Patent Description:
<CIT> describes a blow-molded bottle-shaped container of biaxially oriented thermoplastic synthetic resin.

<CIT> describes a method of forming a blow moulded container in the form of a tub.

<CIT> describes system and method for forming elongated and involute thermoplastic articles, and means for controllably heating a sheet of thermoplastic material.

<CIT> describes a method for forming deep drawn highly oriented thin-walled thermoplastic articles.

<CIT> describes Plastic multi-piece containers for storing beverages and other foodstuff are disclosed, and further, methods, devices and systems for making some or all components of such containers.

<CIT> describes an improved base configuration for a blow molded plastic container used in hot-fill applications.

<CIT> describes a method for forming a molecularly oriented thermos-plastic container.

Hollow articles, such as beverage containers and beverage ingredient cartridges, are often formed by blow molding methods. Blow molding methods include extrusion blow molding and injection blow molding, such as injection stretch blow molding (ISB). In ISB molding methods, a preform can be used as the starting material for forming the container. The preform can be heated above its glass transition temperature and arranged on a mold cavity that defines an outer shape of the container. A plunger or rod can be used to press on the heated preform so as to push a portion of the preform into the mold cavity, causing the preform to stretch and deform. A gas can then be applied or "blown" into the mold cavity so as to cause the preform to further stretch and deform and to press the preform material against the mold cavity in order to provide a container having the shape defined by an inner wall of the mold.

Some embodiments described herein relate to a method for blow molding a container, that includes heating a central region of a preformed puck to a first temperature, and heating an annular region surrounding the central region of the preformed puck to a second temperature, wherein the second temperature is greater than the first temperature. The method may further include arranging the heated preformed puck at an upper end of a mold cavity of a mold, wherein an inner wall of the mold cavity defines an outer shape of the container, stretching the heated preformed puck by pressing a plunger into the heated preformed puck and into the mold cavity in a longitudinal direction of the mold cavity toward a lower end of the mold cavity, and applying pressurized air to the mold so that the heated preformed puck stretches to conform to the shape of the inner wall of the mold cavity.

Some embodiments described herein relate to a method of blow molding a container, that includes heating a preformed puck to a temperature at or above a glass transition temperature of a material of the preformed puck, and arranging the preformed puck at an upper end of a mold cavity of a mold, wherein the preformed puck comprises a circular plate having an upstanding wall at a perimeter of the circular plate, and a flange extending outwardly from an upper end of the upstanding wall, and wherein an inner wall of the mold cavity defines an outer shape of the container. The method may further include securing the preformed puck to the upper end of the mold cavity by a securing member of the mold such that the flange is secured between the upper end of the mold cavity and the securing member, stretching the heated preformed puck by pressing a plunger into the heated preformed puck and into the mold cavity along a longitudinal axis of the mold cavity, and applying pressurized air to the mold cavity so that the preformed puck stretches to conform to the inner wall of the mold cavity.

Some embodiments described herein relate to a method of forming a container, that includes heating the preformed puck non-uniformly such that a first portion of the preformed puck is at a first temperature and a second portion of the preformed puck is at a second temperature that differs from the first temperature, and arranging the heated preformed puck at an upper end of a mold cavity of a mold, wherein an inner wall of the mold cavity defines an outer shape of the container. The method may further include securing the heated preformed puck to the upper end of the mold cavity, stretching the heated preformed puck using plunger by pressing the plunger into the heated preformed puck and into the mold cavity along a longitudinal direction of the mold cavity, and applying pressurized air to the mold cavity when the plunger is at a depth of <NUM>% to <NUM>% of a depth of the mold cavity so that the heated preformed puck conforms to a shape of the inner wall of the mold cavity.

In any of the various embodiments described herein, stretching the heated preformed puck may include using the plunger having a maximum diameter that is the same as a diameter of the central region of the preformed puck.

In any of the various embodiments described herein, heating the central region and the annular region may include conductive heating.

In any of the various embodiments described herein, applying pressurized air may be performed with a tip of the plunger spaced from a lower end of the mold cavity.

In any of the various embodiments described herein, applying pressurized air may include applying the air at a pressure of <NUM> bar to <NUM> bar.

In any of the various embodiments described herein, the method may further include maintaining a second annular region surrounding the annular region at a third temperature that is less than each of the first temperature and the second temperature.

In any of the various embodiments described herein, the second temperature may be <NUM> to <NUM> greater than the first temperature.

In any of the various embodiments described herein, the preformed puck may include a circular plate having an upstanding wall at a perimeter of the circular plate and a flange extending outwardly from an upper end of the upstanding wall.

In any of the various embodiments described herein, the preformed puck may be formed of polyethyelene terephthalate.

In any of the various embodiments described herein, heating the preformed puck may include non-uniformly heating the preformed puck.

In any of the various embodiments described herein, the method may further include heating a central region of the preformed puck to a first temperature, and heating an annular region of the preformed puck surrounding the central region to a second temperature that is greater than the first temperature.

In any of the various embodiments described herein, the plunger may have a maximum diameter that is <NUM>% to <NUM>% of a diameter of an opening of the mold cavity.

In any of the various embodiments described herein, the circular plate may have a greater thickness than a thickness of the flange of the preformed puck.

In any of the various embodiments described herein, pressurized air may be applied to the mold cavity when the plunger is at a depth of <NUM>% to <NUM>% of the depth of the mold cavity.

In any of the various embodiments described herein, stretching the heated preformed puck may include pressing the plunger with a speed of <NUM>/s to <NUM>/s.

In any of the various embodiments described herein, the preformed puck may include a flange at a perimeter of the circular plate, wherein the flange is not stretched during stretching the heated preformed puck.

In any of the various embodiments described herein, the plunger may include a rounded tip configured to contact the heated preformed puck.

In any of the various embodiments described herein, the plunger may be formed of metal.

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles thereof and to enable a person skilled in the pertinent art to make and use the same.

Reference will now be made in detail to representative embodiments illustrated in the accompanying drawing.

Beverage containers, and the like are often filled by a hot filling process in which the liquid filled into the beverage container is heated to high temperatures of <NUM> or more so as to sterilize the interior of the container. As a result, the beverage container must be manufactured so as to withstand the high temperatures experienced during the filling operation. This may require the beverage container to be manufactured from materials having a glass transition temperature above the temperature of the hot filling process, and the wall thickness of the beverage container may depend on the material used to form the container so that the container has the desired structural properties.

Beverage containers may alternatively be filled by an aseptic filling process in which the beverage is flash heated for several minutes and is then filled into a container at a lower temperature. Thus, the beverage container is not subjected to high temperatures as in the hot filling process. In such aseptic filling processes, the same beverage containers that are used in hot filling processes may be used. However, the beverage containers are not exposed to high temperatures and it is therefore possible to redesign the beverage container to have a lower wall thickness and to use less material while still providing a container having the desired performance characteristics. As thousands of beverage containers are produced, substantial savings (e.g., in cost, material, and weight) can be realized by manufacturing beverage containers with less material.

Beverage containers may be formed by blow molding, such as injection stretch blow (ISB) molding. However, various problems may arise in the blow molding process, particularly when using polyethylene terephthalate (PET). Conditions suitable for blow molding polypropylene (PP) or other materials may not be suitable for blow molding PET, due to differences in the physical properties. For example, it may be difficult to cause the preform to completely fill the mold cavity to provide a container with the desired shape, particularly for containers having complex shapes. Further, it may be difficult to control the thickness of the container in different portions of the container, which may be desirable to ensure that the completed container has the desired performance characteristics. It may also be difficult to form a container having a horizontal or flat flange that is perpendicular to a longitudinal axis of the container.

Some embodiments described herein relate to a method for blow molding a container that allows for improved control of the wall thickness of the resulting container. Some embodiments described herein relate to a method for blow molding a container that allows for improved uniformity and consistency in producing containers that fully conform to the shape of the mold. Some embodiments described herein relate to a method for blow molding a container by securing a preformed puck having a flange to an upper end of a mold cavity using a securing member such that the shape and orientation of the flange is preserved during the molding process in order to provide a container having a horizontal or flat flange.

As used herein, the term "container" may refer to any article having one or more walls defining an interior volume in which a substance, such as a liquid or solid, may be held. A container may refer to, for example, a beverage container, such as a bottle, or a beverage ingredient cartridge or pod for storing liquid or dry ingredients, among others.

Some embodiments described herein relate to a method for blow molding a container <NUM>, as shown for example in <FIG>. In operation, a preformed puck <NUM> is used as the starting material for molding the container. In operation <NUM>, the preformed puck <NUM> is heated to a temperature at or above its glass transition temperature so that the preformed puck <NUM> is compliant, such as by a conductive heating element <NUM>. In operation <NUM>, the preformed puck <NUM> is arranged on an upper end of a mold cavity <NUM> of a mold <NUM>, wherein mold cavity <NUM> has an inner wall <NUM> that defines an outer shape of a resultant container <NUM>. In operation <NUM>, preformed puck <NUM> is secured to the upper end of mold cavity <NUM> via a securing member <NUM> of mold <NUM>. In operation <NUM>, a portion of the preformed puck <NUM> is stretched into mold cavity <NUM> by a plunger <NUM> of mold <NUM>. In operation <NUM>, the plunger <NUM> may be moved in a longitudinal direction (downward in <FIG>) of mold cavity <NUM> toward a lower end of mold cavity <NUM>. Once the preformed puck <NUM> is stretched, pressurized air (represented by arrows A in <FIG>) is applied to the mold cavity <NUM> so as to cause the stretched preform material to conform to a shape of the inner wall <NUM> of mold cavity <NUM>. In operation <NUM>, the mold and the molded container may be cooled and the molded container can be removed from the mold. Optionally, one or more finishing operations may be performed on the molded container, such as to remove flash, apply a surface treatment, apply a design or decoration, or to apply a texture, among others.

In some embodiments described herein, a preformed puck <NUM> for use in blow molding a beverage container is shown at <FIG> and <FIG>. Preformed puck <NUM> may have a generally circular shape in a top-down view, as shown in <FIG>. Preformed puck <NUM> may include a circular plate <NUM> and an upstanding wall <NUM> extending from circular plate <NUM> at a perimeter <NUM> of circular plate <NUM>. Upstanding wall <NUM> may be substantially perpendicular to circular plate <NUM>. Upstanding wall <NUM> may extend around an entire perimeter <NUM> of circular plate <NUM>. Preformed puck <NUM> may further include a flange <NUM> extending outwardly from an upper end <NUM> of upstanding wall <NUM>, such that flange <NUM> is an outermost portion of preformed puck <NUM>. Flange <NUM> may extend entirely around upstanding wall <NUM> such that flange <NUM> has an annular shape. Further, flange <NUM> may be arranged in a plane that is generally parallel to a plane of circular plate <NUM>. Circular plate <NUM> may have a thickness T<NUM> that is greater than a thickness T<NUM> of flange, wherein thickness is measured from a first surface of preformed puck <NUM> to an opposing second surface.

Preformed puck <NUM> may be used to form a hollow article <NUM>, such as a beverage ingredient cartridge, as shown for example in <FIG>. Article <NUM> may include a base <NUM> defining a lowermost portion of article <NUM> and a sidewall <NUM> extending from base <NUM>. Sidewall <NUM> and base <NUM> define an interior volume of beverage cartridge. Sidewall <NUM> may further define an opening <NUM> at an upper end <NUM> of sidewall <NUM> of article <NUM>. Hollow article <NUM> may include a shoulder region <NUM> as sidewall <NUM> transitions to opening <NUM> at upper end <NUM>, such that a diameter of opening <NUM> is smaller than a maximum diameter of hollow article <NUM> at sidewall <NUM>. In some embodiments, a flange <NUM> may extend outwardly from upper end <NUM> of sidewall <NUM>. Flange <NUM> may surround opening <NUM> of hollow article <NUM>, such that flange <NUM> has an annular shape. Flange <NUM> may facilitate securement of a closure to article <NUM>, such as a plastic membrane or a metal film, foil, or cap, so as to cover and seal opening <NUM> of article <NUM>. Flange <NUM> may not include threading, and a closure such as a plastic membrane or foil, may be secured to flange <NUM> by bonding, adhesives, or ultrasonic welding, among other fastening methods. Flange <NUM> may be arranged in a plane so that flange <NUM> is substantially flat. Further, flange <NUM> may be arranged in a plane that is perpendicular to longitudinal axis Y of article <NUM>.

In some embodiments, a hollow article <NUM>, such as a container, formed by a method herein may have a volume of about <NUM> oz to <NUM> oz (<NUM> to <NUM>). In order to form a hollow article <NUM> with a greater size or volume, a larger or thicker preformed puck may be used, and as the thickness of the preformed puck increases, the puck may become less compliant and may be harder to stretch using a plunger as described in further detail herein.

In some embodiments, flange <NUM> of preformed puck <NUM> may correspond to a flange <NUM> of the resulting article <NUM>. When molded, circular plate <NUM> may correspond to a base <NUM> of the resulting article <NUM> and also sidewall <NUM> of article <NUM>. Upstanding wall <NUM> may correspond to an upper portion of sidewall <NUM> of article <NUM>, such as shoulder region <NUM> as shown in <FIG>.

In some embodiments, a preformed puck <NUM> may include a circular plate <NUM> and a flange <NUM> extending outwardly from an outer perimeter <NUM> of circular plate <NUM>, as shown in <FIG>. Flange <NUM> may extend from an upper end <NUM> of circular plate <NUM>. Thus, in such embodiments, preformed puck <NUM> does not include an upstanding wall as in the preformed puck <NUM> of <FIG> and <FIG>. Instead, a top surface of circular plate <NUM> may be coplanar with a top surface of flange <NUM>, as shown in <FIG>. Preformed puck <NUM> having flange <NUM> may help to produce an article having a flange, as discussed above with respect to preformed puck <NUM>. However, as puck <NUM> lacks an upstanding wall, puck <NUM> may have less ability to allow for tailoring of wall thickness of the resulting article. Increasing a thickness of preformed puck <NUM> beyond a certain extent may make puck <NUM> less compliant and deformable such that puck <NUM> cannot be easily stretched and the material uniformly distributed during molding.

In some embodiments, preformed puck <NUM>, <NUM> may be formed from a plastic, such as polyethylene terephthalate (PET). Preformed pucks <NUM>, <NUM> may include recycled PET, and may include about <NUM>% recycled PET to about <NUM>% recycled PET. In some embodiments, preformed pucks <NUM>, <NUM> may include a multilayer PET (e.g., with a gas barrier layer disposed between layers of PET). However, in some embodiments, preformed puck <NUM>, <NUM> may be formed from polypropylene (PP), polyolefins, polyesters, polyethylene furanoate (PEF), polyethylene naphthalates, polyglycolide (PGA), or a combination thereof, among other recyclable thermoplastic materials, among other materials.

Preformed puck <NUM>, <NUM> may be formed by a molding method, such as compression molding, transfer molding, or injection molding, among other molding methods. Preformed pucks <NUM>, <NUM> may be easily stored and transported to a location for blow molding a container using the preformed pucks <NUM>, <NUM>.

For the sake of clarity, the following discussion will refer to preformed puck <NUM>. However, it is understood that the following applies equally to preformed puck <NUM> except where expressly noted. In order to form an article from preformed puck <NUM>, preformed puck <NUM> may be heated to an elevated temperature at or above a glass transition temperature of preformed puck <NUM>. In this way, preformed puck <NUM> may become compliant so as to fill the mold and conform to a shape of the inner wall of the mold to provide a container having an outer shape as defined by the mold.

In some embodiments, blow molding an article using a preformed puck <NUM> may include heating preformed puck <NUM> non-uniformly, such that different regions of the preformed puck <NUM> are heated to different temperatures, as shown in <FIG>. For example, preformed puck <NUM> may be heated such that a first region <NUM> of preformed puck <NUM> is heated to a first temperature and a second region <NUM> is heated to a second temperature that differs from the first temperature. In some embodiments, heating of preformed puck <NUM> may vary along a diameter of preformed puck <NUM>. In some embodiments, a central region <NUM> of preformed puck may be heated to the first temperature, and an annular region <NUM> surrounding central region <NUM> may be heated to a second temperature that differs from the first temperature. Central region <NUM> may have a generally circular shape when preformed puck <NUM> is viewed in a top-down manner. Central region <NUM> may be arranged centrally on circular plate <NUM> of preformed puck <NUM>. Annular region <NUM> may surround central region <NUM> of circular plate <NUM>. Annular region <NUM> may extend from central region <NUM> to upstanding wall <NUM> (and in some embodiments may include upstanding wall <NUM>).

In some embodiments, first temperature of central region <NUM> may be about <NUM> to <NUM>. However, one of ordinary skill in the art will understand that the temperature selected depends in part upon the material used to form preformed puck <NUM> (and the glass transition temperature of the material). First temperature may be at or above a glass transition temperature of the material of preformed puck <NUM>. Second temperature of annular region <NUM> may be greater than the first temperature. In some embodiments, second temperature may be about <NUM> to about <NUM> greater than the first temperature, about <NUM> to about <NUM> greater than the first temperature, or about <NUM> to about <NUM> greater than the first temperature. As annular region <NUM> is heated to a higher temperature than central region <NUM>, annular region <NUM> is more compliant and will stretch or deform to a greater extent than the relatively cool central region <NUM> during molding.

In some embodiments, a second annular region <NUM> may be at a third temperature that differs from the first and second temperatures. Second annular region <NUM> may surround annular region <NUM>, and second annular region <NUM> may be the outermost region of preformed puck <NUM>. Second annular region <NUM> may encompass flange <NUM>, and in some embodiments may also encompass upstanding wall <NUM>. In some embodiments, the third temperature may be less than the first and second temperatures. In some embodiments, the third temperature is ambient temperature or "room" temperature, such that the second annular region <NUM> is not heated. If the second annular region <NUM> is not heated, the second annular region <NUM> is not stretched or deformed during the blow molding process. For example, when second annular region <NUM> encompasses flange <NUM>, flange <NUM> of preformed puck <NUM> is maintained in the same configuration in the resulting article <NUM> formed as the result of the blow molding process. In this way, flange <NUM> of resulting article <NUM> may be substantially flat and is not deformed by the molding process.

Preformed puck <NUM> may be heated using any of various heating devices, such as an electrical resistance heating element (see, e.g., heater <NUM> in <FIG>). Electrical resistance heating element may be configured to as to heat a first region of preformed puck <NUM> to a first temperature and a second region of preformed puck to a second temperature (e.g., central and annular regions). For example, an electrical resistance heating element may include a first heating coil having a circular shape for heating central region <NUM> of preformed puck <NUM> and a second heating coil having an annular shape for heating annular region <NUM> of preformed puck <NUM>. Preformed puck <NUM> may be conductively heated. Conductive heating allows for precise heating of different regions of preformed puck <NUM> to different temperatures.

The heated preformed puck <NUM> may be arranged on an open upper end <NUM> of a mold <NUM> having a mold cavity <NUM> with an inner wall <NUM> that defines an outer shape of the desired article, as shown in <FIG>. Particularly, flange <NUM> of puck <NUM> may rest on upper end <NUM> of mold <NUM>. Heated preformed puck <NUM> may be secured on upper end <NUM> of mold cavity <NUM> by a securing member <NUM> of mold <NUM>. Securing member <NUM> may include a tubular shaft <NUM> surrounding a plunger <NUM> of mold <NUM>. Lower end <NUM> of tubular shaft <NUM> may be placed in contact with flange <NUM> of preformed puck <NUM> so that flange <NUM> is arranged between upper end <NUM> of mold cavity <NUM> and lower end <NUM> of tubular shaft <NUM>. In this way, flange <NUM> maintains its shape during the molding process so that the resulting article has a flat flange.

The heated preformed puck <NUM> is stretched, such as by a plunger <NUM>, as shown in <FIG>. Plunger <NUM> is arranged in a direction of a longitudinal axis Y of mold <NUM> and is moved toward mold cavity <NUM> along axis Y so as to contact heated preformed puck <NUM> and press a portion of heated preformed puck <NUM> (e.g., the portion formed by circular plate <NUM>) into mold <NUM>. Plunger <NUM> may have a circular transverse cross sectional area, and plunger <NUM> may have a generally cylindrical shape. In some embodiments, plunger <NUM> may be formed from a metal, such as a metal, such as aluminum, copper, or steel, or a polymer. Material of plunger <NUM> may be selected based on the desired thermal conductivity and coefficient of friction for the molding process. For example, a material with a high thermal conductivity may serve as a heat sink. In some embodiments, plunger <NUM> includes a tip <NUM> configured to contact preformed puck <NUM> and press a portion of puck <NUM> into mold <NUM>. Tip <NUM> may be rounded and may have a dome-like shape.

Plunger <NUM> may have a maximum diameter D<NUM> that is less than a diameter D<NUM> of an upper opening of mold cavity <NUM>. In some embodiments, maximum diameter D<NUM> of plunger is <NUM>% to <NUM>% of a diameter D<NUM> of upper opening of mold cavity <NUM>. Reducing maximum diameter D<NUM> of plunger relative to diameter D<NUM> of mold <NUM> facilitates selection of wall thickness of the resulting article. As the diameter of plunger <NUM> increases, a greater amount of the preform material is pressed toward a lower portion or base of mold cavity <NUM>, which may result in a container having thin and relatively weaker sidewalls. If the sidewalls are too weak, the resulting article may not have sufficient physical properties to withstand storage and transportation. By reducing a diameter of plunger <NUM> relative to an opening of mold cavity <NUM>, preform material may be better and more precisely distributed within mold cavity <NUM>.

Further, plunger <NUM> may have a maximum diameter D<NUM> that is the same as a diameter of central region <NUM> of preformed puck <NUM>. In this way, plunger <NUM> may press central region <NUM> toward a lower end mold <NUM> such that central region <NUM> forms a base of the resulting molded article, while stretching annular region <NUM> of preformed puck <NUM> so that annular region <NUM> forms sidewall of the resulting article. Due to their different temperatures as described above, central region <NUM> may stretch to a lesser degree than annular region <NUM>, resulting in portions of container formed by annular region having a smaller thickness than portions of container formed by central region. Accordingly, thicknesses of different portions of the resulting container may be affected by selection of affected by the diameter of plunger <NUM> and the central region of preformed puck <NUM> (in addition to the different first, second, and third temperatures as described above).

In some embodiments, mold cavity <NUM> has a depth L<NUM> as measured along longitudinal axis X from lower end <NUM> of mold cavity <NUM> to upper end <NUM> of mold cavity <NUM>. Plunger <NUM> is inserted into mold cavity <NUM> to a predetermined distance L<NUM> that is less than L<NUM>. In some embodiments, plunger <NUM> may be inserted to a depth L<NUM> that is <NUM>% to <NUM>% of L<NUM>, <NUM>% to <NUM>% of L<NUM>, or <NUM>% to <NUM>% of L<NUM>. Thus, tip <NUM> of plunger <NUM> is spaced from and does not contact the inner wall <NUM> at the lower end <NUM> of mold cavity <NUM>. The inventors of the present invention found that by inserting plunger <NUM> to a depth less than L<NUM>, the preformed puck <NUM> more fully and uniformly conformed to a shape of inner wall <NUM> of mold cavity <NUM> when pressurized air is applied to mold cavity <NUM>, as discussed below. It is believed that the space between the tip <NUM> of plunger <NUM> and inner wall <NUM> at lower end <NUM> of mold cavity <NUM> allows for improved airflow within mold cavity <NUM> and thus an improved distribution of preformed puck <NUM> onto inner wall <NUM> of mold cavity <NUM>.

In some embodiments, plunger <NUM> may be moved along axis Y at a speed of about <NUM>/s to about <NUM>/s, about <NUM>/s to about <NUM>/s, or about <NUM>/s to about <NUM>/s. It has been found that speed in this range facilitates conformation of the preform material to the lower end <NUM> of mold cavity <NUM>, and higher speeds resulted in relatively poor distribution of preform material onto lower end <NUM> of mold cavity <NUM>.

Once preformed puck <NUM> is stretched by plunger <NUM>, pressurized air is applied to mold cavity <NUM> and to preformed puck <NUM>, as shown in <FIG>. As used herein, pressurized air may refer to any gas, such as air, oxygen, nitrogen, carbon dioxide, or a combination thereof, among other gases. Pressurized air may be applied to the mold at a pressure of <NUM> bar to <NUM> bar, <NUM> bar to <NUM> bar, or <NUM> bar to <NUM> bar. Pressurized air may be applied by, for example, an air compressor. Further, pressurized air may be applied at a constant pressure, rather than by ramping the pressure from a lower pressure to the target pressure. As air is applied at a pressure less than existing blow molding methods, which may use an air pressure of about <NUM> bar, a smaller condenser may be used which may conserve space and energy.

Claim 1:
A method for blow molding a container using a preformed puck (<NUM>, <NUM>) comprising a circular plate (<NUM>, <NUM>) and a flange (<NUM>, <NUM>), the method, comprising:
heating a central region (<NUM>) of the circular plate of the preformed puck (<NUM>, <NUM>) to a first temperature;
heating an annular region (<NUM>) surrounding the central region (<NUM>) of the circular plate (<NUM>, <NUM>) of the preformed puck (<NUM>, <NUM>) to a second temperature, wherein the second temperature is greater than the first temperature;
arranging the heated preformed puck (<NUM>, <NUM>) at an upper end of a mold cavity (<NUM>) of a mold (<NUM>), wherein an inner wall (<NUM>) of the mold cavity (<NUM>) defines an outer shape of the container;
stretching the heated preformed puck (<NUM>, <NUM>) by pressing a plunger (<NUM>) into the heated preformed puck (<NUM>, <NUM>) and into the mold cavity (<NUM>) in a longitudinal direction of the mold cavity toward a lower end of the mold cavity; and
applying pressurized air to the mold cavity (<NUM>) so that the heated preformed puck (<NUM>, <NUM>) stretches to conform to the shape of the inner wall (<NUM>) of the mold cavity.