CA1225068A - Purge trap tray - Google Patents
Purge trap trayInfo
- Publication number
- CA1225068A CA1225068A CA000433389A CA433389A CA1225068A CA 1225068 A CA1225068 A CA 1225068A CA 000433389 A CA000433389 A CA 000433389A CA 433389 A CA433389 A CA 433389A CA 1225068 A CA1225068 A CA 1225068A
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- tray
- sheet
- area
- reservoir
- thermoplastic sheet
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Abstract
ABSTRACT Of THE INVENTION
The present invention relates to a food tray for supporting, containing and displaying food products whir tend to exude or purge juices or liquids. In particular, the present invention relates to a food tray which comprises a sunken exudate reservoir. The reservoir is formed by adhering a sheet of a liquid impermeable material in a liquid tight manner to a raised shoulder area of a support portion of the tray to form a false bottom. The sheet material is further supported by standoffs rising up from the tray bottom. The sheet material is also perforated so as to allow flow of the exudate or purge through the sheet down into the reservoir where the exudate is trapped and retained out of contact with a food product which is located on top of said supported sheet. Preferably, the sheet material is opaque and the exudate is thereby hidden from view. Even more preferably, the sheet material is of the same color as the tray.
The present invention relates to a food tray for supporting, containing and displaying food products whir tend to exude or purge juices or liquids. In particular, the present invention relates to a food tray which comprises a sunken exudate reservoir. The reservoir is formed by adhering a sheet of a liquid impermeable material in a liquid tight manner to a raised shoulder area of a support portion of the tray to form a false bottom. The sheet material is further supported by standoffs rising up from the tray bottom. The sheet material is also perforated so as to allow flow of the exudate or purge through the sheet down into the reservoir where the exudate is trapped and retained out of contact with a food product which is located on top of said supported sheet. Preferably, the sheet material is opaque and the exudate is thereby hidden from view. Even more preferably, the sheet material is of the same color as the tray.
Description
YIELD OF THE INVENTION
The field of the present invention broadly encompasses that of trays for supporting and displaying food products. More particularly, the field of the present invention is directed to trays for supporting and displaying a food product which exudes juices or other purge liquids.
BACKGROUND OF THE INVENTION
.
Research has shown that the liquids dripping from poultry are a focal point of bacterial spoilage within packaged fresh meat and other poultry products. The growth of micro-organisms, particularly bacteria and yeast, occurs at a very rapid rate in such exuded fluids. The exudate is objectionable from an appearance standpoint, and moreover, the packed meat rapidly becomes objectionable because of odor and yeast growth even though the meat, itself, may be in a normal wholesome condition. Con-sequently, although the meat, itself, may be wholesome and acceptable, the fluid exuded from top meat Rand contained within the package will cause the whole package of meat or poultry to be untellable.
It is very important in the display and sale of packaged poultry and precut meats that -the package present a clean and wholesome appear-ante. The problem of maintaining such a clean and wholesome appearance is greatly aggravated by the fact that, as stated above, many meats, particularly prick meats and poultry, exude moisture containing sup-penned solids which cause the package to appear unclean. Further problems arise in that this exudate often evaporates or is absorbed in the pack-aging materials and then the suspended solids may be deposited on the food product and/or on the package. Accordingly, it is desirable from both a health and an aesthetic standpoint to remove the purge juices not only from the vicinity of the packaged product but also completely from view.
Y19LG2/sb It has been conventional practice to display meat, poultry, and other food products in individual packages which comprise a supporting tray with an absorbent pad of tissue-like paper wadding in the bottom of the tray to absorb any juices or liquids exuded from the food product. A
transparent outer plastic wrapping is also usually employed to cover and totally surround the package. A major problem associated with packages of this sort, as stated above, is the fact that the exuded liquids support the rapid growth of bacteria. In many cases the bacteria migrate from the absorbent pad back to the food product itself and result in the spoilage and discoloration of the food product. Such spoilage and disk coloration quickly renders the food product unsuitable for sale.
In an effort to alleviate the above problems, and to extend the shelf-life of such food products, it has previously been proposed to employ an absorbent pad in the package which includes an imperforate plastic film positioned above a layer of absorptive wadding in such manner that the plastic film acts to retard the reverse migration of the liquids from the absorbent wadding back to the food product. Also, it has been previously proposed to position a non-sbsorptive barrier above the absorbent material for this purpose, note U.S. Patent No. 3,026,209 to Nib lack et at. While the above package constructions do provide a special relationship between the exuded liquids in the pad and the food product, they nevertheless still permit the substantial migration of bacteria back to the food product and are thus not totally satisfactory.
Another proposal in this area is disclosed in U.S. Patent Nos.
4,321,997 and 4,275,811 both to ASH. Miller. U.S. Patent No 4,275,811 discloses an absorbent pad which comprises a mat of liquid absorbent material 9 an imperforate, liquid impermeable upper sheet overlying and covering the mat of absorbent material, and a bottom sheet of liquid impermeable material underlying the mat. The peripheral edges of the upper and bottom sheets are sealed together-to enclose the mat of absorb Y19LG3/sb I
bent material there between, and the bottom sheet includes a plurality of openings which permit passage of a liquid into the absorbent material so that the liquid is held, by the mat, out of contact with the food product.
United States Patent No. 4,321,997 essentially deals with an improvement on the structure disclosed in the '411 patent wherein the improvement includes spacer means disposed between the two sheets of material thereby maintaining the separation of the sheets under the compressive load exerted by food products or the like resting thereon. Utilization of the spacer means minimizes the compression o-f the mat by the food product and thus increases the ability of the mat to absorb and retain liquids while subjected to such a load.
While the inventions disclosed in the patents to Miller have resulted in advancements within the present field, a fund-mental problem in this area continues to persist. This fundamental problem is the labor cost involved in inserting any type of pad into a tray. This cost encompasses not only the labor cost but, alternatively, the cost of purchasing and maintaining a machine which is adapted to place pads in each tray. A machine of this type is disclosed in United States Patent No. 3,832,823 to Curries Of course, an additional intrinsic cost is the cost of the pad it-self.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the deficiencies intrinsic in the prior art tray products discussed above.
The invention provides a tray adapted to display a pro-duct which exudes a liquid comprising: a support portion comprise in: a reservoir area adapted to contain said liquid; a shoulder area raised from and completely surrounding said reservoir area;
standoff means rising from said reservoir area; and a perforated, liquid impermeable thermoplastic sheet having a border area;
wherein said border area of said sheet is adhered to said shoulder area in a liquid tight manner and said standoff means is adapted to support said sheet.
The improved packaging tray is particularly suitable for packaging fresh poultry and other meats or juicy foods. The reservoir area acts as a hidden purge reservoir which isolates the purge or exudate from a food product resting on the tray, so that the packaging tray presents a wholesome and clean appearance to a customer.
The tray as herein disclosed includes a sunken reservoir into which the juices or purge material may drain and be retained out of contact with the food product. The reservoir is formed by heat sealing a perforated liquid impermeable thermoplastic sheet in a liquid tight manner to a raised shoulder area of the tray to form a perforated false bottom through which the juices may drain.
The thermoplastic sheet is further supported by the standoff means which may be integral with the tray bottom and which rise up from the interior tray bottom. The volume of the reservoir can be varied, as desired, by varying the height that the shoulder area and standoffs are raised from the interior of the tray bottom.
Additionally, the volume of the reservoir can be increased by recessing or sinking the reservoir area of the tray bottom to the extent that the corresponding exterior area of the tray bottom is I
lowered with respect to the peripheral exterior tray bottom area.
In one embodiment the thermoplastic sheet material is opaque and the reservoir and juices contained therein remain hidden from the view of a customer. In a more preferred embodiment, the thermos plastic sheet is colored so as to correspond with the color of the tray and, therefore, the tray and sheet of thermoplastic material heat sealed thereto present a unitary appearance.
Still further features and the broad scope of applique-ability of the present invention and its numerous cognate benefits and features will become apparent to those of ordinary skill in the art from the details given hereinafter. However, it should be understood that the following detailed description and specific examples which indicate the presently preferred embodiments of the present invention are given by way of illustration only since various changes and modifications within the spirit and scope of the invention will become apparent to those of ordinary skill in the art from this detailed description.
Figure I is a top plan view of a preferred embodiment of a food tray in accordance with the present invention.
Figure II is a cross-sectional view of the tray of Figure I with the cross-section being taken along the line A-A
depicted in Figure I.
Figure III is a cross-sectional view of the tray of Figure I with the cross-section being taken along the line B-B
depicted in Figure I.
Figure IV is a bottom plan view of the tray of Figure I.
Figure V is an isometric view of the tray depicted in Figure I.
: I
Seiko cap 3 in the attached condition, as will be more fully discussed with reference to Figs. 3 and 4.
The closure cap 3 is advantageously made of a suitable plastic material or an aluminum alloy.
The closure cap 3 of Fig. 1, shown in an enlarged sectional view in Fig 3, is provided according to the invention with detachable bottom 6. In order to be broken out of the closure cap 3, bottom 6 is joined to peripheral wall 7 of closure cap 3 by an area of reduced material strength in the form of line 8. To enable the bottom 6 to be broken out of the closure cap 3 along the area of reduced material strength 8, which constitutes the break line, without any tools, the invention provides for exterior surface 9 of detachable cap bottom 6 to be stops offset inwardly with respect to outer surface 10 of peripheral wall 7 to permit a relative displacement movement by applying pressure and thereby produce breakage along breaking line I `
In the attached condition of closure cap 3, cap bottom 6 is positioned on top of the upper rim of neck 4 or, as in the illustrated embodiment on the top surface of rubber stopper 2, either in its entirety or with annular shoulder 11. Thus closure cap 3 encompasses with its peripheral wall I
7 beaded rim 5 of glass bottle 1 as well as the upward flange of rubber stopper I and with annular beaded portion 13, provided on the inner side of peripheral wall 7, extends beneath beaded rim 5 of neck 4. Accordingly, closure cap 3 is of the snap-on type which is easy to attach to bottle 1 and which, as is shown in Fig. 3, completely and tightly encloses neck 4 with beaded rim 5 and the stopper In order to produce the relative displacement movement between cap bottom 6 and peripheral wall 7, required to break cap bottom 6 out, it is merely necessary to exert pressure upon elevated top surface 10 of peripheral wall 7 in order to push peripheral wall 7 downward, as viewed in the illustration, to slid ably displace it into the region of the narrow portion of bottleneck 4 (as is indicated by the dash-dotted lines in Fig.
I while cap bottom 6 remains in engagement with stopper 2. This causes, by necessity, bottom 6 to break out of the cap along break line 8. Since during this process stopper 2 is resiliently pushed onward a slight extent, it will, following the completion of the breaking out of the cap bottom resiliently return to its initial position whereby the now detached cap bottom is pushed out of ~%~
preferred embodiment, support ribs 5, support the thermoplastic sheet 8 and a product which may be placed thereon. Thus, the number, size, shape and pattern of standoffs 7 may vary depending upon the weight of the product which is to be supported. An adequate n~ber of appropriately spaced and sized support ribs 5 could, if desired, be utilized as the sole standoff means. Thermoplastic sheet 8 is perforated at numerous points by holes 11 which are designed so as to allow juices or other purge liquids exuding from a product placed thereon to pass, by capillary action, down into reservoir area 6. Additionally, thermoplastic film 8 is provided with a centrally located larger -perforation 10 which is designed to allow free flow of juices or other purge liquids down into reservoir 6. The larger perforation 10 is centrally located to minimize the reverse flow of purge or other exuded liquids out of the reservoir 6 by way of perforation 10 upon tilting of tray 1 by a consumer or other individual. No immediate reverse flow will occur by way of the capillary perforations 11 upon tilting of tray I Accordingly, while the purge juices will readily accumulate within reservoir 6 the juices will still be retained in reservoir 6 even though tray 1 is tilted to a great degree.
Of course, no reverse flow, whatsoever, will occur while the tray is in a planar position unless the reservoir 6 has been completely filled with purge.
Figures II and III are cross-sectional views of the tray 1 of Figure I taken along lines A-A and B-B, respectively. These figures further illustrate the same features which are present in Figure I from different perspectives and thus further clarify the disclosed tray struck lure. In these views the thickness of thermoplastic sheet 8 has been enlarged for purposes of clarity and such is also the case, where nieces-spry, with regard to other features illustrated throughout the drawings.
Additionally, if heat sealing is selected as the method for adhering border area 9 of sheet 8 to tray shoulder area 4, the border area 9 of Y19BG9/sb S
sheet 8 will generally be fused into shoulder area 4. Accordingly, sheet will usually not be elevated above the surface of shoulder area 4.
Figure IV is a bottom plan view of the tray of figure I. This view discloses the presence of tray bottom 12 which includes, in this disclosed preferred embodiment, a pattern of indentations or dimples 13 which are created during the formation of standoffs 7. Figures XVI and XVII are front and end plan views of another possible tray bottom 12 con-figuration in accordance with the present invention. These figures disclose an embodiment where the reservoir area 6 of the tray has been recessed or sunken to the extent that the corresponding exterior tray bottom area aye has been lowered with respect to the peripheral exterior tray bottom area 12b. This recessing increases the volume of reservoir 6. Preferably, exterior tray bottom area aye is not lowered to an extent where it interferes with the nesting of a stack of trays.
Our research and experimentation has revealed that the pattern of capillary perforations 11 significantly affects the flow rate of purge juices or liquids down into reservoir 6. This fact was revealed by an experiment in which whole chicken breasts were placed on four trays wherein the thermoplastic sheet 8 had the perforation patterns illustrated in Figures XII,-XIII, XIV and XV. The trays 1 and the sup-ported product, i.e. chicken breasts, were over wrapped and placed in a lab refrigerator for approximately three days. The results of this experiment were as follows:
In the sample utilizing the perforation pattern of figure XII
only approximately one-third of the available purge liquids drained down in reservoir 6. This result was considered poor. It was noted that after all the chicken was removed the remaining liquid did, in fact, drain down into reservoir 6.
In the sample utilizing the perforation pattern illustrated in figure XIII most of the available liquid had drained down into reservoir Y19LG10/kd /
I
The closure caps described in the foregoing are in the form of snap caps to be applied to the bottleneck For this purpose, the inner side of the peripheral wall of the closure cap is provided with an annular bead or ridge for engagement with the underside of the beaded rim of the bottleneck. As the closure cap is applied to the bottle by a snapping action, the peripheral wall in the area of the annular bead expands momentarily until the annular bead is in place underneath the annular beaded rim of the bottleneck with the result that the closure cap is firmly seated on the bottleneck, securely sealing the mouth of the bottle This requires relatively narrow tolerances as to the height of the beaded rim of the glass bottle, the height of the rubber stopper and the interior height of the closure cap such tolerances, however, cannot always be maintained, with the undesirable result that in extreme cases the closure cap cannot even be attached to the bottleneck, or the rubber stopper is so tightly pressed together in its center that it becomes a problem to pierce it with an injection needle.
In the embodiment of Fig. 6, cap bottom I, in the applied condition of closure cap 3 to bottleneck 4, is positioned on the upper edge of I
generally cylindrical in shape. Those skilled in the art Jill readily recognize that standoffs having different geometric shapes and forming various geometric patterns are acceptable so long as adequate support of thermoplastic sheet 8 is provided. For example, standoffs having go-metric shapes and patterns such as diamonds, circles, pyramids, fee-tangles and/or maze like ribs are within the scope of the present invent lion. The standoff means may even be limited to an adequate number and arrangement of support ribs 5 as is the case in one embodiment of the present invention wherein the sole standoff means consists of two pairs of support ribs 5 with each rib extending in an offset, parallel and laterally overlapping fashion from opposing sides of the tray reservoir area 6. In any event, those skilled in the art will readily recognize that support ribs 5 merely illustrate a type of standoff which performs the function of providing lateral structural support to the tray in addition to otherwise supporting sheet 8.
Among some of the types of plastic materials-~hich are suitable for fabrication into the support portion of tray structures of the pro-sent invention are the polyolefins such as polyethylene, polypropylene, polybutene, polystyrene, high impact polystyrene, polyurethane, polyp vinylidene chloride, -paper -pulp,- acetate and others. A particular material which has been found to be well suited for fabrication of the present tray structure is foamed polystyrene. The closed cell structure of the foamed polystyrene prohibits absorption or penetration of liquids into the tray body and the foam material itself is extremely lightweight permitting ease of handling and transport.
As herein before indicated, a preferred material employed in the formation of the support portion of the tray structure of the present invention is plastic and, in particular, foam thermoplastic materials and especially polystyrene foam. The polystyrene foam may be manufactured Y19LG12/kd I
utilizing any one of the number of conventional extrusion techniques, for example, extrusion of formable polystyrene beads, i.e. beads which have a blowing agent already incorporated in them prior to delivery to an extra-soon apparatus or, for example, by direct injection extrusion techniques wherein a formable agent is added to a molten mass of polystyrene con-twined with an extrude prior to extrusion thereof from a die orifice.
After the polystyrene foam sheet material has been produced utilizing the conventional extrusion techniques such as those discussed above, it may be molded to form the support structure of the tray of the present invention. In general, it is desirable to preheat the foamed polystyrene sheet before it is molded in order to assure that the sheet will be at a sufficiently elevated temperature to permit rapid forming of the desired tray structure in the mold. Additionally, the mold may, likewise, be heated, by means well known in the art, to further assist in the rapid molding of the desired tray structure. An example of such heating means is hot water circulating within the mold sections. After preheating the foamed polystyrene sheet, the molded support structure of the tray in accordance with the present invention may be conveniently formed utilizing a molding operation. A cross-sectional view of a pro-furred embodiment of a mold-which may be utilized to form the molded support structure of a tray in accordance with the present invention is illustrated in Figure VII. Such a mold is generally designated at 21.
The mold comprises a male section 22 and a-female section 23. The sea-lions interface as indicated by the arrow in Figure VII. Male mold section 22 includes tray lip forming area 24, tray wall forming area 25 and tray shoulder forming area 26. A support rib forming area may also be included in the male mold section however it is not depicted in this particular cross-sectional view and is only necessary when the added support and rigidity of support ribs 5 is desired. Male mold section 22 further comprises a vacuum chamber 27 which has a vacuuming inlet 28 Yl9LG13/kd I
I
which may be connected to vacuumizing apparatus (not shown) well known in the art. Vacuum chamber 27 further commutes with vacuum channels 29 which are shaped so as to generate the desired geometric shape, for example cylindrical, of standoffs 7. Male mold section 22 also includes tray reservoir forming areas 30. Female mold section 23 includes tray bottom forming area 31 and prongs 32 which, during the molding process, cooperate with and are inserted into vacuum channels 29. If the tray support structure of figures XVI and VOW is desired, the female mold section 23 would include a recessed area to allow for the further recess-in or sinking of tray bottom 12 as at aye. The insertion ox prongs 32 into channels 29 assists the vacuumizing force provided by way of vacuum chamber 27 and vacuum channels 29 in the formation of standoffs 7.
Prongs 32 are not essential to the formation of standoffs 7 since it has been found that standoffs 7 of adequate height can be formed solely through utilization of the vacuumizing force applied by way of vacllum channels 29. However, prongs 32 have proved helpful in the formation of standoffs 7 of greater height. Care should be taken to assure that prongs 32 are not so long that they physically perforate the polystyrene sheet and form standoffs 7 having holes therein. Such structure is undesirable- in that the purge juices could drain completely out of the tray. -As stated previously, it may be desired to have the height of standoffs vary decreasingly toward the center of the tray and, in par-titular, toward the location of large perforation 10. zone method for accomplishing such a configuration is to form the standoffs 7 which are furtherest from perforation 10 by utilization of both a vacuumizing force applied by vacuum channels 29 and also by utilization of prongs 32 while forming the standoffs 7 located near perforation 10 only by vacuumizing force. In other words, utilization of prongs 32 would be omitted in formation of standoffs 7 located near perforation 10.
Y19LG14/kd MY
rum the above it can be seen that formation of the support structure of a thermoplastic tray 1 in accordance with the teachings of the present invention takes place when a heated sheet of appropriately desired thermoplastic material is placed between the mold sections 22 and 23 and the mold sections are closed down to a desired mold gap which will be equivalent to the desired thickness of the finished molded tray. As the mold sections 22 and 23 are closed the thermoplastic material is deformed by the various areas of the mold sections described above.
Moreover, prongs 32 push portions of the heated material up into vacuum channels 29. At the same time the vacuumizing force applied to vacuum channels 29 by way of vacuum chamber 27 and vacuum inlet port 28 pulls the thermoplastic material up into vacuum channels 29 and forms standoffs 7 of the desired geometric pattern and shape.
' Turning to figure VI which, in block diagram form, depicts the various processing steps associated with the wholesale manufacture and distribution of a tray in accordance with the present invention, it can be seen that molding step 15, discussed above is followed by the step of applying a perforated thermoplastic sheet 8 to the support structure of tray-l. This application step is designated as step 16 in Figure VI.
Figure VIII is a cross-sectional view of a preferred embodiment of an apparatus 36 which may be utilized to apply a perforated sheet 8 to the support structure of tray 1. The means of application utilized by this preferred apparatus is heat sealing. however, other appropriate sealing means such as ultrasonic sealing or gluing may be appropriately utilized. ~igure-VIII reveals that the support structure of tray 1 is positioned with respect to a backing plate 33. Backing plate 33 provides support for the support portion of tray 1 at the moment of application of the thermoplastic sheet 8 thereto. A support bar 34 which comprises a hot cutting frame 35 shaped so as to cut or melt out an appropriately Y19LG15/kd ~22~
sized portion of material from the thermoplastic sheet 8 is appropriately positioned with regard to the support portion of tray 1. If desirable, other cutting means may be substituted. Examples of such means are hot wire means, punch and die means or shearing knife means. Clamping eye-mints aye serve to retain the thermoplastic sheet 8, which is provided from roll pa, in a horizontally stationary position during the totality of application step 16. Since the heat associated with hot cutting frame 35 will adversely affect thermoplastic sheet 8, clamping elements aye, preferably, are vertically movable so that sheet 8 may be temporarily brought into close physical proximity with hot cutting frame 35 as will be later described.
Apparatus 36 comprises a transfer block 37 which is formed from a material having a low thermal conductivity. Examples of such materials are wood, asbestos and ceramics. A preferred ceramic is an epoxy filled ceramic such as syntactic foam. The low thermal conductivity of transfer block 37 allows it to be positioned close to heated-sealing frame 38 and still maintain a low temperature. This is desirable in order to avoid any sticking or tackiness of sheet 8 upon its contact with transfer block 37 as hereinafter described. The coating of transfer block 37 with a fluorocarbon polymer such as tetrafluoroethylene or a fluorinated ethylene-propylene material alas also been found to greatly reduce or eliminate such sticking. These materials are commonly referred to as Teflon Teflon is a trademark of E. I. Dupont de Numerous & Co. Transfer block 37, in this embodiment, has a generally rectangular shape and is slidingly coupled to a generally rectangular sealing frame 38 by way of means 41. Preferably, means 41 includes at least two pairs of pins with each pair extending from opposite sides of transfer block 37 and which cooperate with notches in sealing frame 38. Utilization of a pair of pins, as opposed to a single pin, on each opposing side of transfer block 37 greatly reduces any potential cocking or tilting of block 37 during Y19:LG16/kd Jo its ovine nut as will be hereinafter described. Additionally, transfer block 37 is resiliently mounted on sealing frame 38 by way of spring means 40. Sealing frame 38 is also provided with a cross plate structure 39. Preferably, cross plate structure 39 comprises an upper plate 39b and a lower plate aye in close proximity. Upper plate 39b is provided with a grid of holes 39c, for example a 10 by 20 grid for a total of 200 holes. In practice perforation pins 42 which are, preferably, stainless steel are inserted through holes 39c in a pattern corresponding to the perforation pattern desired for sheet 8. Each pin 42 is provided with a flattened planer head 42b perpendicular to its longitudinal axis. The width of the pin head 42b is designed to be greater than the diameter of holes 39c. Accordingly, the pin heads 42b will be trapped by and no-twined between plates aye and 39b upon plate aye being brought into close physical proximity to plate 39b and into planer contact with the pin heads. Plates aye and 39b may be coupled about their periphery by means well known in the art such as bolts. This arrangement provides an easy means whereby -the perforation pin pattern may be readily rearranged.
Figure XVIII is a cross-sectional view of a small -portion of plates aye and 39b including one hole 39c and an associated perforation pin 42. Of course, -other embodiments of perforation pins 42 are possible. For example, perforation pins 42 may comprise piano wire which has been folded in a doubled-up fashion. In this instance, the free ends of the piano wire may be attached to lower plate aye with the doubled-up wire being inserted through the holes 39c in plate 39b. The perforation pins are also arranged so as to be inserted into and through perforation pin channels 43 which pass entirely through the thickness of transfer block 37.
inure IX is a top plan view of the apparatus 36 illustrated in cross-section in Figure VIII. The pattern of perforation pin channels 43 Y19LG17/kd Jo and perforation pins 42 illustrated in Figure IX is a patter which may be utilized to obtain the perforation pattern illustrated in Figure XIV.
As previously stated, this perforation pattern is preferred. Addition- i ally, Figure IX gives a more distinct view of the larger perforation pin channel aye and the larger perforation pin aye which are centrally located in transfer block 37. Elements aye and aye cooperate to form the larger central perforation 10 discussed above.
Figure IX discloses yet another feature of transfer block 37.
This is the presence of vacuum ports 45 at the corners of transfer block 37. The vacuum ports 45 are the portals of vacuum channels 49 which progress completely through transfer block 37 as do the perforation pin channels 43. Vacuum channels 49 are connected by way of vacuum tubing or other means well known in the art to a vac~umizing source (not shown.
The arrangement and number of vacuum ports is not critical, however, a triangular arrangement of three ports in each corner of the transfer block assay been found to be satisfactory. Vacuum ports 45 serve -the function of temporarily retaining the thermoplastic sheet material 8 on the face of transfer block 37 during the step of applying the sheet 8 to the shoulder areas 4 of the molded portion offer 1.
Figure X is a cross-sectional view of the apparatus 36 along to plane C-C denoted in ire IX. This cross sectional view is some-what more detailed than the view of Figure YO-YO. In particular, Figure X
depicts means for maintaining the sealing frame 38-at an elevated tempera-lure. This means may be by any appropriate means conventionally known to those in the art. Examples of such include circulation of hot water through serpentine channels within the sealing frame 38 or use of elect tribal resistance. In one embodiment, hot water or another heating element would enter sealing frame 38 at entrance 46 and wind, in serpent tine fashion, throughout the interior of sealing frame 38 as illustrated YlgI.G18/kd Jo at 47. The heating element or fluid would exit the sealing frame 38 at exit port 48. Another way by which the temperature of sealing head 44 could be readily controlled is through the utilization of small cartridge heaters which are controlled by thermocouples in a manner well known to those in the art. One important function of the heating element is to assure that the sealing head 44 of the sealing frame 38 is maintained at a sufficient temperature to heat seal the thermoplastic sheet 8 to the support portion of tray 1. In particular the temperature of sealing head 44 should be adjusted so that a good liquid tight heat seal is formed. This temperature will vary with the materials which are utilized for sheet 8 and the support structure of tray 1 and may be arrived at without undue experimentation. Generally speaking, this temperature will fall within a range having a lower boundary where the sheet 8 is not adequately adhered, erg nonuniform and thus non-liquid tight, to the support structure of tray 1 and an upper boundary where the sheet 8 and support structure will be melted. For purposes of example only, we have found that when the support portion of tray 1 is formed from a foamed polystyrene material and sheet 8 comprises an oriented polystyrene having an approximate thickness of 1.2 miss., the temperature of sealing Hyde should be maintained between 290 and 320F. As was stated with regard to transfer block 37, sealing head 44 is, preferably, coated with Teflon so as to reduce any sticking of border area 9 of sheet 8 to sealing head 44 during the heat sealing of border area 9 to shoulder area 4. Another important function of the heating means is that cross plate 39 and thus perforation pins 42 and aye may be indirectly heated by conduction of heat through direct or indirect contact with the heated sealing frame 38.
The heating of perforation pins 42, aye assists the ends 42c of pins 42 and aye in perforating the thermoplastic sheet 8. The ends 42c of per-formation pins 42 and aye may be either pointed as in figure XVIII, or Y19LGl9/kd Jo aye somewhat blunt as would be the case if folded piano wire was utilized.
We have also found that when the perforation pins 42, aye are heated, as discussed above, each perforation in sheet 8 is cylindrical in shape and surrounded by a rib of material which was melted during perforation.
This is to be contrasted with a perforation formed by a room temperature perforation pin. In this case the perforation is funnel shaped and no surrounding rib is present.
A further important feature of the apparatus 36 is that the perforation pins 42 and aye are of a length such that their ends or tips 42c are just slightly above the plane of the sealing head 44. This feature allows the perforation pins 42 and aye to perforate the thermos plastic sheet 8 upon depression of the resiliently mounted transfer block 37 as will hereinafter be discussed in more detail.
Figure XI is a cross-sectional view of the apparatus 36 taken along the plane D-D as denoted in Figure IX. Such detail has been no-moved prom this cross-sectional view so that it may primarily illustrate the details of apparatus 36 which are related to vacuumizing ports 45.
Figure IX reveals that vacuumizing ports 45 are the openings for vacuumizing channels 49 which pass entirely through transfer block 37.
Thereafter, vacuum tubing- 50 is connected, by means well known in the art, to vacuum channels 49. Upon the attachment of vacuumizing apparatus (not shown) well known in the art to vacuum tubing 50 it can be seen that a vacuum may readily be drawn through vacuum ports 45. The presence of a vacuum at the corners of transfer block 37 readily retains a thermos plastic sheet 8 in place while it is in contact with transfer block 37.
Figure XI also illustrates one embodiment of a possible resilient mounting 40 of transfer block 37 onto apparatus 36. In particular no-silent spring means 40 may be mounted between the transfer block 37 and the cross plate 39 or, alternatively, between the transfer block 37 and Y19LG20/kd the sealing frame 38. In a preferred embodiment transfer block 37 is provided with four leg members aye with each leg aye located at a bottom corner of transfer block 37 and extending through an appropriately sized aperture in cross plate 39. In this embodiment the four resilient spring means 40 are each mounted between the bottom of a respective leg member and sealing frame 38. Accordingly, in this preferred embodiment, trays-for block 37 can be viewed as a table structure which is resiliently supported by spring means 40 under each leg aye. This structure is generally depicted in figure XIX from which much detail has been removed.
Such resilient mounting allows the transfer block 37 to be depressed upon the application of pressure to the face of transfer block 37. Of course, cross plate 39 should be arranged within the sealing frame 38 so that the depression of transfer block 37 at least to the plane of sealing head 44 will not be hindered. Such depression is necessary so as to allow the ends 42c of perforating pins 42 to be ox-posed from perforating pin channels 43 and thus be able to perforate a thermoplastic sheet 8 which is retained on the face of transfer block 37.
In view of the above discussion and turning back to Figure VIII
those skilled in the art will recognize that the application step 16 of Figure VI may proceed as follows:
Upon the initial indexing of the support portion of tray 1 from a mold, for example 21 illustrated in figure VII, to a position directly above apparatus 36 and directly below backing plate 33 clamping means aye will engage the sheet of thermoplastic material 8 and retain it in a relatively fixed horizontal position. At this point clamping means aye and apparatus 36 will proceed to move toward hot cutting frame 35 and the support portion of tray 1. The vertical movement of clamping means aye will stop when sheet 8 is just slightly below hot cutting frame 35.
Apparatus 36 will, however, continue toward sheet 8. upon contact of the Yl9LG21/kd I
transfer block 37 of apparatus 36 with thermoplastic sheet 8 the vacuumizing force which is applied to sheet 8 by way of vacuum ports 45 will act to retain sheet 8 in firm contact with transfer block 37.
Further movement of apparatus 36 will bring the retained sheet 8 into contact with hot cutting frame 35 and a section of thermoplastic sheet 8 will be cut out of sheet 8 and retained on transfer block 37. Hot cutting frame 35 will be sized so as to allow the passage of apparatus 36 there through. Moreover, hot cutting frame 35 will be sized to cut a portion of thermoplastic sheet 8 which is approximately the size of sealing frame 38. In other words, the edges of the portion of thermos plastic sheet 8 extend completely or, at least, substantially cover sealing head 44. This area of sheet 8 which extends over sealing head 44 has previously been referred to as border area 9. Further continued movement of apparatus 36 toward the support portion of tray 1 and backing plate 33 brings the cut out portion of thermoplastic sheet 8 into contact with the support portion of tray 1. The support portion of tray 1 will be pushed backward by this contact into contact with -fixed backing plate 33 which provides temporary physical support for the support portion of tray 1 during the remainder of the application step 16. At this point the simultaneolls heat sealing of the border area 9 of the cut out portion of the thermoplastic sheet 8 and perforation of thermoplastic sheet 8 is accomplished by continuing the movement of apparatus 36 toward the support portion of try until such time as the sealing head 44 presses the overlying border area 9 of the thermoplastic sheet 8 into contact with the shoulder area 4 of the support portion of Ray l. This pressurized contact of the heated seal-in head 44 accomplishes the liquid tight heat sealing of the border area 9 to raised shoulder area 4. Thus, the cut out portion of thermoplastic sheet 8 will be heat sealed completely about border area 9 to shoulder Yl9L~22/kd . I
.~.
area 4. Such sealing of sheet 8 about its entire periphery tire. border area 9) to shoulder area 4 in liquid tight manner serves to prohibit any purge juices or otter liquids which have flowed into reservoir 6 from exiting reservoir 6 by means of the juncture of sheet 8 and shoulder area 4. During this final step of movement of apparatus 36 towards the sup-port portion of tray 1 which is supported by backing plate 33, the no-silent means 40 which support transfer block 37 which, as was stated earlier, is slidingly attached by means 41 to sealing frame 38 will be compressed and transfer block 37 will be depressed to the plane of seal-in head 44. This depression of transfer block 37 will result in the tips of heated perforation pins 42 and aye being exposed from the per-formation pin channels 43 and aye. Upon the tips of the heated pins 42 and aye being exposed they will perforate the thermoplastic sheet in the desired perforation pattern. After sealing and perforation has occurred, apparatus 36 is drawn away from the support portion of tray 1 leaving behind the cut out portion of thermoplastic sheet 8 which has been perforated and heat sealed about its border area 9 to shoulder-area 4. Thereafter a new support portion of tray 1 and portion of thermoplastic sheet material 8 are indexed into position and the application step is repeated.
Figure VI reveals that after the cut out piece of thermoplastic sheet 8 has -been applied to the support portion of tray 1, each individual tray is separated from the roll of trays by means well known in the art. For example, the trays may by separated by cutting blades.
Thereafter the separated individual trays are passed to a stacking stay lion where they are stacked and prepared for packaging. After the trays have been packaged they may either be stored for inventory or shipped to an ultimate user.
Examples of thermoplastic materials which may be utilized to form thermoplastic sheet 8 are polymers and polymeric blends of the Y19LG23/kd following monomers: the mono-olefins and conjugated dolphins, e g.
ethylene, propylene, button, isobutene, 1,3 butadiene, isoprene and other aliphatic moo and dolphins; the halogen substituted olefins, e.g. vinyl chloride, vinylidene chloride; the mono/vinylidene aromatic compounds, e.g. styrenes alpha methylstyrene, chlorostyrene, other art-matte olefins and other unsaturated monomers such as acryonitrile, awry-loomed and the like. Polyamide polymers, e.g. nylon 66 and nylon 6 may also be used. In one preferred embodiment the material from which thermos plastic sheet 8 is manufactured is the same as that from which the sup-port structure of tray 1 is molded from. In another preferred embodiment thermoplastic sheet material 8 may be made from a foamed polystyrene which is the same as the material from which molded portion of tray 1 is made. Thermoplastic sheet material 8 may be dyed or otherwise colored to be the same or, at least, substantially the same color as the molded port lion of tray 1. In this instance the presence of purge reservoir or juice trap 6 is very effectively hidden from view. Moreover, the opaque color of thermoplastic sheet 8 will completely hide the presence of the drained off purge materials from view.
While the present tray was designed so as to eliminate the necessity of a soaker pad or other absorbent material being placed within a tray, the present invention does, indeed, readily lend itself to utile-ration of such absorbent materials. Materials of this sort may be placed within the reservoir area 6 of the molded portion of tray prior to the application, preferably by heat sealing, of thermoplastic sheet 8 to the raised shoulder area 4 of tray 1. The absorbent padding or wadding may contain bactericidal agents. The preferred bacteriostats are the broad spectrum antibiotics such as tetracycline, e.g. chlortetracycline and oxytetracycline; penicillin; sorbic acid; alkyd substituted or alkyd aureole Y19LG24/kd so substituted quarter nary ammonium compounds such as trimethyldodecyl-ammonium chloride, cetyltrimethylammonium bromide and alkyldimethyl-benzylammonium chloride; chlorine containing compounds such as the hype-chlorite and chloramines; iodine compounds such as sodium hypoiodite;
phenol and its derivatives such as pentachlorophenol and orthophenyl-phenol; dehydroactic acid; per oxygen compounds such as hydrogen peroxide, potassium per sulfate, parasitic acid and sodium perorate. The Beatrice-dual or bacteriostatic agents may be applied to the absorbent material in any preferred manner. Two basic methods are firstly wetting the absorb-live material with an aqueous solution of the agent and then drying, or, secondly, mixing or impregnating the absorptive material with a dry agent Of course, any method of placing the bacteriostatic or beater-icidal agents within the absorptive material so that they will come in contact with the exudate but not adversely affect product quality is acceptable.
Although the present invention has been described with pro-furred embodiments, it is to be understood that-modifications and vane-lions may be resorted to, without departing from the spirit and scope of the present invention. or example, the support portion of the tray does not have to be molded and any other appropriate means of formation is satisfactory.
Additionally, the top surface of sheet 8 may be etched by means known in the art to reduce the surface tension thereof and allow more rapid flow of purge liquids into the reservoir 6 which may contain a wetting agent to assist in the purge which has dripped therein to more rapidly and evenly spread out within the confines of the reservoir. As those skilled in the art will readily understand, such variations and modifications are considered to be within the purview and scope of the appended claims.
Y19LG25/kd 5
The field of the present invention broadly encompasses that of trays for supporting and displaying food products. More particularly, the field of the present invention is directed to trays for supporting and displaying a food product which exudes juices or other purge liquids.
BACKGROUND OF THE INVENTION
.
Research has shown that the liquids dripping from poultry are a focal point of bacterial spoilage within packaged fresh meat and other poultry products. The growth of micro-organisms, particularly bacteria and yeast, occurs at a very rapid rate in such exuded fluids. The exudate is objectionable from an appearance standpoint, and moreover, the packed meat rapidly becomes objectionable because of odor and yeast growth even though the meat, itself, may be in a normal wholesome condition. Con-sequently, although the meat, itself, may be wholesome and acceptable, the fluid exuded from top meat Rand contained within the package will cause the whole package of meat or poultry to be untellable.
It is very important in the display and sale of packaged poultry and precut meats that -the package present a clean and wholesome appear-ante. The problem of maintaining such a clean and wholesome appearance is greatly aggravated by the fact that, as stated above, many meats, particularly prick meats and poultry, exude moisture containing sup-penned solids which cause the package to appear unclean. Further problems arise in that this exudate often evaporates or is absorbed in the pack-aging materials and then the suspended solids may be deposited on the food product and/or on the package. Accordingly, it is desirable from both a health and an aesthetic standpoint to remove the purge juices not only from the vicinity of the packaged product but also completely from view.
Y19LG2/sb It has been conventional practice to display meat, poultry, and other food products in individual packages which comprise a supporting tray with an absorbent pad of tissue-like paper wadding in the bottom of the tray to absorb any juices or liquids exuded from the food product. A
transparent outer plastic wrapping is also usually employed to cover and totally surround the package. A major problem associated with packages of this sort, as stated above, is the fact that the exuded liquids support the rapid growth of bacteria. In many cases the bacteria migrate from the absorbent pad back to the food product itself and result in the spoilage and discoloration of the food product. Such spoilage and disk coloration quickly renders the food product unsuitable for sale.
In an effort to alleviate the above problems, and to extend the shelf-life of such food products, it has previously been proposed to employ an absorbent pad in the package which includes an imperforate plastic film positioned above a layer of absorptive wadding in such manner that the plastic film acts to retard the reverse migration of the liquids from the absorbent wadding back to the food product. Also, it has been previously proposed to position a non-sbsorptive barrier above the absorbent material for this purpose, note U.S. Patent No. 3,026,209 to Nib lack et at. While the above package constructions do provide a special relationship between the exuded liquids in the pad and the food product, they nevertheless still permit the substantial migration of bacteria back to the food product and are thus not totally satisfactory.
Another proposal in this area is disclosed in U.S. Patent Nos.
4,321,997 and 4,275,811 both to ASH. Miller. U.S. Patent No 4,275,811 discloses an absorbent pad which comprises a mat of liquid absorbent material 9 an imperforate, liquid impermeable upper sheet overlying and covering the mat of absorbent material, and a bottom sheet of liquid impermeable material underlying the mat. The peripheral edges of the upper and bottom sheets are sealed together-to enclose the mat of absorb Y19LG3/sb I
bent material there between, and the bottom sheet includes a plurality of openings which permit passage of a liquid into the absorbent material so that the liquid is held, by the mat, out of contact with the food product.
United States Patent No. 4,321,997 essentially deals with an improvement on the structure disclosed in the '411 patent wherein the improvement includes spacer means disposed between the two sheets of material thereby maintaining the separation of the sheets under the compressive load exerted by food products or the like resting thereon. Utilization of the spacer means minimizes the compression o-f the mat by the food product and thus increases the ability of the mat to absorb and retain liquids while subjected to such a load.
While the inventions disclosed in the patents to Miller have resulted in advancements within the present field, a fund-mental problem in this area continues to persist. This fundamental problem is the labor cost involved in inserting any type of pad into a tray. This cost encompasses not only the labor cost but, alternatively, the cost of purchasing and maintaining a machine which is adapted to place pads in each tray. A machine of this type is disclosed in United States Patent No. 3,832,823 to Curries Of course, an additional intrinsic cost is the cost of the pad it-self.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the deficiencies intrinsic in the prior art tray products discussed above.
The invention provides a tray adapted to display a pro-duct which exudes a liquid comprising: a support portion comprise in: a reservoir area adapted to contain said liquid; a shoulder area raised from and completely surrounding said reservoir area;
standoff means rising from said reservoir area; and a perforated, liquid impermeable thermoplastic sheet having a border area;
wherein said border area of said sheet is adhered to said shoulder area in a liquid tight manner and said standoff means is adapted to support said sheet.
The improved packaging tray is particularly suitable for packaging fresh poultry and other meats or juicy foods. The reservoir area acts as a hidden purge reservoir which isolates the purge or exudate from a food product resting on the tray, so that the packaging tray presents a wholesome and clean appearance to a customer.
The tray as herein disclosed includes a sunken reservoir into which the juices or purge material may drain and be retained out of contact with the food product. The reservoir is formed by heat sealing a perforated liquid impermeable thermoplastic sheet in a liquid tight manner to a raised shoulder area of the tray to form a perforated false bottom through which the juices may drain.
The thermoplastic sheet is further supported by the standoff means which may be integral with the tray bottom and which rise up from the interior tray bottom. The volume of the reservoir can be varied, as desired, by varying the height that the shoulder area and standoffs are raised from the interior of the tray bottom.
Additionally, the volume of the reservoir can be increased by recessing or sinking the reservoir area of the tray bottom to the extent that the corresponding exterior area of the tray bottom is I
lowered with respect to the peripheral exterior tray bottom area.
In one embodiment the thermoplastic sheet material is opaque and the reservoir and juices contained therein remain hidden from the view of a customer. In a more preferred embodiment, the thermos plastic sheet is colored so as to correspond with the color of the tray and, therefore, the tray and sheet of thermoplastic material heat sealed thereto present a unitary appearance.
Still further features and the broad scope of applique-ability of the present invention and its numerous cognate benefits and features will become apparent to those of ordinary skill in the art from the details given hereinafter. However, it should be understood that the following detailed description and specific examples which indicate the presently preferred embodiments of the present invention are given by way of illustration only since various changes and modifications within the spirit and scope of the invention will become apparent to those of ordinary skill in the art from this detailed description.
Figure I is a top plan view of a preferred embodiment of a food tray in accordance with the present invention.
Figure II is a cross-sectional view of the tray of Figure I with the cross-section being taken along the line A-A
depicted in Figure I.
Figure III is a cross-sectional view of the tray of Figure I with the cross-section being taken along the line B-B
depicted in Figure I.
Figure IV is a bottom plan view of the tray of Figure I.
Figure V is an isometric view of the tray depicted in Figure I.
: I
Seiko cap 3 in the attached condition, as will be more fully discussed with reference to Figs. 3 and 4.
The closure cap 3 is advantageously made of a suitable plastic material or an aluminum alloy.
The closure cap 3 of Fig. 1, shown in an enlarged sectional view in Fig 3, is provided according to the invention with detachable bottom 6. In order to be broken out of the closure cap 3, bottom 6 is joined to peripheral wall 7 of closure cap 3 by an area of reduced material strength in the form of line 8. To enable the bottom 6 to be broken out of the closure cap 3 along the area of reduced material strength 8, which constitutes the break line, without any tools, the invention provides for exterior surface 9 of detachable cap bottom 6 to be stops offset inwardly with respect to outer surface 10 of peripheral wall 7 to permit a relative displacement movement by applying pressure and thereby produce breakage along breaking line I `
In the attached condition of closure cap 3, cap bottom 6 is positioned on top of the upper rim of neck 4 or, as in the illustrated embodiment on the top surface of rubber stopper 2, either in its entirety or with annular shoulder 11. Thus closure cap 3 encompasses with its peripheral wall I
7 beaded rim 5 of glass bottle 1 as well as the upward flange of rubber stopper I and with annular beaded portion 13, provided on the inner side of peripheral wall 7, extends beneath beaded rim 5 of neck 4. Accordingly, closure cap 3 is of the snap-on type which is easy to attach to bottle 1 and which, as is shown in Fig. 3, completely and tightly encloses neck 4 with beaded rim 5 and the stopper In order to produce the relative displacement movement between cap bottom 6 and peripheral wall 7, required to break cap bottom 6 out, it is merely necessary to exert pressure upon elevated top surface 10 of peripheral wall 7 in order to push peripheral wall 7 downward, as viewed in the illustration, to slid ably displace it into the region of the narrow portion of bottleneck 4 (as is indicated by the dash-dotted lines in Fig.
I while cap bottom 6 remains in engagement with stopper 2. This causes, by necessity, bottom 6 to break out of the cap along break line 8. Since during this process stopper 2 is resiliently pushed onward a slight extent, it will, following the completion of the breaking out of the cap bottom resiliently return to its initial position whereby the now detached cap bottom is pushed out of ~%~
preferred embodiment, support ribs 5, support the thermoplastic sheet 8 and a product which may be placed thereon. Thus, the number, size, shape and pattern of standoffs 7 may vary depending upon the weight of the product which is to be supported. An adequate n~ber of appropriately spaced and sized support ribs 5 could, if desired, be utilized as the sole standoff means. Thermoplastic sheet 8 is perforated at numerous points by holes 11 which are designed so as to allow juices or other purge liquids exuding from a product placed thereon to pass, by capillary action, down into reservoir area 6. Additionally, thermoplastic film 8 is provided with a centrally located larger -perforation 10 which is designed to allow free flow of juices or other purge liquids down into reservoir 6. The larger perforation 10 is centrally located to minimize the reverse flow of purge or other exuded liquids out of the reservoir 6 by way of perforation 10 upon tilting of tray 1 by a consumer or other individual. No immediate reverse flow will occur by way of the capillary perforations 11 upon tilting of tray I Accordingly, while the purge juices will readily accumulate within reservoir 6 the juices will still be retained in reservoir 6 even though tray 1 is tilted to a great degree.
Of course, no reverse flow, whatsoever, will occur while the tray is in a planar position unless the reservoir 6 has been completely filled with purge.
Figures II and III are cross-sectional views of the tray 1 of Figure I taken along lines A-A and B-B, respectively. These figures further illustrate the same features which are present in Figure I from different perspectives and thus further clarify the disclosed tray struck lure. In these views the thickness of thermoplastic sheet 8 has been enlarged for purposes of clarity and such is also the case, where nieces-spry, with regard to other features illustrated throughout the drawings.
Additionally, if heat sealing is selected as the method for adhering border area 9 of sheet 8 to tray shoulder area 4, the border area 9 of Y19BG9/sb S
sheet 8 will generally be fused into shoulder area 4. Accordingly, sheet will usually not be elevated above the surface of shoulder area 4.
Figure IV is a bottom plan view of the tray of figure I. This view discloses the presence of tray bottom 12 which includes, in this disclosed preferred embodiment, a pattern of indentations or dimples 13 which are created during the formation of standoffs 7. Figures XVI and XVII are front and end plan views of another possible tray bottom 12 con-figuration in accordance with the present invention. These figures disclose an embodiment where the reservoir area 6 of the tray has been recessed or sunken to the extent that the corresponding exterior tray bottom area aye has been lowered with respect to the peripheral exterior tray bottom area 12b. This recessing increases the volume of reservoir 6. Preferably, exterior tray bottom area aye is not lowered to an extent where it interferes with the nesting of a stack of trays.
Our research and experimentation has revealed that the pattern of capillary perforations 11 significantly affects the flow rate of purge juices or liquids down into reservoir 6. This fact was revealed by an experiment in which whole chicken breasts were placed on four trays wherein the thermoplastic sheet 8 had the perforation patterns illustrated in Figures XII,-XIII, XIV and XV. The trays 1 and the sup-ported product, i.e. chicken breasts, were over wrapped and placed in a lab refrigerator for approximately three days. The results of this experiment were as follows:
In the sample utilizing the perforation pattern of figure XII
only approximately one-third of the available purge liquids drained down in reservoir 6. This result was considered poor. It was noted that after all the chicken was removed the remaining liquid did, in fact, drain down into reservoir 6.
In the sample utilizing the perforation pattern illustrated in figure XIII most of the available liquid had drained down into reservoir Y19LG10/kd /
I
The closure caps described in the foregoing are in the form of snap caps to be applied to the bottleneck For this purpose, the inner side of the peripheral wall of the closure cap is provided with an annular bead or ridge for engagement with the underside of the beaded rim of the bottleneck. As the closure cap is applied to the bottle by a snapping action, the peripheral wall in the area of the annular bead expands momentarily until the annular bead is in place underneath the annular beaded rim of the bottleneck with the result that the closure cap is firmly seated on the bottleneck, securely sealing the mouth of the bottle This requires relatively narrow tolerances as to the height of the beaded rim of the glass bottle, the height of the rubber stopper and the interior height of the closure cap such tolerances, however, cannot always be maintained, with the undesirable result that in extreme cases the closure cap cannot even be attached to the bottleneck, or the rubber stopper is so tightly pressed together in its center that it becomes a problem to pierce it with an injection needle.
In the embodiment of Fig. 6, cap bottom I, in the applied condition of closure cap 3 to bottleneck 4, is positioned on the upper edge of I
generally cylindrical in shape. Those skilled in the art Jill readily recognize that standoffs having different geometric shapes and forming various geometric patterns are acceptable so long as adequate support of thermoplastic sheet 8 is provided. For example, standoffs having go-metric shapes and patterns such as diamonds, circles, pyramids, fee-tangles and/or maze like ribs are within the scope of the present invent lion. The standoff means may even be limited to an adequate number and arrangement of support ribs 5 as is the case in one embodiment of the present invention wherein the sole standoff means consists of two pairs of support ribs 5 with each rib extending in an offset, parallel and laterally overlapping fashion from opposing sides of the tray reservoir area 6. In any event, those skilled in the art will readily recognize that support ribs 5 merely illustrate a type of standoff which performs the function of providing lateral structural support to the tray in addition to otherwise supporting sheet 8.
Among some of the types of plastic materials-~hich are suitable for fabrication into the support portion of tray structures of the pro-sent invention are the polyolefins such as polyethylene, polypropylene, polybutene, polystyrene, high impact polystyrene, polyurethane, polyp vinylidene chloride, -paper -pulp,- acetate and others. A particular material which has been found to be well suited for fabrication of the present tray structure is foamed polystyrene. The closed cell structure of the foamed polystyrene prohibits absorption or penetration of liquids into the tray body and the foam material itself is extremely lightweight permitting ease of handling and transport.
As herein before indicated, a preferred material employed in the formation of the support portion of the tray structure of the present invention is plastic and, in particular, foam thermoplastic materials and especially polystyrene foam. The polystyrene foam may be manufactured Y19LG12/kd I
utilizing any one of the number of conventional extrusion techniques, for example, extrusion of formable polystyrene beads, i.e. beads which have a blowing agent already incorporated in them prior to delivery to an extra-soon apparatus or, for example, by direct injection extrusion techniques wherein a formable agent is added to a molten mass of polystyrene con-twined with an extrude prior to extrusion thereof from a die orifice.
After the polystyrene foam sheet material has been produced utilizing the conventional extrusion techniques such as those discussed above, it may be molded to form the support structure of the tray of the present invention. In general, it is desirable to preheat the foamed polystyrene sheet before it is molded in order to assure that the sheet will be at a sufficiently elevated temperature to permit rapid forming of the desired tray structure in the mold. Additionally, the mold may, likewise, be heated, by means well known in the art, to further assist in the rapid molding of the desired tray structure. An example of such heating means is hot water circulating within the mold sections. After preheating the foamed polystyrene sheet, the molded support structure of the tray in accordance with the present invention may be conveniently formed utilizing a molding operation. A cross-sectional view of a pro-furred embodiment of a mold-which may be utilized to form the molded support structure of a tray in accordance with the present invention is illustrated in Figure VII. Such a mold is generally designated at 21.
The mold comprises a male section 22 and a-female section 23. The sea-lions interface as indicated by the arrow in Figure VII. Male mold section 22 includes tray lip forming area 24, tray wall forming area 25 and tray shoulder forming area 26. A support rib forming area may also be included in the male mold section however it is not depicted in this particular cross-sectional view and is only necessary when the added support and rigidity of support ribs 5 is desired. Male mold section 22 further comprises a vacuum chamber 27 which has a vacuuming inlet 28 Yl9LG13/kd I
I
which may be connected to vacuumizing apparatus (not shown) well known in the art. Vacuum chamber 27 further commutes with vacuum channels 29 which are shaped so as to generate the desired geometric shape, for example cylindrical, of standoffs 7. Male mold section 22 also includes tray reservoir forming areas 30. Female mold section 23 includes tray bottom forming area 31 and prongs 32 which, during the molding process, cooperate with and are inserted into vacuum channels 29. If the tray support structure of figures XVI and VOW is desired, the female mold section 23 would include a recessed area to allow for the further recess-in or sinking of tray bottom 12 as at aye. The insertion ox prongs 32 into channels 29 assists the vacuumizing force provided by way of vacuum chamber 27 and vacuum channels 29 in the formation of standoffs 7.
Prongs 32 are not essential to the formation of standoffs 7 since it has been found that standoffs 7 of adequate height can be formed solely through utilization of the vacuumizing force applied by way of vacllum channels 29. However, prongs 32 have proved helpful in the formation of standoffs 7 of greater height. Care should be taken to assure that prongs 32 are not so long that they physically perforate the polystyrene sheet and form standoffs 7 having holes therein. Such structure is undesirable- in that the purge juices could drain completely out of the tray. -As stated previously, it may be desired to have the height of standoffs vary decreasingly toward the center of the tray and, in par-titular, toward the location of large perforation 10. zone method for accomplishing such a configuration is to form the standoffs 7 which are furtherest from perforation 10 by utilization of both a vacuumizing force applied by vacuum channels 29 and also by utilization of prongs 32 while forming the standoffs 7 located near perforation 10 only by vacuumizing force. In other words, utilization of prongs 32 would be omitted in formation of standoffs 7 located near perforation 10.
Y19LG14/kd MY
rum the above it can be seen that formation of the support structure of a thermoplastic tray 1 in accordance with the teachings of the present invention takes place when a heated sheet of appropriately desired thermoplastic material is placed between the mold sections 22 and 23 and the mold sections are closed down to a desired mold gap which will be equivalent to the desired thickness of the finished molded tray. As the mold sections 22 and 23 are closed the thermoplastic material is deformed by the various areas of the mold sections described above.
Moreover, prongs 32 push portions of the heated material up into vacuum channels 29. At the same time the vacuumizing force applied to vacuum channels 29 by way of vacuum chamber 27 and vacuum inlet port 28 pulls the thermoplastic material up into vacuum channels 29 and forms standoffs 7 of the desired geometric pattern and shape.
' Turning to figure VI which, in block diagram form, depicts the various processing steps associated with the wholesale manufacture and distribution of a tray in accordance with the present invention, it can be seen that molding step 15, discussed above is followed by the step of applying a perforated thermoplastic sheet 8 to the support structure of tray-l. This application step is designated as step 16 in Figure VI.
Figure VIII is a cross-sectional view of a preferred embodiment of an apparatus 36 which may be utilized to apply a perforated sheet 8 to the support structure of tray 1. The means of application utilized by this preferred apparatus is heat sealing. however, other appropriate sealing means such as ultrasonic sealing or gluing may be appropriately utilized. ~igure-VIII reveals that the support structure of tray 1 is positioned with respect to a backing plate 33. Backing plate 33 provides support for the support portion of tray 1 at the moment of application of the thermoplastic sheet 8 thereto. A support bar 34 which comprises a hot cutting frame 35 shaped so as to cut or melt out an appropriately Y19LG15/kd ~22~
sized portion of material from the thermoplastic sheet 8 is appropriately positioned with regard to the support portion of tray 1. If desirable, other cutting means may be substituted. Examples of such means are hot wire means, punch and die means or shearing knife means. Clamping eye-mints aye serve to retain the thermoplastic sheet 8, which is provided from roll pa, in a horizontally stationary position during the totality of application step 16. Since the heat associated with hot cutting frame 35 will adversely affect thermoplastic sheet 8, clamping elements aye, preferably, are vertically movable so that sheet 8 may be temporarily brought into close physical proximity with hot cutting frame 35 as will be later described.
Apparatus 36 comprises a transfer block 37 which is formed from a material having a low thermal conductivity. Examples of such materials are wood, asbestos and ceramics. A preferred ceramic is an epoxy filled ceramic such as syntactic foam. The low thermal conductivity of transfer block 37 allows it to be positioned close to heated-sealing frame 38 and still maintain a low temperature. This is desirable in order to avoid any sticking or tackiness of sheet 8 upon its contact with transfer block 37 as hereinafter described. The coating of transfer block 37 with a fluorocarbon polymer such as tetrafluoroethylene or a fluorinated ethylene-propylene material alas also been found to greatly reduce or eliminate such sticking. These materials are commonly referred to as Teflon Teflon is a trademark of E. I. Dupont de Numerous & Co. Transfer block 37, in this embodiment, has a generally rectangular shape and is slidingly coupled to a generally rectangular sealing frame 38 by way of means 41. Preferably, means 41 includes at least two pairs of pins with each pair extending from opposite sides of transfer block 37 and which cooperate with notches in sealing frame 38. Utilization of a pair of pins, as opposed to a single pin, on each opposing side of transfer block 37 greatly reduces any potential cocking or tilting of block 37 during Y19:LG16/kd Jo its ovine nut as will be hereinafter described. Additionally, transfer block 37 is resiliently mounted on sealing frame 38 by way of spring means 40. Sealing frame 38 is also provided with a cross plate structure 39. Preferably, cross plate structure 39 comprises an upper plate 39b and a lower plate aye in close proximity. Upper plate 39b is provided with a grid of holes 39c, for example a 10 by 20 grid for a total of 200 holes. In practice perforation pins 42 which are, preferably, stainless steel are inserted through holes 39c in a pattern corresponding to the perforation pattern desired for sheet 8. Each pin 42 is provided with a flattened planer head 42b perpendicular to its longitudinal axis. The width of the pin head 42b is designed to be greater than the diameter of holes 39c. Accordingly, the pin heads 42b will be trapped by and no-twined between plates aye and 39b upon plate aye being brought into close physical proximity to plate 39b and into planer contact with the pin heads. Plates aye and 39b may be coupled about their periphery by means well known in the art such as bolts. This arrangement provides an easy means whereby -the perforation pin pattern may be readily rearranged.
Figure XVIII is a cross-sectional view of a small -portion of plates aye and 39b including one hole 39c and an associated perforation pin 42. Of course, -other embodiments of perforation pins 42 are possible. For example, perforation pins 42 may comprise piano wire which has been folded in a doubled-up fashion. In this instance, the free ends of the piano wire may be attached to lower plate aye with the doubled-up wire being inserted through the holes 39c in plate 39b. The perforation pins are also arranged so as to be inserted into and through perforation pin channels 43 which pass entirely through the thickness of transfer block 37.
inure IX is a top plan view of the apparatus 36 illustrated in cross-section in Figure VIII. The pattern of perforation pin channels 43 Y19LG17/kd Jo and perforation pins 42 illustrated in Figure IX is a patter which may be utilized to obtain the perforation pattern illustrated in Figure XIV.
As previously stated, this perforation pattern is preferred. Addition- i ally, Figure IX gives a more distinct view of the larger perforation pin channel aye and the larger perforation pin aye which are centrally located in transfer block 37. Elements aye and aye cooperate to form the larger central perforation 10 discussed above.
Figure IX discloses yet another feature of transfer block 37.
This is the presence of vacuum ports 45 at the corners of transfer block 37. The vacuum ports 45 are the portals of vacuum channels 49 which progress completely through transfer block 37 as do the perforation pin channels 43. Vacuum channels 49 are connected by way of vacuum tubing or other means well known in the art to a vac~umizing source (not shown.
The arrangement and number of vacuum ports is not critical, however, a triangular arrangement of three ports in each corner of the transfer block assay been found to be satisfactory. Vacuum ports 45 serve -the function of temporarily retaining the thermoplastic sheet material 8 on the face of transfer block 37 during the step of applying the sheet 8 to the shoulder areas 4 of the molded portion offer 1.
Figure X is a cross-sectional view of the apparatus 36 along to plane C-C denoted in ire IX. This cross sectional view is some-what more detailed than the view of Figure YO-YO. In particular, Figure X
depicts means for maintaining the sealing frame 38-at an elevated tempera-lure. This means may be by any appropriate means conventionally known to those in the art. Examples of such include circulation of hot water through serpentine channels within the sealing frame 38 or use of elect tribal resistance. In one embodiment, hot water or another heating element would enter sealing frame 38 at entrance 46 and wind, in serpent tine fashion, throughout the interior of sealing frame 38 as illustrated YlgI.G18/kd Jo at 47. The heating element or fluid would exit the sealing frame 38 at exit port 48. Another way by which the temperature of sealing head 44 could be readily controlled is through the utilization of small cartridge heaters which are controlled by thermocouples in a manner well known to those in the art. One important function of the heating element is to assure that the sealing head 44 of the sealing frame 38 is maintained at a sufficient temperature to heat seal the thermoplastic sheet 8 to the support portion of tray 1. In particular the temperature of sealing head 44 should be adjusted so that a good liquid tight heat seal is formed. This temperature will vary with the materials which are utilized for sheet 8 and the support structure of tray 1 and may be arrived at without undue experimentation. Generally speaking, this temperature will fall within a range having a lower boundary where the sheet 8 is not adequately adhered, erg nonuniform and thus non-liquid tight, to the support structure of tray 1 and an upper boundary where the sheet 8 and support structure will be melted. For purposes of example only, we have found that when the support portion of tray 1 is formed from a foamed polystyrene material and sheet 8 comprises an oriented polystyrene having an approximate thickness of 1.2 miss., the temperature of sealing Hyde should be maintained between 290 and 320F. As was stated with regard to transfer block 37, sealing head 44 is, preferably, coated with Teflon so as to reduce any sticking of border area 9 of sheet 8 to sealing head 44 during the heat sealing of border area 9 to shoulder area 4. Another important function of the heating means is that cross plate 39 and thus perforation pins 42 and aye may be indirectly heated by conduction of heat through direct or indirect contact with the heated sealing frame 38.
The heating of perforation pins 42, aye assists the ends 42c of pins 42 and aye in perforating the thermoplastic sheet 8. The ends 42c of per-formation pins 42 and aye may be either pointed as in figure XVIII, or Y19LGl9/kd Jo aye somewhat blunt as would be the case if folded piano wire was utilized.
We have also found that when the perforation pins 42, aye are heated, as discussed above, each perforation in sheet 8 is cylindrical in shape and surrounded by a rib of material which was melted during perforation.
This is to be contrasted with a perforation formed by a room temperature perforation pin. In this case the perforation is funnel shaped and no surrounding rib is present.
A further important feature of the apparatus 36 is that the perforation pins 42 and aye are of a length such that their ends or tips 42c are just slightly above the plane of the sealing head 44. This feature allows the perforation pins 42 and aye to perforate the thermos plastic sheet 8 upon depression of the resiliently mounted transfer block 37 as will hereinafter be discussed in more detail.
Figure XI is a cross-sectional view of the apparatus 36 taken along the plane D-D as denoted in Figure IX. Such detail has been no-moved prom this cross-sectional view so that it may primarily illustrate the details of apparatus 36 which are related to vacuumizing ports 45.
Figure IX reveals that vacuumizing ports 45 are the openings for vacuumizing channels 49 which pass entirely through transfer block 37.
Thereafter, vacuum tubing- 50 is connected, by means well known in the art, to vacuum channels 49. Upon the attachment of vacuumizing apparatus (not shown) well known in the art to vacuum tubing 50 it can be seen that a vacuum may readily be drawn through vacuum ports 45. The presence of a vacuum at the corners of transfer block 37 readily retains a thermos plastic sheet 8 in place while it is in contact with transfer block 37.
Figure XI also illustrates one embodiment of a possible resilient mounting 40 of transfer block 37 onto apparatus 36. In particular no-silent spring means 40 may be mounted between the transfer block 37 and the cross plate 39 or, alternatively, between the transfer block 37 and Y19LG20/kd the sealing frame 38. In a preferred embodiment transfer block 37 is provided with four leg members aye with each leg aye located at a bottom corner of transfer block 37 and extending through an appropriately sized aperture in cross plate 39. In this embodiment the four resilient spring means 40 are each mounted between the bottom of a respective leg member and sealing frame 38. Accordingly, in this preferred embodiment, trays-for block 37 can be viewed as a table structure which is resiliently supported by spring means 40 under each leg aye. This structure is generally depicted in figure XIX from which much detail has been removed.
Such resilient mounting allows the transfer block 37 to be depressed upon the application of pressure to the face of transfer block 37. Of course, cross plate 39 should be arranged within the sealing frame 38 so that the depression of transfer block 37 at least to the plane of sealing head 44 will not be hindered. Such depression is necessary so as to allow the ends 42c of perforating pins 42 to be ox-posed from perforating pin channels 43 and thus be able to perforate a thermoplastic sheet 8 which is retained on the face of transfer block 37.
In view of the above discussion and turning back to Figure VIII
those skilled in the art will recognize that the application step 16 of Figure VI may proceed as follows:
Upon the initial indexing of the support portion of tray 1 from a mold, for example 21 illustrated in figure VII, to a position directly above apparatus 36 and directly below backing plate 33 clamping means aye will engage the sheet of thermoplastic material 8 and retain it in a relatively fixed horizontal position. At this point clamping means aye and apparatus 36 will proceed to move toward hot cutting frame 35 and the support portion of tray 1. The vertical movement of clamping means aye will stop when sheet 8 is just slightly below hot cutting frame 35.
Apparatus 36 will, however, continue toward sheet 8. upon contact of the Yl9LG21/kd I
transfer block 37 of apparatus 36 with thermoplastic sheet 8 the vacuumizing force which is applied to sheet 8 by way of vacuum ports 45 will act to retain sheet 8 in firm contact with transfer block 37.
Further movement of apparatus 36 will bring the retained sheet 8 into contact with hot cutting frame 35 and a section of thermoplastic sheet 8 will be cut out of sheet 8 and retained on transfer block 37. Hot cutting frame 35 will be sized so as to allow the passage of apparatus 36 there through. Moreover, hot cutting frame 35 will be sized to cut a portion of thermoplastic sheet 8 which is approximately the size of sealing frame 38. In other words, the edges of the portion of thermos plastic sheet 8 extend completely or, at least, substantially cover sealing head 44. This area of sheet 8 which extends over sealing head 44 has previously been referred to as border area 9. Further continued movement of apparatus 36 toward the support portion of tray 1 and backing plate 33 brings the cut out portion of thermoplastic sheet 8 into contact with the support portion of tray 1. The support portion of tray 1 will be pushed backward by this contact into contact with -fixed backing plate 33 which provides temporary physical support for the support portion of tray 1 during the remainder of the application step 16. At this point the simultaneolls heat sealing of the border area 9 of the cut out portion of the thermoplastic sheet 8 and perforation of thermoplastic sheet 8 is accomplished by continuing the movement of apparatus 36 toward the support portion of try until such time as the sealing head 44 presses the overlying border area 9 of the thermoplastic sheet 8 into contact with the shoulder area 4 of the support portion of Ray l. This pressurized contact of the heated seal-in head 44 accomplishes the liquid tight heat sealing of the border area 9 to raised shoulder area 4. Thus, the cut out portion of thermoplastic sheet 8 will be heat sealed completely about border area 9 to shoulder Yl9L~22/kd . I
.~.
area 4. Such sealing of sheet 8 about its entire periphery tire. border area 9) to shoulder area 4 in liquid tight manner serves to prohibit any purge juices or otter liquids which have flowed into reservoir 6 from exiting reservoir 6 by means of the juncture of sheet 8 and shoulder area 4. During this final step of movement of apparatus 36 towards the sup-port portion of tray 1 which is supported by backing plate 33, the no-silent means 40 which support transfer block 37 which, as was stated earlier, is slidingly attached by means 41 to sealing frame 38 will be compressed and transfer block 37 will be depressed to the plane of seal-in head 44. This depression of transfer block 37 will result in the tips of heated perforation pins 42 and aye being exposed from the per-formation pin channels 43 and aye. Upon the tips of the heated pins 42 and aye being exposed they will perforate the thermoplastic sheet in the desired perforation pattern. After sealing and perforation has occurred, apparatus 36 is drawn away from the support portion of tray 1 leaving behind the cut out portion of thermoplastic sheet 8 which has been perforated and heat sealed about its border area 9 to shoulder-area 4. Thereafter a new support portion of tray 1 and portion of thermoplastic sheet material 8 are indexed into position and the application step is repeated.
Figure VI reveals that after the cut out piece of thermoplastic sheet 8 has -been applied to the support portion of tray 1, each individual tray is separated from the roll of trays by means well known in the art. For example, the trays may by separated by cutting blades.
Thereafter the separated individual trays are passed to a stacking stay lion where they are stacked and prepared for packaging. After the trays have been packaged they may either be stored for inventory or shipped to an ultimate user.
Examples of thermoplastic materials which may be utilized to form thermoplastic sheet 8 are polymers and polymeric blends of the Y19LG23/kd following monomers: the mono-olefins and conjugated dolphins, e g.
ethylene, propylene, button, isobutene, 1,3 butadiene, isoprene and other aliphatic moo and dolphins; the halogen substituted olefins, e.g. vinyl chloride, vinylidene chloride; the mono/vinylidene aromatic compounds, e.g. styrenes alpha methylstyrene, chlorostyrene, other art-matte olefins and other unsaturated monomers such as acryonitrile, awry-loomed and the like. Polyamide polymers, e.g. nylon 66 and nylon 6 may also be used. In one preferred embodiment the material from which thermos plastic sheet 8 is manufactured is the same as that from which the sup-port structure of tray 1 is molded from. In another preferred embodiment thermoplastic sheet material 8 may be made from a foamed polystyrene which is the same as the material from which molded portion of tray 1 is made. Thermoplastic sheet material 8 may be dyed or otherwise colored to be the same or, at least, substantially the same color as the molded port lion of tray 1. In this instance the presence of purge reservoir or juice trap 6 is very effectively hidden from view. Moreover, the opaque color of thermoplastic sheet 8 will completely hide the presence of the drained off purge materials from view.
While the present tray was designed so as to eliminate the necessity of a soaker pad or other absorbent material being placed within a tray, the present invention does, indeed, readily lend itself to utile-ration of such absorbent materials. Materials of this sort may be placed within the reservoir area 6 of the molded portion of tray prior to the application, preferably by heat sealing, of thermoplastic sheet 8 to the raised shoulder area 4 of tray 1. The absorbent padding or wadding may contain bactericidal agents. The preferred bacteriostats are the broad spectrum antibiotics such as tetracycline, e.g. chlortetracycline and oxytetracycline; penicillin; sorbic acid; alkyd substituted or alkyd aureole Y19LG24/kd so substituted quarter nary ammonium compounds such as trimethyldodecyl-ammonium chloride, cetyltrimethylammonium bromide and alkyldimethyl-benzylammonium chloride; chlorine containing compounds such as the hype-chlorite and chloramines; iodine compounds such as sodium hypoiodite;
phenol and its derivatives such as pentachlorophenol and orthophenyl-phenol; dehydroactic acid; per oxygen compounds such as hydrogen peroxide, potassium per sulfate, parasitic acid and sodium perorate. The Beatrice-dual or bacteriostatic agents may be applied to the absorbent material in any preferred manner. Two basic methods are firstly wetting the absorb-live material with an aqueous solution of the agent and then drying, or, secondly, mixing or impregnating the absorptive material with a dry agent Of course, any method of placing the bacteriostatic or beater-icidal agents within the absorptive material so that they will come in contact with the exudate but not adversely affect product quality is acceptable.
Although the present invention has been described with pro-furred embodiments, it is to be understood that-modifications and vane-lions may be resorted to, without departing from the spirit and scope of the present invention. or example, the support portion of the tray does not have to be molded and any other appropriate means of formation is satisfactory.
Additionally, the top surface of sheet 8 may be etched by means known in the art to reduce the surface tension thereof and allow more rapid flow of purge liquids into the reservoir 6 which may contain a wetting agent to assist in the purge which has dripped therein to more rapidly and evenly spread out within the confines of the reservoir. As those skilled in the art will readily understand, such variations and modifications are considered to be within the purview and scope of the appended claims.
Y19LG25/kd 5
Claims (14)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A tray adapted to display a product which exudes a liquid comprising:
a support portion comprising:
a reservoir area adapted to contain said liquid;
a shoulder area raised from and completely surrounding said reservoir area;
standoff means rising from said reservoir area; and a perforated, liquid impermeable thermoplastic sheet having a border area;
wherein said border area of said sheet is adhered to said shoulder area in a liquid tight manner and said standoff means is adapted to support said sheet.
a support portion comprising:
a reservoir area adapted to contain said liquid;
a shoulder area raised from and completely surrounding said reservoir area;
standoff means rising from said reservoir area; and a perforated, liquid impermeable thermoplastic sheet having a border area;
wherein said border area of said sheet is adhered to said shoulder area in a liquid tight manner and said standoff means is adapted to support said sheet.
2. The tray of claim 1, wherein said border area is heat sealed to said shoulder area.
3. The tray of claim 1, wherein said perforated sheet has a centrally located perforation having a diameter larger than a diameter of all other perforations.
4. The tray of claim 1, wherein said standoff means comprises at least two standoffs rising from said reservoir area to a substantially equal height.
5. The tray of claim 1, wherein said standoff means comprises at least two standoffs rising from said reservoir area to different heights.
6. The tray of claim 1, wherein said support portion comprises a foamed polystyrene material.
7. The tray so claim 1, wherein said thermoplastic sheet comprises a foamed polystyrene material.
8. The tray of claim 1, wherein said thermoplastic sheet comprises a polyethylene material.
9. The tray of claim 1, wherein said support portion and said thermoplastic sheet are of a substantially same color.
10. The tray of claim 1, wherein said reservoir area contains an absorbent material.
11. The tray of claim 1, wherein said thermoplastic sheet is opaque.
12. The tray according to claim 3, wherein said diameter of said other perforations is adapted to allow capillary flow of said exuded liquid.
13. The tray of claim 6, wherein said thermoplastic sheet comprises foamed polystyrene material.
14. The tray according to claim 10, wherein said absorbent material contains a bactericidal agent.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/443,933 | 1982-11-23 | ||
| US06/443,933 US4609654A (en) | 1981-12-01 | 1982-11-23 | Derivatives of cephalosporins substituted in 3 position by a thiomethyl heterocycle group; and pharmaceutical compositions containing them |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1225068A true CA1225068A (en) | 1987-08-04 |
Family
ID=23762773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000433389A Expired CA1225068A (en) | 1982-11-23 | 1983-07-27 | Purge trap tray |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1225068A (en) |
-
1983
- 1983-07-27 CA CA000433389A patent/CA1225068A/en not_active Expired
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |