (45% polyester/55% wood pulp), having an areal weight of 68 grams/m 2 and thickness of 13 mils (0.013 in or 0.033 cm).
- the adhesive webs were of the type sold by Bostik Findley, Inc., and were about 8-10 mils (0.008 to 0.01 inches) thick. (The thickness varied depending on how much pressure was applied to the web during measuring.)
- EXAMPLE 2 Preparation of Multilayer Sheet: Bicomponent third layer A multilayer sheet or liner for hot food packaging was made according to the process described above and as illustrated in Figure 2 wherein the first layer, 1 , was a water-wicking material, second layer, 2, was an absorbent and insulating material, and a third layer, 3, was a structural layer.
- the structural layer, 1 was a bicomponent film of polyester and a heat-sealable layer.
- the heat- sealable layer acts as the adhesive required to laminate the structural layer to the absorbing and insulating layer.
- An adhesive scrim, 4, as described in Example 1 (above) was used to adhere the absorbent and insulation layer, 1 , to the water-wicking nonwoven layer, 2.
- the structural film layer, 1 was of the type sold by DuPont Teijin Films of Wilmington, Delaware, under the tradename Mylar ® OL and was a biaxially oriented PET film having a heat-sealable layer. In this embodiment, the film was 1.5 mils (0.0015 inch or 0.00375 cm) thick.
- the composition of the heat-sealable layer was an isophthalic acid-base copolyester and comprised 10-50% of the thickness of the total film thickness; 15-30% was preferred.
- the absorbing and insulating material, 2 was a fiberfill batt of the type sold by E. I. du Pont de Nemours and Company under the trademark Thermolite® Active Original.
- the fiberfill batt had an areal weight of 80 gm/m 2 at a specified thickness of 0.25 inch (0.63 cm) or a bulk density of 0.013 gm/cm 3 .
- the water-wicking layer, 3, was a nonwoven fabric available from E. I. du Pont de Nemours and Company under the trademark Sontara ® .
- the Sontara ® used in this example comprised hydroentangled, white fibers (45% polyester/55% wood pulp), having an areal weight of 68 grams/m 2 and thickness of 13 mils (0.013 in or 0.033 cm).
- the adhesive webs were of the type sold by Bostik Findley, Inc., and were about 8-10 mils (0.008 to 0.01 inches) thick. (The thickness varied depending on how much pressure was applied to the web during measuring.)
- EXAMPLE 3 Chicken Nuggets - Insulated v. Un-insulated trays Using a small-scale deep fryer, two portions of chicken nuggets were produced to test the effectiveness of the multilayer sheet or liner in packaging for heat retention with moisture control.
- the deep fryer was filled with vegetable oil and set to 340°F. A batch consisting of 18 frozen "Banquet” brand chicken nuggets was placed into the hot oil for 4 minutes. After cooking, the hot nuggets were allowed to drain for 15 seconds. After draining, the nuggets were quickly placed into a "take ouf-style, polyester (PET) tray, typically available in supermarkets or restaurants for packaging fresh, hot foods.
- PET polyester
- the PET tray comprised a bottom tray reservoir portion and a top tray or lid, similar in size and shape to the bottom tray.
- the lid fitted over the bottom portion to generally seal along the perimeter (where the lid and bottom portion meet) and lock in place, typically through the use of small protruding notches on the perimeter of the lid which fit into matching cavities in the bottom portion, or vice versa, thus locking and sealing the tray container.
- the trays used for this test were Ivex Model #5720-9MO, Microwave Supreme, medium entree style trays.
- One tray was insulated using a multilayer sheet or liner as described in the invention herein. The multilayer sheet or liner was placed on the interior on the inside lid.
- the multilayer sheet comprised a first layer of Sontara ® , a second layer of fiberfill batt, and an outer layer of Mylar ® , as constructed and described in Example 2.
- the other tray was not insulated.
- (Comparative Ex. I) After loading the tray with the hot food product, chicken nuggets, the lid was snapped into place and two separate digital temperature probes were inserted into the interior of the tray. One probe was used to measure the temperature of the air space in the top of the container, while the second probe was placed in the bottom of the tray among the food. The container was placed on a countertop at ambient conditions and readings were taken from one to twenty minutes at various intervals as shown in Table 1. Table 1 - Chicken Nugget Deep fry Test Un-insulated - - Comp. Ex.
- EXAMPLE 4 Chicken Breast Strips - Tray Liner and Pouch An experiment was conducted as described in Example 3, except that the food product used was frozen chicken breast strips, rather than chicken nuggets. Four chicken strips were placed in each package. Temperature, humidity, and dew point were recorded using a digital hygrometer. Three different packaging methods were tested; two being modifications to the PET "take-out" tray.
- the package for Example 4A had the multilayer sheet of the invention herein (similar to that described in Example 2) attached to the lid on the exterior of the PET tray covering holes that were punched in the lid to allow moisture to escape from inside the container. Each hole was A inch in diameter, and there were 36 holes in the lid, for a total area of 7 square inches.
- the package used in Example 4B was a pouch formed from the multilayer sheet of the invention herein (similar to that described in Example 2).
- the pouch was formed as described in Example 6.
- the package used in Example 4C was a PET "take-out" tray with a liner comprising the multilayer sheet of the invention herein attached to the inside lid. The results are shown in Table 2.
- Example 4A Example 4B
- Example 4C Time (min) Top °F Bottom °F Top °F Top °F Bottom °F 117 114 106 140 151 1 121 118 108 148 151 1.5 151 150 2 128.5 122 112.5 153 149 2.5 130.2 123 115 155 147.5 3 131.5 123.1 116 156 146.5 3.5 132.3 123.2 115.7 156 145 4 132.8 123.2 115.6 156.5 144 4.5 133 123 115.2 156.3 142 5 132 121 113.5 154 137 7 129 119 111 151 132.9 9 128 117 110 148.6 130 10 123 113 105 141 123 15
- RH % Dew point °F RH % Dew point °F RH % Dew point °F RH % Dew point °F 100 103.7 100 118 1 100 100 108.9 100 1.5 100 99 110 100 123.3 2 100 112 93 110 88 122.5 2.5 100 113.2 88 110 83.5 121.6 3 100 113.4 86.5 110.4 80 122 3.5 100 114 86 110.1 78 122 4 100 115.1 82.3 109.5 77 121.2 4.5 100 116.1 76.8 106.6 75.4 121 5 91.6 114 75.7 103.8 74 118.5 7 87.7 112 78.5 102.8 67 113.5 9 87.1 110.8 78.9 101.7 67 112 10 87.5 107 86.9 100.2 72.3 108.6 15
- EXAMPLE 5 Chicken Breast Strips - Tray Liner Testing was performed using chicken breast strips as the food product using the procedure described in Examples 3 and 4.
- the trays used for Examples 5A, 5B and 5C were similar to that in Example 4C, that is, a PET "take-out" tray with a liner comprising the multilayer sheet of the invention herein attached to the inside lid.
- the multilayer sheet of the invention herein was attached to the exterior lid of the PET tray covering holes in the lid as described in Example 4.
- Comparative Example II used an uninsulated tray. Results are shown in Tables 3 and 4. Table 3 Example 5A, Internally Example 5B, Internally Example 5C, Internally insulated insulated insulated insulated
- Example 5D Externally Example 5E, Externally Comp.Ex. II, insulated insulated Uninsulated tray
- Example 5A After 30 minutes the internal chicken temperature was 140°F, and the external air temperature was 117°F. Subjective testing by a food taster rated the product as "excellent". The food quality rating was focused on the crispness of the food and the scale ran from "excellent", “very good”, “satisfactory”, to “poor”. In Example 5B, the internal chicken temperature was 137°F after 30 minutes, and the external temperature was 129°F. The product was again rated as "excellent”. Also, by way of comparison, one freshly-cooked chicken finger was left outside of the container for 30 minutes to observe how the temperature changed during cooling without any packaging to retain heat.
- Example 5C The external temperature was 86°F while the internal temperature was 93.5°F after 30 minutes.
- Example 5C the internal chicken temperature was 137°F and the external chicken temperature was 133°F after 30 minutes. Product was rated as "excellent”. Again, by way of comparison, a freshly-cooked chicken finger was left outside the test package for 30 minutes. After 30 minutes, the internal temperature was 103°F while the external temperature was 94°F.
- Example 5D after 30 minutes the internal chicken temperature was 138°F and the external temperature was 133°F. The food product was rated as "very good”.
- Example 5E the internal chicken temperature was 126°F, and the external temperature was 122°F after 30 minutes. The food product was rated as "very good”.
- Example 3 Chicken Tenders and Steak Fries - Pouches An experiment was conducted as described in Example 3, except the food product used was chicken tenders (Barber brand "Italian style") and the packaging tested was a pouch made from a multilayer sheet as constructed and described in Example 1 (Ex. 6A). Two pieces of the multilayer sheet, each the same size (approximately 12 in. x 12 in.) were used to form a pouch by aligning the two sheets and sealing on three sides with masking tape. Table 5 Ex.
- the pouches were formed as discussed above. This constituted Comparative Examples III and IV. Temperature, relative humidity and dew point were recorded for 15 minutes. Results are shown in Tables 7 and 8. Table 7 - Cornp. Ex. HI - Chicken tenders, un-insulated pouch Time (min) Temp (°F) RH DP (°F) 1 87.8 100 89.7 2 97.8 100 95 3 98.5 100 98.3 5 96.5 100 98.7 7 95.2 100 98.9 9 91.9 100 94.9 10 91.3 100 89.8 15 92.1 100 86 Condensation was observed in the pouch after 2 minutes.
- the pouch was formed from two pieces of the multilayer sheet, each the same size, here approximately 10 in. x 10 in., sealed on three sides with masking tape.
- Four pieces of chicken tenders (approximately 240 g) were cooked at 340°F for four minutes, drained of cooking oil for 15 seconds, and then placed in the pouch. Temperature, relative humidity and dew point were recorded for 15 minutes. The results are shown in Table 9.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Textile Engineering (AREA)
- Packages (AREA)
- Wrappers (AREA)
- Laminated Bodies (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US55458504P | 2004-03-19 | 2004-03-19 | |
PCT/US2005/008560 WO2005092606A1 (en) | 2004-03-19 | 2005-03-16 | Multilayer sheet or liner for packing hot foods |
Publications (1)
Publication Number | Publication Date |
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EP1725395A1 true EP1725395A1 (en) | 2006-11-29 |
Family
ID=34962831
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP05725615A Withdrawn EP1725395A1 (en) | 2004-03-19 | 2005-03-16 | Multilayer sheet or liner for packing hot foods |
Country Status (7)
Country | Link |
---|---|
US (1) | US20050208243A1 (ja) |
EP (1) | EP1725395A1 (ja) |
JP (1) | JP2007529347A (ja) |
CN (1) | CN1956843A (ja) |
AU (1) | AU2005225429A1 (ja) |
BR (1) | BRPI0508209A (ja) |
WO (1) | WO2005092606A1 (ja) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8769716B2 (en) | 2010-09-01 | 2014-07-08 | Point 3 Basketball, Llc | Moisture control garment |
JP2016513046A (ja) * | 2013-02-19 | 2016-05-12 | ディーエスエム アイピー アセッツ ビー.ブイ. | 食品を含む包装体 |
US10604324B2 (en) * | 2013-03-14 | 2020-03-31 | Bemis Company, Inc. | Multilayer adhesive absorbent laminate |
JP6433052B2 (ja) * | 2014-09-09 | 2018-12-05 | 理研計器株式会社 | ガス測定装置用素子 |
EP3532820B1 (en) * | 2016-10-31 | 2023-12-20 | TSI Incorporated | Composite wicks for low noise particle counting |
CN111705421B (zh) * | 2020-06-22 | 2021-01-08 | 浙江王金非织造布有限公司 | 一种含有水刺复合纤维层的保鲜垫及其制备方法 |
EP4433011A1 (en) * | 2021-11-16 | 2024-09-25 | The Procter & Gamble Company | Package system for article |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3044631A1 (de) * | 1980-11-27 | 1982-06-03 | Fa. Carl Freudenberg, 6940 Weinheim | Vliesstoff mit dochtwirkung |
US4436780A (en) * | 1982-09-02 | 1984-03-13 | Kimberly-Clark Corporation | Nonwoven wiper laminate |
US4851273A (en) * | 1987-10-15 | 1989-07-25 | Zorbit Corporation | Method and apparatus for degreasing fried foods |
US4871597A (en) * | 1988-02-08 | 1989-10-03 | Hobson Michael A | Light-weight multi-layer insulating enclosure |
CA2096237C (en) * | 1989-04-04 | 2000-05-23 | Linda L. Bunker | A composite integral sheet of wrap material and method of making |
JPH0734865Y2 (ja) * | 1990-02-21 | 1995-08-09 | 株式会社クラレ | 食品の包装材 |
DE69205683T2 (de) * | 1991-06-13 | 1996-05-02 | James River Corp | Hochabsorbierendes verpackungsmaterial mit wasserdampfdurchlässiger filmabdeckung. |
US5459912A (en) * | 1992-03-31 | 1995-10-24 | E. I. Du Pont De Nemours And Company | Patterned spunlaced fabrics containing woodpulp and/or woodpulp-like fibers |
US5350625A (en) * | 1993-07-09 | 1994-09-27 | E. I. Du Pont De Nemours And Company | Absorbent acrylic spunlaced fabric |
US5713881A (en) * | 1993-10-22 | 1998-02-03 | Rezai; Ebrahim | Non-continuous absorbent composites comprising a porous macrostructure of absorbent gelling particles and a substrate |
US20010023159A1 (en) * | 1995-11-13 | 2001-09-20 | First Brands Corporation | Absorbent pad |
JPH1194260A (ja) * | 1997-09-25 | 1999-04-09 | Kuraray Co Ltd | 保水性に優れた電子レンジ加熱用食品包装材 |
US6534174B1 (en) * | 2000-08-21 | 2003-03-18 | The Procter & Gamble Company | Surface bonded entangled fibrous web and method of making and using |
-
2005
- 2005-03-16 WO PCT/US2005/008560 patent/WO2005092606A1/en active Application Filing
- 2005-03-16 EP EP05725615A patent/EP1725395A1/en not_active Withdrawn
- 2005-03-16 CN CNA2005800160917A patent/CN1956843A/zh active Pending
- 2005-03-16 BR BRPI0508209-9A patent/BRPI0508209A/pt not_active IP Right Cessation
- 2005-03-16 AU AU2005225429A patent/AU2005225429A1/en not_active Abandoned
- 2005-03-16 JP JP2007504025A patent/JP2007529347A/ja active Pending
- 2005-03-18 US US11/083,491 patent/US20050208243A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
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See references of WO2005092606A1 * |
Also Published As
Publication number | Publication date |
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BRPI0508209A (pt) | 2007-07-17 |
CN1956843A (zh) | 2007-05-02 |
US20050208243A1 (en) | 2005-09-22 |
JP2007529347A (ja) | 2007-10-25 |
AU2005225429A1 (en) | 2005-10-06 |
WO2005092606A1 (en) | 2005-10-06 |
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