U.S. patent application number 10/800566 was filed with the patent office on 2004-09-09 for pasteurizable wide-mouth container.
Invention is credited to Semersky, Frank, Stewart, Robert A., Tobias, John W..
Application Number | 20040173565 10/800566 |
Document ID | / |
Family ID | 32929919 |
Filed Date | 2004-09-09 |
United States Patent
Application |
20040173565 |
Kind Code |
A1 |
Semersky, Frank ; et
al. |
September 9, 2004 |
Pasteurizable wide-mouth container
Abstract
A wide-mouth blow-molded plastic container capable of
accommodating, without undesirable distortion, super-baric
pressures when filled with volatile food products and pasteurized,
and sub-baric pressures after cooling to ambient temperatures. A
method of packaging a food product in the container is also
disclosed.
Inventors: |
Semersky, Frank; (Toledo,
OH) ; Tobias, John W.; (Spartanburg, SC) ;
Stewart, Robert A.; (York, PA) |
Correspondence
Address: |
HOWSON AND HOWSON
ONE SPRING HOUSE CORPORATION CENTER
BOX 457
321 NORRISTOWN ROAD
SPRING HOUSE
PA
19477
US
|
Family ID: |
32929919 |
Appl. No.: |
10/800566 |
Filed: |
March 15, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10800566 |
Mar 15, 2004 |
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10129885 |
May 10, 2002 |
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10129885 |
May 10, 2002 |
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PCT/US00/31834 |
Nov 20, 2000 |
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60168357 |
Dec 1, 1999 |
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Current U.S.
Class: |
215/382 ;
215/375; 220/606 |
Current CPC
Class: |
B65D 2501/0036 20130101;
B65D 1/44 20130101; B65D 1/0223 20130101 |
Class at
Publication: |
215/382 ;
215/375; 220/606 |
International
Class: |
B65D 008/04; B65D
006/28 |
Claims
1. A wide-mouth blow-molded plastic container (10) capable of
accommodating without undesirable distortion super-baric pressures
when filled with product at elevated temperatures and capped and
sub-baric pressures after cooling to ambient temperatures
comprising; a sidewall (11) having a plurality of peripheral
vertically spaced grooves (11d); a dome (12) located above said
sidewall (11) having a wide mouth opening (12a) adapted to receive
a sealed closure; a footed, pressure resistant, base (13) below
said sidewall (11); an upper label bumper (15) extending around the
upper end (11a) of said sidewall (11) subjacent said dome (12); and
a lower label bumper (16) extending around the lower end (11b) of
said sidewall (11) superadjacent said base (13); whereby the
sidewall grooves (11d) cooperate with the dome (12) and base (13)
to stiffen the container (10) against undesirable distortion due to
the swing from super-baric to sub-baric pressures within the
container (10) when filled and capped.
2. A wide-mouth blow-molded PET plastic container (10) capable of
accommodating without undesirable distortion super-baric pressures
when filled with product at elevated temperatures and capped and
sub-baric pressures after cooling to ambient temperatures
comprising; a cylindrical sidewall (11) having a plurality of
peripheral vertically spaced grooves 11d); said sidewall (11)
having a crystallinity in excess of 25 percent; a dome (12) located
above said sidewall (11) having a blown wide-mouth opening (12a)
adapted to receive a sealed closure; said opening (12a) having a
diameter (D.sub.2) sufficient to afford access to and withdrawal of
said food product by means of a conventional item of tableware; a
petaloid footed base (13) below said sidewall (11); an upper label
bumper (15) extending outwardly and peripherally around the upper
end (11a) of said sidewall (11) subjacent said dome (12); and a
lower label bumper (16) extending outwardly and peripherally around
the lower end (11b) of said sidewall (11) superadjacent said base
(13); whereby the sidewall grooves (11d) cooperate with the dome
(12) and base (13) to stiffen the container (10) against
undesirable distortion due to the swing from super-baric to
sub-baric pressures within the container when filled and
capped.
3. An energy-efficient method of packaging a food product,
comprising the steps of: selecting a blow-molded PET plastic
container (10) having a sidewall (11) with a plurality of
peripheral vertical grooves (11d), a dome (12) located above said
sidewall (11) having a blown, wide-mouth opening (12a) adapted to
receive a sealed closure, a footed base (13) below said sidewall
(11), an upper label bumper (15) extending around the upper end
(11a) of said sidewall (11) subjacent said dome (12), a lower label
bumper (16) extending around the lower end (11b) of said sidewall
(11) superadjacent said base (13); hot-filling the container (10)
with said food product; capping the filled container (10); heating
the filled and capped container (10) for a time at a temperature
sufficient to pasteurize said food product; and cooling the
pasteurized filled and capped container (10) to ambient
temperature.
4. The method according to claim 3 wherein said food product is a
volatile vegetable in an aqueous medium.
5. The method according to claim 4 where said volatile vegetable is
selected from the group consisting of: pickles, relish, sauerkraut
and artichokes.
6. The method according to claim 3 wherein said filled and capped
container is heated to a temperature in a range of at least about
190-210.degree. F. for a period in a range of 5-20 minutes.
7. The method-according to claim 3 wherein said hot-filling steps
occurs at a temperature of at least about 180.degree. F.
8. The method according to claim 3 wherein the container is at
ambient temperature prior to hot-filling.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to blow-molded plastic
containers, and more particularly, the present invention relates to
a wide-mouth blow-molded plastic container which is particularly
suited for containing volatile food products that require
pasteurization at elevated temperatures after the container
has-been filled and capped.
BACKGROUND OF THE INVENTION
[0002] Glass has been the material of choice for pasteurizable
containers designed to package volatile food products that off-gas
after filling and sealing. Such products include, but are not
limited to, pickles, relish, sauerkraut, and the like. Glass has
been desirable because of its strength and low cost; however, glass
containers are heavy and breakable.
[0003] There is a need for a plastic container which is
particularly suited for packaging the afore-described products by
being robust enough to withstand the rigors of heat pasteurization.
For instance, such a container must be capable of withstanding
internal pressures at high temperatures, followed by internal
vacuum at lower and ambient temperatures. Hot-filled PET
(polyethylene terepthalate) narrow neck bottles have been
commercialized for containing liquids, and hot-filled PET
wide-mouth food jars have been commercialized for containing
non-volatile food products such as applesauce, jams, jellies, and
the like which do not off-gas after filling and capping. To date,
there is no known commercially-available, wide-mouth, PET container
that is capable of being filled with volatile food products,
capped, and subsequently pasteurized.
[0004] U.S. Pat. No. 5,980,128 discloses a narrow-mouth,
blow-molded plastic container used to contain liquid products which
are pasteurized after filling and capping. The disclosed container
uses specifically defined peripheral flex panels to accommodate the
pressure and volume changes inside the capped container.
[0005] U.S. Pat. No. 4,642,968 disclosed a wide-mouth, blow-molded
plastic container that is used for containing products that undergo
pasteurization. The container disclosed in this patent utilizes
bottom-bulging of the container body to accommodate internal
pressure and volumetric changes.
[0006] U.S. Pat. No. 5,887,739, owned by Graham Packaging Co.,
L.P., discloses a wide-mouth, blow-molded PET container suitable
for hot filling with viscous food products such as applesauce.
OBJECT OF THE INVENTION
[0007] With the foregoing in mind, a primary object of the present
invention is to provide a pasteurizable plastic container which
satisfactorily resists internal pressures due to increased vapor
pressures during heating and contained volatile food products while
withstanding internal vacuum conditions on cool-down to ambient
temperatures after pasteurization.
SUMMARY OF THE INVENTION
[0008] More specifically, the present invention provides a
wide-mouth blow-molded plastic container which is capable of
accommodating, without undesirable distortion, super-baric
pressures when filled with volatile food products and pasteurized,
and sub-baric pressures after cooling to ambient temperatures. The
plastic container comprises a cylindrical sidewall having a
plurality of peripheral vertically-spaced grooves. A dome with a
wide-mouth opening adapted to receive a sealed closure is located
above the sidewall, and a footed pressure-resistant base is located
below the sidewall. An upper label bumper extends around the upper
end of the sidewall subjacent the dome, and a lower label bumper
extends around the lower end of the sidewall super-adjacent the
base. In the aforedescribed structure, the sidewall grooves
cooperate with the dome and base to stiffen the sidewall against
undesirable distortion due to the swing from super-baric to
sub-baric pressures within the container. Preferably, the sidewall
has a crystallinity in excess of 25 percent; the base is of
petaloid configuration; and the wide-mouth opening has a diameter
which is sufficiently large to afford access to the container and
removal of contained food products by means of a conventional item
of tableware.
BRIEF DESCRIPTION OF THE DRAWING
[0009] The foregoing and other objects, features and advantages of
the present invention should become apparent from the following
description when taken in conjunction with the accompanying
drawing, in which:
[0010] FIG. 1 is a side elevational view of a container embodying
the present invention;
[0011] FIG. 2 is a plan view of the container of FIG. 1;
[0012] FIG. 3 is an inverted plan view of the container illustrated
in FIG. 1;
[0013] FIG. 4 is a transverse sectional view taken on line 4-4 of
FIG. 1; and
[0014] FIG. 5 is a longitudinal sectional view taken on line 5-5 of
FIG. 3.
DESCRIPTION OF PREFERRED EMBODIMENT
[0015] FIG. 1 illustrates a container 10 which embodies the present
invention. The container 10 has a sidewall 11, a dome 12
superadjacent the sidewall 11, and a base 13 below the sidewall 11.
The dome 12 has a wide-mouth, threaded finish 12a which is
blow-molded such as in the manner described in U.S. Pat. No.
5,887,739, the disclosure of which is incorporated by reference
wherein.
[0016] The base 13 is of conventional construction, being of a
so-called footed, petaloid, pressure-resistant configuration. The
base 13 includes a plurality of radially extending, downwardly
concave ribs 13a which extend outwardly from the longitudinal axis
"A" of the container 10 to the outer surface 13b of the base 13.
The disclosed footed, petaloid base design is well known in the art
and is exemplified in expired U.S. Pat. No. 3,935,955. Such bases
have found particular utility in carbonated beverage
containers.
[0017] The sidewall 11 is adapted to receive a conventional label.
In order to protect the label, as well known in the art, an upper
label bumper 15 is provided subjacent bottom of the dome 12 around
the upper edge 11a of the sidewall 11. A similar lower label bumper
16 is provided superadjacent the base 13 around the lower edge 11b
of the sidewall 11. The upper and lower label bumpers 15 and 16
extend radially outward a slight distance from the sidewall 11 and
about the container periphery to provide protection for a label,
not shown, applied to the sidewall 11 as well known in the art.
[0018] The disclosed container has a capacity of twenty-four
ounces. The sidewall 11 has a length "L" which is substantially
equal to its diameter in D.sub.2. The blown finish 12a has an outer
diameter D.sub.2. Preferably, the diameter D.sub.1 is about 80
percent of the diameter D.sub.1. This enables the contents of the
container 10 to be accessed readily by means of a conventional item
of tableware, such as a fork or tablespoon.
[0019] In the illustrated embodiment, the sidewall 11 is reinforced
at spaced vertical intervals by means of a plurality of continuous
peripheral grooves 11d. Desirably, the grooves 11d are located on
approximately 0.6 inch centers and extend continuously about the
periphery of the sidewall 11. Desirably, each groove 11d has a
depth of approximately 0.08 inches and is formed by bottom radius
of curvature of 0.0.06 inches and upper and lower bottom connecting
radii of curvatures of 0.118 inches. This groove construction
enables the sidewall to accommodate changes in volume and pressure
inside the container, as will be discussed.
[0020] The disclosed container 10 is preferably molded of PET. The
container 10 is blow-molded from a preform that has a portion which
is blown outwardly to form the finish 12a, after which a moil
portion of the blown preform above the finish 12a is severed. In
the molding process the preform is stretched axially, and the mold
temperature and residence time is designed to provide the sidewall
11 with a crystallinity of at least 25 percent throughout its
entire length L. The thickness of the sidewall 11 is about 0.030
inches above and below, and in between, the grooves 11b. The
nominal weight of the disclosed container 10 is preferably less
than about 53 grams.
[0021] A container of the configuration illustrated in the drawing
has been blown and tested in a laboratory setting. The test
container 10, illustrated in FIG. 1 (drawn to full scale) had an
overall sidewall length of 3.264 inches; an outer sidewall diameter
D.sub.1 of 3.4 inches; and a finish diameter D.sub.2 of slightly
less than 2.75 inches. The container 10 was filled with a volatile
vegetable that off-gases, such as pickles in an aqueous medium, to
a level of 0.250 inch from the upper edge of the finish 12a. A
sealed cap was applied to the finish 12a, and the thus-filled
container 10 was pasteurized at a temperature of in a range of
200-210.degree. F. for 10-20 minutes. A control glass jar of like
capacity and size was used to simulate the pressures and
temperatures developed inside the container 10 during and after
pasteurization. The container was allowed to cool to ambient
temperature subsequent to the pasteurization cycle. During
pasteurization, pressures within the container 10 exceeded 10
inches Hg. The container did not undergo undesirable distortion
such as would be considered unsatisfactory in commercial
practice.
[0022] It is believed that the petaloid, pressure-resistant, footed
base 13 enabled the container 10 to withstand the internal
pressures developed during pasteurization while the grooved
sidewall 11 cooperated with the other disclosed structures to
accommodate both super-baric and sub-baric pressure and volume
changes resulting from cool down of the container 10 to ambient
temperatures.
[0023] Since pasteurization is a time-temperature phenomenon, the
temperature range in practice may be as low as 190.degree. F. when
longer residence times are used, and the time as short as 5 minutes
when higher temperatures are used. Also, while the test was
conducted with pickles, other volatile vegetables including,
relish, sauerkraut, artichokes, and the like may be suitably
pasteurized in the disclosed container.
[0024] An advantage of selecting the disclosed container for use in
packaging pickles is the energy and water savings that can be
realized. This is because for the past seventy five years pickles
have been packed in glass jars which require staged heat treatment
due to the inability of glass to accommodate rapid temperature
changes. Currently, cold pickles are charged into empty, pre-heated
glass jars, and brine at 130.degree. F. is added. After capping,
the sealed glass jar is heated to a temperature in a range of
195-210.degree. F. for 10-20 minutes to heat the center of the
pickles contained in the jar to a minimum temperature of
165.degree. F. for 15 minutes. Thereafter, the pasteurized jar is
stage cooled to 180.degree. F. for 10-20 minutes, followed by
140.degree. F. for 10-20 minutes, and then cooling to ambient.
[0025] With the disclosed PET plastic container, brine can be added
at 180.degree. F. to a container at ambient temperatures with
sterilization at 190.degree. F. for a shorter period of time,
followed by cooling to ambient. This results in a shorter
processing time, reduced energy consumption, and a savings in
water.
[0026] In view of the foregoing, it is apparent that the present
invention provides a wide-mouth, blow-molded PET plastic container
which can be substituted for glass to contain food products that
off-gas during pasteurization.
[0027] While a preferred embodiment of the present invention has
been described in detail, various modifications, alterations and
changes may be made without departing from the spirit and scope of
the present invention as defined in the appended claims.
* * * * *