Preform and container having debossed support flange

The present disclosure provides a container and a method of making a container. In one example, the container includes an upper portion having a finish defining a longitudinal axis and an opening into the container. A shoulder region is integrally formed with and extends from the upper portion. A sidewall portion extends from the shoulder region to a base portion. A tamper evident (TE) band is formed on the finish and defines an outermost surface of the plastic container above the shoulder region. A neck defining a cylindrical sidewall is integrally formed with and extends between the finish and the shoulder region. The neck defines a uniform cylindrical sidewall along its entire height between the finish and the shoulder region. The container further includes a debossed support flange defined on the upper portion. The debossed support flange defines a diameter less than a diameter defined by the TE band.

TECHNICAL FIELD

This disclosure generally relates to containers for retaining a commodity, such as a solid or liquid commodity. More specifically, this disclosure relates to a blown polyethylene terephthalate (PET) container having a debossed support flange.

BACKGROUND

As a result of environmental and other concerns, plastic containers, more specifically polyester and even more specifically polyethylene terephthalate (PET) containers are now being used more than ever to package numerous commodities previously supplied in glass containers. Manufacturers and fillers, as well as consumers, have recognized that PET containers are lightweight, inexpensive, recyclable and manufacturable in large quantities.

Blow-molded plastic containers have become commonplace in packaging numerous commodities. PET is a crystallizable polymer, meaning that it is available in an amorphous form or a semi-crystalline form. The ability of a PET container to maintain its material integrity relates to the percentage of the PET container in crystalline form, also known as the “crystallinity” of the PET container. The following equation defines the percentage of crystallinity as a volume fraction:

%⁢⁢Crystallinity=(ρ-ρa⁢ρc-ρa)×100
where ρ is the density of the PET material; ρais the density of pure amorphous PET material (1.333 g/cc); and ρcis the density of pure crystalline material (1.455 g/cc).

Container manufacturers use mechanical processing and thermal processing to increase the PET polymer crystallinity of a container. Mechanical processing involves orienting the amorphous material to achieve strain hardening. This processing commonly involves stretching an injection molded PET preform along a longitudinal axis and expanding the PET preform along a transverse or radial axis to form a PET container. The combination promotes what manufacturers define as biaxial orientation of the molecular structure in the container. Manufacturers of PET containers currently use mechanical processing to produce PET containers having approximately 20% crystallinity in the container's sidewall.

Thermal processing involves heating the material (either amorphous or semi-crystalline) to promote crystal growth. On amorphous material, thermal processing of PET material results in a spherulitic morphology that interferes with the transmission of light. In other words, the resulting crystalline material is opaque, and thus, generally undesirable. Used after mechanical processing, however, thermal processing results in higher crystallinity and excellent clarity for those portions of the container having biaxial molecular orientation. The thermal processing of an oriented PET container, which is known as heat setting, typically includes blow molding a PET preform against a mold heated to a temperature of approximately 250° F.-350° F. (approximately 121° C.-177° C.), and holding the blown container against the heated mold for approximately two (2) to five (5) seconds. Manufacturers of PET juice bottles, which must be hot-filled at approximately 185° F. (85° C.), currently use heat setting to produce PET bottles having an overall crystallinity in the range of approximately 25%-35%.

Typically, an upper portion of the plastic container defines an opening. This upper portion is commonly referred to as a finish and includes some means for engaging a cap or closure to close off the opening. In the traditional injection-stretch blow molding process, the finish remains substantially in its injection molded state while the container body is formed below the finish. The finish may include at least one thread extending radially outwardly around an annular sidewall defining a thread profile. In one application, a closure member or cap may define a complementary thread, or threads, that are adapted to cooperatively mate with the threads of the finish.

An alternative method may be used to form the finish portion of the container. This alternative method is known as a blown finish. During this alternative process, the finish portion of the container is created in the blow mold utilizing a process similar to the blow molding process described above. This alternative process enables production of a lighter-weight finish portion, and thus container, than is possible through the traditional injection molding production method.

Typically, the finish of the container includes an outwardly facing support flange. Such a support flange can be used to carry or orient a preform through and at various stages of manufacture. For example, the preform may be carried by the support flange, the support flange may be used to aid in positioning the preform in a mold, or an end consumer may use the support flange to carry the plastic container once manufactured.

SUMMARY

Accordingly, the present disclosure provides a container and a method of making a container. In one example, the container includes an upper portion including a finish defining a longitudinal axis and an opening into the container. A shoulder region is integrally formed with and extends from the upper portion. A sidewall portion extends from the shoulder region to a base portion. The base portion closes off an end of the container. A tamper evident (TE) band is formed on the finish and defines an outermost surface of the plastic container above the shoulder region. A neck defining a cylindrical sidewall that is integrally formed with and extends from the finish and the shoulder region.

According to additional features, the neck defines a uniform cylindrical sidewall along its entire height between the finish and the shoulder region. The TE band defines a first diameter at the outermost surface. The container further includes a debossed support flange defined on the upper portion. The debossed support flange defines a second diameter. The first diameter is greater than the second diameter.

Additional benefits and advantages of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION

The following description is merely exemplary in nature, and is in no way intended to limit the disclosure or its application or uses.

FIG. 1shows one embodiment of the present container. In the Figures, reference number10designates a one-piece plastic, e.g. polyethylene terephthalate (PET), hot-fillable container. The container10is shown with an exemplary cap12. The cap12includes a breakaway band14. The container10and cap12are collectively referred to herein as a bottle assembly18. As shown inFIGS. 1 and 2, the exemplary container10defines a longitudinal axis L1and has an overall height H1of about 177.10 mm (6.97 inches). The container10may be substantially cylindrical in cross section. In this particular embodiment, the container10has a volume capacity of about 32 fl. oz. (946 cc). Those of ordinary skill in the art would appreciate that the following teachings are applicable to other containers, such as rectangular, triangular, hexagonal, octagonal or square shaped containers, which may have different dimensions and volume capacities. It is also contemplated that other modifications can be made depending on the specific application and environmental requirements.

The container10according to the present teachings defines a body20and includes an upper portion22having a finish24. The finish24defines an opening30into the container10. Integrally formed with the finish24and extending downward therefrom is a shoulder region32. The shoulder region32merges into and provides a transition between the finish24and a sidewall portion36. The sidewall portion36extends downward from the shoulder region32to a base portion40having a base42. An upper bumper portion44may be defined at a transition between the shoulder region32and the sidewall portion36. A lower bumper portion45may be defined at a transition between the base portion40and the sidewall portion36. A neck46defining a cylindrical sidewall47is integrally formed with the finish24and extends between the finish24and the shoulder region32. In one example, the cylindrical sidewall47can define a uniform radius along its entire height.

The container10has been designed to retain a commodity. The commodity may be in any form such as a solid or liquid product. In one example, a liquid commodity may be introduced into the container10during a thermal process, typically a hot-fill process. For hot-fill bottling applications, bottlers generally fill the container10with a liquid or product at an elevated temperature between approximately 155° F. to 205° F. (approximately 68° C. to 96° C.) and seal the container10with the cap12before cooling. In addition, the container10may be suitable for other high-temperature pasteurization or retort filling processes or other thermal processes as well. In another example, the commodity may be introduced into the container10under ambient temperatures.

With continued reference toFIG. 2and further reference toFIG. 3, the finish24will be described in greater detail. The finish24of the container10generally includes a radial sidewall48defining a threaded region50having threads52, and a tamper evident (TE) band54. Each thread52defines a thread start portion58, a thread intermediate portion59, and a thread run-out portion60. As shown, each thread52slopes generally away from the opening30from the thread start portion58to the thread run-out portion60. In general, a thread start portion58of one thread52is longitudinally aligned (i.e. aligned in a direction parallel to the longitudinal axis L1of the container10) with a thread run-out portion60of an adjacent thread52. As best shown inFIG. 2, each thread52defines a first depth62at the thread start portion58and a second depth64at the thread intermediate portion59. According to the present teachings, the first depth62is less than the second depth64. More specifically, the first depth62is approximately 5-50% less than the second depth64. By reducing the thread depth at the thread start portion58, an improvement in repeatability of forming the thread run-out portion60is realized. In the exemplary finish24, four (4) threads52are included, however additional or fewer threads52are contemplated.

The TE band54will now be described. The TE band54is generally perpendicular to the longitudinal axis L1of the container10. The TE band54is collectively defined by a plurality of disconnected radial protrusions70. Each radial protrusion70generally defines a body74and a ramped support portion76. The body74further defines terminal sloped ends78. A gap72is defined on the radial sidewall48of the finish24between adjacent radial protrusions70. Each gap72is longitudinally aligned with a respective thread start portion58and a thread run-out portion60. Explained further, a line L2parallel to the longitudinal axis L1extends through the thread start portion58of a first thread52, the thread run-out portion60of a second thread52, and the gap72(seeFIG. 2). Depending on a thread pitch chosen for a given container, the gap72can range between approximately 5-32 degrees of the finish diameter. Furthermore, a line L3parallel to the longitudinal axis L1extends through a terminal end of the thread run-out portion60and a counter-clockwise (as viewed from the opening30) terminal sloped end78of a body74(seeFIG. 2). The discontinuous nature of the TE band54and more specifically the spacing of the gap72relative to the thread run-out portion60improves the formation of the thread run-out portion60, and the threads52as a whole.

With reference toFIG. 3, exemplary dimensions for the finish24will be described. It is appreciated that other dimensions may be used. A diameter D1is defined at an outermost surface79of the TE band54. A diameter D2is defined at an outermost surface80of the thread52. A diameter D3is defined at the thread start portion58. It is appreciated in the example shown, that the relative placement of the threads52around the finish24allows a diameter to be defined across diametrically opposed outermost surfaces80as well as diametrically opposed thread start portions58. Those skilled in the art will appreciate that such an arrangement is not required.

A diameter D4is defined by the radial sidewall48. A TE band depth84is defined laterally between the outermost surface79of the TE band54and the radial sidewall48. The TE band54is formed between a first and second height88and92, respectively on the finish24. The first height88extends between an upper surface90of the radial sidewall48and an upper boundary of the TE band54. The second height92extends between the upper surface90of the radial sidewall48and a lower boundary of the TE band54.

According to one example, the diameter D1can be 63.02 mm (2.48 inches). The diameter D2can be 62.08 mm (2.44 inches). The diameter D3can be 61.32 mm (2.41 inches). The diameter D4can be 59.99 mm (2.36 inches). An angle α1of the thread52extends from a line perpendicular to the finish24to the thread52can be about 45 degrees. An angle α2of the TE band54extends from a line perpendicular to the finish24to the TE band54can be about 30 degrees.

With specific reference toFIGS. 1 and 3, the container10defines a debossed support flange94. The debossed support flange94is defined by an inwardly extending wall96. The inwardly extending wall96transitions into the cylindrical sidewall47of the neck46. The debossed support flange94can provide a means for holding and/or gripping the container10. The debossed support flange94provides a significant weight reduction of approximately 5-10% or more over a typical blown plastic container that incorporates an outwardly facing support flange.

Because the container10defines the debossed support flange94, the TE band54defines an outermost surface of the container10above the shoulder region32. As can be appreciated, once the breakaway band14breaks away from the cap12upon initial uncapping, the breakaway band, identified in phantom at14′ inFIG. 1, will fall onto the shoulder region32. In this way, the breakaway band14′ occupies a position offset from the TE band54defining a gap98. The gap98is a strong visual aid to a customer in that it helps identify whether or not a container has been opened or tampered with prior to initial opening of the container by the end user. The debossed support flange94permits the breakaway band14to drop a greater distance, thereby increasing the distance identified by the gap98as compared to a typical plastic container incorporating a conventional outwardly facing support flange that would catch the breakaway band14at a position above the shoulder region32.

The container10according toFIGS. 1-5of the present disclosure is a blow molded, biaxially oriented container with a unitary construction from a single or multi-layer material. A well-known stretch-molding, heat-setting process for making the container10generally involves the manufacture of a preform P1(FIG. 4) of a polyester material, such as polyethylene terephthalate (PET), having a shape well known to those skilled in the art similar to a test-tube with a generally cylindrical cross section and a length typically approximately fifty percent (50%) that of the resultant container height.

An exemplary method of forming the container10will be described. At the outset, the preform P1may be placed into a mold cavity102. In general, the mold cavity102has an interior surface corresponding to a desired outer profile of the blown container. More specifically, the mold cavity102according to the present teachings defines a body-forming region108, a finish forming region110and a moil forming region112. The resultant structure, hereinafter referred to as an intermediate container120, as illustrated inFIG. 5, generally includes a body122, a finish124and a moil126.

In one example, a machine (not illustrated) places the preform P1heated to a temperature between approximately 190° F. to 250° F. (approximately 88° C. to 121° C.) into the mold cavity102. The mold cavity102may be heated to a temperature between approximately 250° F. to 350° F. (approximately 121° C. to 177° C.). A stretch rod apparatus (not illustrated) stretches or extends the heated preform P1within the mold cavity102to a length approximately that of the intermediate container120thereby molecularly orienting the polyester material in an axial direction generally corresponding with the central longitudinal axis L1of the container10. While the stretch rod extends the preform P1, air having a pressure between 300 PSI to 600 PSI (2.07 MPa to 4.14 MPa) assists in extending the preform P1in the axial direction and in expanding the preform P1in a circumferential or hoop direction thereby substantially conforming the polyester material to the shape of the mold cavity102and further molecularly orienting the polyester material in a direction generally perpendicular to the axial direction, thus establishing the biaxial molecular orientation of the polyester material in most of the intermediate container120. The pressurized air holds the mostly biaxial molecularly oriented polyester material against the inner surface of the mold cavity102for a period of approximately two (2) to five (5) seconds before removal of the intermediate container120from the mold cavity102. This process is known as heat setting and results in a heat-resistant container suitable for filling with a product at high temperatures.

In another example, a machine (not illustrated) places the preform P1heated to a temperature between approximately 185° F. to 239° F. (approximately 85° C. to 115° C.) into the mold cavity102. The mold cavity102may be chilled to a temperature between approximately 32° F. to 75° F. (approximately 0° C. to 24° C.). A stretch rod apparatus (not illustrated) stretches or extends the heated preform P1within the mold cavity102to a length approximately that of the intermediate container120thereby molecularly orienting the polyester material in an axial direction generally corresponding with the central longitudinal axis L1of the container10. While the stretch rod extends the preform P1, air having a pressure between 300 PSI to 600 PSI (2.07 MPa to 4.14 MPa) assists in extending the preform P1in the axial direction and in expanding the preform P1in a circumferential or hoop direction thereby substantially conforming the polyester material to the shape of the mold cavity102and further molecularly orienting the polyester material in a direction generally perpendicular to the axial direction, thus establishing the biaxial molecular orientation of the polyester material in most of the intermediate container120. The pressurized air holds the mostly biaxial molecularly oriented polyester material against the inner surface of the mold cavity102for a period of approximately two (2) to five (5) seconds before removal of the intermediate container120from the mold cavity102. This process is utilized to produce containers suitable for filling with product under ambient conditions or cold temperatures.

Alternatively, other manufacturing methods using other conventional materials including, for example, high density polyethylene, polypropylene, polyethylene naphthalate (PEN), a PET/PEN blend or copolymer, and various multilayer structures may be suitable for the manufacture of container10. Those having ordinary skill in the art will readily know and understand container manufacturing method alternatives.

Once the intermediate container120has been formed, the intermediate container120may be removed from the mold cavity102. As can be appreciated, the intermediate container120defines the container10(FIG. 1) and the moil126prior to formation of the opening30(FIG. 2). An intersection between the finish124and the moil126defines a cutting plane130(FIG. 5). The moil126is subsequently severed from the finish124at the cutting plane130. The severing process may be any suitable cutting procedure that removes the moil126and creates the opening30.

FIG. 6shows a one-piece plastic, e.g. polyethylene terephthalate (PET), hot-fillable container210according to additional features. While not specifically shown, the container210can cooperate with a cap having a breakaway band such as the cap12illustrated inFIG. 1. As shown inFIG. 6, the exemplary container210defines a longitudinal axis L4and has an overall height H2of about 158.40 mm (6.24 inches). The container210may be substantially cylindrical in cross section. In this particular embodiment, the container210has a volume capacity of about 22.9 fl. oz. (678 cc). Those of ordinary skill in the art would appreciate that the following teachings are applicable to other containers, such as rectangular, triangular, hexagonal, octagonal or square shaped containers, which may have different dimensions and volume capacities. It is also contemplated that other modifications can be made depending on the specific application and environmental requirements.

The container210according to the present teachings defines a body220and includes an upper portion222having a finish224. The finish224defines an opening230into the container210. Integrally formed with the finish224and extending downward therefrom is a shoulder region232. The shoulder region232merges into and provides a transition between the finish224and a sidewall portion236. The sidewall portion236extends downward from the shoulder region232to a base portion240having a base242. A lower bumper portion245may be defined at a transition between the base portion240and the sidewall portion236. A neck246defining a cylindrical sidewall247is integrally formed with the finish224and extends between the finish224and the shoulder region232. In one example, the cylindrical sidewall247can define a uniform radius along its entire height. As will be described in greater detail below, the container210also defines a debossed support flange294.

The container210has been designed to retain a commodity. The commodity may be in any form such as a solid or liquid product. In one example, a liquid commodity may be introduced into the container210during a thermal processor under ambient temperatures as discussed above with respect to the container10.

FIG. 7illustrates a preform P2used for blow molding the container210. As will be described, during blow molding of the container210, the neck246and all of the features above the neck246including the debossed support flange294and the finish224remain substantially in their injection molded state while the container body220is formed below the neck246. For reference purposes, the neck246, the debossed support flange294, and the finish224of the container210are identified with like reference numerals on the preform P2. The preform P2also defines a shoulder forming region248, a sidewall forming region249, and a base forming region250.

With reference toFIGS. 6 and 7, the finish224generally includes a radial sidewall251defining a threaded region252having threads253, and a tamper evident (TE) band254. In the exemplary finish224, four (4) threads253are included, however additional or fewer threads253are contemplated. The TE band254is generally perpendicular to the longitudinal axis L4of the container210. The TE band254is continuously formed around the finish224.

The debossed support flange294will now be described. The debossed support flange294is defined by an annular ring295having an inwardly extending wall296. The debossed support flange294can provide a means for holding and/or gripping the preform P2throughout the manufacturing process as well as the resultant container210. The debossed support flange294provides a significant weight reduction of approximately 5-10% or more over a typical injection molded preform or blown plastic container that incorporates an outwardly facing support flange. Because the container210includes the debossed support flange294, the TE band254defines an outermost surface of the container210above the shoulder region232.

With reference toFIG. 7, exemplary dimensions for the finish224will be described. It is appreciated that other dimensions may be used. A diameter D5is defined at an outermost surface279of the TE band254. A diameter D6is defined by the debossed support flange294at the annular ring295. A diameter D7is defined by the cylindrical sidewall247of the neck246. A diameter D8is defined by the radial sidewall251of the finish224. A diameter Dg is defined by the sidewall forming portion249of the preform P2.

According to one example, the diameter D5can be 43.40 mm (1.75 inches). The diameter D6can be 40.80 mm (1.61 inches). The diameter D7can be 37.80 mm (1.49 inches). The diameter D8can be 39.30 mm (1.55 inches). The diameter D9can be 27.0 mm (1.07 inches). A ratio of the diameter D5relative to the diameter D6can range between approximately 1.5 and preferably be approximately 1.1. A ratio of the diameter D6relative to the diameter D9can range between approximately 2.0 and preferably be approximately 1.5. A ratio of the diameter D5relative to the diameter D7can range between approximately 1.3 and preferably be approximately 1.1.

Turning now toFIG. 8, an exemplary method of forming the container210will be described. At the outset, the preform P2may be placed into a mold cavity302. In general, the mold cavity302has an interior surface corresponding to a desired outer profile of the blown container. More specifically, the mold cavity302according to the present teachings defines a shoulder forming region304, a sidewall forming region306, and a base forming region308.

The preform P2can be heated to a temperature between approximately 190° F. to 250° F. (approximately 88° C. to 121° C.) and placed into the mold cavity302. The mold cavity302may be heated to a temperature between approximately 250° F. to 350° F. (approximately 121° C. to 177° C.). A stretch rod apparatus (not illustrated) stretches or extends the heated preform P2within the mold cavity302to a length approximately that of the resultant container210thereby molecularly orienting the polyester material in an axial direction generally corresponding with the central longitudinal axis L4of the container210. While the stretch rod extends the preform P2, air having a pressure between 300 PSI to 600 PSI (2.07 MPa to 4.14 MPa) assists in extending the preform P2in the axial direction and in expanding the preform P2in a circumferential or hoop direction thereby substantially conforming the polyester material to the shape of the mold cavity302and further molecularly orienting the polyester material in a direction generally perpendicular to the axial direction, thus establishing the biaxial molecular orientation of the polyester material in the resultant container210. The pressurized air holds the mostly biaxial molecularly oriented polyester material against the inner surface of the mold cavity302for a period of approximately two (2) to five (5) seconds before removal of the container210from the mold cavity302. Other methods of blow molding the preform P2into the mold cavity302can be used.

While the above description constitutes the present disclosure, it will be appreciated that the disclosure is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.