Method of forming a container with shrink label

Abstract

A method of applying a label to a container. The container is a clear annealed polymeric container. The method includes the following: forming the container from a preform; applying a label to the container by heat-shrinking the label onto the container; after applying the label, filling the container with a product at a temperature less than 150°F; and capping the container.

Description

METHOD OF FORMING A CONTAINER WITH SHRINK LABELFIELD

[0001] The present disclosure relates to a method of applying a label to a polymeric container.BACKGROUND

[0002] This section provides background information related to the present disclosure, which is not necessarily prior art.

[0003] 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.

[0004] 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:% Crystallinitywhere p is the density of the PET material; pa is the density of pure amorphous PET material (1 .333 g / cc); and pc is the density of pure crystalline material (1 .455 g / cc).

[0005] 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 containerscurrently use mechanical processing to produce PET containers having approximately 20% crystallinity in the container’s sidewall.

[0006] 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 or annealing, 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. This process produces PET bottles having an overall crystallinity in the range of approximately 25% - 35%, which resists deformation and shrinking caused heat related processing such as applying a heat shrinkable label using a heat tunnel.SUMMARY

[0007] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0008] The present disclosure includes, in various features, a method of applying a label to a polymeric container. The method including: forming the polymeric container with an annealing blow mold process from a preform; applying a label to the polymeric container by heat-shrinking the label onto the polymeric container; after applying the label, filling the container with a product; and capping the container.

[0009] The present disclosure further includes a method of applying a label to a clear, heat-set polymeric container, the method comprising: forming the polymeric container from a preform including heating the preform to about 109°C, heating a mold to about 250°C, and blow-molding the preform into the mold to provide the container with a crystallinity of at least 25% and a rigid pushup base; applying a label to the polymeric container by exposing the container to steam sleeving tunnel conditions at a temperature range of 27.7°C - 84.8°C for about 15 seconds to heat-shrink the label onto the polymeric container shortly after forming the container up to about 12 monthsafter forming the container; after applying the label, filling the container with a product at a temperature less than 150°F; and capping the container.

[0010] The present disclosure also includes: a clear, annealed polymeric container, the comprising: a finish defining an opening; a neck and a body extending from the finish; a base; and a label heat-shrunk onto at least the body over a clear surface of the body; wherein the container has a crystallinity of at least 25%.

[0011] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0012] 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 disclosure.

[0013] FIG. 1 is a side view of a preform in accordance with the present disclosure;

[0014] FIG. 2 is a cross-sectional view of a container mold and the preform of FIG. 1 seated in the container mold;

[0015] FIG. 3 is a side-view of a container in accordance with the present disclosure, the container formed by injection molding the preform of FIG. 1 into the mold of FIG. 2;

[0016] FIG. 4 is a side view of the container of FIG. 3 with a shrink-wrapped label applied thereto; and

[0017] FIG. 5 illustrates a method in accordance with the present disclosure for forming a container and applying a label to the container.

[0018] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0019] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0020] Polymeric containers sometimes include colored resin and or require labels to distinguish various brands. When colored resin is used, it may prevent thecontainers from being considered recyclable. The present disclosure is thus directed to clear (i.e., colorless) resins. To maintain brand appearance and be recyclable, a potential solution is to apply a shrink sleeve label within a shrink sleeve tunnel. This option may present issues because shrink sleeve tunnels are typically used to apply the heat shrink label to rigid glass containers.

[0021] Applying a shrink sleeve to an empty non-annealed PET container will cause deformation and inconsistent shrinkage of the container due to its sensitivity to heat, during the process of shrinking the label. Testing with the non-annealed containers shows that when the shrink tunnel is adjusted to apply just enough heat to adequately shrink the sleeve, the nonannealed containers shrank up to 0.4% of their internal volume, over 6mL for a 1.75L package. This level of inconsistency versus the acceptable amount of volumetric variability is considered unacceptable to use on fill lines. The present disclosure provides for methods, systems, preforms, and containers that address these issues. For example, the present disclosure includes a method of annealing clear PET containers for the purpose of resisting deformation when exposed to heat, applying the label to an empty PET container, shrinking the label in a heat shrink tunnel, and then filling and capping the container.

[0022] FIG. 1 illustrates an exemplary preform 10 in accordance with the present disclosure. The preform 10 is formed in any suitable manner, such as by injection molding of any suitable polymeric material into a mold. For example, the preform 10 may be formed by injecting any suitable polymeric resin into a mold corresponding to the size and shape of the preform 10. Suitable polymeric resins include, but are not limited to, polyethylene terephthalate (PET), and recycled polyethylene terephthalate (rPET), etc. Regardless of the type of material, the present disclosure is directed to a clear (i.e., colorless) resin that will result in a clear preform 10 and a clear container 110.

[0023] The preform 10 generally includes a finish 12, which defines an opening 14 of the preform 10. At an outer surface of the finish 12 are threads 16, which are configured to cooperate with any suitable closure for closing the opening 14. The threads 16 may be external threads as illustrated, or internal threads. Below the threads 16 is a flange 20 for supporting the preform 10 in a mold when the preform 10 is blow molded into a container. For example, FIG. 2 illustrates the preform 10 seated in a mold 210 for forming exemplary container 110 of FIG. 3.

[0024] With particular reference to FIGS. 2 and 3, the preform 10 is heated (such as to 98°C to 102°C or about 100°C) and stretched into the mold 210 with a preform to container axial stretch ratio of 1 .7 to 3 (see FIG. 2 at A), and a hoop stretch ratio of 2.8 to 4.5 (see FIG. 2 at H), with a combined blow up ratio (BUR) (axial x hoop) stretch ratio of 6 to 12.2 to form the container 110 by injection stretch blow molding. The mold 210 itself is heated during this process, such as to 220°C to 260°C, or about 250°C, for example. The mold 210 may have any suitable size and shape corresponding to a desired container, such as the container 110. The container 110 includes the finish 12, as well as the opening 14, the threads 16, and the flange 20. The preform body 30 is stretched against sidewalls of the mold 210 to form a container body 130. The preform tip 40 is stretched to a base of the mold 210 to form the container base 140. The container base 140 can be any suitable rigid base designed to resist deformation and sagging due to higher molding temperatures. The resulting container 110 may have any suitable shape, such as that illustrated in FIG. 3. The container 110 may have a volume of 100ml to 2L, or 1.75L, for example, and may be configured as a spirits container. The container 110 has a crystallinity of 25% to 35%, or about 30%.

[0025] FIG. 4 illustrates the container 110 including a label 310. The label 310 is applied to the container 110 by heat shrinking the label 310 onto the container 110 in a heat shrink tunnel. Suitable heat shrink sleeving tunnels include steam, infrared, radiant, convection, hot air, and induction heat tunnels, The label 310 may cover the neck and body 130 of the container 110 as illustrated, or any other suitable portion of the container 110. The label 310 is made of any suitable material, such as any suitable polyethylene terephthalate (PET) based heat shrink label material, polyethylene terephthalate glycol (PETG), oriented polystyrene, polylactic acid (PLA), polyvinyl chloride (PVC), and the like. The label 310 may be in the form of a sleeve, or roll fed, and can be a full or partial label covering the desired portion of a container or container closure. The label 310 may also be perforated. The label 310 may have any suitable color, text, design, or other graphics. The label 310 is configured to shrink up to about 78%.

[0026] With reference to FIG. 5, an exemplary method 410 in accordance with the present disclosure for applying the label 310 to the container 110 will now be described. At block 420 of the method 410, the preform 10 is formed as described above. To form the container 110, the preform 10 is heated at block 430, such as to 98°C to 102°C. At block 440, the mold 210 is heated, such as to 220°C to 260°C. Atblock 450, the heated preform 10 is stretch blow molded into the heated mold 210 to form the container 110. At block 460, the label 310 is applied to the container 110 by heat shrinking the label 310 onto the container 110, such as in a heat sleeving tunnel. The label 310 is heated to any suitable temperature, such as 130°F to 150°F, and applied to the container 110 in the sleeving tunnel during a dwell time in the tunnel of 14 to 18 seconds, or about 15 seconds. After the label 310 is applied to the container 110, the container 110 is filled with any suitable product at block 470. The container 110 may be filled with any suitable liquid, water, juice, spirit, wine, etc. The fill temperature of the product is, for example, greater that 40°F and less than 150°F, or at ambient room temperature, for example. Thus, the container 110 is not hot-filled with product at about 185°F, for example. At block 480, the container 110 is capped, or otherwise closed, with any suitable closure.

[0027] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0028] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0029] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a,” "an," and "the" 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 statedfeatures, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, 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 their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0030] 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, connected 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 engaged 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 a like fashion (e.g., “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.

[0031] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be only 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 could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0032] Spatially relative terms, such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one 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 depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" canencompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Claims

CLAIMSWhat is claimed is:1 . A method of applying a label to a container, which is a clear annealed polymeric container, the method comprising: forming the container from a preform; applying a label to the container by heat-shrinking the label onto the container; after applying the label, filling the container with a product at a temperature less than 150°F; and capping the container.

2. The method of claim 1 , wherein the container includes recycled material.

3. The method of claim 1 , wherein the container is configured to store spirits and wine.

4. The method of claim 1 , wherein forming the container from the preform includes heating the preform to about 109°C, and blow-molding the preform into a mold.

5. The method of claim 4, further comprising heating the mold to about 250°C.

6. The method of claim 1 , wherein the container has a crystallinity of at least 25%.

7. The method of claim 1 , wherein the container has a crystallinity of 25% - 35%.

8. The method of claim 1 , wherein the container includes a rigid pushup base.

9. The method of claim 1 , wherein filling the container includes filling the container with a product at 40°F to 150°F.

10. The method of claim 1 , wherein filling the container includes filling the container with a product at ambient temperature.11 . The method of claim 1 , wherein applying the label to the container includes exposing the container to steam sleeving tunnel conditions at a temperature range of 27.7°C - 84.8°C for about 15 seconds.

12. The method of claim 1 , wherein forming the container from the preform includes blow-molding the container into a mold at a combined axial and hoop blow up stretch ratio of 6 to 12.2.

13. A method of applying a label to a container, the container is a clear, annealed polymeric container, the method comprising: forming the container from a preform including heating the preform to about 109°C, heating a mold to about 250°C, and blow-molding the preform into the mold to provide the container with a crystallinity of at least 25% and a rigid heat-set pushup base; applying a label to the container by exposing the container to steam sleeving tunnel conditions at a temperature range of 27.7°C - 84.8°C for about 15 seconds to heat-shrink the label onto the container; after applying the label, filling the container with a product at a temperature less than 150°F; and capping the container.

14. The method of claim 13, wherein filling the container includes filling the container with a product at ambient temperature.

15. The method of claim 13, wherein the container includes recycled material and is configured to store spirits and wine.

16. The method of claim 13, wherein the container has a crystallinity of 35% - 35%.

17. A container comprising: a finish defining an opening; a neck and a body extending from the finish; a base; and a label heat-shrunk onto at least the body over a clear surface of the body; wherein the container is a clear, annealed polymeric container with a crystallinity of at least 25%.

18. The container of claim 17, wherein the base is a rigid pushup base.

19. The container of claim 17, wherein the container is a blow-molded container.

20. The container of claim 17, wherein the container is configured to store wine or spirits therein.

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