US3374922A

US3374922A - Foamed containers

Info

Publication number: US3374922A
Application number: US392186A
Authority: US
Inventors: Richard K Shelby
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1963-04-12
Filing date: 1964-08-26
Publication date: 1968-03-26
Anticipated expiration: 1985-03-26
Also published as: NL129552C; NL6403833A; GB1123401A; GB1063811A; BE646495A; DE1569151A1; DE1569151B2

Description

March 26, 1968 R. K` SHELBY FOAMED CONTAINERS 3 Sheets-Sheet l Filed Aug. 26, 1964 INVENTOR RICHARD K. SHELBY ATTORNEY March 26, 1968 R. K, SHELBY FOAMED CONTAINERS Filed Aug. 26. 1964 3 Sheets-Sheet :"2

lNvENToR RICHARD K. SHELBY ATTORNEY March 26, 1968 Filed Aug. 2e, 1964` R. K. SHELBY FOAMED CONTAINERS 3 Sheets-Sheet 5 FIG. 4

FIG.5

INVENTOR RICHARD K. SHELBY MMM/@QW ATTORNEY United States Patent Oiice Patented Mar. 26, 1968 3,374,922 FOAMED CONTAINERS Richard K. Shelby, Downers Grove, Ill., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware Filed Aug. 26, 1964, Ser. No. 392,186

11 Claims. (Cl. 220v-97) observer. The vending machine must be adapted toacquently,` do not readily lend themselves to nesting in stacks in a relatively friction fr ee manner. These foamed commodate suitably designed containers of proper size and shape, and which are capable of being nested in a stack of like containers. The containers must lbereadily removable from the stack of containers and unitarily separated therefrom. In most coin-operated beverage dispensing machines, the machine is designedto transfer a cup to :a particular station upon the receipt of'a coin and Vis further designed to iill the container to a desired level with a beverage selected by Ethe purchaser. The cups are nested in a large stack and contained within a dispensing tube which is operable by a suitable mechanism to dispense each cup upon the receipt of the proper amount of money. If however, one of thegcups should not separate from the nested stack, orshould become jammed within the passageway leading to the beverage lilling station, then the purchaser is unable to receive the consideration yfor his coin. Furthermore, this vending machine is unsuitable for operation until av repairman has had the opportunity to remove the lodged c up or lcorrect any other malfunction with regard to the dispensing of the cups, Not only does such a malfunction lead to a loss of profits, but the good will lost from irate customers materially reduces the future sales in that particular vending machine.

From the standpoint of the customer, the vending ma,- chine operators are also confronted with another problern, particularly with vending machines that dispense hot fluids. It has been the pr-actice to employ paper containers in the vending machines for such drinks as lhot tea, hot coffee and hot chocolate. These paper containers proved to be unsuitable inasmuch as they had very little heat insulating qualities and the purchaser had considerable diiculty in holding the container for a long period of time. Moreover, the paper seemed to have a tendency to ruin the taste of the beverage conta-ined therein, and finally, the container itself would often become soggy and U.S. Letters Patent 2,967,328. While these plastic containers have obviated most of the problems presented with paper containers, they have not corrected the leiciencies in heat insulating which were present in the paper containers. The purchaser of a hot beverage has as much difficulty in retaining a plastic cup containing the hot beverage as he does retaining a paper cup containing a hot beverage.

Recently, there have been new developments in the production of the so-called foamed container. These containers are formed, usually by injection molding, of a modified polystyrene plastic material and are expanded in order to provide the foamed surface. However, these cont-ainers have proved to be totally unacceptable for'use in vending machines inasmuch as the surface ofthe container possesses a high friction co-eicient and consecontainers have a tendency to frictionally vengage the interior wallsof the containers in which they are nested andv are, therefore, unsuitable for vending machine operations. Due to the high friction co-'eftcient of a foamed surface,'the container cannot engage the wall of the tube in which it travelsto the dispensing station, and moreover, must be designed 'so that it does not engage -the wall of a simil-ar con-tainer in which itis nested. The solution of this problem has further been complicated by the fact that the dispensing tubes in many vending machines' 'are not truly vertical and, therefor e,`,i ty isditcult for the nested containers to become properlyI aligned inthestack.

Itis -therefore the primary object of thepresent invention to provide` a nestable foamed container which is capable of being usedin vendingtmachine operations. f It is another object of the present invention vto provide a foamed container of the type stated which is provided with a series of novel stacking rings whichprovid for a relatively efficient nesting of 'the -containersin a stack.

It is a further object o f'the present invention to provide a foamed container ofthe'type stated which iseconomical to' manufacture `and competitive with conventional containers. t

Itis a further object ofthe present invention toy provide acontainer of the type statedv which hashigh heat insulating qualities and also has a commerciallyrattractive outer appearance.

With the above and other objects in view, my invention resides in the novel features in form, construction, arrangement, and combination of parts' presently .devscribed and pointed out. v l In the accompanying drawings: Y l FIGURE l is a perspectiveview of afoamed container constructed in accordance `with :and embodying the present invention;

FIGURE 2 is -a vertical sectionalview of the container of FIGURE l taken along .the axial centerline of the container of FIGURE 1;

FIGURES is :a sectional view partly brokeniaway of two nested containers ofthe type shown in FIGURE 1; FIGURE 4 isa perspective view of amodiiied form of container constructed iny accordance with and embodying the present invention;4

`FIGURE 5 is a vertical` sectional view of the container of FIGURE 4 and being 'taken along the axial centerline of the containerpf FIGURE 4; and f FIGURE 6 is a sectional View, partially Abrokenaway of two nested containers of the type shown in FIGURE 4. Generally speaking, the present invention -relates to nestable plastic containers of the so-called throwvaway or disposable type, which have partially foamed outer sur.- faces. The containers of the presentinvention vgenerally comprise a conically shaped skirt portion or side wallsection which merges at its upper end intoa series of novel stacking rings and at its lower end into a 'double conical base. The containers are generally formed of polyethylene, polystyrene, polybutadiene or modified polystyrene. A portion of their outer surfaces are expanded or foamed in accordance with the procedure set forth in copending application Ser. No. 272,540, liledvApr. 12, 1963, now Patent No. 3,262,625 issued Iuly 26, 1966. c

The containers which form the subject matter of this inventionare so designed, that `the foamed surfaces thereof do not comein .contact with the dispensing tube in conventional vending machines, and moreover, the foamed surface of one container will not come in contact with the interior wall of a similar container in which it is nested.

Referring now'in more detail and by reference characters to the drawings which illustrate practical embodiments of the present invention, A designates a cup of the so-called disposable type and which has been preferably molded in a unitary structure of modified polystyrene. The particular compositions used in the formulation of the thermoplastic material from which the container A is formed, are more fully described in the aforementioned copending application. The container A is nonjamming when in nested positions, and is of the so-called thin-walled type, and is moreover formed of integral construction. The container A generally comprises an upwardly and outwardly tapering side wall S having a socalled skirt portion 1 with an overall maximum wall thickness of approximately 0.01() inch. Moreover, the side wall 1 tapers outwardly at an angle with respect to the vertical centerline of the container A of 7 degrees 50 minutes. In this connection, it should be pointed out that the minimum angle of taper of the side wall 1 is critical and is never less than 7`degrees 50 minutes.

Along Vits lower margin, the side wall 1 integrally merges into a so-called double-conical base 2 which consists of an outer base ring 3 extending inwardly and upwardly at a dihedral angle of approximately 11.5 degrees. The base 2 also includes an inner base ring 4 which integrally merges into the outer base ring 3 and tapers upwardly and inwardly at an angle of approximately 13.5 degrees displaced from the horizontal or from a plane passing through the base of the container A. The overall base has an outer diameter of approximately 1.798 inches, and at the geometric center thereof, the base is set inwardly from a plane passing along the peripheral margin of the base by approximately 0.187 inch. Through the double-conical base, each of the portions of which taper inwardly and upwardly at a different angle, and as a result thereof a much stronger base is obta-ined. In many of the plastic cups of the prior art, a hot beverage contained within the cup would tend to weaken the base until it would bow somewhat downwardly of the skirt portion and moreover, cause a stretching of the plastic material to a point where slight contact with a relatively sharp surface would rupture the surface of the base. This problem has been eliminated by the double-conicaly shaped base described herein.

In the cup A, the skirt portion 1 of the side wall S has an overall length of approximately 2.816l inches and at its upper end integrally merges into an outwardly flaring arcuately shaped supporting shoulder 5 and which has an overall radius of `0.040 inch. The innermost edge of the supporting shoulder 5 is displaced from the axial cen.- terline of the cup A by a' distance of 1.278 inches and the outermost margin of the supporting shoulder 5 is displaced from the axial centerline of the cup A by a distance of 1.313 inches. The upper edge of the supporting shoulder 5 integrally -merges into an upwardly and inwardly tapering spacing skirt 6 which extends upwardly from the upper margin of the skirt portion 1 for a distance of 0.240 inch. The spacing skirt 6 tapers inwardly at an angle of approximately 7 degrees with respect to the axial centerline of the container A so that the upper margin thereof is spaced from the axial centerline of the cup A by a distance of approximately 1.297 inches.

The spacing skirt 6 is integrally formed with an upwardly and outwardly curving stacking shoulder 7 along its upper margin, the arcuate shape of which is formed by a radius of 0.040 inch. By reference to FIGURE 3, it can be seen that the point of integral adjoinment of the stacking shoulder 7 and the spacing skirt 6 forms an annular stacking edge 8.

The stacking shoulder 7 integrally merges at its upper end into an upwardly extending and outwardly tapering upper side wall 9 which tapers at an angle of 7 degrees with respect to the axial centerline of the container A. The upper wall 9 is integrally formed with an outwardly flaring rim 10 consisting of an upper rim-forming wall 11 which merges into a reversely bent flange 12., thereby de iining an outer rim 4margin 13, substantially as shown in FGURES 2 and 3. The vertical distance between the lower margin of the stacking shoulder 7 and the upper margin of the upper rim-forming wall 11 is approximately 0.200 inch and the outer margin 13 of the rim 10 is displaced from the axial centerline of the container A by a distance of approximately 1.456 inches.

The container A after being formed in a suitable molding operation such as by the process described in U.S. Letters Patent No. 2,967,328 is foamed on a por tion of the side wall S in accordance with the method described in copending application Ser. No. 272,540, tiled Apr. 12, 1963 now Patent No. 3,262,625, issued July 26, 1966i. The container A is suitably masked in those areas in which it is not desired to produce a foamed surface and is then steeped by immersing the container A into a suitable solvent such as trichlorofluoromethane for a period of approximately ten seconds. Thereafter, the container A is withdrawn from this solvent, retained for an interval in dry room conditions, and then subsequently immersedinto a hot water .bath or subjected to a hot air stream for a predetermined period of time. This procedure results in a foamed outer surface throughout the area of solvent immersion. Moreover, -it has been found that partially foaming the surface of the container A by this method produces expansion of the plastic material by approximately one-third of its overall thickness. It has `also been found by this procedure, that the overall structural properties of the cup are not altered by this' steeping operation while the insulating properties of the cup are materially increased. In the present invention, the side wall S of the container A is provided with an annularly extending foamed section 14 which extends to a point three-eighths of an inch above the lower margin of the container A and to a point one inch below the upper peripheral margin of the container A. The foamed section 14 has an overall thickness, measured from the outer surface of Ithe skirt portion 1 extending outwardly, of 0.012 inch thereby rendering an overall side wall and foamed section thickness of 0.022 inch. By further reference to FIGURE 2, it can be seen that the foamed section of the container A is so located that it never comes in contact with a straight-walled surface. This can be readily illustrated by drawing a straight line between two of the outermost annularly located points of the container A which, for example, would be the outer margin 13 of the rim 10 and the lower annular margin of the container A at the base 2. It can thus .be seen that the foamed section 14 never comes in contact with this straight line. Consequently, a series of containers A lo cated in the dispensing tube of a vending machine, will never come in contact with the wall of the dispensing tube. The inner base ring 4 of the base 2 is also entirely foamed for preventing condensation of vapor on a surface on which the container A is supported.

In use, the containers A are readily adaptable to being nested and stacked with a series of like containers in the manner as shown in FIGURE 3. When placed in thev nested position, it can be seen that the outer surface of the supporting shoulder 5 is engaged by the annular supporting margin 8 of the stacking shoulder 7. The supporting edge 8 is located at a point which is spaced inwardly from the skirt portion 1 so that the foamed surface 14 of one container A never comes into contact with the interior surface of a similar container A in which it is nested. This type of stacking shoulder arrangement in combination with the foamed surface 14 has been found particularly suitable for those containers, which when disposed within vending machines and similar dispensing devices, are located in a substantially upright position and where the dispensing tube does not have a great amount of curvature.

It is possible to provide a modified form of container B, substantially as shown in FIGURES 4-6 and which is substantially similar to the previously described container A. The container B is designed with a somewhat modified form of stacking shoulder arrangement for those dispensing tubes where the containers maybe shifted slightly from a purely vertical position or where the dispensing tube may contain a slight amount of curvature as is often the case in lmany d-ispensing machines.

The container B is also of the so-called disposable type and is preferably molded in a unitary integral structure of modified polystyrene. Again, the particular cornpositions used in the formulation of the thermoplastic material from which the container B is formed are more fully described in the aforementioned copending application. The container B generally comprises an upwardly and outwardly tapering side wall k which integrally merges at its lower margin into a so-called doubleconical base 16, the latter consisting of an outer base ring 17 which extends inwardly and upwardly at anangle of approximately 11.5 degrees. The base 16 also includes an inner base ring 18 which integrally merges into the outer base ring 17 and tapers upwardly and inwardly at an angle of approximately 13.5 degrees displaced from the horizontal or from a plane passing through the base of the container B. The relative dimensions of the side wall 15 and the Vbase 16 are the same as the relative dimensions of the side wall 1 and the base 2 in the container A.

integrally formed along the upper margin ofthe side wallv 15 is an outwardly flaring supporting shoulder 19 which is formed by an arcuately shaped convex bight portion 20, the latter also being defined by an outwardly and downwardly extending flange 21. The flange 21 tapers outwardly and downwardly at an angle of approximately 45 degrees with respect to the axial centerline of thev container B. Along its lower margin, the flange 21 ntegrally merges into an arcuate supporting edge 22 having an overall thickness of approximately 0.020 inch andy which integrally merges into an upwardly and inwardly' tapering intermediate wall 23. By further reference to FIGURES 5 and 6, it can be seen that the supporting edge 22 is spaced from the side wall 15 by a distance of approximately 0.12 inch and furthermore, the inter-v mediate wall 23 tapers upwardly and inwardly at an angle of approximately 8.5 degrees with respect to the axial' centerline of the container B.

The intermediate wall 23 is integrally formed along its upper margin with an annular outwardly extending stacking shoulder 24 consisting of an arcuately shaped inwardly projecting annular stacking edge 25 substantially as shown in FIGURE 6. By reference to FIGURE 6, it can be seen that the stacking edge 25 is spaced slightly inwardly of the plane in which the side wall 1 lies. The stacking edge 25 integrally merges intoa concave arcuate bend 26 which is sized to snugly, but nevertheless removably accommodate the supporting edge 22 and the supporting shoulder 19. The arcuate bend 26 ultimately merges into an up-Y wardly extending upper side wall 27 which tapers upwardly and outwardly at an angle of 7 degrees with respect to the axial centerline of the container A. The upper side wall 27 is integrally formed with an outwardly flaring rim 28 consisting of an upper rim-forming wall 29 which merges into a reversely bent flange 30, thereby defining an upper rim margin 31, substantially as shown in'FIG-

URES

5 and 6. The outer margin 31 of the rim 28 is displaced from the axial centerline of the container B by a distance of approximately 1.456 inches, the same as in the container A.

In the container B, the skirt portion or side wall 15 has an overall length of approximately 2.816 inches. The innermost edge of the supporting shoulder19 is displaced from the axial centerline of the container A by a distance of 1.278 inches and the outermost marginfof the support` and outwardly at an angle of approximately 7 degrees50 minutes with respect to the axial centerline of the container B, so that the upper margin thereof is spaced from the axial centerline of the container B by a distance of approximately 1.297 inches. By further vreference to FIG- URE 6, it can be seen that the upper side wall 27 is substantially parallel to the side Wall 15 but is displaced outwardly therefrom.

The side wall 15 of the container B is provided with an annularly extending foamed section 32 which extends to a point three eighths of an inch above the lower margin of the container B and to a point one inch below the upper peripheral margin of the container B. The foamed section 32 has an overall thickness, vmeasured from the outer surface of the side wall 1,A extending outwardly, of approximately 0.012 inch, thereby rendering an overall side wall and foamed section thickness of 0.022 inch. By further reference to FIGURE 5, it can be seen that the foamed section of the container B is also located so that it never comes in contact with a straight-walled surface. This again can readily be illustrated by drawing a straight line between two of the outermost annularly located points of the container B, which for example, would be the outer margin 31 of the rim 28 and the lower annular Vmargin at the base 16.`As a result thereof, it can be seenthat the foamed section 32 never comes into contact with the straight line. Consequently, a series ofthe containers B located in a dispensing tube of a vending machine will never contact the wall of the dispensing tube. The inner base ring 18 is also foamed for its entire surface area, in the same manner as the inner base ring 4.

When placed in the nested position, it can be seen that the supporting edge 22 ofone container tits snugly but nevertheless slidably within the stacking shoulder 26 of a similar container. Again, it can be seen that the supporting shoulder 19 is spaced outwardly from'the side wall 15 by a distance which is sufficient to prevent thefoamed surface 32 of one cup from engaging the interior surface of the side wall of a container in which it is nested. It can also be seen by reference to FIGURE 6, that the arcuate edge 25 of one container engages the arcuate bend-20 of a container in which it is nested. By means of the above tainer B, and hence, it is impossible for the foamed surface 32 of one container to engage the interior surface ofthe side wall of the container B in which it is nested.

It should be obvious that it is possible to provide ice cream containers, cheese containers and theflike, which are substantially similar to the previously described container A. These latter containers can also be formed with the novel stacking shouldersand can be provided-withv a foamed surface. However since easy removability from a stack of nested' containers is not of critical importance, the entire side wall of the` container and the entire surface area of the base can be foamed. t

' It should be understoodthat changes and modifications in the form, construction, arrangement and combination of parts may be made and substituted for those herein described without departing from the nature and principle of my invention. f

Having thus described my invention, what I desire to claim and secure by Letters Patent is:

1. A one-piece. plastic container having a base, a side wallwith substantially parallel opposed, inside and outsi-de surfaces, va portion of said side wall composed throughout ofa single layer of thermoplastic'material which comprises a foamed polymer portion extending from within the body of said thermoplastic material and form-ing said outside surface, and -a non-foamed polymer portion integral with said foamed polymer portion and forming said -inside surface, said foamed polymer portion extending outwardly lbeyond the remainder of'rsaid wall, and nesting means for maint-aining said foamed polymer portion of said side wall out of contact with the inside su-rface of the side wall of a like container when one container -is supported within another of said like containers.

2. A thin-walled nestable plastic container of integral const-ruction comprising a bottom wall and an upwardly extending side wall forming a substantially open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout -of a single layer of thermoplastic material which comprises a foamed polymer portion extending from within the body of said thermoplastic material and forming said outside surface thereof, and a non-foamed polymer section integral with said foamed polymer portion forming said inside surf-ace, said foamed polymer portion forming said inside surface, said foamed polymer portion extending outwardly beyond the remainder of said side wall, said side wall having nesting means for maintaining said foamed polymer portion of said side wall of a like container when one container is supported within another of said like containers, said bottom Wall being formed by a rst conically shaped portion which merges into said side wall and a second conically shaped portion which substantially closes the remainder of sai-d bottom wall.

3. A thin-walled nestable plastic container of integral construction comprising a bottom wall and an upwardly extending side wall form-ing a substantially open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout of a single layer of thermoplastic material which comprises a foamed polymer section extending from within the body of said thermoplastic material and forming the outside surface thereof, and a non-foamed polymer section integral with said foamed polymer section forming said inside surface, said foamed polymer section forming said inside surface, said foamed polymer section extending outwardly beyond the remainder of said side wall, said non-foamed polymer section of said side wall having a thickness of not more than 0.010 inch, said side wall having nesting means for maintaining the outside surface of said side wall out of contact with the inside surface of the side wall of a like container when one container is supported wit-hin another of said like containers, said foamed section extending to a `point displaced from the periphery of said bottom wall by a distance of not less than three-eighths of an inch.

4. A thin-walled nestable plastic container of integral construction comprising a bottom wall and an upwardly extending side wall forming a substantially open yupper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout of a single layer of thermoplastic material which comprises -a foamed polymer section extending from within the body of said thermoplastic material and forming the outside surface thereof, and a non-foamed polymer section integral with said foamed polymer section forming said inside surface, said foamed polymer section extending outwardly beyond the remainder of said side wall, said upper end being defined by an annularly extending rim-forming member, said non-foamed polymer section of said side wall having a thickness of not more than 0.010 inch, said side wall having nesting means for maintaining the outside surface of sa-id side wall out of contact with the inside surface of the side lwall of a like container when one container is supported within another of said like containers, said foamed section extending to a point displaced from the periphery of said bottom wall by a distance of not less than three-eighths of an inch, said foamed area extending to a point displaced from the upper -margin of said container by at least one inch.

5. A thin-walled nestable plastic container of integral construction cornprising a bottom wall and an upwardly and -outwardly tapering side wall forming an open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout of a single layer of thermoplastic 8 material which comprises a foamed polymer section extending from within the body of said thermoplastic material and forming the outside surface thereof, and a nonfoamed polymer section integral with said foamed polymer section forming said inside surface, said foamed polymer section extending outwardly beyond the remainder of said side wall, an annularly extending stack-ing shoulder formed in said side wall and being spaced downwardly from said open upper end, and an .annularly extending supporting shoulder formed in said side wall and being spaced downwardly from said stacking shoulder,` the supporting shoulder of one such container being sized to rest on the stacking shoulder of a like container, and to keep the foamed section of said side wall out of contact with the interior surface of said like container when one of such containers is disposed in supported position in another of such like containers.

6. A thin-'walled nestable plastic container of integral construction comprising a bottom Wall and an upwardly and outwardly tapering side wall forming an open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout of a single layer of thermoplastic material which comprises a foamed polymer section extending from within the body of said thermoplastic material and forming the outside surface thereof, and a nonfoarned polymer section, integral with said foamed polymer section forming said inside surface, said foamed polymer section extending outwardly beyond the -remainder of said side wall, an annularly extending supporting shoulder formed in said side wall and being spaced downwardly from said open upper end, sai-d supporting shoulder having a curved surface, -a portion of which is disposed substantially perpendicular to the normal central axis of said container, and an annularly extending stacking shoulderv formed in said side wall and being spaced upwardly from said supporting shoulder, the supporting shoulder of one such container bein-g sized to rest on the stack-ing shoulder of a like container, and to keep the foamed section of said side wall out of contact with the interior surface of said like container when one of such containers is dis-posed in supported position in another of such like containers.

7. A thin-Walled nestable plastic container of integral construction comprising a bottom wall and an upwardly and outwardly tapering side Wall to form an open upper end, said side wall h-aving .substantially parallel inside and outside surfaces, a portion of said side wal-l composed throughout of a single layer of thermoplastic material `wnich comprises a foamed polymer section extending from within the body of said thermoplastic material and forming the outside surface thereof, and a non-foamed polymer section, integral with said foamed polymer section forming said inside surface, said foamed polymer section extending outwardly beyond the remainder of said side wall, an annularly extending supporting shoulder formed in said side wall and being spaced downwardly from said open upper end, said supporting shoulder having a curved surface, a port-ion of which is disposed substantially perpendicular to the normal central axis o-f said container, an annularly extending stacking shoulder formed in said side wall and being spaced upwardly from said supporting shoulder, the portion of the side wall located between said supporting shoulder and said stacking shoulder extending upwardly and taper-ing inwardly, the supporting shoulder of one such container being sized to rest on the stacking shoulder of a like container when one of such containers is disposed in supported position in another of such like containers, said foamed portion formed with said side wall extending from a point spaced below said supporting shoulder to a point spaced above the outer periphery of said bottom wall.,

8. A thin-walled nestable plastic container of integral construction comprising a bottom wall and an upwardly and outwardly tapering side wall to form an open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout of a single layer of 'thermoplastic material which comprises `a foamed polyme-r section extending from within the body of said thermoplastic material and forming the outside surf-ace thereof, and a non-foamed polymer section integral with said foamed polymer section forming said inside surface, said foamed po'ymer section extending outwardly beyond the remainder of said side wall, an annularly extending supporting shoulder formed in sai-d side wall and being spaced downwardly from said open upper end, said supporting shoulder having a curved surface, a portion of 4which is disposed su-bstantially perpendicular to the normal central axis of said container, an annularly extending stacking shoulder formed -in said si-de wall and being spaced upwardly from said supporting shoulder, the portion of the side wall located between said supporting shoulder and said stacking shoulder extending upwardly and tapering inwardly, 'the supporting shoulder of one such container being sized to rest on the stacking shoulder of a like container when one of such containers is disposed in supported position in another of such like containers, said foamed portion formed with said side wall extending from a point spaced below said supporting shoulder to a point spaced above the outer periphery of said bottom wall, said foamed section having a suflicient cross-sectional thickness so that it does not contact the interior surface of a like container when one of such containers is disposed in supported position in another of such like containers.

9. A thin-walled nestable plastic container of integr-al construction comprising a bottom wall and an upwardly and -outwardly tapering side wall to form an open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said side wall composed throughout of =a single layer of thermoplastic material which comprises a foamed polymer section extending from within the body of said thermoplastic material and forming the outside surface thereof, and a non-foamed polymer section integral with said foamed polymer section forming said inside su-rface, said foamed polymer section extending outwardly beyond the remainder of said side wall, an annularly extending supporting shoulder formed in said side wall and being spaced downwardly from said open upper end, said supporting shoulder having a curved surface, a portion of which is disposed substantially perpendicular to the normal central axis of said container, an lannularly extending stacking shoulder formed in said side wall and being spaced upwardly from said supporting shoulder, the portion of the side wall located between said stack-ing shoulde-r `and said supporting shoulder extending upwardly and tapering inwardly, the supporting shoulder of one such container .being sized to rest on Ithe sta-cking shoulder of a like container when one of such containers is disposed in supported position in another o-f such like containers, sai-d foamed section formed with said side wall extending from a point spaced below said supporting shoulder to a point spaced above the outer periphery of said bottom wall, said foamed section having a cross-sectional thickness of not more than 0.022 inch so that it does not contact the interior surface of a like container when said container is disposed in supported position in another of such like containers.

10. A thin walled nestable plastic container of integral construction comprising a bottom wall and 4an upwardly and outwardly tapering side wall to form an open upper end, said side wall having substantially parallel inside and outside surfaces, a portion of said s'ide wall composed throughout of a substantially thermoplastic material which comprises a foamed polymer portion extending from within Ithe body o-f said thermoplastic material to the outside surface thereof and a non-foamed polymer section inte- -grally connected to said foamed polymer portion, an annularly extending supporting shoulder formed in said side wall and being spaced downwardly from said open upper end, said supporting shoulder having an outwardly and convex -downwardly extending bight surface, a portion of which -is disposed substantially perpendicular to the normal central axis of said container, and an annularly extending stacking shoulder formed in said side 'wall being spaced upwardly from said supporting shoulder, said stacking shoulder having an outwardly and concave downwardly protruding surface, the portion of the side wall located between said stacking shoulder and said nesting shoulder exten-ding upwardly and tapering inwardly, the outwardly convex downwardly extending bight surface of the supporting shoulder of one such container being sized to rest within the outwardly and concave downwardly protruding surface of the stacking shoulder of -a like container when one of such containers is disposed in supported position in another of such like containe-rs.

11. A thin walled nestable plastic container of integral construction comprising a bottom wall and an -uplwardly and outwardly tapering side wall to form an open upper end, said side wall having substantial'ly parallel inside and outside surfaces, a portion of said side wall composed throughout of a substantially thermoplastic material which comprises a foamed polymer portion eX- tending from within the body of said 'thermoplastic material to the outside surface thereof, and a non-foamed polymer section integrally connected with said foamed polymer portion, an annularly extending supporting shoulder formed in said side wall and being spaced `downwardly from said open upper end, said supporting shoulder having an outwardly and convex downwardly extending bight surface, a portion of which is disposed substantially perpendicular to the normal central axis of said container, and an annularly extending stacking shoulder formed in said side wall and being spaced upwardly from said supporting shoulder, said stacking shoulder having an outwardly and concave downwardly protruding surface, the portion of the side wall located between said stacking shoulder and said nesting shoulder extending upwardly `and tapering inwardly, the portion of the side wall extending upwardly from said stacking shoulder and the outermost peripheral edges of the supporting shoulder lying in the same plane, which plane is substantially parallel to the side wall of the container, the 4outwardly fand convex ldownwardly extending bright surface of the supporting shoulder of one such container being sized to 'rest within the outwardly and concave downwardly protruding surface of the stacking shoulder of a like container when one of such containers is disposed in supported position in another of such like containers.

References Cited UNITED STATES PATENTS 3,049,277 8/ 1962 Shappell 229-15 3,094,240 A6/ 1963 Wanderer 220-97 3,126,139 3/ 1964 Schechter 22094 3,139,213 `6/1964 Edwards 220-97 THERON E. CONDO'N, Primary Examiner.

JOSEPH R. LECLAIR, GEORGE E. LOWRANCE, Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,374,922 March Z6, 1968 Richard K. Shelby' pear-s in the above identified It is certified that error ap hereby corrected as patent and that said Letters Patent are shovm below:

Column 7, linesv 13 and lll, 34 and 35, after "surface,", each occurrence, cancel "said foamed polymer portion forming sai inside surface," line 17, after "side wall" insert out of f the side wall 7 Contact with the inside surface o Signed and sealed this 19th day of August 1969.

(SEAL) Attest:

Edward M. Fletcher, Ir. Commissioner of Patents Attesting Officer

Claims

1. A ONE-PIECE PLASTIC CONTAINER HAVING A BASE, A SIDE WALL WITH SUBSTANTIALLY PARALLEL OPPOSED, INSIDE AND OUTSIDE SURFACES, A PORTION OF SAID SIDE WALL COMPOSED THROUGHOUT OF A SINGLE LAYER OF THERMOPLASTIC MATERIAL WHICH COMPRISES A FOAMED POLYMER PORTION EXTENDING FROM WITHIN THE BODY OF SAID THERMOPLASTIC MATERIAL AND FORMING SAID OUTSIDE SURFACE, AND A NON-FOAMED POLYMER PORTION INTEGRAL WITH SAID FOAMED POLYMER PORTION FORMING SAID INSIDE SURFACE, SAID FOAMED POLYMER PORTION EXTENDING OUTWARDLY BEYOND THE REMAINDER OF SAID WALL, AND NESTING MEANS FOR MAINTAINING SAID FOAMED POLYMER PORTION OF SAID SIDE WALL OUT OF CONTACT WITH THE INSIDE SURFACE OF THE SIDE WALL OF A LIKE CONTAINER WHEN ONE CONTAINER IS SUPPORTED WITHIN ANOTHER OF SAID LIKE CONTAINERS.