US3718274A - High strength open bottom packaging trays - Google Patents

High strength open bottom packaging trays Download PDF

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Publication number
US3718274A
US3718274A US3718274DA US3718274A US 3718274 A US3718274 A US 3718274A US 3718274D A US3718274D A US 3718274DA US 3718274 A US3718274 A US 3718274A
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Prior art keywords
tray
ribs
meat
accordance
side walls
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R Reifers
K Bixler
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PACKAGINING Corp OF AMERICA A DE CORP
Packaging Corp of America
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Diamond International Corp
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Assigned to PACKAGING CORPORATION OF AMERICA reassignment PACKAGING CORPORATION OF AMERICA ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DIAMOND INTERNATIONAL CORPORATION
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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
    • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D81/24—Adaptations for preventing deterioration or decay of contents; Applications to the container or packaging material of food preservatives, fungicides, pesticides or animal repellants
    • B65D81/26—Adaptations for preventing deterioration or decay of contents; Applications to the container or packaging material of food preservatives, fungicides, pesticides or animal repellants with provision for draining away, or absorbing, or removing by ventilation, fluids, e.g. exuded by contents; Applications of corrosion inhibitors or desiccators
    • B65D81/261—Adaptations for preventing deterioration or decay of contents; Applications to the container or packaging material of food preservatives, fungicides, pesticides or animal repellants with provision for draining away, or absorbing, or removing by ventilation, fluids, e.g. exuded by contents; Applications of corrosion inhibitors or desiccators for draining or collecting liquids without absorbing them
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
    • Y02A40/90—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in food processing or handling, e.g. food conservation
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W90/00—Enabling technologies or technologies with a potential or indirect contribution to greenhouse gas [GHG] emissions mitigation
    • Y02W90/10—Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics

Definitions

  • each inverted V-shaped rib being on the order of several 56 R f d times the thickness of the remainder of the tray, and 1 e erences e the total volume of the inverted V-shaped ribs being UNITED STATES PATENTS approximately equal to the volume 01' a bottom of an "961 E Dglzlg imperforate bottom tray of the same size. D191,545 10 mery .7
  • FIELD OF INVENTION BACKGROUND Molded wood or paper pulp food trays have served the food packaging industry well for many years for the packaging of meat, fish and poultry.
  • Such trays have the advantage, besides low price and low cost to the consumer, of being clean, sturdy and safe; of being biodegradable so as to minimize the solids pollution problem; of being capable of assimilating the free liquid juices which exude from meat, fish and poultry; and of being air and vapor permeable so as to maintain color and freshness of meat and permit passage of liquid vapors.
  • trays collect liquid exudants in puddles from the meta, fish and poultry packaged therein, thereby not only causing discoloration of the packaged product, but also serving as a bacterial breeding ground and further serving to opacify the package itself and provide distortion in the remaining transparent areas thereby contributing to the very problem which such trays were designed to overcome; blood that goes under the tray acts to release the sealed film causing soiled hands, soiled check out counters, leaking packages, etc.
  • the conventional plastic trays being formed of non-breathable material, inhibit oxygen migration to the meat at the bottom of the tray; this causes further discoloration of the meat and it is well known that meat in plastic trays deteriorates on the bottom first.
  • Another defect of the clear plastic trays involves their transmission of light along the plane of the tray walls, i.e. a light pipe or fiber optic effect; this causes further discoloration of the bottom of the meat.
  • Light has a negative effect on meat quality causing discoloration more quickly than meat which is maintained more in the dark but under otherwise similar conditions.
  • meat packaged in clear plastic has its bottom exposed to light constantly even when the tray rests on an opaque object such as the bottom of the meat cooler or an underlying package or between two packages.
  • Meat packaging trays have evolved substantially over the years. The earlier trays had essentially straight side walls and a flat peripheral lip, and these served the trade successfully for many years. However, as the nature of transparent plastic wrap film changed and nonelastic and non-shrink cellophane was replaced with more elastic thermoplastic or stretch overwrap films, the tray in accordance with Reifers U.S. Pat. No. 3,185,371 was developed improving the tray performance. In more recent years there has been a strong consumer desire for greater visibility of fresh meat packaged in trays.
  • a recent approach, corresponding to the invention of the Bixler application Ser. No. 53,545 uses a plurality of meeting or intersecting, inverted V or U- cross-section shaped ribs extending across the bottom of the tray and merging with the side walls of such tray.
  • This construction provides maximum visibility with minimum meat contact, and the inverted V-shaped ribs provides for a reinforced structure.
  • This construction of the Bixler application is, in many respects, a successful approach to the problem, and the present invention constitutes an improvement on this basic construction.
  • the embodiment illustrated in the Bixler application Ser. No. 53,545 still suffers, under certain conditions, from some weakness, these weaknesses being manifested when a tray containing meat, fish or poultry is tightly overwrapped with transparent stretch film which strongly squeezes the tray side walls inwardly distorting them and causing failure where ribs only are the single support to side walls.
  • the embodiment illustrated in Bixler Ser. No. 53,545 needs to be strengthened, particularly where the V-ribs are joined tothe side walls of the tray.
  • the smaller trays in accordance with Bixler application Ser. No. 53,545 may fail at this location because of the compressive force of the film alone while the larger size trays fail more easily here because of the compressive force of the film and because of greatly reduced beam strength in relation to the increased strength that is actually needed in the longer side walls.
  • the present invention provides such an improved structure by the utilization of an improved force transfer distribution zone or transition zone between the side walls of the tray and the ribs of inverted V- cross-section such that the major rib beams are moved inwardly away from the side walls themselves, preferably by the provision of a peripheral gutter-like bottom wall or channel.
  • an improved force transfer distribution zone or transition zone between the side walls of the tray and the ribs of inverted V- cross-section such that the major rib beams are moved inwardly away from the side walls themselves, preferably by the provision of a peripheral gutter-like bottom wall or channel.
  • ribs may be utilized. Greater rib strength is preferably provided when the tray is molded of wood pulp by the use of a narrow U- or V- angle. Increased strength may also be optionally obtained by the use of higher ribs; it is found in accordance with the present invention that it is desirable that the inverted V-shaped ribs be of substantial height to provide a thick platform or pallet upon which the meat is supported, wherein the total volume of the primary ribs forming the platform and defining the open windows is approximately percent of the volume and weight of the same area of a bottom of a conventional tray, such as that shown in Reifers U.S. Pat. No. 3,185,371.
  • the height of the primary ribs may vary considerably depending on the size of the window openings therebetween, so that the smaller the opening and the greater the number of ribs, the smaller the ribs need be, both for sufficient strength factor and for packaged product maintenance. In this latter regard the packaged meat should be kept off the overwrap film on the bottom of the tray.
  • molded of wood pulp there may be a slight variation in rib height of a given rib design based on furnish variation and weight variation. In general, many small ribs tend to reduce visibility so that the preferred minimum rib height should be on the order of about one-fourth inch with openings therebetween of about 13/16 X l3/l6 inch at the bottom of the inverted V-shaped ribs.
  • the transition between such ribs and the side and end walls of the tray should be such that minimal or no fault lines or notches are provided in the side or end wall and the transition zone, and this is preferably accomplished when the tray is molded of wood pulp by providing relatively thin ribs at the end and side walls thereby promoting filling in of the V-structure.
  • such ribs may be reduced in height. If desired, the ribs may be terminated at the annular boundary rib prior to reaching the end and side walls.
  • the tray of the present invention provides improved oxygen transmission, moisture vapor and blood control under the meat, no fiber optic problem like clear polystyrene trays all resulting in improved meat appearance with unequaled protection to meat freshness.
  • the characteristics of the package provided in accordance with the present invention are accomplished by the use of relatively high support beams, namely, the inverted V cross-section ribs, which are themselves strong, which are coupled via a force transfer distribution zone to the side and end walls in a way that maintains high side wall beam strength, for highest total package strength.
  • this rib connection with the force transfer zone which takes the force transfer from the side walls, is preferably achieved by making sure that the force transfer ribs at the point of connection to the end and side walls are relatively solid, i.e. filled in at the bottoms so that there will be a relatively uninterrupted lower side or end wall edge, with minimum notch formation.
  • Rib forms have been shown previously in trays of uniform material thickness, such as plastic, that have the liability of an interrupted lower edge.
  • Rib filling when the tray is manufactured of wood pulp, will determine the precise configuration; the filling, in turn, is determined by the rib V-angle, the type of material from which the tray is formed, and the weight, height and rib thickness. These factors are selected to optimize window visibility, strength and nesting of the tray. In general, the included V-angle will lie in the range of about 5 to 35.
  • the fundamental aspects of the tray in accordance with the present invention may be said to be: spaced beam members, the spacing being open between such beam members to allow for viewing the tray contents between each beam of relatively solid material.
  • the section modulus of the beams is such that in combination with the end and side walls, the total strength equals or exceeds the beam strength of a tray of the same material of equal or slightly more weight with a flat, solid bottom.
  • FIG. 1 is a plan view of an embodiment of a tray in accordance with the present invention.
  • FIG. 2 is a front elevation of the tray of FIG. 1;
  • FIG. 3 is a section taken along line 3 3 of FIG. 1;
  • FIGS. 4, 5 and 6 are sections taken along lines 4 4, 5 5 and 6 6, respectively, of FIG. 3;
  • FIG. 7 is a plan view of a second embodiment of a tray in accordance with the present invention.
  • FIG. 8 is a side elevation of the tray of FIG. 7;
  • FIG. 9 is an end elevation of the tray in accordance with FIG. 7;
  • FIG. 10 is a section taken along line 10 10 of FIG.
  • FIG. 11 is a plan view of a third embodiment of a tray in accordance with the present invention.
  • FIGS. 12-14 are sections taken along lines 12 12, 13 13 and 14 14 of FIG. 11;
  • FIG. 15 is a partially broken away section view showing a completed package.
  • a tray 10 is provided for the packaging of meat, fish or poultry in association with an overwrap film of transparent material such as plastic film or heat-scalable cellophane.
  • the food tray 10 has two upwardly and outwardly inclined opposite end walls 18, both the end walls and side walls preferably being bowed as described in the Reifers US Pat. No. 3,185,371.
  • adjacent end and side wall merges at a rounded comer 20, and the side and end walls terminate at their upper end in a downwardly and outwardly extending peripheral lip 22; however, the preferred peripheral lip is unlike anything previously used, and this is described in greater detail below.
  • the tray 10 is provided with a plurality of ribs 24 extending between the bottom of the end walls 18, and, preferably at right angles thereto, a plurality of ribs 26 extending between the side walls 16.
  • these ribs form in cross section an inverted V- shape with their apices forming the internal bottom of the tray upon which the meat rests; it is clear from inspection that the V-apex of each rib is well rounded unlike sharp ribs that might cut or otherwise damage the meat.
  • the V-angle in this embodiment is approximately 30 included angle. It will also be clear from FIG. 3 that the bottom of each inverted V-rib terminates in a plane passing through the bottom of the side and end walls 16 and 18.
  • the height of the inverted V-shaped ribs 24 and 26 is about three-eights seven-sixteenth inches, over five times the thickness of the pulp material, i.e. about one-sixteenth inch, forming the side and end walls of the tray. From this it will be understood that the ribs 24 and 26 are of substantial height to provide a thick platform or pallet upon which the meat is supported.
  • the cross-sectional area, in a vertical plane passing through the ribs 24 or 26 forming the platform is approximately equal to the cross-sectional area taken along a vertical plane of a conventional tray of equal size with a flat solid bottom of thickness equal to its side walls.
  • the transition zone is provided in the form of an annular rib 28' and a peripheral gutter-like bottom wall 28 which is not provided with windows and which merges with the bottom portions of the end and side walls 16 and 18 along a rounded corner 30. It is preferred to provide such a peripheral gutter-like bottom wall 28 since it provides, along with the annular rib 28', a stronger structure and by having such a wall it is easier to prevent the formation of fault lines, notches or breaks in the side or end walls, such fault lines", notches and breaks providing for reduced beam strength.
  • the reduction in rib height, as shown in FIGS. 4 and 5, to promote filling of the rib bottom at 26" preserves the lower tray edge without notching as is seen from the smooth configuration at the bottom of the tray side wall 16 as shown in FIG. 2, compared with the FIGS. 8 and 11 embodiments where the rib height is not substantially reduced as it approaches the side wall.
  • the embodiment of FIGS. 1-6 with the greater reduction in rib height as it approaches the side and end walls, results in an increased beam pick-up strength, although there is a slight disadvantage produced by providing a slight reduction in side wall deflection resistance.
  • An alternative embodiment terminates the ribs 24 and 26 at the boundary rib in which case there is no extension of the ribs through the gutter or channel 28 to the side and/or end walls.
  • This embodiment has a decreased side wall deflection resistance, although it is entirely satisfactory for many purposes, particularly if the tray is wrapped with cellophane rather than stretch or shrink film.
  • FIGS. 7-10 Another embodiment 100 is shown in FIGS. 7-10.
  • the tray 100 has side walls 116, end walls 118, a peripheral lip 122, crossing inverted V-ribs 124 and 126 which form open windows therebetween, and a peripheral gutter-like bottom wall 128 between the end and side walls and the open window bottom portion.
  • the embodiment 100 of FIGS. 7-10 differs from the embodiment of FIGS. 1-6 in primarily two respects.
  • This construction provides for additional side wall deflection resistance, although it does have a tendency to produce the notches 140 as shown in FIGS. 8 and 9 when molded of wood pulp with an included V-angle of about 2030", and these notches reduce the beam pick-up strength.
  • the construction of FIGS. 7-l0 is entirely suitable and the presence of the small notches 140 do not present any serious defect.
  • a 20 percent increase in windows area is obtained by varying the included V-angle from about 2040 at the intersection of the ribs to about 10 or even less at a point midway between each intersection.
  • This V-angle variation provides bowed windows with undulating ribs. Not only does this embodiment provide for increased window area, but better light entry results insuring improved viewing of the product packaged.
  • the rib back filling at the 10 points provides for stiffer beam structure, as well as denesting, and the 2040 flare aids screen formation used to cover forming dies used if the article is made of a molded pulp of synthetic or natural biodegradable materials.
  • This tray 200 has bowed side walls 216, bowed end walls 218, a peripheral lip 222, crossing inverted V-ribs 224 and 226 of about 10 included V-angle about five-sixteenths inch high defining open windows, and a peripheral gutter section 228 between the end and side walls and the open bottom portion.
  • These ribs are almost solid as seen in FIG. 14 and are very strong; they have a volume of about 90 percent that of a bottom of a standard solid bottom tray of equal size.
  • Such ribs are preferably of the undulating type with a minimum included angle between each intersection about 10 or less, and the maximum included angle adjacent each intersection on the order of about 30.
  • Tray 200 provides increased beam strength along with increased side wall deflection resistance by the use of staggered merging ribs 224' and 226 which are also of about one-fourth to three-eighths inch height and of about l0 included U or V-angle.
  • staggered merging ribs 224' and 226 which are also of about one-fourth to three-eighths inch height and of about l0 included U or V-angle.
  • the primary inverted V-ribs 224 and 226 are terminated at the boundary rib 228' and staggered secondary or force-transfer ribs 224 and 226 extend across the gutter 228 to the side and end walls; the staggering permits the use of an additional rib 224' and 226 so that in the illustrated version there are five primary ribs 224 besides the two defining the gutter 228 and six secondary ribs 224', and this improves both beam strength and side wall deflection resistance, the staggered secondary ribs acting as a shock absorber for inward side wall force during wrapping.
  • such secondary ribs 224' and 226 are full height as seen in FIGS. 12-14, increasing side wall deflection resistance.
  • Another feature of the secondary ribs 224 and 226', contributing to beam strength by the elimination of notches, fault lines or breaks in the side and end walls, is their provision in substantially solid form, being substantially filled in at the bottom when molded of wood pulp, noting FIG. 14, thus reducing notch formation at the side and end walls, and contributing to less warpage during free drying.
  • such ribs 224. and 226' may be made thinner than rigs 224 and 226 with less rounded tops because they extend only across the peripheral gutter and do not provide substantial meat support.
  • the tray of the present invention is preferably formed of conventional molded wood or paper pulp stock which may be formed or preformed from a water slurry, it will be understood that other materials may be used; the ribs may be made of harder paper stock, or such ribs may be specially pressed or otherwise treated.
  • the wood pulp stock comprises about 3 percent ureaformaldehyde wet strength resin or about 1 k percent melamine-formaldehyde wet strength resin (both FDA approved) and, furthermore, has a large capacity to accept free liquids which have exuded from the problem cuts" or heavy bleeders, as they are known in the art; in this embodiment the bottom of the tray ribs may be specially treated with an inert, impervious water-resistant substance, e.g. wax or plastic such as polyethylene, while the upper portions of the ribs will accept this free liquid and expand to provide a softened cushion for the meat. If desired, the rib tops may also be coated with the impervioussubstance, leaving the side rib surfaces and it center free to accept excess free liquids.
  • an inert, impervious water-resistant substance e.g. wax or plastic such as polyethylene
  • the lip 222 is provided with a special shape, particularly useful when used in combination with the special wood pulp stock having large free liquid accepting capacity.
  • the peripheral lip 222 has an outwardly extending horizontal terminal portion 230 and, as seen in the drawing, the film 60 contacts the lip 222 along two distinct and separated portions, i.e. the end of the terminal portion 230 and the top of the lip at point 232, to provide a double gasket or sealing function.
  • the lip 222 of FIG. 15 has mechanical advantages even without the use of the special accepting furnish, the latter normally having particular desirability in conjunction with problem cuts.
  • the lip 222 is provided with greater material mass which provides additional beam strength to resist inward force provided by the tension exerted by the stretched film 60.
  • the horizontal portion 230 being at a height considerably lower than the top 232 of the lip 222, absorbs inwardly directed forces in a manner that stresses the side wall less because the resultant lever arm is lower, e.g. 30-35 percent lower. Additionally vector analysis shows that the net effect in inward deflection resulting from inward force is reduced and there is 12% less bending moment.
  • the tray of the present invention may be formed of other, equivalent materials, the structural advantages of the tray deriving from its geometry.
  • the tray may be formed of plastic foam, such as structural cellular polystyrene foam comprising on the order of percent void space, or porous polyolefin material, or a biodegradable plastic such as biodegradable foam polystyrene. If formed of materials having different strength characteristics, various changes in the configuration may be necessary and, depending on the material, certain advantages may be absent. When made of conventional foam polystyrene, sufficient strength may be provided by completely filling in the channel 228 to provide a continuous annular rib corresponding to the section shown in FIG. 13.
  • the tray of the present invention has many advantages, a number of which have been delineated above. In brief, however, it may be noted:
  • the open meat suspending structure promotes oxygen transfer as does the absence of free liquid pools which in other packages clog the pores of the overwrap film. This maintains better meat color and provides for maintenance of meat bloom and quality over the extended period for store sale to home storage.
  • no anaerobic bacteria, such as slime bacteria or botulism, are possible with the high oxygen transmission provided.
  • the ribbed tray suspends the entire bottom of the meat in a moisture saturated atmosphere, desirable for meat quality preservation. Only a small amount of liquid and a portion of this water evaporates to provide this moisture laden atmosphere; the remaining portion of exuded liquid is controlled by the pulp. This controlled acceptance of free liquids enhances appearance, maintains near perfect visibility and prolongs the freshness and bloom of the meat.
  • the actual contact of the meat with the tray is less than any tray structure even known in commercial use. This minimal contact of the meat with the tray together with the maintenance of the moisture saturated atmosphere inhibits the exuding of liquids and insures that the meat retains its moist surface and juicy character but without forming puddles or pools of liquid.
  • the inverted V-shaped ribs are preferably indented in the bottom to match or complement the upper part of the rib shape thereby reducing the stacking interval with consequent reduced storage and shipping costs without a sacrifice in strength.
  • Refrigeration Beam bottom construction holds meats suspended, providing improved circulation of moisture saturated air for oxygenation, and rapid cooling of the meat.
  • the multiple window frame construction of the trays of the present invention accepts into the frame itself any excessive non-evaporated seepage of liquid from the meat. This prevents the free flowing of bloody liquid from draining into the window opening that is composed of film alone. This is in contradistinction to the window area or rib patterns on the non-breathable clear polystyrene trays, which are covered by the extra bottom layers or layers of breathable transparent film that is rendered useless in the breathing function, and again reduces the effective visibility of the polystyrene tray.
  • the trays of the present invention with the multiple open window features maintain the advantages of control of exuding liquid, primarily by maintaining a saturated atmosphere about the meat but also by controlled acceptance while at the same time taking advantage of this control to maintain excellent visibility in the windows that are breathable, maintain great effectiveness of the transparent film over the entire surface of the package, protecting it to the maximum freshness and minimum bacterial action.
  • the trays of the present invention also have no problem of cutting film like the clear plastic trays because the film is protected by the soft edges of the pulp tray.
  • the meat contained in the clear polystyrene tray is exposed to bacteria and other contamination when the film has been cut by the sharp edges of the polystyrene tray. After extended storage the meat in the clear polystyrene trays nearly always discolors on the bottom first because of the destructive effects of the non-breathing, light transmitting, clear styrene 5 material.
  • the trays of the present in- 15 the precise configuration, spacing, height and arrangement of the ribs and the windows may be made, e.g. the ribs may intersect or meet at such angles to provide brick-work, diamond shaped, etc. window patterns.
  • a generally rectangular molded tray for the packaging of fresh meat, fish or poultry in conjunction with a transparent overwrap film heat-sealed thereabout, said tray comprising a pair of upwardly and outwardly inclined side walls, each said side wall forming a long side of said tray; a pair of upwardly and outwardly inclined end walls, each said end wall being adjacent to ends of said side walls, and thereby forming the rectangular configuration of said tray; a generally rounded corner between each said side wall and each said end wall; and a peripheral lip extending outwardly from said side and end walls and defining the periphery of said tray, the improvement comprising:
  • said breathing and support means comprising a plurality of strong, substantially solid primary ribs having an inverted V-shaped cross-section with rounded apices, some of said primary ribs extending in one direction, and other of said primary ribs extending in a different direction, said primary ribs meeting and defining therebetween a plurality of open windows, said ribs having a section modulus in combination with said end and side walls such that the total strength is substantially equal to the beam strength of a tray of the same material of equal weight with a flat, imperforate bottom;
  • a tray in accordance with claim 1 molded of wood 3.
  • a tray in accordance with claim 1 wherein said peripheral lip comprises a relatively large and thick portion dome-shaped in cross-section, and a horizontal portion extending outwardly from said dome-shaped portion at a location substantially below the top of the dome-shaped portion.
  • a tray in accordance with claim 12 molded of a wood pulp having large free liquid accepting capacity, and provided with a liquid impervious coating on the bottom surface thereof.
  • a generally rectangular molded tray for the packaging of meat, fish or poultry in conjunction with a transparent overwrap film heat-sealed thereabout, said tray comprising a pair of upwardly and outwardly inclined side walls, each said side wall forming a long side of said tray; a pair of upwardly and outwardly inclined end walls, each said end wall being adjacent to ends of said side walls, and thereby forming the rectangular configuration of said tray; a generally rounded corner between each said side wall and each said end wall; and a peripheral lip extending outwardly from said side and end walls and defining the periphery of said tray, the improvement comprising:
  • said breathing and suspending means comprising a plurality of strong, substantially solid primary ribs of inverted V- shaped cross-section with rounded apices and height substantially greater than the thickness of said side and end walls, some of said primary ribs extending in one direction and other of said primary ribs extending in a different direction, said primary ribs joining and defining therebetween a plurality of open windows;
  • a tray in accordance with claim 14 molded of wood ulp and wherein said end and side walls are of bowe construction, said primary ribs extending generally parallel to said side and end walls and joining to form generally rectangular open windows.
  • a tray in accordance with claim 14 further comprising secondary ribs extending across said gutter-like bottom wall to said end and side walls, said secondary ribs having a height substantially equal to said primary ribs and being staggered in relation to said primary ribs, said primary and secondary ribs having an included V- angle of about 10.
  • a generally rectangular molded tray for the packaging of meat, fish or poultry in conjunction with a transparent overwrap film heat-sealed thereabout, said tray comprising a pair of upwardly and outwardly inclined side walls, each said side wall forming a long side of said tray; a pair of upwardly and outwardly inclined and walls, each said end wall being adjacent to ends of said side walls, and thereby forming the rectangular configuration of said tray; a generally rounded corner between each said side wall and each said end wall; and a peripheral lip extending outwardly from said side and end walls and defining the periphery of said tray, the improvement comprising:
  • said means comprising a plurality of strong, high, substantially solid primary ribs of inverted V-shaped cross-section with rounded apices and molded of wood-pulp, some of said primary ribs extending in one direction and other of said primary ribs extending in a different direction, said primary ribs intersecting and defining therebetween a plurality of open windows; peripheral gutter-like bottom wall between said end and side walls and said primary ribs; and
  • peripheral lip comprises a relatively large and thick portion dome-shaped in cross-section, and a horizontal portion extending outwardly from said dome-shaped portion at a location substantially below the top of the dome-shaped portion.
  • a tray in accordance with claim 17 molded of a wood pulp having large free liquid accepting capacity, and provided with a liquid impervious coating on the bottom surface thereof.

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Mechanical Engineering (AREA)
  • Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
  • Packages (AREA)
  • Containers Having Bodies Formed In One Piece (AREA)
  • Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
US3718274D 1972-04-24 1972-04-24 High strength open bottom packaging trays Expired - Lifetime US3718274A (en)

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US24660072A 1972-04-24 1972-04-24

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JP (1) JPS4921273A (lt)
AU (1) AU467753B2 (lt)
BR (1) BR7206741D0 (lt)
CA (1) CA973842A (lt)
CH (1) CH565686A5 (lt)
FR (1) FR2182783A2 (lt)
GB (1) GB1344949A (lt)
IL (1) IL40355A (lt)
IT (1) IT1045210B (lt)
LU (1) LU66206A1 (lt)
NO (1) NO136617C (lt)
SE (1) SE375960B (lt)
ZA (1) ZA726095B (lt)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3761011A (en) * 1972-08-15 1973-09-25 Diamond Int Corp Food packaging tray
US3845896A (en) * 1973-01-31 1974-11-05 Keyes Fibre Co Open bottom tray with multiple pedestal display platform
US3885727A (en) * 1974-04-18 1975-05-27 Keyes Fibre Co Packaging tray with juice trapping viewing windows
US3894679A (en) * 1974-06-21 1975-07-15 Diamond Int Corp High strength open bottom packaging tray
US3997101A (en) * 1975-04-21 1976-12-14 Mobil Oil Corporation Meat tray or the like
US4162759A (en) * 1977-12-30 1979-07-31 Diamond International Corporation Food packaging tray
US4349146A (en) * 1980-11-28 1982-09-14 Mobil Oil Corporation Packaging tray
WO1985000339A1 (en) * 1983-07-12 1985-01-31 Atmosphere Packaging Pty. Ltd. Packaging foodstuffs
US4603052A (en) * 1979-06-27 1986-07-29 General Foods Corporation Method for oven-heating frozen fried foods
AU572175B2 (en) * 1983-07-12 1988-05-05 Garwood Limited Improved packaging
WO1993014995A1 (en) * 1992-01-27 1993-08-05 Andersen, Irma A package tray for liquid-containing food products, such as meat
US5335770A (en) * 1992-08-06 1994-08-09 Moulded Fibre Technology, Inc. Molded pulp fiber interior package cushioning structures
US5656135A (en) * 1993-02-16 1997-08-12 Moulded Fibre Technology, Inc. Molded product manufacturing apparatus and methods
US6352170B1 (en) 1999-10-18 2002-03-05 Paul Winkler Plastics Corp. Storage assembly including a lid with an egress barrier
US20020179607A1 (en) * 2000-04-06 2002-12-05 Yoshio Iwasaki Packaging container, packaging body including the same, and packaging method
US6513675B1 (en) 2000-05-31 2003-02-04 Paul Winkler Plastics Corp. Food container with rigid base plate
US6595366B1 (en) 2000-05-01 2003-07-22 Pwp Industries Food package whose lid has descending ribs to help hold food product and toppings in position
US20050092763A1 (en) * 2003-11-03 2005-05-05 Kraft Foods Holdings, Inc. Package for storing and dispensing edible film strips
US20140335240A1 (en) * 2011-03-16 2014-11-13 Cryovac Inc. Thermoplastic Tray
US10173824B2 (en) 2014-03-06 2019-01-08 Lucas Karel Johannes van den Broek Container for packaging products, in particular food products such as fresh meat products, as well as a method for packaging such products

Families Citing this family (3)

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Publication number Priority date Publication date Assignee Title
FR2290153A1 (fr) * 1974-11-08 1976-06-04 Soplaril Sa Procede et emballage pour la conservation de viande fraiche sous atmosphere controlee
WO1986007036A1 (en) * 1985-05-30 1986-12-04 Garwood Limited Packaging
AUPO469397A0 (en) * 1997-01-21 1997-02-13 Food & Packaging Centre Management Limited Insulated transport container

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US442500A (en) * 1890-12-09 Tray for holding caramels
US2310465A (en) * 1939-08-18 1943-02-09 Autoyre Co Inc Carton and tray therefor
US2918379A (en) * 1958-08-04 1959-12-22 Campbell Lurie Plastics Inc Meat packaging and the like
US2922541A (en) * 1954-08-05 1960-01-26 Martelli Guido Fruit packing
US3056232A (en) * 1957-06-03 1962-10-02 Diamond National Corp Molded pulp article
US3185371A (en) * 1963-05-24 1965-05-25 Diamond Int Corp Molded pulp article
US3217962A (en) * 1964-06-22 1965-11-16 Plastic Packaging Corp Packaging means
US3346400A (en) * 1965-02-08 1967-10-10 American Excelsior Corp Tray
US3357625A (en) * 1966-06-07 1967-12-12 Malanco Inc Meat tray with window
US3480178A (en) * 1968-09-16 1969-11-25 Henry Z Morgan Containers that are compactly nestable when empty and stackable in spaced relation when full
US3682365A (en) * 1971-01-27 1972-08-08 Diamond Int Corp High strength open bottom meat container

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US442500A (en) * 1890-12-09 Tray for holding caramels
US2310465A (en) * 1939-08-18 1943-02-09 Autoyre Co Inc Carton and tray therefor
US2922541A (en) * 1954-08-05 1960-01-26 Martelli Guido Fruit packing
US3056232A (en) * 1957-06-03 1962-10-02 Diamond National Corp Molded pulp article
US2918379A (en) * 1958-08-04 1959-12-22 Campbell Lurie Plastics Inc Meat packaging and the like
US3185371A (en) * 1963-05-24 1965-05-25 Diamond Int Corp Molded pulp article
US3217962A (en) * 1964-06-22 1965-11-16 Plastic Packaging Corp Packaging means
US3346400A (en) * 1965-02-08 1967-10-10 American Excelsior Corp Tray
US3357625A (en) * 1966-06-07 1967-12-12 Malanco Inc Meat tray with window
US3480178A (en) * 1968-09-16 1969-11-25 Henry Z Morgan Containers that are compactly nestable when empty and stackable in spaced relation when full
US3682365A (en) * 1971-01-27 1972-08-08 Diamond Int Corp High strength open bottom meat container

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3761011A (en) * 1972-08-15 1973-09-25 Diamond Int Corp Food packaging tray
US3845896A (en) * 1973-01-31 1974-11-05 Keyes Fibre Co Open bottom tray with multiple pedestal display platform
US3885727A (en) * 1974-04-18 1975-05-27 Keyes Fibre Co Packaging tray with juice trapping viewing windows
US3894679A (en) * 1974-06-21 1975-07-15 Diamond Int Corp High strength open bottom packaging tray
US3997101A (en) * 1975-04-21 1976-12-14 Mobil Oil Corporation Meat tray or the like
US4162759A (en) * 1977-12-30 1979-07-31 Diamond International Corporation Food packaging tray
US4603052A (en) * 1979-06-27 1986-07-29 General Foods Corporation Method for oven-heating frozen fried foods
US4349146A (en) * 1980-11-28 1982-09-14 Mobil Oil Corporation Packaging tray
WO1985000339A1 (en) * 1983-07-12 1985-01-31 Atmosphere Packaging Pty. Ltd. Packaging foodstuffs
AU572175B2 (en) * 1983-07-12 1988-05-05 Garwood Limited Improved packaging
WO1993014995A1 (en) * 1992-01-27 1993-08-05 Andersen, Irma A package tray for liquid-containing food products, such as meat
US5335770A (en) * 1992-08-06 1994-08-09 Moulded Fibre Technology, Inc. Molded pulp fiber interior package cushioning structures
US5656135A (en) * 1993-02-16 1997-08-12 Moulded Fibre Technology, Inc. Molded product manufacturing apparatus and methods
US6048440A (en) * 1993-02-16 2000-04-11 Moulded Fibre Technology, Inc. Molded product manufacturing apparatus and methods
US6352170B1 (en) 1999-10-18 2002-03-05 Paul Winkler Plastics Corp. Storage assembly including a lid with an egress barrier
US20020179607A1 (en) * 2000-04-06 2002-12-05 Yoshio Iwasaki Packaging container, packaging body including the same, and packaging method
US6595366B1 (en) 2000-05-01 2003-07-22 Pwp Industries Food package whose lid has descending ribs to help hold food product and toppings in position
US6513675B1 (en) 2000-05-31 2003-02-04 Paul Winkler Plastics Corp. Food container with rigid base plate
US20050092763A1 (en) * 2003-11-03 2005-05-05 Kraft Foods Holdings, Inc. Package for storing and dispensing edible film strips
US20140335240A1 (en) * 2011-03-16 2014-11-13 Cryovac Inc. Thermoplastic Tray
US8895092B1 (en) * 2011-03-16 2014-11-25 Cryovac, Inc. Package including a thermoplastic tray
US10173824B2 (en) 2014-03-06 2019-01-08 Lucas Karel Johannes van den Broek Container for packaging products, in particular food products such as fresh meat products, as well as a method for packaging such products

Also Published As

Publication number Publication date
JPS4921273A (lt) 1974-02-25
CA973842A (en) 1975-09-02
AU467753B2 (en) 1975-12-11
BR7206741D0 (pt) 1974-01-08
ZA726095B (en) 1973-07-25
FR2182783A2 (lt) 1973-12-14
LU66206A1 (lt) 1973-04-02
NO136617C (no) 1977-10-05
NO136617B (lt) 1977-06-27
IL40355A (en) 1976-03-31
DE2247912B2 (de) 1976-12-23
IT1045210B (it) 1980-05-10
CH565686A5 (lt) 1975-08-29
SE375960B (lt) 1975-05-05
AU4639872A (en) 1974-03-14
DE2247912A1 (de) 1973-11-08
GB1344949A (en) 1974-01-23

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Legal Events

Date Code Title Description
AS Assignment

Owner name: PACKAGINING CORPORATION OF AMERICA, EVANSTON, ILL.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST. EFFECTIVE SEPT 26,1983;ASSIGNOR:DIAMOND INTERNATIONAL CORPORATION,;REEL/FRAME:004311/0207

Effective date: 19840731

AS Assignment

Owner name: PACKAGING CORPORATION OF AMERICA EVANSTON, IL A CO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DIAMOND INTERNATIONAL CORPORATION;REEL/FRAME:004359/0673

Effective date: 19850803