BR112020024973B1 - CONTAINER PREFORM - Google Patents

Abstract

The present invention relates to a preform configured to form a container by stretch blow molding. A finishing portion of the preform is at a first end of the preform. The finishing portion is a finish of the container. A support flange is on the finishing portion. A tip portion is at a second end of the preform opposite the first end, and is configured to form a container base. A neck portion is adjacent to the support flange and is configured to form a neck portion. An external stretch radius is on an external surface of the neck portion. An internal stretch radius is on an internal surface of the neck portion. A first distance is between the inner stretching radius and the outer stretching radius and is equal to, or greater than, four times a second distance between the outer stretching radius and the support flange.

Description

CROSS REFERENCE TO RELATED ORDERS

[001] This application claims priority to US Provisional Application No. 5 621688,690, filed on June 22, 2018. The entire invention of the above application is hereby incorporated by reference.

FIELD

[002] The present invention relates to a polymeric preform configured to be blow molded into a container.

BACKGROUND

[003] This section provides background information related to the present invention, which is not necessarily prior art.

[004] 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 goods previously supplied in glass containers. . Manufacturers and bottlers as well as consumers have recognized that PET containers are lightweight, cheaply recyclable and manufacturable in large quantities.

[005] Blow molded plastic containers have become common in packaging numerous goods. PET is a crystallizable polymer, meaning it is available in an amorphous form or a semi-crystalline form. The ability of a PET container to maintain its material integrity is related to the percentage in 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:

[006] where p is the density of the PET material; pa is the density of pure amorphous PET material (1.333 glee); and pc is the density of pure crystalline material (1.455 glee).

[007] Container manufacturers use mechanical processing and thermal processing to increase the crystallinity of a container's PET polymer. Mechanical processing involves guiding the amorphous material to achieve strain hardening. This processing generally 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. PET container manufacturers currently use mechanical processing to produce PET containers with approximately 20% crystallinity on the container sidewall.

[008] Thermal processing involves heating the material (whether amorphous or semicrystalline) to promote crystal growth. In an amorphous material, thermal processing of PET material results in a spherulitic morphology that interferes with light transmission. In other words, the resulting crystalline material is opaque and therefore generally undesirable. Used after mechanical processing, however, thermal processing results in greater crystallinity and excellent clarity for those portions of the container with biaxial molecular orientation. 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). °C) and hold 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 thermal tuning to produce PET bottles with an overall crystallinity in the range of approximately 25% - 35%.

[009] Injection blow molded PET containers have historically had straight necks that are uncontrollable without the use of process aids that have the potential to compromise other attributes of the container. With the growth of aseptic packaging and equipment that requires greater accuracy and precision for optimal performance, it is critical that straight necks are managed so that performance is not compromised for a straight neck.

[010] In traditional hot filling lines, bottles are transported by upright conveyor belts (supported base) or by air conveyors, which keep the bottle directly below the support flange (supported neck). Air conveyors require a more consistent neck geometry to properly transport the blown bottle. Having a straight neck that maintains greater cylindricity is advantageous for handling efficiency.

[011] Aseptic packaging lines require greater consistency in the straight neck than any other current filling process. Many aseptic filling lines transfer containers through a commercially sterile environment using both the straight neck directly below the support flange and the geometry above the support flange. The straight neck is a critical performance factor in injection blow molded PET bottles for this application. Transfer failures due to irregularities in the straight neck can result in dropped, jammed or mishandled containers being ejected from filling. Aseptic lines must undergo rigorous sterilization prior to filling to ensure the environment and equipment within the filling are commercially sterilized. An event where leaking bottles begin to affect filling performance will require operators to break sterility to clean the bottles. This type of event incurs significant downtime as the filler takes hours to become commercially sterile after the filler is exposed to the external environment.

[012] Although current preforms and containers are suitable for their intended use, they are subject to improvement. For example, and with reference to Figures 1A and 1B, a prior art preform is illustrated at reference numeral 110'. The preform 110' is made from any suitable polymeric material, such as polyethylene terephthalate (PET), for example. The preform 110' itself may be formed in any suitable manner, such as by injection molding. The preform 110' is configured to form a container 210' (see prior art Figures 2A, 2B and 2C) in any suitable manner, such as by blow molding. Container 210' may be any suitable container of any suitable size, such as a 20-ounce hot-fill container. The container 210' will be further described in this document after the description of the preform 110'.

[013] The preform 110' generally includes a first end 112' and a second end 114' opposite this. At the first end 112' is a finishing portion 120' of the preform 110', which is also a container finish of the container 210'. At the first end 112', the trim 120' defines an opening 122' of the preform 110', which also provides a container opening of the container 210'. Extending from an outer surface of the finish 120' are threads 124', which may be any suitable threads, configured to cooperate with a closure to close the opening 122'. Also extending from the finish 120' is a support flange or ring 126', which can be used to support the preform 110' in a stretch blow molding machine, and which can provide the finish 120' with increased strength.

[014] Between the finish 120' and the second end 114', the preform 110' includes a neck portion 128', a shoulder portion 130', a body portion 132' and a tip or base/heel portion 134'. The neck portion 128' is adjacent or generally adjacent to the support flange 126'. The shoulder portion 130' is between the neck portion 128' and the body portion 132'. The base/heel portion 134' extends from the second end 114' toward the first end 112'. The body portion 132' is between the shoulder portion 130' and the base/heel portion 134'.

[015] Referring to Figure 1B of the prior art, the neck portion 128' includes an external stretching point or radius 150' and an internal stretching point or radius 152'. The external stretch point 150' is a distance X' from the support flange 126'. The internal stretching point 152' is a distance Y' from the support flange 126' and a distance Z' from the external stretching point 150'.

[016] With continued reference to Figures 1A and 1B, and with further reference to Figures 2A, 2B and 2C, the neck portion 128' is configured to form a container neck 222', and the shoulder portion 130' is configured to form a container shoulder 224' of the container 210'. The body portion 132' is configured to form a container main body portion 226' of the container 210'. The base/heel portion 134' is configured to form a container base 240' and a container heel 242' of the container 210'. The preform 110' further includes an outer surface 140' and an inner surface 142', which is opposite the outer surface 140'. The inner and outer surfaces 140' and 142' extend around each of the neck portion 128', the shoulder portion 130', the body portion 132', and the base/heel portion 134'. The preform 110' is generally circular and is closed at the second end 114' by the base/heel portion 134'. A longitudinal axis A of the preform 110' extends through an axial center of the opening 122' at the first end 112', and through an axial center of the base/heel portion 134' at the second end 114'.

[017] The prior art container 210' undesirably has a bulge 250' in the neck 222', as illustrated in Figures 2A, 2B and 2C. The protuberance 250' is generally formed at a distance X' from the support flange 126' and has a thickness T'. The protrusion 250' is undesirable as it inhibits the ability of the claws to grasp the container 210' at the container neck 222' in order to pick up the container 210' below the support flange 126' without sticking or snagging during transportation.

[018] The bulge 250' is a deformation typically observed when the preform 110' has the external stretch point 150' located three millimeters from the bottom of the support flange 126' (i.e., the distance X' is about three millimeters), and the internal stretch point 152' is 5.1 millimeters from the bottom of the support flange 126' (i.e., Y' is about 5.1 millimeters), and the distance between the point of external stretch point 150' and the internal stretch point 152' is 2.1 millimeters (i.e. Z' is about 2.1 millimeters).

[019] Straight neck cylindricity starting from the preform geometry is critical to improving line efficiency in hot filling and aseptic lines. The present invention advantageously prevents bulging from the injection blow molding process, and provides greater control of neck distortion created by the stretch initiation point in the preform. Specifically, the present invention advantageously eliminates, or at least significantly reduces, the protuberance 250', as explained in detail herein. One skilled in the art will appreciate that the present invention provides numerous additional advantages as well as unexpected results.

SUMMARY

[020] This section provides a general summary of the invention and is not a comprehensive invention of its full scope or all of its features.

[021] The present invention includes a preform configured to form a container by blow molding and stretch. A finishing portion of the preform is at a first end of the preform. The finishing portion is a container finishing portion of the container. A support flange is on the finishing portion. A tip portion is at a second end of the preform opposite the first end and is configured to form a container base. A neck portion is adjacent to the support flange and is configured to form a neck portion. An external stretch radius is on an external surface of the neck portion. An internal stretch radius is on an internal surface of the neck portion. A first distance is between the inner stretching radius and the outer stretching radius and is equal to, or greater than, four times a second distance between the outer stretching radius and the support flange.

[022] Other areas of applicability will become apparent from the description provided in this document. The specific description and examples in this summary are intended for illustration purposes only and are not intended to limit the scope of the present invention.

DESIGNS

[023] The drawings described herein are for illustrative purposes only of selected embodiments, and not all possible implementations, and are not intended to limit the scope of the present invention.

[024] Figure 1A illustrates a prior art container preform;

[025] Figure 1B illustrates area 1B of Figure 1A;

[026] Figure 2A illustrates a prior art container formed from the prior art preform of Figure 1A;

[027] Figure 2B illustrates area 2B/2C of Figure 2A

[028] Figure 2B illustrates area 2B/2C of Figure 2A

[029] Figure 3A illustrates a preform according to the present invention;

[030] Figure 3B illustrates area 3B/3C of Figure 3A

[031] Figure 3C illustrates area 3B/3C of Figure 3A

[032] Figure 4A illustrates a container according to the present invention; formed from the preform of Figure 3A

[033] Figure 4B illustrates area 4B/4C of Figure 4A

[034] Figure 4C illustrates area 4B/4C of Figure 4A

[035] Figure 5 illustrates the flatness of the straight neck of various containers according to the present invention; It is

[036] Figure 6 illustrates the relationship between the external stretching point of the preform and the blown bottle bulge point of various containers according to the present invention.

[037] Corresponding reference numbers indicate corresponding parts throughout the various views of the drawings.

DETAILED DESCRIPTION

[038] Exemplary embodiments will now be described more fully with reference to the attached drawings.

[039] With reference to Figures 3A, 3B and 3C, a container preform in accordance with the present invention is illustrated at reference numeral 110. Preform 110 includes a number of features that are similar to the preform 110'. These similar features are identified in the drawings using the same reference numerals used in Figures 1A and 1B, but without the line designation ('). The description of these similar characteristics set forth in the background section is also sufficient to describe similar characteristics of preform 110, with the exception of the specific differences described herein.

[040] The preform 110 includes an outer stretch point or radius 150 and an inner stretch point or radius 152, which are stretch initiation points, the location and position of which influence how the preform 110 is stretched and formed. in a final container during blow molding. With particular reference to Figure 3B, the external stretching point 150 and the internal stretching point 152 of the preform 110 are arranged differently compared to the external stretching point 150' and the internal stretching point 152' of the preform. -form of the prior art 110'. Specifically, and compared to the preform 110', the external stretching point 150 is arranged closer to the support flange 126, and the internal stretching point 152 is arranged further away from the support flange 126. Therefore, the distance Z between the outer stretch point 150 and the inner stretch point 152 is greater than the dimension Z' between the outer stretch point 150' and the inner stretch point 152'. Thus, dimension X is smaller than dimension X', dimension Y is larger than dimension Y', and dimension Z is larger than dimension Z'.

[041] More specifically, with respect to the preform 110 of the present invention, the distance Z between the external stretching point 150 and the internal stretching point 152 is greater than or equal to four times (or about four times) the distance X between the outer stretch point 150 and the support flange 126. For example, in applications where the distance 152 and the external stretch point 150 will be 4 mm, or at least about 4 mm. Thus, the distance Y between the internal stretch point 152 and the support flange 126 will be 5 mm, or at least about 5 mm. Arranging the external stretching point 150 and the internal stretching point 152 in this matter offers numerous advantages, as explained below.

[042] Container 210 is blow molded from preform 110. Specifically, preform 110 can be heated by oven lamps in a blow molding machine, and inserted into a blow mold where a rod stretching stretches the preform 110 longitudinally along the longitudinal axis A, while high pressure air simultaneously expands the preform 110. The preform is forced into the mold walls. This creates the final shape of the container 210. The combination of heating the preform 110, stretching and expanding creates stretch-induced crystallinity in the polyethylene terephthalate material. In an additional step, the container may be heated by the mold walls to create heat-induced crystallinity. This combination of stretch and heat-induced crystallinity is referred to as thermosetting, which results in a stronger rigid container that resists shrinkage and is suitable for filling with heated products.

[043] Arrange the external stretching point 150 closer to the support flange 126 (such as in relation to the position of the external stretching point 150' in relation to the support flange 126'), arrange the internal stretching point 152' relatively further away of the support flange 126 (compared to the distance between the internal stretching point 152' and the support flange 126') and increasing the distance between the stretching points 150 and 152 (compared to the distance between the internal stretching points and 150' and 152'), eliminates or significantly reduces deformation of the resulting container 210 (see Figures 4A, 4B and 4C) at the neck portion 222. For example, and as illustrated in Figures 4A, 4B and 4C, the exemplary container 210 formed from the preform 110 has only a very small bulge 250 at the neck 222. The bulge 250 has a thickness T, which is much smaller than the thickness T' of the bulge 250'. The relatively small thickness T advantageously does not inhibit gripping of the container 210 by claws used to pick up the container 210 below the support flange 126 and allows gripping without sticking or binding during transport. Figure 5 illustrates the flatness of the straight neck of various containers in accordance with the present invention, and Figure 6 illustrates the relationship between the external stretching point of the preform and the blown bottle bulge point of various containers, in accordance with with the present invention.

[044] Exemplary embodiments are provided so that this invention is complete and fully conveys the scope to those skilled in the art. Numerous specific details are presented as examples of specific components, devices, and methods, to provide a complete understanding of embodiments of the present invention. It will be apparent to those skilled in the art that specific details need not be used, that exemplary embodiments can be embodied in many different forms, and that none of them should be construed to limit the scope of the invention. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[045] The terminology used in this document is intended to describe particular exemplary embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the/a" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "including" and "having", are inclusive and therefore specify the presence of presented features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other characteristics, integers, steps, operations, elements, components and/or groups thereof. The method steps, processes and operations described herein are not to be construed as necessarily requiring performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

[046] When an element or layer is referred to as being "on", "engaged to", "connected to" or "coupled to" another element or layer, it may be directly on, engaged with, connected to or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on", "directly coupled to", "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in the same way (for example, "between" versus "directly between", "adjacent" versus "directly adjacent", etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

[047] Although the terms first, second, third, etc. may be used in this document to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections shall not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as "first", "second" and other numerical terms, when used herein, do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below, may be called a second element, component, region, layer or section, without departing from the teachings of the exemplary embodiments.

[048] Spatially relative terms, such as "internal", "external", "below", "below", "inferior", "above", "upper" and the like, may be used herein for ease of description , to describe an element or feature's relationship to another element(s) or feature(s) as illustrated in the Figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation outlined in the Figures. For example, if the device in the Figures were turned, elements described as "below" or "below" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an above and a below orientation. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[049] The preceding description of the embodiments was provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and may be used in a selected embodiment, even if not specifically shown or described. The same can also be varied in many ways. Such variations should not be considered a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims (6)

1. Preform (110) configured to form a container (210) by blow molding and stretch, characterized in that the preform (110) comprises: a finishing portion at a first end of the preform (110 ), the finishing portion is a container finishing of the container (210); a support flange (126) of the finishing portion; a tip portion at a second end of the preform (110) opposite the first end, the tip portion configured to form a container base of the container (210); a neck portion adjacent the support flange (126), the neck portion configured to form a neck portion of the container (210); an external stretching radius on an external surface of the neck portion; an inner stretch radius on an inner surface of the neck portion, a first distance between the inner stretch radius and the outer stretch radius is equal to, or greater than, four times a second distance between the outer stretch radius and the flange support (126); a shoulder portion adjacent to the neck portion and configured to form a container shoulder of the container (210); and a body portion between the shoulder portion and the tip portion, the body portion configured to form a container body of the container (210). 2. Preform (110), according to claim 1, characterized in that the first distance is 4 mm. 3. Preform (110), according to claim 2, characterized in that the second distance is 1 mm. 4. Preform (110), according to claim 3, characterized in that the internal stretching radius is 5 mm from the support flange (126). 5. Preform (110), according to claim 1, characterized in that the external stretching radius is between the internal stretching radius and the support flange (126). 6. Preform (110), according to claim 1, characterized in that the preform (110) is configured to form a hot filling container.